From 28cb4ca596e14cc6a937acd7cf3ab5a3b8fb5f78 Mon Sep 17 00:00:00 2001
From: mindfn <lang_c@outlook.com>
Date: Mon, 9 Mar 2026 19:31:26 +0800
Subject: [PATCH 1/2] docs: restore governed message pipeline intent record

Carry the docs-only governance baseline from the rich-media message delivery branch into a standalone intent PR. This archives the completed message-related feature records under docs/features/archive and openspec/changes/archive, restores the active feature index to the currently governed entries, and adds a new active rich-media message pipeline aggregation record for PR #204.

The new active feature record intentionally stays at the intent stage for now; a follow-up commit will replace the placeholder Intent PR / review links with the real docs-only PR URLs before merge so governance-evidence-truth and governance-intent-gate can validate the implementation PR chain.
---
 docs/design/Architecture.md                   |   2 +-
 docs/design/Interfaces.md                     |  38 +++-
 .../modules/agent/DareAgent_Detailed.md       |   3 +-
 docs/design/modules/agent/README.md           |   8 +-
 .../modules/agent/ReactAgent_Detailed.md      |   3 +-
 .../modules/agent/SimpleChatAgent_Detailed.md |   5 +-
 docs/design/modules/context/README.md         | 164 ++++++++++++----
 docs/design/modules/model/README.md           |  56 +++++-
 docs/design/modules/transport/README.md       | 175 +++++++++++++++---
 docs/features/README.md                       |   8 +-
 docs/features/archive/README.md               |  10 +
 .../add-anthropic-model-adapter.md            |   2 +-
 .../agentscope-d1-d3-message-pipeline.md      | 113 +++++++++++
 .../agentscope-d2-d4-thinking-transport.md    |   2 +-
 .../agentscope-d5-safe-compression.md         |   2 +-
 .../agentscope-d7-plan-state-tools.md         |   2 +-
 .../{ => archive}/client-session-resume.md    |   2 +-
 .../archive/message-input-boundary-cleanup.md |  59 ++++++
 .../{ => archive}/p0-default-eventlog.md      |   2 +-
 .../{ => archive}/p0-step-driven-execution.md |   2 +-
 .../transport-typed-payload-cutover.md        | 103 +++++++++++
 docs/features/rich-media-message-pipeline.md  |  85 +++++++++
 docs/guides/Tool_Approval_Memory.md           |  14 +-
 .../agentscope_domain_execution_todos.md      |  92 +++++----
 docs/todos/project_overall_todos.md           |   6 +-
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/anthropic-model-adapter/spec.md     |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/core-runtime/spec.md                |   0
 .../specs/define-trust-boundary/spec.md       |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   2 +
 .../design.md                                 | 171 +++++++++++++++++
 .../proposal.md                               |  46 +++++
 .../specs/chat-runtime/spec.md                |  40 ++++
 .../specs/interaction-dispatch/spec.md        |  27 +++
 .../specs/rich-media-message-schema/spec.md   |  32 ++++
 .../specs/transport-channel/spec.md           |  68 +++++++
 .../tasks.md                                  |  27 +++
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../agentscope-thinking-transport/spec.md     |   0
 .../specs/chat-runtime/spec.md                |   0
 .../specs/transport-channel/spec.md           |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/agentscope-safe-compression/spec.md |   0
 .../specs/chat-runtime/spec.md                |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/chat-runtime/spec.md                |   0
 .../specs/plan-runtime/spec.md                |   0
 .../tasks.md                                  |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/client-host-orchestration/spec.md   |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   2 +
 .../design.md                                 |  60 ++++++
 .../proposal.md                               |  28 +++
 .../specs/plan-module/spec.md                 |  14 ++
 .../specs/rich-media-message-schema/spec.md   |  13 ++
 .../specs/session-loop/spec.md                |  13 ++
 .../specs/transport-channel/spec.md           |  13 ++
 .../tasks.md                                  |   5 +
 .../.openspec.yaml                            |   0
 .../2026-03-09-p0-default-eventlog}/design.md |   0
 .../proposal.md                               |   0
 .../specs/core-runtime/spec.md                |   0
 .../specs/default-event-log/spec.md           |   0
 .../specs/observability/spec.md               |   0
 .../specs/session-loop/spec.md                |   0
 .../2026-03-09-p0-default-eventlog}/tasks.md  |   0
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/core-runtime/spec.md                |   0
 .../specs/define-trust-boundary/spec.md       |   0
 .../specs/security-policy-gate/spec.md        |   0
 .../specs/validation/spec.md                  |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/core-runtime/spec.md                |   0
 .../specs/plan-module/spec.md                 |   0
 .../specs/session-loop/spec.md                |   0
 .../specs/step-driven-execution/spec.md       |   0
 .../tasks.md                                  |   0
 .../.openspec.yaml                            |   2 +
 .../design.md                                 | 107 +++++++++++
 .../proposal.md                               |  43 +++++
 .../specs/chat-runtime/spec.md                |  19 ++
 .../specs/interaction-dispatch/spec.md        |  19 ++
 .../specs/transport-channel/spec.md           |  20 ++
 .../specs/typed-transport-replies/spec.md     |  24 +++
 .../tasks.md                                  |  19 ++
 .../.openspec.yaml                            |   0
 .../design.md                                 |   0
 .../proposal.md                               |   0
 .../specs/core-runtime/spec.md                |   0
 .../tasks.md                                  |   0
 openspec/specs/chat-runtime/spec.md           |  28 ++-
 openspec/specs/interaction-dispatch/spec.md   |  67 ++++++-
 .../specs/rich-media-message-schema/spec.md   |  37 ++++
 openspec/specs/transport-channel/spec.md      |  50 +++--
 .../specs/typed-transport-replies/spec.md     |  29 +++
 117 files changed, 1817 insertions(+), 166 deletions(-)
 rename docs/features/{ => archive}/add-anthropic-model-adapter.md (99%)
 create mode 100644 docs/features/archive/agentscope-d1-d3-message-pipeline.md
 rename docs/features/{ => archive}/agentscope-d2-d4-thinking-transport.md (99%)
 rename docs/features/{ => archive}/agentscope-d5-safe-compression.md (99%)
 rename docs/features/{ => archive}/agentscope-d7-plan-state-tools.md (99%)
 rename docs/features/{ => archive}/client-session-resume.md (99%)
 create mode 100644 docs/features/archive/message-input-boundary-cleanup.md
 rename docs/features/{ => archive}/p0-default-eventlog.md (99%)
 rename docs/features/{ => archive}/p0-step-driven-execution.md (99%)
 create mode 100644 docs/features/archive/transport-typed-payload-cutover.md
 create mode 100644 docs/features/rich-media-message-pipeline.md
 rename openspec/changes/{add-anthropic-model-adapter => archive/2026-03-09-add-anthropic-model-adapter}/.openspec.yaml (100%)
 rename openspec/changes/{add-anthropic-model-adapter => archive/2026-03-09-add-anthropic-model-adapter}/design.md (100%)
 rename openspec/changes/{add-anthropic-model-adapter => archive/2026-03-09-add-anthropic-model-adapter}/proposal.md (100%)
 rename openspec/changes/{add-anthropic-model-adapter => archive/2026-03-09-add-anthropic-model-adapter}/specs/anthropic-model-adapter/spec.md (100%)
 rename openspec/changes/{add-anthropic-model-adapter => archive/2026-03-09-add-anthropic-model-adapter}/tasks.md (100%)
 rename openspec/changes/{add-security-boundary-policy-gate => archive/2026-03-09-add-security-boundary-policy-gate}/.openspec.yaml (100%)
 rename openspec/changes/{add-security-boundary-policy-gate => archive/2026-03-09-add-security-boundary-policy-gate}/design.md (100%)
 rename openspec/changes/{add-security-boundary-policy-gate => archive/2026-03-09-add-security-boundary-policy-gate}/proposal.md (100%)
 rename openspec/changes/{add-security-boundary-policy-gate => archive/2026-03-09-add-security-boundary-policy-gate}/specs/core-runtime/spec.md (100%)
 rename openspec/changes/{add-security-boundary-policy-gate => archive/2026-03-09-add-security-boundary-policy-gate}/specs/define-trust-boundary/spec.md (100%)
 rename openspec/changes/{add-security-boundary-policy-gate => archive/2026-03-09-add-security-boundary-policy-gate}/tasks.md (100%)
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/.openspec.yaml
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/design.md
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/proposal.md
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/chat-runtime/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/interaction-dispatch/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/rich-media-message-schema/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/transport-channel/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/tasks.md
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/.openspec.yaml (100%)
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/design.md (100%)
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/proposal.md (100%)
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/specs/agentscope-thinking-transport/spec.md (100%)
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/specs/chat-runtime/spec.md (100%)
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/specs/transport-channel/spec.md (100%)
 rename openspec/changes/{agentscope-d2-d4-thinking-transport => archive/2026-03-09-agentscope-d2-d4-thinking-transport}/tasks.md (100%)
 rename openspec/changes/{agentscope-d5-safe-compression => archive/2026-03-09-agentscope-d5-safe-compression}/.openspec.yaml (100%)
 rename openspec/changes/{agentscope-d5-safe-compression => archive/2026-03-09-agentscope-d5-safe-compression}/design.md (100%)
 rename openspec/changes/{agentscope-d5-safe-compression => archive/2026-03-09-agentscope-d5-safe-compression}/proposal.md (100%)
 rename openspec/changes/{agentscope-d5-safe-compression => archive/2026-03-09-agentscope-d5-safe-compression}/specs/agentscope-safe-compression/spec.md (100%)
 rename openspec/changes/{agentscope-d5-safe-compression => archive/2026-03-09-agentscope-d5-safe-compression}/specs/chat-runtime/spec.md (100%)
 rename openspec/changes/{agentscope-d5-safe-compression => archive/2026-03-09-agentscope-d5-safe-compression}/tasks.md (100%)
 rename openspec/changes/{agentscope-d7-plan-state-tools => archive/2026-03-09-agentscope-d7-plan-state-tools}/.openspec.yaml (100%)
 rename openspec/changes/{agentscope-d7-plan-state-tools => archive/2026-03-09-agentscope-d7-plan-state-tools}/design.md (100%)
 rename openspec/changes/{agentscope-d7-plan-state-tools => archive/2026-03-09-agentscope-d7-plan-state-tools}/proposal.md (100%)
 rename openspec/changes/{agentscope-d7-plan-state-tools => archive/2026-03-09-agentscope-d7-plan-state-tools}/specs/chat-runtime/spec.md (100%)
 rename openspec/changes/{agentscope-d7-plan-state-tools => archive/2026-03-09-agentscope-d7-plan-state-tools}/specs/plan-runtime/spec.md (100%)
 rename openspec/changes/{agentscope-d7-plan-state-tools => archive/2026-03-09-agentscope-d7-plan-state-tools}/tasks.md (100%)
 rename openspec/changes/{client-session-resume => archive/2026-03-09-client-session-resume}/design.md (100%)
 rename openspec/changes/{client-session-resume => archive/2026-03-09-client-session-resume}/proposal.md (100%)
 rename openspec/changes/{client-session-resume => archive/2026-03-09-client-session-resume}/specs/client-host-orchestration/spec.md (100%)
 rename openspec/changes/{client-session-resume => archive/2026-03-09-client-session-resume}/tasks.md (100%)
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/.openspec.yaml
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/design.md
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/proposal.md
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/plan-module/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/rich-media-message-schema/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/session-loop/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/transport-channel/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/tasks.md
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/.openspec.yaml (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/design.md (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/proposal.md (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/specs/core-runtime/spec.md (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/specs/default-event-log/spec.md (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/specs/observability/spec.md (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/specs/session-loop/spec.md (100%)
 rename openspec/changes/{p0-default-eventlog => archive/2026-03-09-p0-default-eventlog}/tasks.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/.openspec.yaml (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/design.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/proposal.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/specs/core-runtime/spec.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/specs/define-trust-boundary/spec.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/specs/security-policy-gate/spec.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/specs/validation/spec.md (100%)
 rename openspec/changes/{p0-enforce-security-boundary => archive/2026-03-09-p0-enforce-security-boundary}/tasks.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/.openspec.yaml (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/design.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/proposal.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/specs/core-runtime/spec.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/specs/plan-module/spec.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/specs/session-loop/spec.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/specs/step-driven-execution/spec.md (100%)
 rename openspec/changes/{p0-step-driven-execution => archive/2026-03-09-p0-step-driven-execution}/tasks.md (100%)
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/.openspec.yaml
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/design.md
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/proposal.md
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/chat-runtime/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/interaction-dispatch/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/transport-channel/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/typed-transport-replies/spec.md
 create mode 100644 openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/tasks.md
 rename openspec/changes/{unify-agent-output-envelope => archive/2026-03-09-unify-agent-output-envelope}/.openspec.yaml (100%)
 rename openspec/changes/{unify-agent-output-envelope => archive/2026-03-09-unify-agent-output-envelope}/design.md (100%)
 rename openspec/changes/{unify-agent-output-envelope => archive/2026-03-09-unify-agent-output-envelope}/proposal.md (100%)
 rename openspec/changes/{unify-agent-output-envelope => archive/2026-03-09-unify-agent-output-envelope}/specs/core-runtime/spec.md (100%)
 rename openspec/changes/{unify-agent-output-envelope => archive/2026-03-09-unify-agent-output-envelope}/tasks.md (100%)
 create mode 100644 openspec/specs/rich-media-message-schema/spec.md
 create mode 100644 openspec/specs/typed-transport-replies/spec.md

diff --git a/docs/design/Architecture.md b/docs/design/Architecture.md
index a8591be3..8d200f1b 100644
--- a/docs/design/Architecture.md
+++ b/docs/design/Architecture.md
@@ -412,7 +412,7 @@ sequenceDiagram
 
 ```python
 class IAgent(Protocol):
-    async def run(self, task: "str | Task", deps: Any | None = None) -> "RunResult": ...
+    async def __call__(self, task: "str | Message", deps: Any | None = None) -> "RunResult": ...
 
 class IContext(Protocol):
     def stm_add(self, message: "Message") -> None: ...
diff --git a/docs/design/Interfaces.md b/docs/design/Interfaces.md
index d2e5f479..9e23e3d9 100644
--- a/docs/design/Interfaces.md
+++ b/docs/design/Interfaces.md
@@ -33,10 +33,22 @@ dare_framework/<domain>/
 ### 1.1 上下文契约（context/types.py）
 
 - `Message`
-  - `role: str`
-  - `content: str`
+  - framework 内部唯一 canonical message
+  - `id: str | None`
+  - `role: MessageRole`
+  - `kind: MessageKind`
+  - `text: str | None`
+  - `attachments: list[AttachmentRef]`
+  - `data: dict[str, Any] | None`
   - `name: str | None`
   - `metadata: dict[str, Any]`
+  - `mark: MessageMark`
+- `AttachmentRef`
+  - `kind: AttachmentKind`（首版 `IMAGE`）
+  - `uri: str`
+  - `mime_type: str | None`
+  - `filename: str | None`
+  - `metadata: dict[str, Any]`
 - `Budget`
   - limits: `max_tokens/max_cost/max_time_seconds/max_tool_calls`
   - usage: `used_tokens/used_cost/used_time_seconds/used_tool_calls`
@@ -49,6 +61,8 @@ dare_framework/<domain>/
 ### 1.2 计划与运行结果契约（plan/types.py）
 
 - `Task`: `description/task_id/milestones/metadata/previous_session_summary`
+  - `input_message: Message | None`
+  - `description` 作为编排输入保留，不再视为真实消息载体
 - `Milestone`: `milestone_id/description/user_input/success_criteria`
 - `ProposedPlan` vs `ValidatedPlan`
 - `Envelope`: `allowed_capability_ids/budget/done_predicate/risk_level`
@@ -71,7 +85,17 @@ dare_framework/<domain>/
 - `TransportEnvelope`
   - `id/reply_to/kind/payload/meta/stream_id/seq`
 - `EnvelopeKind`
-  - `MESSAGE/ACTION/CONTROL`
+  - `MESSAGE/SELECT/ACTION/CONTROL`
+- `EnvelopePayload`
+  - 公共字段：`id/metadata`
+- `MessagePayload`
+  - `id/metadata/role(MessageRole)/message_kind(MessageKind)/text/attachments/data`
+- `SelectPayload`
+  - `id/metadata/select_kind(SelectKind)/select_domain(SelectDomain)/prompt/options/selected`
+- `ActionPayload`
+  - `id/metadata/resource_action/params`
+- `ControlPayload`
+  - `id/metadata/control_id/params`
 
 ---
 
@@ -83,7 +107,7 @@ dare_framework/<domain>/
 class IAgent(ABC):
     async def __call__(
         self,
-        message: str | Task,
+        message: str | Message,
         deps: Any | None = None,
         *,
         transport: AgentChannel | None = None,
@@ -104,7 +128,7 @@ class IAgent(ABC):
 class IAgentOrchestration(ABC):
     async def execute(
         self,
-        task: str | Task,
+        task: Message,
         *,
         transport: AgentChannel | None = None,
     ) -> RunResult: ...
@@ -113,7 +137,8 @@ class IAgentOrchestration(ABC):
 ### 2.3 关键说明
 
 - 统一入口是 `__call__`，而非历史文档中的 `run(...)`。
-- `Task` 与 `str` 并存：支持 simple/react/five-layer 统一调用面。
+- `Message` 是首选直接输入；`Task` 仅用于编排。
+- Public agent input is `Message` (or plain `str` normalized into `Message`); `Task.input_message` 保存 canonical 首轮用户消息，`Task.description` 仅保留给内部规划/里程碑描述。
 
 ---
 
@@ -158,6 +183,7 @@ class IContext(ABC):
     def list_tools(self) -> list[CapabilityDescriptor]: ...
     def assemble(self) -> AssembledContext: ...
     def compress(self, **options: Any) -> None: ...
+
 ```
 
 ---
diff --git a/docs/design/modules/agent/DareAgent_Detailed.md b/docs/design/modules/agent/DareAgent_Detailed.md
index c8a58d59..1b22d233 100644
--- a/docs/design/modules/agent/DareAgent_Detailed.md
+++ b/docs/design/modules/agent/DareAgent_Detailed.md
@@ -40,7 +40,8 @@
 
 输入：
 
-- `str | Task`
+- `str | Message`
+- Public input 先归一为 canonical `Message`；`Task.input_message` 保存内部会话首轮用户消息
 - `Task.task_id` 缺失时在执行入口补齐
 
 输出：
diff --git a/docs/design/modules/agent/README.md b/docs/design/modules/agent/README.md
index 98071c84..36c1c9c1 100644
--- a/docs/design/modules/agent/README.md
+++ b/docs/design/modules/agent/README.md
@@ -30,8 +30,8 @@
 
 ## 4. 对外接口（Public Contract）
 
-- 统一入口：`IAgent.__call__(task, transport=None)`
-- 编排入口：`IAgentOrchestration.execute(task, transport)`
+- 统一入口：`IAgent.__call__(message, transport=None)`，其中 public input 支持 `str | Message`
+- 编排入口：`IAgentOrchestration.execute(message, transport)`，内部统一接收 canonical `Message`
 - 结果契约：统一输出 `RunResult`（含 `output_text`），其中 `RunResult.output` 使用 envelope 结构：
   - `content: str`
   - `metadata: dict`
@@ -44,7 +44,9 @@
 
 ## 5. 核心字段（Core Fields）
 
-- 统一任务输入：`Task`（`description/task_id/milestones/metadata`）
+- 统一顶层输入：`str | Message`
+- `Message`：首选直接用户输入
+- `Task`：内部编排对象（`description/task_id/milestones/metadata/input_message`），不再作为 public agent input
 - 统一运行输出：`RunResult`（`success/output/output_text/errors/metadata`）
   - `output.content`：统一可展示文本
   - `output_text`：与 `output.content` 对齐，供展示与兼容链路消费
diff --git a/docs/design/modules/agent/ReactAgent_Detailed.md b/docs/design/modules/agent/ReactAgent_Detailed.md
index ef4b3c97..37c6e5bd 100644
--- a/docs/design/modules/agent/ReactAgent_Detailed.md
+++ b/docs/design/modules/agent/ReactAgent_Detailed.md
@@ -33,7 +33,8 @@
 
 输入：
 
-- `str | Task`
+- `str | Message`
+- `Message` 是首选直接输入；`Task` 仅作为编排对象
 
 输出：
 
diff --git a/docs/design/modules/agent/SimpleChatAgent_Detailed.md b/docs/design/modules/agent/SimpleChatAgent_Detailed.md
index 1157248d..5e4cdcb0 100644
--- a/docs/design/modules/agent/SimpleChatAgent_Detailed.md
+++ b/docs/design/modules/agent/SimpleChatAgent_Detailed.md
@@ -33,8 +33,9 @@
 
 输入：
 
-- `str | Task`
-- `str` 在入口处转换为 `Task.description`
+- `str | Message`
+- `Message` 是首选直接输入；`str` 会升级为 canonical `Message`
+- `Task` 仅用于编排，真实首轮用户消息来自 `Task.input_message`（若为空则退化为 `description`）
 
 输出：
 
diff --git a/docs/design/modules/context/README.md b/docs/design/modules/context/README.md
index 2ec5968d..0122bded 100644
--- a/docs/design/modules/context/README.md
+++ b/docs/design/modules/context/README.md
@@ -1,12 +1,13 @@
 # Module: context
 
-> Status: baseline fusion behavior landed in canonical runtime (2026-02-27).
+> Status: canonical message redesign baseline updated for rich-media inputs (2026-03-09).
 > 本文分两层：先说明当前实现（as-is），再给出目标态详细设计（to-be）。
 
 ## 1. 定位与职责
 
 - Context-centric：`Context` 是会话态中心，负责把多来源信息组装成一次模型调用可消费的输入。
 - 统一持有引用：`short_term_memory`、`long_term_memory`、`knowledge`、`budget`、`tool provider`、`sys_prompt`。
+- `Message` 是 framework 内部唯一 canonical message；所有会话语义最终都归一到该类型。
 - 输出 `AssembledContext(messages, sys_prompt, tools, metadata)`，作为 Agent 进入 Model 的唯一上下文入口。
 
 ## 2. 当前实现基线（as-is）
@@ -26,11 +27,91 @@
 
 ### 2.2 现状限制
 
+- 旧的 `Message.content: str` 路径已经切除，但仍需确保所有运行时入口使用 canonical `Message` 而非重新退化到 `Task.description`。
 - 预算控制依赖轻量 token 估算（字符启发式），与模型真实 tokenizer 仍可能存在偏差。
 - 当前默认策略未实现高级检索重排与分级压缩（摘要折叠、去重重排等）。
 - `retrieval` metadata 已提供基础字段，但跨模块 taxonomy 仍需统一。
 
-## 3. 关键对象与分层语义
+## 3. Canonical Message 设计（to-be）
+
+### 3.1 设计原则
+
+- 不重新定义平行的 framework message 类型；直接升级现有 `context.types.Message`。
+- transport `kind=message` 的 payload 应与 canonical `Message` 高度对齐，允许 1:1 归一化。
+- provider-specific message 只存在于 adapter 内部，不进入 context/history。
+
+### 3.2 `Message` 建议字段
+
+建议将当前：
+
+- `role`
+- `content`
+- `name`
+- `metadata`
+- `mark`
+- `id`
+
+升级为：
+
+- `id`
+- `role`
+-  - 使用确定性枚举 `MessageRole`
+-  - `SYSTEM | USER | ASSISTANT | TOOL`
+- `kind`
+  - 使用确定性枚举 `MessageKind`
+  - `CHAT | THINKING | TOOL_CALL | TOOL_RESULT | SUMMARY`
+- `text: str | None`
+- `attachments: list[AttachmentRef]`
+- `data: dict[str, Any] | None`
+- `name: str | None`
+- `metadata: dict[str, Any]`
+- `mark`
+
+### 3.3 字段语义
+
+- `text`
+  - 通用文本表达。
+- `attachments`
+  - 通用附件表达；首版只要求 `image`。
+  - 附件项必须是强类型 `AttachmentRef`，不再使用裸 `dict`。
+  - 当前字段校验矩阵下，仅 `chat` 与 `tool_result` 允许携带附件；`thinking`、`summary`、`tool_call` 直接拒绝附件。
+- `data`
+  - 仅承载结构化主语义：
+    - `tool_call` 参数
+    - `tool_result` 结构化结果
+    - 后续需要的 summary provenance 等
+  - 当前字段校验矩阵下，`tool_call` 与 `tool_result` 都要求 `data` 非空。
+  - `tool_call/tool_result` 的结构化语义以 `data` 为唯一真相源；`metadata` 不再承担语义回退职责。
+- `name`
+  - 兼容 tool/message 现有命名约定；后续可逐步被 `data` 中的结构化 id 替代。
+
+### 3.4 组合消息表达
+
+当前目标场景“一个用户输入 = 一段文字 + 多张图片”直接使用：
+
+- `kind=chat`
+- `text != None`
+- `attachments = [image1, image2, ...]`
+
+不引入额外的 `combo` / `multimodal_chat` 类型。
+
+### 3.5 `AttachmentRef`
+
+建议最小字段：
+
+- `kind: AttachmentKind`
+  - 首版固定 `IMAGE`
+- `uri`
+- `mime_type?`
+- `filename?`
+- `metadata?`
+
+说明：
+
+- `AttachmentRef` 应作为 framework 内部唯一附件引用结构，同时被 canonical `Message` 与 transport `MessagePayload` 复用。
+- 有限域优先使用枚举；只有 `metadata/data` 这类开放扩展位保留弱结构。
+
+## 4. 关键对象与分层语义
 
 - `STM (short_term_memory)`：
   - 会话工作集，保存最近 user/assistant/tool 交互。
@@ -38,20 +119,21 @@
 - `LTM (long_term_memory)`：
   - 跨会话持久记忆，优先存“可复用且会影响未来决策”的事实和经验。
   - 通过 `get(query, top_k, ...)` 按需召回，不应全量塞回上下文。
+  - 持久化时必须保存 canonical `Message` 的 `role/kind/text/attachments/data/name/metadata/mark/id`；仅检索索引文本允许退化为占位。
 - `Knowledge`：
   - 外部知识源（文档、索引、向量库），优先存“外部事实依据”。
   - 与 LTM 区分：LTM 偏“代理自身历史”，Knowledge 偏“外部知识语料”。
 
-## 4. 详细设计：组装流水线（to-be）
+## 5. 详细设计：组装流水线（to-be）
 
-### 4.1 组装目标
+### 5.1 组装目标
 
 在固定 token 预算内，优先保证：
 1. 当前轮任务可执行（最近指令、未完成约束、关键工具结果不丢）。
 2. 与当前任务强相关的历史与知识被召回。
 3. 可追溯（知道每条上下文来自 STM/LTM/Knowledge，以及如何被压缩）。
 
-### 4.2 组装流程（建议）
+### 5.2 组装流程（建议）
 
 ```mermaid
 flowchart TD
@@ -70,9 +152,9 @@ flowchart TD
   K --> J
 ```
 
-### 4.3 统一候选消息模型（设计约定）
+### 5.3 统一候选消息模型（设计约定）
 
-建议在 `assemble()` 内部把所有来源先归一化为 `Message + metadata`，metadata 至少包含：
+建议在 `assemble()` 内部把所有来源先归一化为 canonical `Message + metadata`，metadata 至少包含：
 
 - `source`: `stm|ltm|knowledge|summary`
 - `score`: 相关性综合分（用于重排和裁剪）
@@ -80,9 +162,9 @@ flowchart TD
 - `retrieval_query`: 本次召回 query（非 STM 可选）
 - `compression_flags`: 是否经过摘要/裁剪/去重
 
-这一步不改变 `Message` 主结构，只扩展 metadata，兼容现有接口。
+这一步不再依赖 `Message.content: str`；输入必须先提升到新的 canonical `Message` 结构。
 
-### 4.4 预算分配（建议）
+### 5.4 预算分配（建议）
 
 单次组装可采用“分桶预算”而不是全局抢占：
 
@@ -95,7 +177,7 @@ flowchart TD
 - 工具执行密集场景：提高 STM 桶；
 - 问答/RAG 场景：提高 Knowledge 桶。
 
-### 4.5 融合排序（建议）
+### 5.5 融合排序（建议）
 
 融合后按综合分排序，示例公式：
 
@@ -106,9 +188,9 @@ flowchart TD
 - `source_priority`: 可配置（例如安全策略要求 Knowledge 证据优先）。
 - `role_priority`: 系统指令、用户硬约束高于普通 assistant 叙述。
 
-## 5. 详细设计：压缩策略（to-be）
+## 6. 详细设计：压缩策略（to-be）
 
-### 5.1 触发点
+### 6.1 触发点
 
 建议至少在以下时机触发压缩检查：
 
@@ -116,7 +198,7 @@ flowchart TD
 2. tool loop 每轮后：工具输出可能导致上下文骤增。
 3. milestone 结束后：阶段性清理并抽取摘要，避免跨阶段污染。
 
-### 5.2 分级压缩管线
+### 6.2 分级压缩管线
 
 压缩不建议一步到位，采用由轻到重的级联策略：
 
@@ -126,7 +208,7 @@ flowchart TD
 4. `summary_fold`: 把旧消息折叠为摘要消息（增量摘要优先）。
 5. `hard_truncate`: 兜底末尾截断（保证绝不超预算）。
 
-### 5.3 摘要压缩约定
+### 6.3 摘要压缩约定
 
 - `rolling summary`：维护一条“会话运行摘要”消息，定期合并历史片段。
 - `segment summary`：对旧 tool 结果或旧对话片段生成局部摘要并替换原文。
@@ -135,22 +217,22 @@ flowchart TD
   - `summary_version`: 摘要迭代版本；
   - `loss_note`: 明确哪些细节被省略。
 
-### 5.4 与现实现的关系
+### 6.4 与现实现的关系
 
 - 当前实现仅覆盖第 5 级（`hard_truncate` 的简化版，且只作用 STM）。
 - 其余级别属于上下文工程增强项，可通过覆盖 `Context.compress()` 分阶段接入。
 
-## 6. STM/LTM/Knowledge 使用策略（to-be）
+## 7. STM/LTM/Knowledge 使用策略（to-be）
 
-### 6.1 STM 使用策略
+### 7.1 STM 使用策略
 
-- 写入：user、assistant、tool message 全量进入 STM。
+- 写入：user、assistant、tool、thinking、summary 等 canonical `Message` 全量进入 STM。
 - 常驻保留（pin）：
   - 当前任务目标与硬约束；
   - 最近一次失败原因和 remediation 建议；
   - 最新关键工具输出摘要（非原始大块日志）。
 
-### 6.2 LTM 使用策略
+### 7.2 LTM 使用策略
 
 - 写入候选（建议由 milestone 完成或 run 结束触发）：
   - 用户偏好（格式、语言、禁忌）；
@@ -160,14 +242,14 @@ flowchart TD
   - 用当前任务 + 最近用户输入构造 query；
   - `top_k` 小批量召回（通常 3~10），经重排后再进入上下文。
 
-### 6.3 Knowledge 使用策略
+### 7.3 Knowledge 使用策略
 
 - 写入：仅通过显式知识摄入路径（如 `knowledge_add` 工具），避免无约束污染。
 - 召回：
   - 面向“事实查询/文档依据”；
   - 与 LTM 分开打分，避免个人历史记忆覆盖外部事实证据。
 
-## 7. 审计与可观测性（to-be）
+## 8. 审计与可观测性（to-be）
 
 建议扩展 `AssembledContext.metadata` 最小字段：
 
@@ -186,7 +268,7 @@ flowchart TD
 
 这些字段可直接支撑 EventLog 与 Hook 的上下文审计。
 
-## 8. 与 Agent 循环的落点
+## 9. 与 Agent 循环的落点
 
 - `SimpleChatAgent` / `ReactAgent` / `DareAgent` 当前都直接调用 `context.assemble()`。
 - 推荐统一落点：在每次模型调用前执行：
@@ -196,20 +278,21 @@ flowchart TD
 
 这样压缩策略可在 Context 域集中治理，不分散到各 Agent。
 
-## 9. 关键接口与实现
+## 10. 关键接口与实现
 
 - Kernel：`dare_framework/context/kernel.py`
   - `IRetrievalContext`
   - `IContext`
 - Types：`dare_framework/context/types.py`
   - `Message`
+  - `AttachmentRef`
   - `Budget`
   - `AssembledContext`
 - Default Impl：`dare_framework/context/context.py`
   - `Context.assemble()`
   - `Context.compress()`
 
-## 10. 扩展点
+## 11. 扩展点
 
 - 自定义 Context：
   - 覆盖 `assemble()` 实现多源检索融合；
@@ -219,22 +302,30 @@ flowchart TD
 - 自定义压缩策略：
   - 保持 `compress(**options)` 入口稳定，按 `strategy`/`budget` 扩展行为。
 
-## 11. TODO / 未决问题
+## 12. TODO / 未决问题
 
 - TODO: 为 `assemble()` 定义标准化 options（`query/top_k/budget_alloc/compression_hint`）。
 - TODO: 规范 `AssembledContext.metadata` 审计字段与哈希计算口径。
 - TODO: 在默认 Agent 调用链接入“预算检查 -> 压缩 -> 组装”的统一顺序。
 - TODO: 明确 LTM 与 Knowledge 的冲突消解与证据优先级规则。
+- 已落地最小校验矩阵：
+  - `chat`: `text/attachments/data?`
+  - `thinking`: `text` only
+  - `summary`: `text` only
+  - `tool_call`: `text + data`
+  - `tool_result`: `text + data + attachments?`
 
-## 12. Design Clarifications (2026-02-05)
+## 13. Design Clarifications (2026-02-05 / 2026-03-09)
 
 - `Context.config` 语义是只读快照，不提供运行时增量更新接口。
 - Skill 注入路径是 `assemble()` 时动态 enrich `sys_prompt`，不是单独消息注入。
 - 目前 `IContext` 已暴露 `compress()`，但默认实现仍是 STM 截断，属于最小实现而非完整压缩框架。
+- `Message` 是 framework 内部唯一 canonical message；`TransportEnvelope(kind=message)` 的 payload 只是其协议承载形式。
+- rich-media 首版只要求 `chat` 消息支持 `text + images[]`，不支持图文混排顺序表达。
 
-## 13. Memory / Knowledge 集成实现细节（merged）
+## 14. Memory / Knowledge 集成实现细节（merged）
 
-### 13.1 当前实现能力（as-is）
+### 14.1 当前实现能力（as-is）
 
 - STM：
   - 默认 `InMemorySTM`；
@@ -249,7 +340,7 @@ flowchart TD
   - 支持 `rawdata` / `vector`；
   - 存储支持 `in_memory` / `sqlite` / `chromadb`（vector）。
 
-### 13.2 组装时的检索参数约定（to-be）
+### 14.2 组装时的检索参数约定（to-be）
 
 `Context.assemble()` 建议向 LTM/Knowledge 统一透传：
 
@@ -260,13 +351,13 @@ flowchart TD
 
 目标是让 `IRetrievalContext.get(query="", **kwargs)` 在跨实现时保持可预测行为。
 
-### 13.3 写入策略约定（to-be）
+### 14.3 写入策略约定（to-be）
 
 - STM：每轮 user/assistant/tool 在线写入。
 - LTM：里程碑完成、run 结束或显式记忆操作时批量持久化。
 - Knowledge：仅允许显式摄入（如 `knowledge_add`）避免隐式污染知识库。
 
-### 13.4 Metadata 打标约定（to-be）
+### 14.4 Metadata 打标约定（to-be）
 
 融合后建议在 `Message.metadata` 统一记录：
 
@@ -275,14 +366,14 @@ flowchart TD
 - `memory_class`: `working|episodic|factual`
 - `session_id` / `timestamp`（可用时）
 
-### 13.5 增补 TODO（memory/knowledge 视角）
+### 14.5 增补 TODO（memory/knowledge 视角）
 
 - TODO: 统一 `get(**kwargs)` 参数协议（`top_k/min_similarity/filters`）。
 - TODO: 给 LTM/Knowledge 定义统一去重 key 与冲突消解规则。
 - TODO: 明确知识写入权限、审计与成本计量策略。
 - TODO: 增加“召回质量 + 压缩损失”评估指标并接入观测。
 
-## 14. 对外接口汇总（Public Contract Snapshot）
+## 15. 对外接口汇总（Public Contract Snapshot）
 
 - `IRetrievalContext.get(query="", **kwargs) -> list[Message]`
 - `IContext`
@@ -293,9 +384,10 @@ flowchart TD
   - `compress(**options) -> None`
   - `set_tool_gateway(tool_gateway)`
 
-## 15. 核心字段汇总（Core Fields Snapshot）
+## 16. 核心字段汇总（Core Fields Snapshot）
 
-- `Message`: `role`, `content`, `name`, `metadata`
+- `Message`: `id`, `role`, `kind`, `text`, `attachments`, `data`, `name`, `metadata`, `mark`
+- `Session/Checkpoint persistence`: 必须以 canonical `Message` 字段为事实源，不得只持久化 `content: str`
 - `Budget`: `max_tokens/max_cost/max_time_seconds/max_tool_calls` + `used_*`
 - `AssembledContext`: `messages`, `sys_prompt`, `tools`, `metadata`
 - 推荐 metadata 最小审计字段：
@@ -303,7 +395,7 @@ flowchart TD
   - `retrieval.query/ltm_count/knowledge_count`
   - `compression.trigger/strategies_applied/before_token_estimate/after_token_estimate`
 
-## 16. 关键流程汇总（Flow Snapshot）
+## 17. 关键流程汇总（Flow Snapshot）
 
 ```mermaid
 flowchart TD
diff --git a/docs/design/modules/model/README.md b/docs/design/modules/model/README.md
index 79889b55..82c93840 100644
--- a/docs/design/modules/model/README.md
+++ b/docs/design/modules/model/README.md
@@ -1,11 +1,12 @@
 # Module: model
 
-> Status: detailed design aligned to `dare_framework/model` (2026-03-05).
+> Status: message-codec boundary updated for canonical rich-media messages (2026-03-09).
 
 ## 1. 定位与职责
 
 - 提供统一模型调用抽象：`IModelAdapter.generate`。
 - 定义模型输入/输出结构：`ModelInput`、`ModelResponse`。
+- 负责把 context domain 的 canonical `Message` 序列化为 provider message。
 - 提供 prompt 装载与分层解析能力（store + loader）。
 
 ## 2. 依赖与边界
@@ -15,6 +16,8 @@
 - 类型：`Prompt`, `ModelInput`, `ModelResponse`, `GenerateOptions`
 - 边界约束：
   - model domain 负责“调用与格式适配”，不负责执行循环与工具决策。
+  - provider message 仅存在于 adapter 内部，不进入 context/history。
+  - adapter 必须消费 canonical `Message`，不得要求上游直接构造 provider-native payload。
 
 ## 3. 对外接口（Public Contract）
 
@@ -39,24 +42,54 @@
 - `GenerateOptions`
   - `temperature`, `max_tokens`, `top_p`, `stop`, `metadata`
 
+canonical `Message` 由 context domain 提供，建议字段口径：
+
+- `id`
+- `role`
+  - `MessageRole`
+- `kind`
+  - `MessageKind`
+- `text: str | None`
+- `attachments: list[AttachmentRef]`
+- `data: dict[str, Any] | None`
+- `name`
+- `metadata`
+
+其中：
+
+- `attachments` 中的附件项必须是强类型 `AttachmentRef`。
+- adapter 必须以 `Message.data` 作为 `tool_call/tool_result` 的结构化主语义来源；`metadata` 仅保留非语义附加信息。
+- adapter 可以对 `data/metadata` 做 provider-specific codec，但不得把附件重新退化为无约束字典再回传上游。
+- 非法 canonical message（例如 `tool_call/tool_result` 缺少 `data`）必须在进入 adapter 前失败，而不是在 adapter 内兜底补语义。
+
 ## 5. 关键流程（Runtime Flow）
 
 ```mermaid
 flowchart TD
   A["Agent execute loop"] --> B["Context.assemble -> ModelInput"]
-  B --> C["IModelAdapter.generate"]
-  C --> D["ModelResponse(content, tool_calls, usage)"]
-  D --> E{"tool_calls empty?"}
-  E -- yes --> F["Write assistant message"]
-  E -- no --> G["Tool loop invoke"]
+  B --> C["adapter codec: Message -> provider message"]
+  C --> D["IModelAdapter.generate"]
+  D --> E["ModelResponse(content, tool_calls, usage)"]
+  E --> F{"tool_calls empty?"}
+  F -- yes --> G["Write assistant message"]
+  F -- no --> H["Tool loop invoke"]
 ```
 
+
 ## 6. 与其他模块的交互
 
-- **Context**：提供 messages/tools。
-- **Tool**：通过 `tool_calls` 触发 `IToolGateway.invoke`。
-- **Config**：`Config.llm` 决定 adapter 类型与连接参数。
-- **Observability**：从 `usage` 提取 token 指标。
+- **Context**
+  - 提供 canonical `Message` / tools。
+- **Tool**
+  - 通过 `tool_calls` 触发 `IToolGateway.invoke`。
+- **Transport**
+  - transport 不直接参与 provider 序列化；只负责 message/select/action/control envelope。
+- **Config**
+  - `Config.llm` 决定 adapter 类型与连接参数。
+- **Observability**
+  - 从 `usage` 提取 token 指标。
+- **Session/Memory persistence**
+  - adapter 不持久化 provider-native message；resume/replay 必须基于 canonical `Message` 重新序列化。
 
 ## 6.1 默认 Adapter 能力矩阵
 
@@ -68,12 +101,15 @@ flowchart TD
 
 - 当前流式输出和增量 tool-call 仍是待补齐项。
 - tool defs 仍以 OpenAI function-call schema 为主。
+- 首版 rich-media 只要求 `chat` 支持 `text + image attachments`；不要求图文混排顺序表达。
+- 首版字段约束中，`thinking`、`summary`、`tool_call` 不允许携带附件；`tool_result` 允许附件以支持后续工具富媒体输出。
 
 ## 8. TODO / 未决问题
 
 - TODO: 增加 streaming 与多模型路由策略。
 - TODO: 明确跨 adapter 的 tool schema 归一化规范。
 - TODO: 收敛 adapter client typing，减少 `Any`。
+- TODO: 为 `Message.kind=text/attachments/data` 定义跨 adapter 能力矩阵与降级规则。
 
 ## 能力状态（landed / partial / planned）
 
diff --git a/docs/design/modules/transport/README.md b/docs/design/modules/transport/README.md
index 104b3a7b..06a942a7 100644
--- a/docs/design/modules/transport/README.md
+++ b/docs/design/modules/transport/README.md
@@ -1,22 +1,24 @@
 # Module: transport
 
-> Status: detailed design aligned to `dare_framework/transport` (2026-02-25).
+> Status: message-format redesign baseline updated for typed envelope payloads (2026-03-09).
 
 ## 1. 定位与职责
 
-- 提供 Agent 与外部客户端（CLI/Web/API）之间的统一信封通信层。
+- 提供 Agent 与外部客户端（CLI/Web/API）之间的统一 envelope 通信层。
 - 通过 `TransportEnvelope` + `AgentChannel` 屏蔽具体连接协议差异。
-- 管理 action/control/message 三类交互路径与错误回执。
+- transport 只负责“帧路由与交互分派”，不直接承载 framework message 语义。
+- `TransportEnvelope.kind` 只区分协议大类；具体业务语义下沉到 typed payload。
 
 ## 2. 依赖与边界
 
 - kernel：`AgentChannel`, `ClientChannel`
-- types：`EnvelopeKind`, `TransportEnvelope`
+- types：`EnvelopeKind`, `TransportEnvelope`, `EnvelopePayload`
 - 默认实现：`DefaultAgentChannel`
 - interaction 子域：`ActionHandlerDispatcher`, `AgentControlHandler`, payload builders
 - 边界约束：
-  - transport 负责消息路由与回压，不负责任务业务语义。
-  - action/control 的业务执行由 dispatcher/agent handler 提供。
+  - transport 负责 envelope 路由、回压、reply 关联，不负责模型/provider 消息格式。
+  - `Message` 属于 context domain 的 canonical framework message；transport 不重新定义一套平行 message。
+  - action/control/select 的业务执行由 dispatcher/agent handler/交互层提供。
 
 ## 3. 对外接口（Public Contract）
 
@@ -31,16 +33,127 @@
   - `attach_agent_envelope_sender(sender)`
   - `agent_envelope_receiver() -> Receiver`
 
-## 4. 关键字段（Core Fields）
+## 4. 核心数据结构（Core Data Structures）
 
-- `EnvelopeKind`
-  - `MESSAGE`, `ACTION`, `CONTROL`
-- `TransportEnvelope`
-  - `id`, `reply_to`, `kind`, `payload`, `meta`, `stream_id`, `seq`
+### 4.1 `EnvelopeKind`
 
-统一返回 payload（interaction/payloads）：
-- success: `{type:"result", kind, target, ok:true, resp}`
-- error: `{type:"error", kind, target, ok:false, code, reason, resp}`
+- 保留现有 4 个协议大类：
+  - `MESSAGE`
+  - `SELECT`
+  - `ACTION`
+  - `CONTROL`
+- `EnvelopeKind` 不承载细粒度业务语义；`chat/thinking/tool_call/tool_result` 不平铺到这里。
+
+### 4.2 `TransportEnvelope`
+
+建议稳定字段：
+
+- `id`
+  - transport frame id；用于 reply/ack/重试/链路追踪。
+- `reply_to`
+  - 关联上游 frame。
+- `kind`
+  - envelope 协议大类。
+- `payload`
+  - typed payload；根据 `kind` 选择对应 payload 家族。
+- `meta`
+  - transport/runtime 元数据。
+- `stream_id`
+  - 流式/多帧关联标识。
+- `seq`
+  - 流式帧序号。
+
+设计收敛结论：
+
+- `event_type` 退出主设计。
+- 原先通过 `event_type` 传递的业务语义，应转入 typed payload。
+- 如果实施时需要过渡，可短期保留 `event_type` 作为兼容字段，但只能由 payload 单向推导，不允许形成第二真相源。
+
+### 4.3 `EnvelopePayload` 抽象接口
+
+所有 payload 家族共享以下公共字段：
+
+- `id`
+  - 语义对象 id；区别于 envelope frame id。
+- `metadata`
+  - 业务元数据。
+
+### 4.4 Payload 家族
+
+#### `MessagePayload`
+
+- `id`
+- `metadata`
+- `role`
+- `message_kind`
+  - 使用确定性枚举 `MessageKind`
+  - `CHAT | THINKING | TOOL_CALL | TOOL_RESULT | SUMMARY`
+- `text: str | None`
+- `attachments: list[AttachmentRef]`
+- `data: dict[str, Any] | None`
+
+说明：
+
+- `chat` 使用 `text + attachments` 表达；不再单独引入 `ChatBody`。
+- `thinking/summary` 通常只使用 `text`。
+- `tool_call/tool_result` 通过 `data` 承载结构化字段，`text` 作为可选人类可读补充。
+- `MessagePayload` 可稳定转换为 context domain 的 canonical `Message`。
+
+#### `SelectPayload`
+
+- `id`
+- `metadata`
+- `select_kind`
+  - 使用确定性枚举 `SelectKind`
+  - `ASK | ANSWERED`
+- `select_domain`
+  - 使用确定性枚举 `SelectDomain`
+  - `APPROVAL | CHOICE | FORM`
+- `prompt`
+- `options`
+- `selected`
+
+说明：
+
+- `approval.pending` / `approval.resolved` 不再属于 message event；统一回收到 `kind=select`。
+- approval 的两阶段语义分别映射为：
+  - `ask`
+  - `answered`
+
+#### `ActionPayload`
+
+- `id`
+- `metadata`
+- `resource_action`
+- `params`
+
+说明：
+
+- `resource_action` 就是 action 主语义，不再额外引入 `action_kind`/`message_kind`。
+- 该字段继续与 `ResourceAction` 对齐解析；是否在 payload 上直接强制为 enum，取决于后续是否允许外部扩展 action id。
+
+#### `ControlPayload`
+
+- `id`
+- `metadata`
+- `control_id`
+- `params`
+
+说明：
+
+- `control_id` 语义上应与 `AgentControl` 一致；当前实现阶段仍保留字符串承载，但后续不应在框架逻辑中散落裸字符串常量。
+
+### 4.5 `AttachmentRef`
+
+首版只要求图片：
+
+- `kind: image`
+- `uri`
+- `mime_type?`
+- `filename?`
+- `metadata?`
+
+该结构既可用于 `MessagePayload.attachments`，也可用于 canonical `Message.attachments`。
 
 ## 5. 关键流程（Runtime Flow）
 
@@ -48,32 +161,44 @@
 flowchart TD
   A["Client sends TransportEnvelope"] --> B["DefaultAgentChannel._enqueue_inbox"]
   B --> C{"kind"}
-  C -- MESSAGE --> D["put inbox -> Agent poll"]
-  C -- ACTION --> E["ActionHandlerDispatcher.handle_action"]
-  C -- CONTROL --> F["AgentControlHandler.invoke"]
-  E --> G["build success/error payload"]
-  F --> G
+  C -- MESSAGE --> D["parse MessagePayload -> canonical Message"]
+  C -- SELECT --> E["dispatch selection / approval interaction"]
+  C -- ACTION --> F["ActionHandlerDispatcher.handle_action"]
+  C -- CONTROL --> G["AgentControlHandler.invoke"]
   D --> H["Agent business loop"]
-  H --> I["channel.send -> outbox"]
-  I --> J["pump_outbox_to_receiver"]
+  F --> I["build typed action reply payload"]
+  G --> J["build typed control reply payload"]
+  H --> K["channel.send -> outbox"]
+  I --> K
+  J --> K
+  K --> L["pump_outbox_to_receiver"]
 ```
 
 ## 6. 与其他模块的交互
 
-- **Agent**：通过 `poll/send` 进入 transport loop 或 direct-call 通道。
-- **Hook/Observability**：可通过 transport 发送事件 envelope 到外部 UI。
-- **Tool/HITL**：审批状态可经 transport payload 回传客户端。
+- **Context**
+  - `kind=message` 的 payload 会被归一化为 canonical `Message`。
+- **Agent**
+  - 通过 `poll/send` 进入 transport loop 或 direct-call 通道。
+- **Model**
+  - transport 不接触 provider message；provider 序列化只在 adapter 内部发生。
+- **Hook/Observability**
+  - 通过 envelope/meta 追踪 transport 级事件，不污染 canonical message 结构。
+- **Tool/HITL**
+  - 审批/选择状态通过 `kind=select` 回传客户端，而不是伪装成 message event。
 
 ## 7. 约束与限制
 
 - 默认 channel 为阻塞回压模型，未提供优先级队列。
 - 未提供持久化队列与断线恢复机制。
+- 本文只定义消息格式与 envelope 结构；`pending delta / active model state / resume rebuild` 不在 transport 设计内处理。
 
 ## 8. TODO / 未决问题
 
 - TODO: 支持 reconnect/resume 与 envelope replay。
 - TODO: 定义 streaming chunk 的标准 envelope 协议。
-- TODO: 增加 action/control schema 校验与版本化。
+- TODO: 为各 payload 家族补齐 schema 校验与版本化。
+- TODO: 清理 `TransportEventType` 历史语义，尤其是 `approval.pending/resolved` 向 `SelectPayload` 归位。
 
 ## 9. 相关文档
 
diff --git a/docs/features/README.md b/docs/features/README.md
index 71dfc904..22f2689f 100644
--- a/docs/features/README.md
+++ b/docs/features/README.md
@@ -37,15 +37,9 @@
 
 ## Active Entries
 
-- `docs/features/add-anthropic-model-adapter.md`
-- `docs/features/agentscope-d2-d4-thinking-transport.md`
-- `docs/features/agentscope-d5-safe-compression.md`
-- `docs/features/agentscope-d7-plan-state-tools.md`
 - `docs/features/enhance-doc-governance-traceability.md`
-- `docs/features/client-session-resume.md`
 - `docs/features/p0-conformance-gate.md`
-- `docs/features/p0-default-eventlog.md`
-- `docs/features/p0-step-driven-execution.md`
+- `docs/features/rich-media-message-pipeline.md`
 
 ## Archive Index
 
diff --git a/docs/features/archive/README.md b/docs/features/archive/README.md
index 7f06be38..e9b1954f 100644
--- a/docs/features/archive/README.md
+++ b/docs/features/archive/README.md
@@ -9,6 +9,16 @@
 - `docs/features/archive/client-headless-event-envelope-v1.md`
 - `docs/features/archive/client-host-orchestration-doc-baseline.md`
 - `docs/features/archive/refactor-dare-agent-structure-split.md`
+- `docs/features/archive/agentscope-d1-d3-message-pipeline.md`
+- `docs/features/archive/transport-typed-payload-cutover.md`
+- `docs/features/archive/add-anthropic-model-adapter.md`
+- `docs/features/archive/agentscope-d2-d4-thinking-transport.md`
+- `docs/features/archive/agentscope-d5-safe-compression.md`
+- `docs/features/archive/agentscope-d7-plan-state-tools.md`
+- `docs/features/archive/client-session-resume.md`
+- `docs/features/archive/message-input-boundary-cleanup.md`
+- `docs/features/archive/p0-default-eventlog.md`
+- `docs/features/archive/p0-step-driven-execution.md`
 
 ## Archive Migration Rules
 
diff --git a/docs/features/add-anthropic-model-adapter.md b/docs/features/archive/add-anthropic-model-adapter.md
similarity index 99%
rename from docs/features/add-anthropic-model-adapter.md
rename to docs/features/archive/add-anthropic-model-adapter.md
index 7793f6a6..a2ce5e8f 100644
--- a/docs/features/add-anthropic-model-adapter.md
+++ b/docs/features/archive/add-anthropic-model-adapter.md
@@ -4,7 +4,7 @@ doc_kind: feature
 topics: ["model", "anthropic", "adapter", "cli-doctor"]
 created: 2026-03-05
 updated: 2026-03-05
-status: active
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/archive/agentscope-d1-d3-message-pipeline.md b/docs/features/archive/agentscope-d1-d3-message-pipeline.md
new file mode 100644
index 00000000..e0e6abe8
--- /dev/null
+++ b/docs/features/archive/agentscope-d1-d3-message-pipeline.md
@@ -0,0 +1,113 @@
+---
+change_ids: ["agentscope-d1-d3-message-pipeline"]
+doc_kind: feature
+topics: ["agentscope", "message-schema", "transport", "context", "model", "rich-media"]
+todo_ids: ["D1-1", "D1-2", "D1-3", "D1-4", "D2-1", "D2-2", "D2-3", "D2-4", "D3-1", "D3-2", "D3-3", "D3-4"]
+created: 2026-03-09
+updated: 2026-03-09
+status: archived
+mode: openspec
+---
+
+# Feature: agentscope-d1-d3-message-pipeline
+
+## Scope
+冻结消息格式基线，统一 transport typed payload、context canonical `Message` 与 model adapter codec 边界，首版支持单条 `chat` 消息携带“一段文字 + 多张图片”。
+
+本特性只覆盖消息格式契约，不覆盖消息投递/缓存/压缩/resume/分发运行时设计。
+
+## OpenSpec Artifacts
+- Proposal: `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/proposal.md`
+- Design: `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/design.md`
+- Specs:
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/rich-media-message-schema/spec.md`
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/transport-channel/spec.md`
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/chat-runtime/spec.md`
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/interaction-dispatch/spec.md`
+- Tasks: `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/tasks.md`
+
+## Progress
+- 已完成：design docs 基线更新（transport/context/model/interfaces/TODO）。
+- 已完成：canonical `Message` schema、typed payload families、rich-media adapter codec 与回归测试。
+- 已完成：主 specs 同步与 OpenSpec 归档。
+
+## Evidence
+
+### Commands
+- `openspec list --json`
+- `openspec new change "agentscope-d1-d3-message-pipeline"`
+- `openspec status --change "agentscope-d1-d3-message-pipeline" --json`
+- `openspec instructions proposal --change "agentscope-d1-d3-message-pipeline" --json`
+- `openspec instructions design --change "agentscope-d1-d3-message-pipeline" --json`
+- `openspec instructions specs --change "agentscope-d1-d3-message-pipeline" --json`
+- `openspec instructions tasks --change "agentscope-d1-d3-message-pipeline" --json`
+- `./.venv/bin/pytest -q tests/unit/test_context_message_types.py tests/unit/test_context_implementation.py tests/unit/test_transport_typed_payloads.py tests/unit/test_transport_types.py tests/unit/test_transport_channel.py tests/unit/test_transport_adapters.py tests/unit/test_base_agent_transport_contract.py tests/unit/test_five_layer_agent.py tests/unit/test_openrouter_adapter.py tests/unit/test_anthropic_model_adapter.py tests/unit/test_openai_model_adapter.py`
+- `./.venv/bin/pytest -q tests/unit/test_context_message_types.py tests/unit/test_context_implementation.py tests/unit/test_context_compression.py tests/unit/test_transport_typed_payloads.py tests/unit/test_transport_types.py tests/unit/test_transport_channel.py tests/unit/test_transport_adapters.py tests/unit/test_base_agent_transport_contract.py tests/unit/test_five_layer_agent.py tests/unit/test_openrouter_adapter.py tests/unit/test_anthropic_model_adapter.py tests/unit/test_openai_model_adapter.py tests/unit/test_checkpoint_message_schema.py tests/unit/test_example_10_agentscope_compat.py tests/integration/test_hook_governance_flow.py`
+- `git diff --check`
+- `openspec validate --changes "agentscope-d1-d3-message-pipeline"`
+
+### Results
+- OpenSpec change 创建成功并完成归档（schema: `spec-driven`）。
+- canonical `Message(role/kind/text/attachments/data)` 已在 context/model/session/memory/transport 主链路落地。
+- rich-media `chat(text + images[])` 已进入 adapter serializer 与回归测试。
+- focused/unit/integration regression suites passed。
+- 文档与 specs 已同步，`git diff --check` 和 `openspec validate` 通过。
+
+### Contract Delta
+- `schema`: changed
+  - transport 从 `payload: Any + event_type` 转为 typed payload。
+  - canonical `Message` 从 `content: str` 转为 `role(MessageRole) + kind(MessageKind) + text + attachments(AttachmentRef[]) + data`。
+- `error semantics`: changed
+  - invalid typed payload / unsupported attachment-message_kind 组合改为 deterministic fail。
+- `retry`: none
+  - 本轮不调整运行时投递/重试机制。
+
+### Golden Cases
+- 新增：`openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/**`
+- 更新：`docs/design/modules/transport/README.md`
+- 更新：`docs/design/modules/context/README.md`
+- 更新：`docs/design/modules/model/README.md`
+- 更新：`docs/design/Interfaces.md`
+- 更新：`docs/todos/agentscope_domain_execution_todos.md`
+- 更新：`docs/todos/project_overall_todos.md`
+
+### Regression Summary
+- rich-media/context/transport/model focused suite passed。
+- compatibility/example/integration suites covering canonical message migration passed。
+
+### Observability and Failure Localization
+- `start`: typed `MessagePayload(chat|thinking|tool_call|tool_result|summary)` enters context normalization
+- `tool_call`: structured tool semantics come from `Message.data`
+- `end`: adapters render canonical message into provider-native request blocks
+- `fail`: none
+
+### Structured Review Report
+- module boundary:
+  - transport 只负责 envelope 与 typed payload，不再承载 message 子语义。
+  - context `Message` 作为唯一 canonical message。
+  - model adapter 只消费 canonical `Message` 并输出 provider message。
+- state:
+  - 本 change 只完成 message schema，不引入 pending delta / prompt state / render cache。
+- concurrency:
+  - 主要风险在 `Message.content` 切除后的大面积调用点迁移。
+- side-effect:
+  - 属于明确 breaking change：移除 `event_type`、移除 `Message.content`、移除 raw transport payload compatibility。
+- coverage:
+  - transport/context/model/session/memory/adapter/example/integration 覆盖已补齐。
+
+### Behavior Verification
+- Happy path:
+  - 单条 `chat` 消息可携带一段文字 + 多张图片，并保持为一个 logical user turn。
+  - `tool_call/tool_result` 结构化语义从 `Message.data` 序列化到 adapter request。
+- Error branch:
+  - invalid typed payload / unsupported attachment-message kind 组合会在 schema validation 分支 deterministic fail。
+
+### Risks and Rollback
+- 风险：实现阶段需要同步改 transport/context/model/session/compression 多个模块。
+- 风险：现有大量测试直接依赖 `Message.content` 与 `event_type`。
+- 回滚：整体回退到旧消息契约；但当前工作区已按非兼容 cutover 前进，不再保留兼容层。
+
+### Review and Merge Gate Links
+- Intent PR: 待创建。
+- Review request: 待创建实现 PR 后补充。
+- Merge gate: 待实现与 CI 完成后补充。
diff --git a/docs/features/agentscope-d2-d4-thinking-transport.md b/docs/features/archive/agentscope-d2-d4-thinking-transport.md
similarity index 99%
rename from docs/features/agentscope-d2-d4-thinking-transport.md
rename to docs/features/archive/agentscope-d2-d4-thinking-transport.md
index 386de938..388cf530 100644
--- a/docs/features/agentscope-d2-d4-thinking-transport.md
+++ b/docs/features/archive/agentscope-d2-d4-thinking-transport.md
@@ -5,7 +5,7 @@ topics: ["agentscope", "transport", "thinking", "tool-events", "model-response"]
 todo_ids: ["D2-1", "D2-2", "D2-3", "D2-4", "D4-1", "D4-2", "D4-3", "D4-4"]
 created: 2026-03-02
 updated: 2026-03-03
-status: draft
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/agentscope-d5-safe-compression.md b/docs/features/archive/agentscope-d5-safe-compression.md
similarity index 99%
rename from docs/features/agentscope-d5-safe-compression.md
rename to docs/features/archive/agentscope-d5-safe-compression.md
index 97db392f..3205af2e 100644
--- a/docs/features/agentscope-d5-safe-compression.md
+++ b/docs/features/archive/agentscope-d5-safe-compression.md
@@ -4,7 +4,7 @@ doc_kind: feature
 topics: ["agentscope", "compression", "context", "react-agent", "budget"]
 created: 2026-03-02
 updated: 2026-03-09
-status: in_review
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/agentscope-d7-plan-state-tools.md b/docs/features/archive/agentscope-d7-plan-state-tools.md
similarity index 99%
rename from docs/features/agentscope-d7-plan-state-tools.md
rename to docs/features/archive/agentscope-d7-plan-state-tools.md
index ddab3d9c..390f58d2 100644
--- a/docs/features/agentscope-d7-plan-state-tools.md
+++ b/docs/features/archive/agentscope-d7-plan-state-tools.md
@@ -4,7 +4,7 @@ doc_kind: feature
 topics: ["agentscope", "plan_v2", "state-machine", "critical-block"]
 created: 2026-03-02
 updated: 2026-03-04
-status: done
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/client-session-resume.md b/docs/features/archive/client-session-resume.md
similarity index 99%
rename from docs/features/client-session-resume.md
rename to docs/features/archive/client-session-resume.md
index f855a5b6..0d9db506 100644
--- a/docs/features/client-session-resume.md
+++ b/docs/features/archive/client-session-resume.md
@@ -5,7 +5,7 @@ topics: ["client-cli", "session-resume", "conversation-history", "t5-1"]
 todo_ids: ["CRES-001", "CRES-002", "CRES-003", "CRES-004", "CRES-005", "CRES-006", "CRES-007"]
 created: 2026-03-04
 updated: 2026-03-05
-status: draft
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/archive/message-input-boundary-cleanup.md b/docs/features/archive/message-input-boundary-cleanup.md
new file mode 100644
index 00000000..6269b188
--- /dev/null
+++ b/docs/features/archive/message-input-boundary-cleanup.md
@@ -0,0 +1,59 @@
+---
+change_ids: ["message-input-boundary-cleanup"]
+doc_kind: feature
+topics: ["message-schema", "agent-input", "transport", "session-loop", "examples"]
+created: 2026-03-09
+updated: 2026-03-09
+status: archived
+mode: openspec
+---
+
+# Feature: message-input-boundary-cleanup
+
+## Scope
+收口 canonical message 的剩余输入边界问题：agent 顶层直接接受 `Message`，`Task` 退回编排对象并通过 `input_message` 保存真实用户消息，transport poll loop 不再把 `MessagePayload` 压扁成字符串。
+
+本特性仍然只覆盖 message 本身相关改动，不包含消息投递/缓存/压缩/resume/分发设计。
+
+## OpenSpec Artifacts
+- Proposal: `openspec/changes/message-input-boundary-cleanup/proposal.md`
+- Design: `openspec/changes/message-input-boundary-cleanup/design.md`
+- Specs:
+  - `openspec/changes/message-input-boundary-cleanup/specs/rich-media-message-schema/spec.md`
+  - `openspec/changes/message-input-boundary-cleanup/specs/transport-channel/spec.md`
+  - `openspec/changes/message-input-boundary-cleanup/specs/session-loop/spec.md`
+  - `openspec/changes/message-input-boundary-cleanup/specs/plan-module/spec.md`
+- Tasks: `openspec/changes/message-input-boundary-cleanup/tasks.md`
+
+## Evidence
+
+### Commands
+- `./.venv/bin/pytest -q tests/unit/test_base_agent_transport_contract.py -k canonical_message_payload`
+- `./.venv/bin/pytest -q tests/unit/test_session_orchestrator_message_input.py tests/unit/test_context_message_types.py -k 'input_message or requires_structured_data_for_tool'`
+- `./.venv/bin/pytest -q tests/unit/test_base_agent_transport_contract.py tests/unit/test_session_orchestrator_message_input.py tests/unit/test_context_message_types.py tests/unit/test_examples_04_cli.py tests/unit/test_examples_cli.py tests/unit/test_examples_cli_mcp.py tests/unit/test_client_cli.py tests/unit/test_dare_agent_hook_governance.py tests/unit/test_react_agent_gateway_injection.py tests/unit/test_five_layer_agent.py`
+- `./.venv/bin/pytest -q tests/unit/test_transport_typed_payloads.py tests/unit/test_transport_types.py tests/unit/test_transport_channel.py tests/unit/test_transport_adapters.py tests/unit/test_openai_model_adapter.py tests/unit/test_openrouter_adapter.py tests/unit/test_anthropic_model_adapter.py tests/unit/test_context_implementation.py tests/unit/test_context_compression.py tests/unit/test_checkpoint_message_schema.py`
+- `./.venv/bin/pytest -q tests/unit/test_client_cli.py tests/integration/test_client_cli_flow.py -k 'conversation_id or mode_plan or execute or run_task'`
+- `./.venv/bin/pytest -q tests/unit/test_dare_agent_hook_governance.py tests/unit/test_react_agent_gateway_injection.py tests/unit/test_five_layer_agent.py`
+
+### Results
+- transport loop now passes canonical `Message` into agent execution without dropping attachments.
+- session loop now prefers `Task.input_message` over `Task.description`.
+- canonical schema now rejects `tool_call/tool_result` messages without `data`.
+- active client/example direct prompt entry points now send `Message`.
+
+### Contract Delta
+- `schema`: changed
+  - `IAgent.__call__` accepts `str | Message`; internal execute/orchestration paths consume canonical `Message`.
+  - `Task` adds `input_message`.
+- `error semantics`: changed
+  - `tool_call/tool_result` without `data` now fail at canonical message construction.
+- `retry`: none
+  - no runtime retry semantics changed.
+
+### Regression Summary
+- focused unit and example suites passed.
+- client CLI focused integration slice passed.
+
+### Risks and Rollback
+- remaining docs/spec references to `str | Task` outside the touched scope still need broader cleanup.
+- rollback would require reverting the public `str | Message` boundary normalization and the `Task.input_message` internal projection.
diff --git a/docs/features/p0-default-eventlog.md b/docs/features/archive/p0-default-eventlog.md
similarity index 99%
rename from docs/features/p0-default-eventlog.md
rename to docs/features/archive/p0-default-eventlog.md
index 45c7dd14..aa2b4cde 100644
--- a/docs/features/p0-default-eventlog.md
+++ b/docs/features/archive/p0-default-eventlog.md
@@ -4,7 +4,7 @@ doc_kind: feature
 topics: ["event-log", "sqlite", "hash-chain", "builder-defaults"]
 created: 2026-03-01
 updated: 2026-03-01
-status: draft
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/p0-step-driven-execution.md b/docs/features/archive/p0-step-driven-execution.md
similarity index 99%
rename from docs/features/p0-step-driven-execution.md
rename to docs/features/archive/p0-step-driven-execution.md
index a671bd51..d32c7523 100644
--- a/docs/features/p0-step-driven-execution.md
+++ b/docs/features/archive/p0-step-driven-execution.md
@@ -4,7 +4,7 @@ doc_kind: feature
 topics: ["execution-mode", "step-driven", "plan-execute-verify"]
 created: 2026-03-01
 updated: 2026-03-01
-status: done
+status: archived
 mode: openspec
 ---
 
diff --git a/docs/features/archive/transport-typed-payload-cutover.md b/docs/features/archive/transport-typed-payload-cutover.md
new file mode 100644
index 00000000..24e60efc
--- /dev/null
+++ b/docs/features/archive/transport-typed-payload-cutover.md
@@ -0,0 +1,103 @@
+---
+change_ids: ["transport-typed-payload-cutover"]
+doc_kind: feature
+topics: ["transport", "typed-payload", "agent-runtime", "client", "protocol"]
+created: 2026-03-09
+updated: 2026-03-09
+status: archived
+mode: openspec
+---
+
+# Feature: transport-typed-payload-cutover
+
+## Scope
+移除 transport 运行时剩余的 legacy 兼容层：删除 `TransportEnvelope.event_type` 与 `message/action/control` 的 raw payload 兼容，把 request/reply 全面收敛到 typed payload families。
+
+## OpenSpec Artifacts
+- Proposal: `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/proposal.md`
+- Design: `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/design.md`
+- Specs:
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/typed-transport-replies/spec.md`
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/transport-channel/spec.md`
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/interaction-dispatch/spec.md`
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/chat-runtime/spec.md`
+- Tasks: `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/tasks.md`
+
+## Progress
+- 已完成：transport/runtime/client/example transport typed payload cutover。
+- 已完成：OpenSpec tasks 1.1-4.2 与对应回归验证。
+
+## Evidence
+
+### Commands
+- `openspec new change "transport-typed-payload-cutover"`
+- `openspec status --change "transport-typed-payload-cutover" --json`
+- `openspec instructions proposal --change "transport-typed-payload-cutover" --json`
+- `openspec instructions design --change "transport-typed-payload-cutover" --json`
+- `openspec instructions specs --change "transport-typed-payload-cutover" --json`
+- `openspec instructions tasks --change "transport-typed-payload-cutover" --json`
+- `./.venv/bin/pytest -q tests/unit/test_transport_types.py tests/unit/test_transport_channel.py tests/unit/test_transport_adapters.py tests/unit/test_interaction_dispatcher.py tests/unit/test_base_agent_transport_contract.py tests/unit/test_agent_event_transport_hook.py tests/unit/test_react_agent_gateway_injection.py tests/unit/test_example_10_agentscope_compat.py`
+- `./.venv/bin/pytest -q tests/unit/test_examples_cli.py tests/unit/test_examples_cli_mcp.py tests/unit/test_dare_agent_hook_transport_boundary.py tests/unit/test_client_cli.py -k 'approvals or transport or approval_pending or hook or event'`
+- `./.venv/bin/pytest -q tests/unit/test_transport_types.py tests/unit/test_transport_channel.py tests/unit/test_transport_adapters.py tests/unit/test_interaction_dispatcher.py tests/unit/test_base_agent_transport_contract.py tests/unit/test_agent_event_transport_hook.py tests/unit/test_react_agent_gateway_injection.py tests/unit/test_example_10_agentscope_compat.py tests/unit/test_examples_cli.py tests/unit/test_examples_cli_mcp.py tests/unit/test_client_cli.py tests/unit/test_dare_agent_hook_transport_boundary.py tests/integration/test_client_cli_flow.py`
+- `git diff --check`
+- `openspec validate --changes "transport-typed-payload-cutover"`
+
+### Results
+- transport request/reply 已全面收敛到 typed payload families。
+- `pytest` focused transport/runtime/example/client suite: `178 passed, 1 warning`
+- `git diff --check`: passed
+- `openspec validate --changes "transport-typed-payload-cutover"`: `14 passed, 0 failed`
+
+### Contract Delta
+- `schema`: changed
+  - 移除 `event_type`
+  - 移除 raw string/dict transport payload
+  - request/reply 均收敛到 typed payload families
+- `error semantics`: changed
+  - message/action/control 的错误回复改由对应 typed payload 自身字段表达
+- `retry`: none
+  - 本切片不调整 retry/timeout 策略
+
+### Golden Cases
+- 更新：typed transport/unit/example/client regression fixtures
+- 新增：`openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/**`
+
+### Regression Summary
+- transport/runtime/example/client targeted regression suite passed with typed request/reply contract.
+
+### Observability and Failure Localization
+- `start`: typed payload request enters `TransportEnvelope(kind, payload)`
+- `tool_call`: ReactAgent emits `MessagePayload(message_kind=tool_call/tool_result)`
+- `end`: BaseAgent/default channel reply with `MessagePayload/ActionPayload/ControlPayload`
+- `fail`: invalid typed payload family now fails at envelope construction or deterministic payload validation branch
+
+### Structured Review Report
+- module boundary:
+  - transport reply 语义回收到 payload family，不再分叉到 `event_type`
+- state:
+  - 不涉及 session/resume/cache
+- concurrency:
+  - 主要风险在 request/reply 契约切换造成 client/test 同步修改
+- side-effect:
+  - 会破坏 legacy transport consumers，属于明确 breaking change
+- coverage:
+  - transport/runtime/example/client/unit+integration 回归已覆盖
+
+### Behavior Verification
+- Happy path:
+  - `message` request -> `MessagePayload(chat)` reply
+  - `action` request -> `ActionPayload(ok/result)` reply
+  - approval pending -> `SelectPayload(ask, approval)`
+- Error branch:
+  - invalid payload family rejected deterministically
+  - action failure returns `ActionPayload(ok=False, code, reason)`
+  - agent execution failure returns `MessagePayload(summary, data.reason/code)`
+
+### Risks and Rollback
+- 风险：大量 tests/examples 依赖 `event_type + dict payload`
+- 回滚：整体回退到当前 transport 兼容契约
+
+### Review and Merge Gate Links
+- Intent PR: 待补
+- Review request: 待补
+- Merge gate: 待补
diff --git a/docs/features/rich-media-message-pipeline.md b/docs/features/rich-media-message-pipeline.md
new file mode 100644
index 00000000..8f7f7a77
--- /dev/null
+++ b/docs/features/rich-media-message-pipeline.md
@@ -0,0 +1,85 @@
+---
+change_ids: ["agentscope-d1-d3-message-pipeline", "transport-typed-payload-cutover", "message-input-boundary-cleanup"]
+doc_kind: feature
+topics: ["message-schema", "rich-media", "transport", "agent-input", "a2a"]
+created: 2026-03-09
+updated: 2026-03-09
+status: active
+mode: openspec
+---
+
+# Feature: rich-media-message-pipeline
+
+## Scope
+
+Land the rich-media message pipeline as a single governed delivery topic: canonical `Message`
+schema cutover, typed transport payloads, public agent input normalization, and A2A/example
+entrypoint migration to `text + attachments + data`.
+
+This topic intentionally excludes the later runtime-lifecycle redesign for message delivery,
+caching, compression, resume, and dispatch orchestration.
+
+## OpenSpec Artifacts
+
+- Proposal:
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/proposal.md`
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/proposal.md`
+  - `openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/proposal.md`
+- Design:
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/design.md`
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/design.md`
+  - `openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/design.md`
+- Specs:
+  - `openspec/specs/rich-media-message-schema/spec.md`
+  - `openspec/specs/transport-channel/spec.md`
+  - `openspec/specs/interaction-dispatch/spec.md`
+  - `openspec/specs/chat-runtime/spec.md`
+  - `openspec/specs/typed-transport-replies/spec.md`
+- Tasks:
+  - `openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/tasks.md`
+  - `openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/tasks.md`
+  - `openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/tasks.md`
+
+## Governance Anchors
+
+- `docs/guides/Development_Constraints.md`
+- `docs/guides/Documentation_First_Development_SOP.md`
+- `docs/design/Interfaces.md`
+- `docs/design/modules/context/README.md`
+- `docs/design/modules/transport/README.md`
+- `docs/design/modules/model/README.md`
+- `docs/design/modules/agent/README.md`
+
+## Evidence
+
+### Commands
+
+- `openspec validate --spec-dir openspec/specs`
+- `git diff --check`
+
+### Results
+
+- `openspec validate --spec-dir openspec/specs`: baseline spec tree is valid before the
+  implementation PR updates runtime code and evidence.
+- `git diff --check`: docs-only intent branch stays formatting-clean and preserves the governed
+  feature-doc template contract.
+
+### Behavior Verification
+
+- Happy path: this intent record establishes the active governed feature topic that the later
+  implementation PR will update while landing the message-schema cutover.
+- Error/fallback path: runtime delivery/caching/resume redesign remains explicitly out of scope for
+  this feature topic and must land through a separate follow-up intent/change.
+
+### Risks and Rollback
+
+- Risk: the implementation PR still needs to append concrete runtime verification evidence and
+  update the active feature record before merge.
+- Rollback: if the topic scope changes materially, replace this intent record before merging the
+  implementation PR instead of silently repurposing it.
+
+### Review and Merge Gate Links
+
+- Intent PR: `TBD`
+- Implementation PR: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/204`
+- Review request: `TBD`
diff --git a/docs/guides/Tool_Approval_Memory.md b/docs/guides/Tool_Approval_Memory.md
index 42548b14..2a59a357 100644
--- a/docs/guides/Tool_Approval_Memory.md
+++ b/docs/guides/Tool_Approval_Memory.md
@@ -131,14 +131,18 @@
 
 若超时未出现 pending，则 `request=null`。
 
-## 5. Transport 审批事件（推荐）
+## 5. Transport 审批协议（推荐）
 
-当 `requires_approval=true` 的工具调用进入 pending 时，runtime 会通过 transport 主动发出：
+当 `requires_approval=true` 的工具调用进入 pending 时，runtime 会通过 transport 主动发出 `kind="select"` 的 typed payload：
 
-- `event_type="approval.pending"`：包含 pending request 详情
-- `event_type="approval.resolved"`：包含 request_id 与最终 decision（allow/deny）
+- `SelectPayload(select_kind="ask", select_domain="approval")`：包含 pending request 详情
+- `SelectPayload(select_kind="answered", select_domain="approval")`：包含 request_id 与最终 decision（allow/deny）
 
-协议说明：客户端应仅使用 `event_type` 做分流；`payload.type` 已移除。
+协议说明：
+
+- transport 层应基于 `TransportEnvelope.kind="select"` 与 `SelectPayload.select_kind/select_domain` 做分流
+- `event_type="approval.pending|approval.resolved"` 不再是 transport 主协议
+- `client --output json` 的 headless 事件流仍会向外发出 `approval.pending` / `approval.resolved` 作为 CLI 事件名，这是独立于 transport 的输出契约
 
 这允许客户端实现 Codex/Claude Code 风格的“消息流里出现审批卡片”，同时再用 `approvals:grant|deny` 完成决策。
 
diff --git a/docs/todos/agentscope_domain_execution_todos.md b/docs/todos/agentscope_domain_execution_todos.md
index efc0c9cf..913fb209 100644
--- a/docs/todos/agentscope_domain_execution_todos.md
+++ b/docs/todos/agentscope_domain_execution_todos.md
@@ -11,8 +11,8 @@
 - 不包含 Session 体系（并行开发中，不在本清单执行范围）。
 - 当前阶段不要求历史兼容（允许直接调整接口，不做迁移层）。
 - 不做 HITL 闭环；本轮关注完整权限模型与工具调用权限治理。
-- `client send` 升级为：`content: string` + `uris: list` + `metadata`。
-- `context.assemble` 负责把 `content + uris` 归一化为内部 message 结构。
+- transport 输入升级为 typed payload：保留 `EnvelopeKind = message/select/action/control`，`kind=message` 时使用 `MessagePayload(text + attachments + data)`。
+- `context.assemble` 负责把 `TransportEnvelope(kind=message)` 的 `MessagePayload` 归一化为内部 canonical `Message`。
 - 当前并行约束：最多 3 个并行 active claim（TODO 级）；拆分主轴为依赖关系、重要度、复杂度；切片仅在对应 TODO 详细位置维护。
 
 ## 0.1 认领声明（Claim Ledger）
@@ -30,16 +30,38 @@
 | CLM-20260302-D7 | D7-1~D7-4 | lang | done | 2026-03-02 | 2026-03-03 | `agentscope-d7-plan-state-tools` | `CLM-20260302-AG3` | PR #138 已合入主干，D7 代码/回归/评审闭环完成。 |
 | ~~CLM-20260302-D1D3~~ | ~~D1 + D3（历史聚合）~~ | ~~lang~~ | ~~deprecated~~ | ~~2026-03-02~~ | ~~2026-03-04~~ | ~~`agentscope-d1-d3-message-pipeline`~~ | ~~`CLM-20260302-AG4`~~ | 历史聚合认领已废弃；后续以 D1/D3 的 TODO 级 claim 为准。 |
 | ~~CLM-20260303-D6D8~~ | ~~D6 + D8（历史聚合）~~ | ~~N/A~~ | ~~deprecated~~ | ~~2026-03-03~~ | ~~2026-03-04~~ | ~~`pending`~~ | ~~`CLM-20260303-AG5`~~ | 聚合占位 claim 已废弃；后续以 D6/D8 的 TODO 级 claim 为准。 |
-| CLM-20260304-D1 | D1 |  | planned | 2026-03-04 | 2026-03-11 | `agentscope-d1-d3-message-pipeline` | `CLM-20260304-AG6` | 已拆分未分配；切片仅在 `5.2` 维护。 |
-| CLM-20260304-D3 | D3 |  | planned | 2026-03-04 | 2026-03-11 | `agentscope-d1-d3-message-pipeline` | `CLM-20260304-AG6` | 已拆分未分配；切片仅在 `5.2` 维护。 |
+| CLM-20260304-D1 | D1 | lang | done | 2026-03-04 | 2026-03-11 | `archive/2026-03-09-agentscope-d1-d3-message-pipeline` | `CLM-20260304-AG6` | canonical rich-media message schema、typed payload families、adapter codec 基线已完成并归档。 |
+| CLM-20260304-D3 | D3 | lang | done | 2026-03-04 | 2026-03-11 | `archive/2026-03-09-agentscope-d1-d3-message-pipeline` | `CLM-20260304-AG6` | context assemble/message normalization、attachment strategy 与 rich-media adapter 接口已完成并归档。 |
 | CLM-20260304-D6 | D6 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `CLM-20260304-AG7` | 已拆分未分配；切片仅在 `5.2` 维护。 |
 | CLM-20260304-D8 | D8 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `CLM-20260304-AG7` | 已拆分未分配；切片仅在 `5.2` 维护。 |
+| CLM-20260309-D2CUT | D2 transport cutover follow-up | lang | done | 2026-03-09 | 2026-03-12 | `archive/2026-03-09-transport-typed-payload-cutover` | `CLM-20260304-AG6` | transport legacy raw payload / `event_type` 兼容已清理完毕，reply typed payload 契约已归档。 |
+| CLM-20260309-D1INPUT | D1/D3 message input boundary cleanup | lang | done | 2026-03-09 | 2026-03-12 | `archive/2026-03-09-message-input-boundary-cleanup` | `CLM-20260304-AG6` | 收口 canonical `Message` 输入边界：agent 直收 `Message`、`Task.input_message`、transport poll 保真、不再把用户输入重新退化成 `Task.description`，并已归档。 |
 
 对账快照（2026-03-04）：
 - 未完成域 `D1/D3/D6/D8` 均已存在 `planned` claim（TODO 级）。
 - 已完成域 `D2/D4/D5/D7` 均已有 `done` claim 并与项目级聚合 claim 对账。
 
----
+## 0.2 消息管线重构拆分约束（2026-03-07）
+
+- 针对当前富媒体与模型消息能力补齐，`D1 + D3` 后续设计明确拆分为两个独立主题，禁止继续在同一轮设计里混合讨论：
+  - 主题 A：`文本/富媒体/模型消息 format` 设计。
+  - 主题 B：`消息投递/缓存/压缩/resume/分发` 设计。
+- 当前优先级：先完成主题 A 的设计收敛，再以单独设计文档/切片推进主题 B。
+- 主题 B 当前仅作为 TODO 记录，不在本轮消息模型设计里直接落实现有 runtime 机制调整。
+- 主题 B 设计必须显式覆盖：
+  - `stm_add`、历史消息、pending delta、模型侧缓存状态之间的边界。
+  - `assemble(incremental/rebuild)` 的触发条件与失效策略。
+  - 压缩 checkpoint、resume 重建、切模型降级、分发/transport 对 runtime state 的影响。
+
+## 0.3 Transport Cutover Follow-up（2026-03-09）
+
+- `agentscope-d1-d3-message-pipeline` 已完成消息 schema 基线，但 transport runtime 仍残留两层历史兼容：
+  - `TransportEnvelope.event_type`
+  - `message/action/control` raw `str` / raw `dict` payload
+- 后续独立切片 `transport-typed-payload-cutover` 专门负责：
+  - 删除上述 legacy compatibility
+  - 把 transport request/reply 统一收敛到 typed payload families
+  - 同步更新 client/example/test 契约
 
 ## 1. 能力/GAP 覆盖总览（用于确认“每个 TODO 支持什么能力”）
 
@@ -66,14 +88,15 @@
 ## D1 `protocol/message`（输入协议与内部消息模型）
 
 **主要改动**
-- 新定义 `ClientSend` 输入协议（`content`, `uris`, `metadata`）。
-- 新定义 `UriAttachment`（最小必须字段 + 可选 metadata）。
-- 内部 `Message` 支持“文本 + 附件引用块”的统一表达（供 assemble 消费）。
-- 明确输入约束：URI 数量/长度、metadata 大小、空文本处理。
+- 将 transport `payload: Any + event_type` 收敛为 typed payload 体系。
+- 保留 `EnvelopeKind = message/select/action/control`，不再平铺 message 子类型。
+- `MessagePayload` 与 canonical `Message` 高度对齐，支持 `text + attachments + data`。
+- 新定义 `AttachmentRef`（最小必须字段 + 可选 metadata），首版只要求图片。
+- 明确输入约束：附件数量/长度、metadata 大小、空文本处理、字段校验矩阵。
 
 **支撑能力**
-- Msg/TextBlock 基础能力。
-- 为多模态（图片/音频/视频）在协议层预留统一入口。
+- canonical message 基础能力。
+- 为多模态（图片/音频/视频）在消息结构层预留统一入口。
 
 **建议改动位置**
 - `dare_framework/transport/types.py`（客户端输入 envelope 相关类型）
@@ -82,22 +105,23 @@
 
 | ID | 任务 | 主要代码改动 | 支持能力 | 依赖 | 状态 | 输出证据 |
 |---|---|---|---|---|---|---|
-| D1-1 | 定义 `ClientSend` | 新类型 + schema 校验 | Msg 输入标准化 | 无 | todo | 单测：合法/非法输入 |
-| D1-2 | 定义 `UriAttachment` | URI 字段规范 + 校验 | 多模态入口 | 无 | todo | 单测：URI 错误码稳定 |
-| D1-3 | 定义内部 `Message` 块结构 | message 内容块结构 | TextBlock/附件表达 | D1-1/2 | todo | assemble 可消费 |
-| D1-4 | 约束与限制策略 | 限额/空值/超限错误模型 | 稳定输入治理 | D1-1/2/3 | todo | 压测与边界测试 |
+| D1-1 | 定义 `EnvelopePayload` 抽象与四类 payload | typed payload + schema 校验 | transport/message 契约统一 | 无 | todo | 单测：合法/非法输入 |
+| D1-2 | 定义 `AttachmentRef` | URI 字段规范 + 校验 | 富媒体入口 | 无 | todo | 单测：URI 错误码稳定 |
+| D1-3 | 升级 canonical `Message` | `text/attachments/data` 结构 | chat/图片/tool 统一表达 | D1-1/2 | todo | assemble 可消费 |
+| D1-4 | 约束与限制策略 | 字段矩阵/空值/超限错误模型 | 稳定输入治理 | D1-1/2/3 | todo | 压测与边界测试 |
 
 ---
 
 ## D2 `transport`（消息类型与payload协议）
 
 **主要改动**
-- 定义消息类型枚举：`message/tool_call/tool_result/thinking/error/status`。
-- 统一 transport payload envelope 与错误模型。
-- sender/receiver 对消息类型和错误码使用同一协议层定义。
+- 保留 `EnvelopeKind` 大类：`message/select/action/control`。
+- 移除 `event_type` 作为主设计，业务语义转入 typed payload。
+- `approval.pending/resolved` 从 message event 迁回 `select` payload。
+- sender/receiver 按 `kind -> payload family` 做确定性解析。
 
 **支撑能力**
-- Tool/ChatModelBase 执行中间态传输。
+- Tool/ChatModelBase/approval 交互协议统一。
 - 后续 observability 的事件采集基础。
 
 **建议改动位置**
@@ -107,17 +131,17 @@
 
 | ID | 任务 | 主要代码改动 | 支持能力 | 依赖 | 状态 | 输出证据 |
 |---|---|---|---|---|---|---|
-| D2-1 | 定义消息类型枚举 | enum + 常量统一 | thinking/tool 事件标准化 | D1-1 | done | `tests/unit/test_transport_types.py` |
-| D2-2 | 定义 payload 协议 | envelope schema + serializer | transport 语义一致 | D2-1 | done | `tests/unit/test_transport_adapters.py` |
-| D2-3 | 错误码标准化 | error payload model | 可观测错误治理 | D2-2 | done | `tests/unit/test_transport_channel.py` |
-| D2-4 | 协议测试矩阵 | e2e + contract test | 端到端稳定性 | D2-1/2/3 | done | `tests/unit/test_transport_types.py`, `tests/unit/test_transport_adapters.py` |
+| D2-1 | 固化 `EnvelopeKind` 与 payload 家族分派 | enum + typed routing | transport 大类稳定 | D1-1 | todo | `tests/unit/test_transport_types.py` |
+| D2-2 | 定义 typed payload 序列化协议 | envelope schema + serializer | transport 语义一致 | D2-1 | todo | `tests/unit/test_transport_adapters.py` |
+| D2-3 | 错误码标准化 | error payload model | 可观测错误治理 | D2-2 | todo | `tests/unit/test_transport_channel.py` |
+| D2-4 | 审批/选择协议回归 | `select ask/answered` contract test | approval 语义归位 | D2-1/2/3 | todo | contract + e2e 测试 |
 
 ---
 
 ## D3 `context`（assemble 归一化与URI策略）
 
 **主要改动**
-- `assemble` 增加 `ClientSend -> Message` 归一化步骤。
+- `assemble` 增加 `TransportEnvelope(kind=message) -> MessagePayload -> Message` 归一化步骤。
 - URI 解析策略：仅解析元信息 or 预取内容（本轮建议“元信息优先”）。
 - 当模型不支持相关模态时，定义 deterministic 降级策略。
 
@@ -132,7 +156,7 @@
 
 | ID | 任务 | 主要代码改动 | 支持能力 | 依赖 | 状态 | 输出证据 |
 |---|---|---|---|---|---|---|
-| D3-1 | 接入归一化管线 | assemble 前置 normalize | Msg 统一进入模型 | D1-3 + D2-2 | todo | 输入到模型链路测试 |
+| D3-1 | 接入归一化管线 | assemble 前置 normalize | typed message 统一进入模型 | D1-3 + D2-2 | todo | 输入到模型链路测试 |
 | D3-2 | URI 构建策略 | resolver + policy | 附件/富媒体引用处理 | D1-2 | todo | URI 成功/失败路径测试 |
 | D3-3 | 降级策略 | text-only fallback 规则 | 多模型兼容执行 | D3-2 | todo | 不支持模态时行为稳定 |
 | D3-4 | 组装链路回归 | context 集成测试 | 旧文本流程不回归 | D3-1/2/3 | todo | 回归全绿 |
@@ -268,9 +292,9 @@
 
 | 接口项 | 生产方 | 消费方 | 冲突风险 | 冻结时点 |
 |---|---|---|---|---|
-| `ClientSend` schema | D1 | D3/D2 | 字段名变动导致 assemble/transport 断裂 | Gate-1 |
+| `EnvelopePayload` schema | D1 | D3/D2 | payload 字段名变动导致 assemble/transport 断裂 | Gate-1 |
 | `Message` 内容块结构 | D1/D3 | D4/D5 | 模型输入与压缩算法理解不一致 | Gate-2 |
-| transport 消息类型枚举 | D2 | D4/D8/CLI | 事件类型命名漂移 | Gate-1 |
+| transport kind/payload 家族 | D2 | D4/D8/CLI | kind/payload 语义漂移 | Gate-1 |
 | tool_call/tool_result payload 结构 | D2 | D4/D5/D8 | tool pair 匹配失败 | Gate-2 |
 | 错误码模型 | D2 | D6/D8 | deny/error 无法统一观测 | Gate-3 |
 | policy decision 结构 | D6 | D8 | 审计日志字段不一致 | Gate-3 |
@@ -314,9 +338,9 @@
 
 | Domain | Slice | 范围 | Depends On | 复杂度 |
 |---|---|---|---|---|
-| `D1` | `D1_a` | `ClientSend`/`UriAttachment` schema 定义 | 无 | 中 |
+| `D1` | `D1_a` | `EnvelopePayload`/`AttachmentRef` schema 定义 | 无 | 中 |
 | `D1` | `D1_b` | 输入约束与错误码主集合 | `D1_a` | 高 |
-| `D1` | `D1_c` | Message 块结构与兼容适配 | `D1_a` | 高 |
+| `D1` | `D1_c` | canonical `Message` 结构与 typed normalize 适配 | `D1_a` | 高 |
 | `D3` | `D3_a` | assemble normalize 主流程接入 | `D1_c` + D2-2 | 高 |
 | `D3` | `D3_b` | URI resolver/policy（元信息优先） | `D1_b` | 中-高 |
 | `D3` | `D3_c` | 多模型降级策略 + D3 回归 | `D3_a` + `D3_b` | 高 |
@@ -342,7 +366,7 @@
 | 第一阶段（基线与协议冻结） | `b` | `D1_a` | 输入 schema 基线定义 |
 | 第一阶段（基线与协议冻结） | `c1` | `D1_b` | 输入约束与错误码冻结 |
 | 第一阶段（基线与协议冻结） | `c2` | `D1_c` | Message 块结构与兼容适配冻结 |
-| 第一阶段（基线与协议冻结） | `c3` | Gate-1 验收 | 完成 `ClientSend/UriAttachment/error-code` 冻结验收 |
+| 第一阶段（基线与协议冻结） | `c3` | Gate-1 验收 | 完成 `EnvelopePayload/AttachmentRef/error-code` 冻结验收 |
 | 第二阶段（核心链路实现） | `d` | `D3_a` | assemble normalize 主流程接入 |
 | 第二阶段（核心链路实现） | `e1` | `D3_b` + `D3_c` | URI resolver 与降级策略闭环 |
 | 第二阶段（核心链路实现） | `e2` | `D6_a` | policy model/evaluator 接口落地 |
@@ -355,20 +379,20 @@
 
 ## 6. 交接 Gate 定义
 
-1. **Gate-1（协议冻结）**  
-   冻结：`ClientSend`、`UriAttachment`、transport 消息类型枚举、错误码主集合。  
+1. **Gate-1（协议冻结）**
+   冻结：`EnvelopePayload`、`AttachmentRef`、transport kind/payload 家族、错误码主集合。
 2. **Gate-2（组装冻结）**  
    冻结：`assemble` 归一化输入输出结构、tool 事件 payload 结构。  
 3. **Gate-3（治理冻结）**  
    冻结：policy decision 结构、plan 状态字段语义、日志主字段键。  
 4. **Gate-4（联调验收）**  
-   `client send -> assemble -> model/tool loop -> policy gate -> transport -> logs` 全链路通过。
+   `typed payload -> assemble -> model/tool loop -> policy gate -> transport -> logs` 全链路通过。
 
 ---
 
 ## 7. 联调验收（跨域）
 
-- `ClientSend(content+uris)` 能稳定进入模型调用链路。
+- `MessagePayload(text+attachments+data)` 能稳定进入模型调用链路。
 - transport 连续输出 `thinking -> tool_call -> tool_result -> final message`。
 - 未授权工具被 deterministic 拒绝，且有可检索审计证据。
 - 压缩不破坏 tool pair，且预算超限自动触发。
diff --git a/docs/todos/project_overall_todos.md b/docs/todos/project_overall_todos.md
index 92518ae8..910ac661 100644
--- a/docs/todos/project_overall_todos.md
+++ b/docs/todos/project_overall_todos.md
@@ -240,9 +240,9 @@ AgentScope 补齐详细 TODO 入口：`docs/todos/agentscope_domain_execution_to
   Evidence：`openspec/changes/archive/2026-03-03-agentscope-d2-d4-thinking-transport/`，`docs/features/agentscope-d2-d4-thinking-transport.md`，`.venv/bin/pytest -q`（`528 passed, 12 skipped, 1 warning`）  
   Last Updated: `2026-03-03`
 
-- [ ] T5-3 图片/音频/视频富媒体消息格式支持  
-  Status: `planned`  
-  范围：定义并落地多模态 message schema（文本 + 图片 + 音频 + 视频），覆盖模型输入、上下文存储、transport 传输与适配器能力探测；统一替代“图片/富媒体一等支持”的原 T4-4 范围（含 A2A 附件链路规范化）。  
+- [ ] T5-3 图片/音频/视频富媒体消息格式支持
+  Status: `planned`
+  范围：定义并落地多模态消息格式基线。保留 `TransportEnvelope.kind = message/select/action/control`，以 typed payload 替代 `payload: Any + event_type`；升级 canonical `Message` 为 `text + attachments + data` 结构，覆盖模型输入、上下文存储、transport 传输与适配器能力探测；统一替代“图片/富媒体一等支持”的原 T4-4 范围（含 A2A 附件链路规范化）。
   交付：跨适配器能力矩阵 + 不支持能力时的降级策略 + 示例用例。
 
 - [ ] T5-4 全链路日志输出整理（模块分层与规范化）  
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diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/.openspec.yaml b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/.openspec.yaml
new file mode 100644
index 00000000..5cb9e8f6
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-03-09
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/design.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/design.md
new file mode 100644
index 00000000..12403d60
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/design.md
@@ -0,0 +1,171 @@
+## Context
+
+当前消息主链路存在三处结构性问题：
+
+1. transport `kind=message` 仍要求 `payload` 为纯字符串，导致协议层无法稳定承载富媒体输入或结构化消息。
+2. context domain 的 `Message` 仍以 `content: str` 为中心，`thinking/tool_call/tool_result` 的结构化语义被迫散落在 `metadata`、`name` 和 ad-hoc 字符串编码中。
+3. provider adapter 虽然各自已经有不同的消息序列化逻辑，但上游没有稳定的 canonical message contract，导致 transport、context、model 三层之间的边界持续模糊。
+
+本次变更只解决“消息格式”问题，不解决运行时缓存、resume、增量投递和压缩状态机。运行时设计会在后续独立主题中处理。
+
+## Goals / Non-Goals
+
+**Goals:**
+
+- 将 transport 从 `payload: Any + event_type` 收敛为 typed payload 体系。
+- 保留现有 `EnvelopeKind = message/select/action/control`，避免 envelope 大类继续膨胀。
+- 升级当前 `context.types.Message`，使其成为 framework 内部唯一 canonical message。
+- 支持首版 `chat(text + images[])` 组合消息输入。
+- 让 adapter 统一从 canonical `Message` 做 provider 序列化。
+- 将 approval 交互从 message event 变回 `select` 语义。
+
+**Non-Goals:**
+
+- 不在本次设计中定义 `pending_delta / active_model_state / render cache`。
+- 不处理富媒体完整模态矩阵；首版只要求图片附件。
+- 不做兼容层或迁移适配器；本轮允许 breaking change。
+- 不支持图文混排顺序表达。
+
+## Decisions
+
+### Decision: 保留 3 层，不新增平行 FrameworkMessage 类型
+
+- 采用 3 层：
+  - `TransportEnvelope`
+  - typed `EnvelopePayload`
+  - canonical `Message`
+- 不新增 `FrameworkMessage` 新类型，直接升级现有 `Message`。
+
+原因：
+
+- 当前 `Message` 已经是 context/model/input 的核心类型，继续平行新增只会制造双重真相源。
+- 文档和代码里大量 `Message(...)` 构造点都以它为 framework canonical message 使用，直接升级成本更可控。
+
+备选方案：
+
+- 方案 A：新增 `FrameworkMessage`，旧 `Message` 保持不动。
+  - 不采用；会引入一轮无意义的双类型迁移。
+- 方案 B：继续维持 `content: str`，把结构放到 `metadata`。
+  - 不采用；会继续模糊 schema 和边界。
+
+### Decision: `EnvelopeKind` 只保留协议大类，细粒度语义进入 payload
+
+- 保留：
+  - `message`
+  - `select`
+  - `action`
+  - `control`
+- `chat/thinking/tool_call/tool_result` 不进入 `EnvelopeKind`，只在 `MessagePayload.message_kind` 中表达。
+
+原因：
+
+- envelope.kind 负责 transport 路由，不负责会话语义。
+- 这样既能保持 inbound routing 简洁，又不丢 message 子类型。
+- 对于有限且确定性的 payload 子语义，优先使用强类型枚举而不是裸字符串，避免框架内部扩散硬编码常量。
+
+备选方案：
+
+- 方案 A：把 `chat/thinking/tool_call/tool_result` 平铺到 `EnvelopeKind`。
+  - 不采用；会把协议层和消息语义层混在一起。
+
+### Decision: 废弃 `event_type` 主设计，typed payload 成为唯一真相源
+
+- `TransportEnvelope.event_type` 不再作为长期主设计。
+- typed payload 上来后，消息/选择/动作/控制的业务语义只能由 payload 表达。
+
+原因：
+
+- `event_type` 与 payload subtype 并存会形成双重真相源。
+- 当前 `approval.pending/resolved` 被塞进 `TransportEventType`，已经导致 approval 语义错误挂靠在 message/status 线上。
+
+备选方案：
+
+- 方案 A：继续保留 `event_type`，只把 payload 补强。
+  - 不采用；长期会留下不可验证的一致性问题。
+
+### Decision: `Message` 使用 `text + attachments + data`，不引入 `ChatBody`
+
+canonical `Message` 字段收敛为：
+
+- `id`
+- `role`
+- `kind`
+- `text`
+- `attachments`
+- `data`
+- `name`
+- `metadata`
+- `mark`
+
+原因：
+
+- `chat`、`thinking`、`summary` 都能直接复用 `text`。
+- `chat`、后续可能的 `tool_result` 都能复用 `attachments`。
+- `tool_call/tool_result` 通过 `data` 承载结构化字段。
+- 不再需要专门的 `ChatBody`，结构更平。
+
+备选方案：
+
+- 方案 A：`Message.body` 做统一联合体。
+  - 不采用；对当前目标来说抽象过重。
+- 方案 B：仅使用 `text + attachments`，完全不要结构化字段。
+  - 不采用；无法稳定表达 tool_call/tool_result。
+
+### Decision: approval 归位到 `SelectPayload`
+
+`SelectPayload` 负责：
+
+- `select_kind = SelectKind.ASK | SelectKind.ANSWERED`
+- `select_domain = SelectDomain.APPROVAL | SelectDomain.CHOICE | SelectDomain.FORM`
+
+approval 的两个阶段分别映射：
+
+- `approval.pending` -> `kind=select`, `select_kind=ask`, `select_domain=approval`
+- `approval.resolved` -> `kind=select`, `select_kind=answered`, `select_domain=approval`
+
+原因：
+
+- approval 不是 message event，而是交互选择的一种。
+- 现有 `EnvelopeKind.SELECT` 已经存在，语义上正好匹配。
+
+补充约束：
+
+- `MessagePayload.message_kind` 使用 `MessageKind` 枚举。
+- `SelectPayload.select_kind` / `SelectPayload.select_domain` 使用 `SelectKind` / `SelectDomain` 枚举。
+- `resource_action` 继续与 `ResourceAction` 对齐解析；是否强制为 enum 保留给后续扩展性评估。
+- `control_id` 语义上与 `AgentControl` 对齐，后续实现不应继续散落硬编码字符串。
+
+## Risks / Trade-offs
+
+- [Breaking schema surface] transport / context / model 多处类型会同时改动
+  → Mitigation：先改 docs 和 OpenSpec，再按 D1 -> D2 -> D3 切片实施。
+
+- [测试面广] 当前大量测试直接断言 `Message.content`、`payload=str`、`event_type`
+  → Mitigation：按模块迁移，优先修正 transport/context/model 三组 contract tests。
+
+- [tool message 历史字段冲突] `name` 与 `data.tool_call_id` 可能并存一段时间
+  → Mitigation：本次保留 `name`，但新结构化主语义以 `data` 为准。
+
+- [adapter 能力差异] 不同 provider 对图片/tool blocks 的要求不同
+  → Mitigation：provider message 仍留在 adapter 内部；当前 change 只冻结 canonical contract。
+
+## Migration Plan
+
+1. 先冻结 docs 设计基线与 OpenSpec 规格。
+2. 在 transport domain 引入 typed payload，并把 approval 从 `event_type` 迁回 `select`。
+3. 升级 canonical `Message` 与 `AttachmentRef`。
+4. 调整 context `assemble()` 和 agent 输入链路，使 `kind=message` 的 payload 能归一化为 canonical `Message`。
+5. 调整 model adapter 从 canonical `Message` 做 provider 序列化。
+6. 同步更新 session/checkpoint/compression/test 契约。
+7. 完成后再进入独立的“消息投递/缓存/压缩/resume/分发”设计切片。
+
+Rollback:
+
+- 由于本次允许 breaking change，不保留运行时双写兼容。
+- 回滚以整体回退到旧 `TransportEnvelope + Message.content: str` 契约为准。
+
+## Open Questions
+
+- `Message.kind=tool_call/tool_result` 的 `data` 最小字段集是否需要在本 change 内完全冻结，还是只冻结承载位，细节留给后续工具链路切片。
+- `SelectPayload.options/selected` 的最小标准化字段是否需要直接兼容当前 ask-user 工具输出。
+- `TransportEnvelope.event_type` 是立即删除，还是实施阶段短暂保留为 deprecated 派生字段。
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/proposal.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/proposal.md
new file mode 100644
index 00000000..4b4711ac
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/proposal.md
@@ -0,0 +1,46 @@
+## Why
+
+当前 runtime 的消息主链路仍以纯字符串为中心：transport `kind=message` payload 要求是 `str`，context `Message` 也只支持 `content: str`。这导致“单条用户消息 = 一段文字 + 多张图片”无法以稳定 schema 进入模型调用链路，也让 `thinking/tool_call/tool_result/approval` 等语义继续分散在 event_type、metadata 和 ad-hoc payload 中。
+
+现在需要先把消息格式基线收敛，形成 transport、context、model 三层一致的 canonical contract，为后续富媒体输入、adapter 能力探测和运行时缓存/resume 设计提供稳定前提。
+
+## What Changes
+
+- 将 transport 从 `payload: Any + event_type` 收敛为 typed payload 体系。
+- 保留 `EnvelopeKind = message/select/action/control`，不再把消息子类型平铺到 envelope kind。
+- 为 transport 定义统一 `EnvelopePayload` 抽象以及 `MessagePayload / SelectPayload / ActionPayload / ControlPayload` 四类 payload。
+- **BREAKING**：升级 canonical `Message`，从 `content: str` 改为 `kind + text + attachments + data` 结构。
+- 在 `Message(kind=chat)` 中支持 `text + image attachments[]`，覆盖“文字 + 多图片”组合消息。
+- 将 `approval.pending / approval.resolved` 从 message event 迁回 `kind=select` 的 `ask / answered` 语义。
+- **BREAKING**：移除 `TransportEventType` 作为主设计，业务语义改由 typed payload 承载。
+- 明确 adapter 只消费 canonical `Message`，provider message 仅存在于 adapter 内部。
+
+## Capabilities
+
+### New Capabilities
+- `rich-media-message-schema`: 定义 canonical `Message`、`AttachmentRef` 和 `kind=message` 的 typed payload 契约，支撑 `text + images[]` 组合消息进入 runtime/model 链路。
+
+### Modified Capabilities
+- `transport-channel`: transport envelope 从 content-agnostic Any payload 演进为 typed payload 家族，并把 approval/selection 语义归位到 `kind=select`。
+- `chat-runtime`: runtime/context/model 调用链从 `Message.content: str` 演进为 canonical rich-media message，并要求 assemble/adapter 消费统一 message 契约。
+- `interaction-dispatch`: deterministic interaction contract 需要显式纳入 `select` 路径与 approval ask/answered 语义，避免继续依赖 message event_type 变体。
+
+## Impact
+
+- Affected docs:
+  - `docs/design/modules/transport/README.md`
+  - `docs/design/modules/context/README.md`
+  - `docs/design/modules/model/README.md`
+  - `docs/design/Interfaces.md`
+  - `docs/todos/agentscope_domain_execution_todos.md`
+- Affected code:
+  - `dare_framework/transport/*`
+  - `dare_framework/context/*`
+  - `dare_framework/model/*`
+  - `dare_framework/agent/*`
+  - `client/runtime/*`
+  - `client/session_store.py`
+- Breaking surface:
+  - `TransportEnvelope` payload parsing
+  - `context.Message` structure
+  - adapter serialization contract
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/chat-runtime/spec.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/chat-runtime/spec.md
new file mode 100644
index 00000000..ab7331d7
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/chat-runtime/spec.md
@@ -0,0 +1,40 @@
+## MODIFIED Requirements
+
+### Requirement: LLM-driven execute loop
+The runtime SHALL invoke the configured `IModelAdapter` during the execute loop, provide the assembled canonical message history and available tool definitions, and iterate over tool calls until the model returns a final response.
+
+- `Context.assemble()` MUST produce canonical `Message` objects rather than plain text-only entries.
+- `IModelAdapter` MUST serialize canonical `Message` into provider-native request messages internally.
+- The execute loop MUST append tool calls and tool results back into canonical message history before continuing.
+
+#### Scenario: Model returns a final response
+- **WHEN** the model response contains no tool calls
+- **THEN** the execute loop returns success and exposes the response content in the run output
+
+#### Scenario: Model requests a tool call
+- **WHEN** the model response includes a tool call
+- **THEN** the runtime executes the tool via `ToolRuntime`, appends the result to the canonical message history, and continues
+
+### Requirement: Retrieval query derives from current user intent
+The default assembly strategy SHALL derive retrieval query from the latest user-intent message in STM.
+
+For `Message(kind="chat")`, retrieval query derivation MUST use the latest non-empty `text` field rather than transport envelope content.
+
+#### Scenario: Latest user chat text drives retrieval query
+- **GIVEN** STM contains multiple turns including a latest user `Message(kind="chat")` with text
+- **WHEN** `Context.assemble()` is called
+- **THEN** LTM and Knowledge retrieval are invoked with that latest user text as query
+
+## ADDED Requirements
+
+### Requirement: Chat messages support text and image attachments in one turn
+The runtime SHALL support a single chat message that contains both text and multiple image attachments.
+
+- `Message(kind="chat")` MUST allow non-empty `text` together with one or more image attachment references.
+- The assembled message history MUST preserve the association as one logical user turn.
+- Model adapters MAY degrade unsupported image history, but the canonical chat message structure MUST remain intact before adapter-specific conversion.
+
+#### Scenario: User sends one text and multiple images
+- **WHEN** the runtime receives one user chat message with text and two image attachments
+- **THEN** the message history contains one canonical `Message(kind="chat")`
+- **AND** both image attachments remain associated with that same user turn
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/interaction-dispatch/spec.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/interaction-dispatch/spec.md
new file mode 100644
index 00000000..554090d3
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/interaction-dispatch/spec.md
@@ -0,0 +1,27 @@
+## ADDED Requirements
+
+### Requirement: Select dispatch is isolated from action, control, and prompt execution
+The system SHALL provide a deterministic dispatch path for `select` envelopes that is separate from prompt execution, action dispatch, and runtime control handling.
+
+- `select` dispatch MUST NOT enter the LLM prompt execution path.
+- `select` dispatch MUST NOT be routed through `ActionHandlerDispatcher`.
+- `select` dispatch MUST preserve `reply_to` correlation semantics for answered selections.
+
+#### Scenario: Select answer does not execute as a prompt
+- **GIVEN** an inbound `TransportEnvelope(kind="select")`
+- **WHEN** the interaction layer processes the envelope
+- **THEN** it does not invoke the LLM-driven agent execution path
+- **AND** it does not route the envelope through `ActionHandlerDispatcher`
+
+### Requirement: Approval interactions use select ask and answered semantics
+The deterministic interaction layer SHALL represent approval interactions as `select` payloads.
+
+- Pending approval MUST use `SelectPayload(select_domain="approval", select_kind="ask")`.
+- Resolved approval MUST use `SelectPayload(select_domain="approval", select_kind="answered")`.
+- The runtime MUST NOT rely on message event aliases such as `approval.pending` or `approval.resolved` as the primary approval contract.
+
+#### Scenario: Approval resolution replies to the pending request
+- **GIVEN** an approval request was emitted as `kind="select"` with `select_kind="ask"`
+- **WHEN** the user resolves the approval
+- **THEN** the resolution is expressed as `kind="select"` with `select_kind="answered"`
+- **AND** the reply references the originating request envelope when available
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/rich-media-message-schema/spec.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/rich-media-message-schema/spec.md
new file mode 100644
index 00000000..d028b498
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/rich-media-message-schema/spec.md
@@ -0,0 +1,32 @@
+## ADDED Requirements
+
+### Requirement: Canonical message schema supports text, attachments, and structured data
+The system SHALL define a canonical framework `Message` schema that is independent from provider-native message formats and can represent chat text, image attachments, and structured tool-related data.
+
+- `Message` MUST remain the single canonical message type inside the framework runtime.
+- `Message` MUST expose `id`, `role`, `kind`, `text`, `attachments`, `data`, `name`, `metadata`, and `mark`.
+- `Message.role` MUST use a deterministic finite type rather than unconstrained strings.
+- `Message.kind` MUST distinguish at least `chat`, `thinking`, `tool_call`, `tool_result`, and `summary`.
+- `Message.kind` SHOULD be represented by a deterministic finite type rather than unconstrained strings.
+- `Message.attachments` MUST support image attachment references via a typed `AttachmentRef` structure rather than raw dictionaries.
+- `Message.data` MUST be available for structured message kinds such as `tool_call` and `tool_result`.
+- `Message.kind="thinking" | "summary" | "tool_call"` MUST reject attachments at schema validation time.
+- `Message.data` MUST be the primary structured source for `tool_call/tool_result`; `metadata` MUST NOT be required as a semantic fallback.
+
+#### Scenario: Chat message carries text and multiple images
+- **WHEN** a user message is represented as `Message(kind="chat")` with non-empty `text` and multiple image attachments
+- **THEN** the runtime preserves both the text and all attachment references in a single canonical message
+
+### Requirement: Message payload normalizes losslessly into canonical message
+The system SHALL define a `MessagePayload` transport contract that can be losslessly normalized into canonical `Message`.
+
+- `MessagePayload` MUST include `id`, `metadata`, `role`, `message_kind`, `text`, `attachments`, and `data`.
+- `MessagePayload.role` and `MessagePayload.message_kind` SHOULD use deterministic finite types rather than unconstrained strings.
+- `MessagePayload.message_kind` MUST map deterministically to `Message.kind`.
+- For `message_kind="chat"`, the payload MUST support `text + attachments` without requiring a separate chat-specific body type.
+- `MessagePayload` MUST reject unsupported attachment/message-kind combinations during payload validation.
+
+#### Scenario: Message payload becomes canonical message
+- **WHEN** the runtime receives `TransportEnvelope(kind="message", payload=<MessagePayload>)`
+- **THEN** the payload is normalized into one canonical `Message`
+- **AND** no message semantics are taken from transport-only fields
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/transport-channel/spec.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/transport-channel/spec.md
new file mode 100644
index 00000000..7258f0ce
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/specs/transport-channel/spec.md
@@ -0,0 +1,68 @@
+## MODIFIED Requirements
+
+### Requirement: Transport envelope is content-agnostic and distinct from context messages
+The system SHALL define a `TransportEnvelope` type that remains distinct from `context.Message` while carrying typed payload families rather than ad-hoc arbitrary payloads.
+
+- The envelope MUST provide a primary strong-typed `kind` categorization that distinguishes `message|select|action|control`.
+- The envelope MUST carry a typed payload family selected by `kind`.
+- For `kind="action"`, the payload MUST carry a deterministic `resource_action` request.
+- For `kind="control"`, the payload MUST carry a deterministic runtime control id from `AgentControl` (e.g. `interrupt|pause|retry|reverse`).
+- The envelope model MUST NOT require a second routing subtype field in addition to `kind` in order to route inbound envelopes.
+
+#### Scenario: Envelope carries a control interrupt
+- **WHEN** a client sends a `TransportEnvelope` with `kind="control"` and a payload whose `control_id="interrupt"`
+- **THEN** the channel can route it to control handling without relying on prompt parsing
+
+### Requirement: Envelope kind supports message, select, action, and control categories
+The transport envelope model SHALL provide a primary categorization field for inbound/outbound envelopes that can distinguish:
+- `message` (canonical message payloads)
+- `select` (approval/choice/form interactions)
+- `action` (deterministic resource actions)
+- `control` (interrupt/pause/retry/reverse)
+
+The envelope model MUST NOT require a separate subtype field in order to route inbound envelopes.
+
+#### Scenario: Select envelope is distinguishable without prompt parsing
+- **GIVEN** a client sends `TransportEnvelope(kind="select", payload=<SelectPayload>)`
+- **WHEN** the channel receives it
+- **THEN** the channel can route the request deterministically without inspecting prompt text
+
+### Requirement: Agent loop consumes prompt messages only
+The runtime integration with `AgentChannel.poll()` SHALL treat polled envelopes as prompt message workload only.
+
+- Agent execution loop MUST NOT be responsible for routing `select`, `action`, or `control`.
+- For `kind="message"`, the agent loop MUST only accept typed `MessagePayload` that can normalize to canonical `Message`.
+- Any non-message envelope reaching the agent loop MUST be treated as routing error.
+
+#### Scenario: Non-message envelope is rejected in agent loop
+- **GIVEN** a non-message envelope is observed in the agent loop
+- **WHEN** runtime validation executes
+- **THEN** runtime returns an error response
+- **AND** does not invoke prompt execution
+
+### Requirement: Entry adapters provide deterministic envelope kinds
+Client entry adapters SHALL normalize input into explicit envelope kinds and typed payloads before transport routing.
+
+- `stdio` adapters MAY map slash commands to structured `ACTION/CONTROL/SELECT` envelopes.
+- `websocket` and `A2A` adapters MUST send explicit `kind` and typed `payload`.
+- Entry adapters MUST NOT rely on transport runtime parsing free-form prompt text to infer action/control/select semantics.
+
+#### Scenario: Websocket sends explicit action envelope
+- **GIVEN** a websocket client wants tool introspection
+- **WHEN** it sends `kind="action"` with an `ActionPayload` that targets `tools:list`
+- **THEN** channel routes the request through action path without text parsing
+
+## ADDED Requirements
+
+### Requirement: Select envelopes carry approval and choice interactions
+The transport channel SHALL support `kind="select"` for deterministic selection interactions.
+
+- `SelectPayload` MUST support `select_kind="ask|answered"`.
+- `SelectPayload` MUST support `select_domain="approval|choice|form"`.
+- Approval interactions MUST use `kind="select"` rather than message event aliases.
+
+#### Scenario: Approval pending is emitted as select ask
+- **GIVEN** a tool invocation requires human approval
+- **WHEN** the runtime emits the interaction to the client
+- **THEN** it sends `TransportEnvelope(kind="select")`
+- **AND** the payload uses `select_domain="approval"` and `select_kind="ask"`
diff --git a/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/tasks.md b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/tasks.md
new file mode 100644
index 00000000..cfb128a4
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-agentscope-d1-d3-message-pipeline/tasks.md
@@ -0,0 +1,27 @@
+## 1. Transport typed payload baseline
+
+- [x] 1.1 Replace `TransportEnvelope.payload: Any + event_type` with typed payload families in `dare_framework/transport/types.py`
+- [x] 1.2 Keep `EnvelopeKind = message/select/action/control` and route inbound envelopes by payload family in transport channel code
+- [x] 1.3 Move approval pending/resolved semantics from message event aliases into `SelectPayload(select_kind=ask|answered, select_domain=approval)`
+- [x] 1.4 Update transport payload builders, dispatcher contracts, and transport-facing tests to validate typed payload parsing and reply correlation
+
+## 2. Canonical message upgrade
+
+- [x] 2.1 Upgrade `dare_framework/context/types.py::Message` to `kind + text + attachments + data` and add `AttachmentRef`
+- [x] 2.2 Update context assemble/STM/query logic to consume canonical `Message` instead of `content: str`
+- [x] 2.3 Replace task-description-as-message usage so agent/runtime input paths construct canonical messages directly
+- [x] 2.4 Update session/checkpoint/memory persistence code to serialize and restore the upgraded `Message`
+
+## 3. Model adapter serialization
+
+- [x] 3.1 Update `ModelInput` consumers so adapters serialize canonical `Message` instead of plain text content
+- [x] 3.2 Implement `chat(text + image attachments[])` serialization for supported adapters and deterministic fallback hooks for unsupported history
+- [x] 3.3 Move `tool_call/tool_result` structured semantics from ad-hoc metadata parsing to canonical `Message.data`
+- [x] 3.4 Update adapter unit tests to cover chat rich-media messages and structured tool message serialization
+
+## 4. Contract and regression verification
+
+- [x] 4.1 Update transport contract tests that currently assert `payload=str` and `event_type`
+- [x] 4.2 Update context/model/integration tests that currently assert `Message.content`
+- [x] 4.3 Add golden-path tests for one chat message containing text plus multiple image attachments
+- [x] 4.4 Add error-path tests for invalid typed payloads and unsupported attachment/message-kind combinations
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diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/.openspec.yaml b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/.openspec.yaml
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index 00000000..5cb9e8f6
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-03-09
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/design.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/design.md
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index 00000000..6144fc9c
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/design.md
@@ -0,0 +1,60 @@
+## Overview
+
+This change closes the remaining gap between the canonical message schema and the runtime execution boundary. The framework already stores and serializes canonical `Message(role, kind, text, attachments, data)`, but direct execution and transport polling still flatten top-level input to strings. The design goal is to make canonical `Message` the first-class user input while keeping `Task` as an orchestration object.
+
+## Architecture
+
+### Entry boundary
+
+- `IAgent.__call__` accepts `str | Message`.
+- `IAgentOrchestration.execute` receives canonical `Message`.
+- `Message` is the preferred direct prompt input.
+- `Task` remains the five-layer orchestration carrier and may optionally hold `input_message`.
+
+### Orchestration boundary
+
+- `Task.description` remains a planning/execution description.
+- `Task.input_message` becomes the source of truth for the canonical first user turn.
+- When `Task.input_message` is absent, runtime derives a default `Message(role=user, kind=chat, text=description)`.
+
+### Transport boundary
+
+- `TransportEnvelope(kind=message, payload=MessagePayload)` normalizes into canonical `Message` before agent execution.
+- The transport loop must not drop `attachments` or `data`.
+
+## Data Structures
+
+### Task
+
+```text
+Task
+- description: str
+- input_message: Message | None
+- milestones / metadata / previous_session_summary / resume_from_checkpoint
+```
+
+### Validation
+
+- `Message.kind in {tool_call, tool_result}` requires non-empty `data`.
+- `thinking/summary/tool_call` reject attachments.
+
+## Workflow
+
+1. Direct caller or transport provides a top-level prompt.
+2. Agent normalizes the input:
+   - `Message` passes through unchanged.
+   - `str` is upgraded at the public agent boundary to `Message(role=user, kind=chat, text=...)`.
+3. Session loop adds the normalized canonical user message to STM.
+4. Model adapters receive assembled canonical `Message` objects without earlier text flattening.
+
+## Error Handling
+
+- Invalid top-level transport message payload remains a deterministic transport error.
+- Invalid canonical messages (for example `tool_call` without `data`) fail at schema construction time.
+
+## Testing
+
+- Transport loop preserves attachments when polling `MessagePayload`.
+- Session loop prefers `Task.input_message`.
+- Canonical schema rejects `tool_call/tool_result` without `data`.
+- Example/client helpers send `Message` rather than `Task(description=...)`.
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/proposal.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/proposal.md
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--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/proposal.md
@@ -0,0 +1,28 @@
+## Why
+
+The previous message-schema cutover established canonical `Message(text, attachments, data)`, but the runtime entry boundary still treated top-level input as `str`/`Task.description`. That leaves a contract hole: transport can carry `MessagePayload(chat + images[])`, yet the agent loop still collapses it to plain text before execution.
+
+## What Changes
+
+- **BREAKING** Promote canonical `Message` to a first-class agent input alongside `Task`.
+- Add `Task.input_message` so orchestration keeps a separate execution description while preserving the original canonical user message.
+- Convert transport-loop `MessagePayload` into canonical `Message` before agent execution instead of collapsing to `str`.
+- Tighten canonical schema validation so `tool_call/tool_result` require structured `data`.
+- Update client/example entry points to send `Message` rather than `Task(description=...)` for direct user prompts.
+
+## Capabilities
+
+### New Capabilities
+- None.
+
+### Modified Capabilities
+- `rich-media-message-schema`: top-level agent/runtime input must preserve canonical `Message` rather than flattening to text.
+- `transport-channel`: message envelopes reaching the agent loop must normalize into canonical `Message`.
+- `session-loop`: session initialization must prefer `Task.input_message` over `Task.description` when constructing the first user turn.
+- `plan-module`: `Task` gains canonical `input_message` for orchestration/message separation.
+
+## Impact
+
+- Affected code: `agent/*`, `plan/types.py`, `transport/*`, `client/runtime/task_runner.py`, active examples, message-schema tests.
+- Affected APIs: `IAgent.__call__`, `IAgentOrchestration.execute`, `Task`.
+- Systems: direct runtime entry, transport poll loop, session initialization, example/client CLIs.
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/plan-module/spec.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/plan-module/spec.md
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--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/plan-module/spec.md
@@ -0,0 +1,14 @@
+## MODIFIED Requirements
+
+### Requirement: Task carries orchestration description separately from canonical input
+The planning module SHALL allow `Task` to retain orchestration metadata without becoming the sole carrier of user prompt semantics.
+
+- `Task` MUST expose `input_message: Message | None`.
+- `Task.description` remains available for plan/milestone descriptions.
+- `Task.to_milestones()` SHOULD prefer `input_message.text` for `Milestone.user_input` when present.
+
+#### Scenario: Milestone user input follows canonical task message
+- **GIVEN** a `Task` with `description="refactor auth"` and `input_message.text="please refactor auth and review these screenshots"`
+- **WHEN** default milestones are derived
+- **THEN** the milestone description remains `"refactor auth"`
+- **AND** `Milestone.user_input` uses the canonical message text
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/rich-media-message-schema/spec.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/rich-media-message-schema/spec.md
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index 00000000..44a218f4
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/rich-media-message-schema/spec.md
@@ -0,0 +1,13 @@
+## MODIFIED Requirements
+
+### Requirement: Canonical message schema supports text, attachments, and structured data
+The framework SHALL preserve canonical `Message` semantics at the runtime input boundary instead of flattening top-level input to raw text.
+
+- Top-level agent execution MUST accept canonical `Message` input directly.
+- Direct user-prompt helpers MUST prefer canonical `Message` over `Task.description`.
+- `Message.kind="tool_call" | "tool_result"` MUST reject construction without structured `data`.
+
+#### Scenario: Direct execution keeps a composite user message intact
+- **WHEN** a caller invokes an agent with `Message(kind="chat", text=<text>, attachments=[image...])`
+- **THEN** the runtime uses that canonical message as the first user turn
+- **AND** `attachments` remain available to context assembly and model serialization
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/session-loop/spec.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/session-loop/spec.md
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index 00000000..202c6858
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/session-loop/spec.md
@@ -0,0 +1,13 @@
+## MODIFIED Requirements
+
+### Requirement: Previous session summary handoff
+The runtime SHALL keep the session-loop user-turn source distinct from orchestration description text.
+
+- `Task` MAY carry `input_message: Message`.
+- Session initialization MUST prefer `Task.input_message` over synthesizing a user message from `Task.description`.
+
+#### Scenario: Session loop uses canonical task input message
+- **GIVEN** a `Task` whose `description` is orchestration text and whose `input_message` is `Message(kind="chat", text=<text>, attachments=[image])`
+- **WHEN** the session loop initializes
+- **THEN** STM receives `Task.input_message` as the first user turn
+- **AND** the runtime does not replace it with a plain-text message from `description`
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/transport-channel/spec.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/transport-channel/spec.md
new file mode 100644
index 00000000..8d47a1dc
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/specs/transport-channel/spec.md
@@ -0,0 +1,13 @@
+## MODIFIED Requirements
+
+### Requirement: Agent loop consumes prompt messages only
+The runtime integration with `AgentChannel.poll()` SHALL normalize inbound `MessagePayload` into canonical `Message` before invoking agent execution.
+
+- The transport loop MUST NOT flatten `MessagePayload` into plain text.
+- `text`, `attachments`, and `data` from `MessagePayload` MUST be preserved in the canonical `Message` passed into agent execution.
+
+#### Scenario: Polled composite chat message reaches agent intact
+- **GIVEN** `AgentChannel.poll()` returns `TransportEnvelope(kind="message", payload=<MessagePayload message_kind="chat" text="look" attachments=[image]>)`
+- **WHEN** the base agent transport loop executes that input
+- **THEN** the concrete agent receives a canonical `Message`
+- **AND** the message still contains the image attachment reference
diff --git a/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/tasks.md b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/tasks.md
new file mode 100644
index 00000000..fb1d27a4
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-message-input-boundary-cleanup/tasks.md
@@ -0,0 +1,5 @@
+- [x] Update design docs to separate canonical `Message` input from orchestration `Task.description`.
+- [x] Add failing tests for transport canonical-message preservation, `Task.input_message`, and stricter `tool_call/tool_result` schema validation.
+- [x] Add `Task.input_message`, normalize public `str` input at the agent boundary, and keep internal execution on canonical `Message`.
+- [x] Update active client/example entry points to send canonical `Message` instead of `Task(description=...)` for direct prompts.
+- [x] Refresh focused tests and replace metadata-only tool-call compatibility assertions with the new canonical schema contract.
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diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/.openspec.yaml b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/.openspec.yaml
new file mode 100644
index 00000000..5cb9e8f6
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-03-09
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/design.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/design.md
new file mode 100644
index 00000000..8bbfd7e3
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/design.md
@@ -0,0 +1,107 @@
+## Context
+
+`agentscope-d1-d3-message-pipeline` 已经完成 canonical `Message` 与 transport typed payload 基线，但 transport 运行时仍保留三层历史兼容：
+
+1. `TransportEnvelope.event_type` 仍承担 reply 语义分派，和 typed payload 并行存在。
+2. `EnvelopeKind.MESSAGE/ACTION/CONTROL` 仍允许裸 `str` / 裸 `dict` payload 进入 runtime。
+3. client/example/test 仍大量围绕 `dict payload + event_type` 解析结果，而不是按 payload family 处理。
+
+这让 envelope `kind`、payload schema、reply semantics 三者没有真正收敛，也继续放大维护成本。
+
+## Goals / Non-Goals
+
+**Goals:**
+- 删除 transport 主设计中的 `event_type`，不再把 reply 语义挂在 envelope 附加字符串上。
+- 删除 message/action/control 的 legacy raw payload 兼容，只接受 typed payload。
+- 让 success/error/result 语义回收到 `MessagePayload/ActionPayload/ControlPayload/SelectPayload` 自身。
+- 更新 runtime/client/example/tests，使 typed payload 成为唯一 transport 契约。
+
+**Non-Goals:**
+- 不修改 canonical `Message` schema。
+- 不处理 pending delta / cache / resume 等运行时状态设计。
+- 不新增 `status` / `error` 之类的 envelope kind。
+
+## Decisions
+
+### Decision: `TransportEnvelope` 只保留 `kind + payload`
+
+删除 `event_type` 字段。reply 分派完全由 `EnvelopeKind` 与 payload 家族决定。
+
+原因：
+- `kind + event_type + payload` 是三套并行语义源。
+- typed payload 已经足够表达请求和响应的结构化语义。
+
+替代方案：
+- 保留 `event_type` 作为 deprecated 字段。
+  - 不采用；仍会继续扩散分支判断和旧测试口径。
+
+### Decision: typed payload 自身承接请求/响应双态
+
+- `MessagePayload`
+  - 请求：`role=user`, `message_kind=chat`
+  - 响应：`role=assistant`, `message_kind=chat|thinking|tool_call|tool_result|summary`
+  - 错误：使用 `text + data{success/code/reason/...}` 表达
+- `ActionPayload`
+  - 请求：`resource_action + params`
+  - 响应：`resource_action + ok/result/code/reason`
+- `ControlPayload`
+  - 请求：`control_id + params`
+  - 响应：`control_id + ok/result/code/reason`
+- `SelectPayload`
+  - 保持 `ask|answered`
+
+原因：
+- 不引入新的 envelope kind。
+- 请求和响应都保留在同一协议家族中，client 侧处理更稳定。
+
+替代方案：
+- 用 `kind=message` 包一个统一 dict reply。
+  - 不采用；会重新引入 dict payload 弱结构。
+
+### Decision: message request error 也回到 `MessagePayload`
+
+message 请求失败时返回：
+- `kind=message`
+- `payload=MessagePayload(role=assistant, message_kind=summary, text=<reason>, data={success:false, code, reason, target})`
+
+原因：
+- 保持“消息请求得到消息回复”的对称性。
+- 不需要单独的 error envelope kind。
+
+替代方案：
+- message error 走 `control` 或 `action` reply。
+  - 不采用；语义错位。
+
+### Decision: transport JSON adapters 只做 typed payload 序列化/反序列化
+
+WebSocket/stdio/direct adapters 保留“dataclass <-> JSON dict”的转换，但不再接受语义上的 raw string payload。
+
+原因：
+- JSON over-the-wire 和 runtime typed payload 并不冲突。
+- 需要保留网络边界的反序列化能力，但不保留 runtime 的 legacy schema。
+
+## Risks / Trade-offs
+
+- [Breaking transport consumers] 现有 example/测试/CLI 解析将失效
+  → Mitigation：同一 change 内同步更新 adapters、client helpers、tests。
+
+- [Error semantics drift] message error 不再通过 `event_type=error` 判断
+  → Mitigation：统一 `MessagePayload.data.success/code/reason` 结构，并增加 error-path tests。
+
+- [Hook observability coupling] 现有 hook transport 事件依赖 `event_type`
+  → Mitigation：改为 `kind=message + MessagePayload.message_kind/data`，hook tests 同步切换。
+
+## Migration Plan
+
+1. 更新 transport/context/model 文档，冻结 typed-reply cutover 设计。
+2. 修改 `TransportEnvelope` 与 default channel/dispatcher，移除 raw payload/event_type 兼容。
+3. 修改 agent transport loop 与 hook transport emitter，改发 typed replies。
+4. 修改 client/example/adapters/tests，切换为 typed payload 解析。
+5. 跑 transport/runtime/example 回归并完成 OpenSpec 证据回写。
+
+Rollback:
+- 该 change 明确允许 breaking change；如需回退，整体回退到引入 typed replies 前的 `event_type + dict payload` 契约。
+
+## Open Questions
+
+- `MessagePayload.data` 的最小 reply 字段集是否需要进一步抽为共享 helper，还是先在 transport/runtime 内按约定使用。
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/proposal.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/proposal.md
new file mode 100644
index 00000000..257d927b
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/proposal.md
@@ -0,0 +1,43 @@
+## Why
+
+当前 transport 主链路虽然已经引入 typed payload，但运行时仍保留多层 legacy 兼容：`EnvelopeKind.MESSAGE/ACTION/CONTROL` 仍接受裸字符串或裸字典，reply 侧仍依赖 `event_type + dict payload` 包装，导致协议层存在双重真相源，client/example/test 也持续分叉。
+
+消息格式切片已经完成，这个兼容壳现在反而阻碍 transport、agent loop、client 消费方彻底收敛到 typed payload 契约，因此需要单独做一次 non-compatible cutover。
+
+## What Changes
+
+- **BREAKING** 删除 `TransportEnvelope.event_type` 作为 transport 主设计字段，reply 语义改由 typed payload 家族自身表达。
+- **BREAKING** 删除 `EnvelopeKind.MESSAGE/ACTION/CONTROL` 对裸 `str` / 裸 `dict` payload 的接收与分派兼容，只保留 typed payload。
+- 将 agent transport loop 的成功/失败回复改为 typed payload：
+  - `message` 请求回复 `MessagePayload`
+  - `action` 请求回复 `ActionPayload`
+  - `control` 请求回复 `ControlPayload`
+  - `select` 保持 `SelectPayload`
+- 更新 stdio/websocket/direct client adapters、dispatcher、example CLI 和相关测试，统一消费 typed payload。
+
+## Capabilities
+
+### New Capabilities
+- `typed-transport-replies`: transport reply envelopes use typed payloads instead of `event_type + dict payload`
+
+### Modified Capabilities
+- `transport-channel`: inbound/outbound envelope validation and routing become typed-payload-only
+- `interaction-dispatch`: action/control dispatch contracts stop accepting legacy string payloads
+- `chat-runtime`: agent transport loop returns canonical assistant message payloads and typed error/result envelopes
+
+## Impact
+
+- Affected code:
+  - `dare_framework/transport/types.py`
+  - `dare_framework/transport/_internal/default_channel.py`
+  - `dare_framework/transport/_internal/adapters.py`
+  - `dare_framework/transport/interaction/dispatcher.py`
+  - `dare_framework/transport/interaction/payloads.py`
+  - `dare_framework/agent/base_agent.py`
+  - `dare_framework/agent/react_agent.py`
+  - `dare_framework/hook/_internal/agent_event_transport_hook.py`
+  - client/example consumers using `DirectClientChannel.ask()` or raw transport events
+- Affected APIs:
+  - transport envelope schema
+  - transport reply parsing in client/example code
+  - action/control request construction in tests/examples
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/chat-runtime/spec.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/chat-runtime/spec.md
new file mode 100644
index 00000000..374dd1a3
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/chat-runtime/spec.md
@@ -0,0 +1,19 @@
+## MODIFIED Requirements
+
+### Requirement: LLM-driven execute loop
+The runtime SHALL invoke the configured `IModelAdapter` during the execute loop, provide the assembled canonical message history and available tool definitions, and iterate over tool calls until the model returns a final response.
+
+- `Context.assemble()` MUST produce canonical `Message` objects rather than plain text-only entries.
+- `IModelAdapter` MUST serialize canonical `Message` into provider-native request messages internally.
+- The execute loop MUST append tool calls and tool results back into canonical message history before continuing.
+- The transport-driven execute loop MUST return typed reply envelopes without using transport `event_type`.
+
+#### Scenario: Model returns a final response
+- **WHEN** the model response contains no tool calls
+- **THEN** the execute loop returns success and exposes the response content in the run output
+- **AND** the transport reply is `EnvelopeKind.MESSAGE` carrying one assistant `MessagePayload`
+
+#### Scenario: Model requests a tool call
+- **WHEN** the model response includes a tool call
+- **THEN** the runtime executes the tool via `ToolRuntime`, appends the result to the canonical message history, and continues
+- **AND** transport intermediate events are emitted as typed message payloads instead of `event_type` aliases
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/interaction-dispatch/spec.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/interaction-dispatch/spec.md
new file mode 100644
index 00000000..1bbffe78
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/interaction-dispatch/spec.md
@@ -0,0 +1,19 @@
+## MODIFIED Requirements
+
+### Requirement: Action dispatcher routes only typed action payloads
+The action dispatch subsystem SHALL route only `ActionPayload` requests and SHALL return structured action results using typed payloads.
+
+- `ActionHandlerDispatcher.handle_action()` MUST read `resource_action` from `ActionPayload`.
+- The dispatcher MUST NOT accept raw string action ids as request payloads.
+- Successful action results MUST populate `ActionPayload.ok=True` and `ActionPayload.result`.
+- Failed action results MUST populate `ActionPayload.ok=False` with deterministic `code/reason`.
+
+#### Scenario: Dispatcher routes supported action payload
+- **WHEN** `handle_action()` receives `TransportEnvelope(kind="action", payload=<ActionPayload resource_action="tools:list">)`
+- **THEN** the matching handler is invoked
+- **AND** the result is returned as a typed action payload
+
+#### Scenario: Dispatcher rejects unsupported action id
+- **WHEN** `handle_action()` receives `ActionPayload` with an unknown `resource_action`
+- **THEN** the dispatcher returns `ok=False`
+- **AND** the error response includes a deterministic `code` and `reason`
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/transport-channel/spec.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/transport-channel/spec.md
new file mode 100644
index 00000000..322dff8a
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/transport-channel/spec.md
@@ -0,0 +1,20 @@
+## MODIFIED Requirements
+
+### Requirement: AgentChannel rejects unsupported inbound envelope payloads deterministically
+The runtime SHALL validate inbound transport envelopes at the channel boundary and reject unsupported payload families with deterministic error semantics before they reach agent execution.
+
+- `EnvelopeKind.MESSAGE` MUST accept only `MessagePayload`.
+- `EnvelopeKind.ACTION` MUST accept only `ActionPayload`.
+- `EnvelopeKind.CONTROL` MUST accept only `ControlPayload`.
+- `EnvelopeKind.SELECT` MUST accept only `SelectPayload`.
+- The runtime MUST NOT accept legacy raw `str` or weakly-typed `dict` payloads as transport request payloads.
+
+#### Scenario: Message envelope with invalid payload is rejected before execution
+- **WHEN** the runtime receives `TransportEnvelope(kind="message")` whose payload is not a `MessagePayload`
+- **THEN** the envelope is rejected before agent execution begins
+- **AND** the requester receives a deterministic typed error reply
+
+#### Scenario: Action envelope with invalid payload is rejected before dispatch
+- **WHEN** the runtime receives `TransportEnvelope(kind="action")` whose payload is not an `ActionPayload`
+- **THEN** the dispatcher is not invoked
+- **AND** the requester receives a deterministic typed error reply
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/typed-transport-replies/spec.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/typed-transport-replies/spec.md
new file mode 100644
index 00000000..36c6e03d
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/specs/typed-transport-replies/spec.md
@@ -0,0 +1,24 @@
+## ADDED Requirements
+
+### Requirement: Transport replies use typed payload families
+The transport layer SHALL return reply envelopes using the same typed payload families as requests, without relying on `event_type` or weakly-typed dictionary wrappers.
+
+- `EnvelopeKind.MESSAGE` replies MUST carry `MessagePayload`.
+- `EnvelopeKind.ACTION` replies MUST carry `ActionPayload`.
+- `EnvelopeKind.CONTROL` replies MUST carry `ControlPayload`.
+- `EnvelopeKind.SELECT` replies MUST carry `SelectPayload`.
+
+#### Scenario: Agent message request returns assistant message payload
+- **WHEN** an agent finishes handling a `TransportEnvelope(kind="message", payload=<MessagePayload>)`
+- **THEN** the reply envelope uses `kind="message"`
+- **AND** the reply payload is one `MessagePayload` representing the assistant-visible result
+
+#### Scenario: Action request returns typed action payload
+- **WHEN** the runtime completes one `TransportEnvelope(kind="action", payload=<ActionPayload>)`
+- **THEN** the reply envelope uses `kind="action"`
+- **AND** the reply payload is one `ActionPayload` containing `ok/result/code/reason`
+
+#### Scenario: Control request returns typed control payload
+- **WHEN** the runtime completes one `TransportEnvelope(kind="control", payload=<ControlPayload>)`
+- **THEN** the reply envelope uses `kind="control"`
+- **AND** the reply payload is one `ControlPayload` containing `ok/result/code/reason`
diff --git a/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/tasks.md b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/tasks.md
new file mode 100644
index 00000000..aec2a3dd
--- /dev/null
+++ b/openspec/changes/archive/2026-03-09-transport-typed-payload-cutover/tasks.md
@@ -0,0 +1,19 @@
+## 1. Transport envelope cutover
+
+- [x] 1.1 Remove `TransportEnvelope.event_type` and legacy raw payload acceptance from `dare_framework/transport/types.py`
+- [x] 1.2 Update default channel and dispatcher so `message/action/control/select` accept only typed payload families and reply with typed payloads
+
+## 2. Agent/runtime reply cutover
+
+- [x] 2.1 Update `BaseAgent` transport loop and `ReactAgent` transport emitters to return typed message/action/control replies without `event_type`
+- [x] 2.2 Remove `build_success_payload/build_error_payload` dict-wrapper usage from transport/runtime paths
+
+## 3. Client/adapters/examples
+
+- [x] 3.1 Update transport adapters (`stdio`/`websocket`/`direct`) and client event pumps to parse/render typed replies
+- [x] 3.2 Update examples and CLI helpers to send typed request payloads and consume typed replies
+
+## 4. Verification
+
+- [x] 4.1 Update transport/runtime/example tests that still assert `event_type` or legacy raw payloads
+- [x] 4.2 Run focused transport/runtime regressions and broader regression suite; sync evidence/docs/tasks
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diff --git a/openspec/specs/chat-runtime/spec.md b/openspec/specs/chat-runtime/spec.md
index ab86bf73..0652c797 100644
--- a/openspec/specs/chat-runtime/spec.md
+++ b/openspec/specs/chat-runtime/spec.md
@@ -4,15 +4,22 @@
 TBD - created by archiving change add-basic-chat-flow. Update Purpose after archive.
 ## Requirements
 ### Requirement: LLM-driven execute loop
-The runtime SHALL invoke the configured `IModelAdapter` during the execute loop, provide the assembled prompt and available tool definitions, and iterate over tool calls until the model returns a final response.
+The runtime SHALL invoke the configured `IModelAdapter` during the execute loop, provide the assembled canonical message history and available tool definitions, and iterate over tool calls until the model returns a final response.
+
+- `Context.assemble()` MUST produce canonical `Message` objects rather than plain text-only entries.
+- `IModelAdapter` MUST serialize canonical `Message` into provider-native request messages internally.
+- The execute loop MUST append tool calls and tool results back into canonical message history before continuing.
+- The transport-driven execute loop MUST return typed reply envelopes without using transport `event_type`.
 
 #### Scenario: Model returns a final response
 - **WHEN** the model response contains no tool calls
 - **THEN** the execute loop returns success and exposes the response content in the run output
+- **AND** the transport reply is `EnvelopeKind.MESSAGE` carrying one assistant `MessagePayload`
 
 #### Scenario: Model requests a tool call
 - **WHEN** the model response includes a tool call
 - **THEN** the runtime executes the tool via `ToolRuntime`, appends the result to the message history, and continues
+- **AND** transport intermediate events are emitted as typed message payloads instead of `event_type` aliases
 
 ### Requirement: Interactive stdin/stdout chat example
 The system SHALL provide a stdin/stdout example that wires the OpenAI adapter, base prompt store, and local command tool into an agent to perform interactive dialogue.
@@ -48,11 +55,18 @@ The canonical default `Context.assemble()` path SHALL include retrieval results
 ### Requirement: Retrieval query derives from current user intent
 The default assembly strategy SHALL derive retrieval query from the latest user-intent message in STM.
 
+For `Message(kind="chat")`, retrieval query derivation MUST use the latest non-empty `text` field rather than transport envelope content.
+
 #### Scenario: Latest user message drives retrieval query
 - **GIVEN** STM contains multiple turns including at least one user message
 - **WHEN** `Context.assemble()` is called
 - **THEN** LTM and Knowledge retrieval are invoked with the latest user message content as query
 
+#### Scenario: Latest user chat text drives retrieval query
+- **GIVEN** STM contains multiple turns including a latest user `Message(kind="chat")` with text
+- **WHEN** `Context.assemble()` is called
+- **THEN** LTM and Knowledge retrieval are invoked with that latest user text as query
+
 ### Requirement: Budget-aware degradation for retrieval sources
 The default assembly strategy SHALL degrade retrieval under low remaining token budget before model invocation.
 
@@ -67,3 +81,15 @@ The default assembly strategy SHALL degrade retrieval under low remaining token
 - **WHEN** `Context.assemble()` is called
 - **THEN** assemble still succeeds with available sources
 - **AND** metadata records degraded source reason
+
+### Requirement: Chat messages support text and image attachments in one turn
+The runtime SHALL support a single chat message that contains both text and multiple image attachments.
+
+- `Message(kind="chat")` MUST allow non-empty `text` together with one or more image attachment references.
+- The assembled message history MUST preserve the association as one logical user turn.
+- Model adapters MAY degrade unsupported image history, but the canonical chat message structure MUST remain intact before adapter-specific conversion.
+
+#### Scenario: User sends one text and multiple images
+- **WHEN** the runtime receives one user chat message with text and two image attachments
+- **THEN** the message history contains one canonical `Message(kind="chat")`
+- **AND** both image attachments remain associated with that same user turn
diff --git a/openspec/specs/interaction-dispatch/spec.md b/openspec/specs/interaction-dispatch/spec.md
index 19f35331..6a87337d 100644
--- a/openspec/specs/interaction-dispatch/spec.md
+++ b/openspec/specs/interaction-dispatch/spec.md
@@ -40,17 +40,20 @@ For deterministic action/control handling, the system SHALL emit responses corre
 - **WHEN** the handler completes successfully
 - **THEN** the system sends a response envelope with `reply_to="req-123"`
 
-### Requirement: Deterministic handler errors use a unified payload schema
-The system SHALL return deterministic action/control/message errors using a unified payload structure aligned with `TransportEnvelope`.
+### Requirement: Deterministic handler errors use typed payload replies
+The system SHALL return deterministic action/control/message errors using typed payload replies aligned with `TransportEnvelope.kind`.
 
-- Successful payloads MUST include `kind`, `target`, `ok=true`, and `resp` (dict).
-- Error payloads MUST include `kind`, `target`, `ok=false`, and `resp` with `code` and `reason`.
-- Unsupported action operations MUST use `resp.code="UNSUPPORTED_OPERATION"`.
+- Successful action results MUST populate `ActionPayload.ok=True` and `ActionPayload.result`.
+- Failed action results MUST populate `ActionPayload.ok=False` with deterministic `code` and `reason`.
+- Successful control results MUST populate `ControlPayload.ok=True` and `ControlPayload.result`.
+- Failed control results MUST populate `ControlPayload.ok=False` with deterministic `code` and `reason`.
+- Unsupported action operations MUST use `code="UNSUPPORTED_OPERATION"`.
 
-#### Scenario: Action timeout returns structured error
+#### Scenario: Action timeout returns typed error
 - **GIVEN** an action request exceeds configured timeout
 - **WHEN** the runtime returns an error response
-- **THEN** the payload includes `code="ACTION_TIMEOUT"`
+- **THEN** the payload is an `ActionPayload`
+- **AND** it includes `code="ACTION_TIMEOUT"`
 - **AND** `reply_to` points to the request id
 
 ### Requirement: Standard runtime control signals are provided and dispatchable
@@ -64,7 +67,7 @@ The interaction layer MUST NOT invoke the agent LLM execution path for control s
 Runtime control signals MUST be routed to a deterministic control handling path (e.g. `ControlHandler`).
 
 #### Scenario: Pause is not executed as a prompt
-- **GIVEN** an inbound control envelope with `kind="control"` and `payload="pause"`
+- **GIVEN** an inbound control envelope with `kind="control"` and `payload=<ControlPayload control_id="pause">`
 - **WHEN** the interaction layer processes the envelope
 - **THEN** it does not invoke the LLM-driven agent execution path
 
@@ -76,7 +79,7 @@ The system SHALL provide a dedicated `AgentControlHandler` for runtime controls.
 - `interrupt` MUST cancel the current execution operation owned by agent runtime.
 
 #### Scenario: Interrupt maps to agent control path
-- **GIVEN** an inbound control envelope with `payload="interrupt"`
+- **GIVEN** an inbound control envelope with `payload=<ControlPayload control_id="interrupt">`
 - **WHEN** control handling executes
 - **THEN** the runtime invokes the agent interrupt method
 - **AND** the current execution operation is cancelled
@@ -91,7 +94,7 @@ The system SHALL enforce a timeout for action handler execution in a single sess
 - **GIVEN** an action handler execution exceeds timeout
 - **WHEN** timeout is reached
 - **THEN** runtime terminates the action attempt
-- **AND** runtime returns `type="error"` with timeout code
+- **AND** runtime returns `ActionPayload(ok=False, code="ACTION_TIMEOUT")`
 
 ### Requirement: Standard action identifiers are provided for core interaction domains
 The system SHALL provide a stable set of standard action identifiers for deterministic interaction handling in the following initial domains:
@@ -120,3 +123,47 @@ The system SHALL provide a deterministic action discovery operation.
 - **GIVEN** a stdio client sends `/`
 - **WHEN** adapter maps it to action `actions:list`
 - **THEN** the runtime returns a deterministic list of supported action ids
+
+### Requirement: Action dispatcher routes only typed action payloads
+The action dispatch subsystem SHALL route only `ActionPayload` requests and SHALL return structured action results using typed payloads.
+
+- `ActionHandlerDispatcher.handle_action()` MUST read `resource_action` from `ActionPayload`.
+- The dispatcher MUST NOT accept raw string action ids as request payloads.
+- Successful action results MUST populate `ActionPayload.ok=True` and `ActionPayload.result`.
+- Failed action results MUST populate `ActionPayload.ok=False` with deterministic `code/reason`.
+
+#### Scenario: Dispatcher routes supported action payload
+- **WHEN** `handle_action()` receives `TransportEnvelope(kind="action", payload=<ActionPayload resource_action="tools:list">)`
+- **THEN** the matching handler is invoked
+- **AND** the result is returned as a typed action payload
+
+#### Scenario: Dispatcher rejects unsupported action id
+- **WHEN** `handle_action()` receives `ActionPayload` with an unknown `resource_action`
+- **THEN** the dispatcher returns `ok=False`
+- **AND** the error response includes a deterministic `code` and `reason`
+
+### Requirement: Select dispatch is isolated from action, control, and prompt execution
+The system SHALL provide a deterministic dispatch path for `select` envelopes that is separate from prompt execution, action dispatch, and runtime control handling.
+
+- `select` dispatch MUST NOT enter the LLM prompt execution path.
+- `select` dispatch MUST NOT be routed through `ActionHandlerDispatcher`.
+- `select` dispatch MUST preserve `reply_to` correlation semantics for answered selections.
+
+#### Scenario: Select answer does not execute as a prompt
+- **GIVEN** an inbound `TransportEnvelope(kind="select")`
+- **WHEN** the interaction layer processes the envelope
+- **THEN** it does not invoke the LLM-driven agent execution path
+- **AND** it does not route the envelope through `ActionHandlerDispatcher`
+
+### Requirement: Approval interactions use select ask and answered semantics
+The deterministic interaction layer SHALL represent approval interactions as `select` payloads.
+
+- Pending approval MUST use `SelectPayload(select_domain="approval", select_kind="ask")`.
+- Resolved approval MUST use `SelectPayload(select_domain="approval", select_kind="answered")`.
+- The runtime MUST NOT rely on message event aliases such as `approval.pending` or `approval.resolved` as the primary approval contract.
+
+#### Scenario: Approval resolution replies to the pending request
+- **GIVEN** an approval request was emitted as `kind="select"` with `select_kind="ask"`
+- **WHEN** the user resolves the approval
+- **THEN** the resolution is expressed as `kind="select"` with `select_kind="answered"`
+- **AND** the reply references the originating request envelope when available
diff --git a/openspec/specs/rich-media-message-schema/spec.md b/openspec/specs/rich-media-message-schema/spec.md
new file mode 100644
index 00000000..756deb5d
--- /dev/null
+++ b/openspec/specs/rich-media-message-schema/spec.md
@@ -0,0 +1,37 @@
+# rich-media-message-schema Specification
+
+## Purpose
+Define the canonical rich-media message schema used across transport, context, persistence, and model adapters.
+
+## Requirements
+
+### Requirement: Canonical message schema supports text, attachments, and structured data
+The system SHALL define a canonical framework `Message` schema that is independent from provider-native message formats and can represent chat text, image attachments, and structured tool-related data.
+
+- `Message` MUST remain the single canonical message type inside the framework runtime.
+- `Message` MUST expose `id`, `role`, `kind`, `text`, `attachments`, `data`, `name`, `metadata`, and `mark`.
+- `Message.role` MUST use a deterministic finite type rather than unconstrained strings.
+- `Message.kind` MUST distinguish at least `chat`, `thinking`, `tool_call`, `tool_result`, and `summary`.
+- `Message.kind` SHOULD be represented by a deterministic finite type rather than unconstrained strings.
+- `Message.attachments` MUST support image attachment references via a typed `AttachmentRef` structure rather than raw dictionaries.
+- `Message.data` MUST be available for structured message kinds such as `tool_call` and `tool_result`.
+- `Message.kind="thinking" | "summary" | "tool_call"` MUST reject attachments at schema validation time.
+- `Message.data` MUST be the primary structured source for `tool_call/tool_result`; `metadata` MUST NOT be required as a semantic fallback.
+
+#### Scenario: Chat message carries text and multiple images
+- **WHEN** a user message is represented as `Message(kind="chat")` with non-empty `text` and multiple image attachments
+- **THEN** the runtime preserves both the text and all attachment references in a single canonical message
+
+### Requirement: Message payload normalizes losslessly into canonical message
+The system SHALL define a `MessagePayload` transport contract that can be losslessly normalized into canonical `Message`.
+
+- `MessagePayload` MUST include `id`, `metadata`, `role`, `message_kind`, `text`, `attachments`, and `data`.
+- `MessagePayload.role` and `MessagePayload.message_kind` SHOULD use deterministic finite types rather than unconstrained strings.
+- `MessagePayload.message_kind` MUST map deterministically to `Message.kind`.
+- For `message_kind="chat"`, the payload MUST support `text + attachments` without requiring a separate chat-specific body type.
+- `MessagePayload` MUST reject unsupported attachment/message-kind combinations during payload validation.
+
+#### Scenario: Message payload becomes canonical message
+- **WHEN** the runtime receives `TransportEnvelope(kind="message", payload=<MessagePayload>)`
+- **THEN** the payload is normalized into one canonical `Message`
+- **AND** no message semantics are taken from transport-only fields
diff --git a/openspec/specs/transport-channel/spec.md b/openspec/specs/transport-channel/spec.md
index efa69654..9279bf72 100644
--- a/openspec/specs/transport-channel/spec.md
+++ b/openspec/specs/transport-channel/spec.md
@@ -10,16 +10,18 @@ The system SHALL define a transport domain that exposes a client-facing adapter
 - **WHEN** a developer provides a `ClientChannel`
 - **THEN** the system can construct an `AgentChannel` that the agent uses for `poll`/`send`
 
-### Requirement: Transport envelope is content-agnostic and distinct from context messages
-The system SHALL define a `TransportEnvelope` type that is independent from `context.Message` and can carry arbitrary payloads with minimal metadata.
+### Requirement: Transport envelope is independent from context messages and carries typed payload families
+The system SHALL define a `TransportEnvelope` type that is independent from `context.Message` and carries one typed payload family selected by `kind`.
 
-- The envelope MUST provide a primary strong-typed `kind` categorization that can distinguish `message|action|control`.
-- For `kind="action"`, the payload MUST be a deterministic action id string in `resource:action` form (e.g. `tools:list`).
-- For `kind="control"`, the payload MUST be a deterministic runtime control id string from `AgentControl` (e.g. `interrupt|pause|retry|reverse`).
-- The envelope model MUST NOT require a separate subtype field (e.g. `type`) in order to route inbound envelopes.
+- The envelope MUST provide a primary strong-typed `kind` categorization that can distinguish `message|select|action|control`.
+- `kind="message"` MUST carry `MessagePayload`.
+- `kind="select"` MUST carry `SelectPayload`.
+- `kind="action"` MUST carry `ActionPayload`.
+- `kind="control"` MUST carry `ControlPayload`.
+- The envelope model MUST NOT require a separate subtype field (e.g. `event_type` or `type`) in order to route inbound envelopes.
 
 #### Scenario: Envelope carries a control interrupt
-- **WHEN** a client sends a `TransportEnvelope` with `kind="control"` and `payload="interrupt"`
+- **WHEN** a client sends a `TransportEnvelope` with `kind="control"` and `payload=<ControlPayload control_id="interrupt">`
 - **THEN** the channel can route it to control handling without relying on prompt parsing
 
 ### Requirement: Channel routes inbound envelopes by kind before agent consumption
@@ -31,7 +33,7 @@ The system SHALL route inbound envelopes by `kind` in the channel implementation
 - If action/control handler bindings are missing at startup, runtime MUST fail fast with configuration error.
 
 #### Scenario: Action envelope does not enter message inbox
-- **GIVEN** a channel receives `TransportEnvelope(kind="action", payload="tools:list")`
+- **GIVEN** a channel receives `TransportEnvelope(kind="action", payload=<ActionPayload resource_action="tools:list">)`
 - **WHEN** inbound routing is applied
 - **THEN** the channel invokes action handling path
 - **AND** `AgentChannel.poll()` does not return that action envelope
@@ -116,15 +118,16 @@ These operations SHALL be handled without entering the model prompt execution pa
 
 ### Requirement: Envelope kind supports message, action, and control categories
 The transport envelope model SHALL provide a primary categorization field for inbound/outbound envelopes that can distinguish:
-- `message` (prompt/result/hook style messages)
+- `message` (canonical chat/thinking/tool/summary payloads)
+- `select` (approval/choice/form interactions)
 - `action` (deterministic resource actions)
 - `control` (interrupt/pause/retry/reverse)
 
-For `kind="control"`, implementations SHALL represent control variants via the payload value (e.g. `payload="interrupt"`).
-The envelope model MUST NOT require a separate subtype field (e.g. `type`) in order to route inbound envelopes.
+For `kind="control"`, implementations SHALL represent control variants via `ControlPayload.control_id`.
+The envelope model MUST NOT require a separate subtype field (e.g. `event_type`) in order to route inbound envelopes.
 
 #### Scenario: Action envelope is distinguishable without slash parsing
-- **GIVEN** a client sends `TransportEnvelope(kind="action", payload="tools:list")`
+- **GIVEN** a client sends `TransportEnvelope(kind="action", payload=<ActionPayload resource_action="tools:list">)`
 - **WHEN** the channel receives it
 - **THEN** the channel can route it deterministically without inspecting prompt text
 
@@ -144,9 +147,28 @@ The runtime integration with `AgentChannel.poll()` SHALL treat polled envelopes
 Client entry adapters SHALL normalize input into explicit envelope kinds before transport routing.
 
 - `stdio` adapters MAY map slash commands to structured `ACTION/CONTROL` envelopes.
-- `websocket` and `A2A` adapters MUST send explicit `kind` and structured `payload`; they MUST NOT rely on slash text inference inside transport runtime.
+- `websocket` and `A2A` adapters MUST send explicit `kind` and typed `payload`; they MUST NOT rely on slash text inference or `event_type` aliases inside transport runtime.
 
 #### Scenario: Websocket sends explicit action envelope
 - **GIVEN** a websocket client wants tool introspection
-- **WHEN** it sends `kind="action"` and `payload="tools:list"`
+- **WHEN** it sends `kind="action"` and `payload=<ActionPayload resource_action="tools:list">`
 - **THEN** channel routes the request through action path without text parsing
+
+### Requirement: AgentChannel rejects unsupported inbound envelope payloads deterministically
+The runtime SHALL validate inbound transport envelopes at the channel boundary and reject unsupported payload families with deterministic error semantics before they reach agent execution.
+
+- `EnvelopeKind.MESSAGE` MUST accept only `MessagePayload`.
+- `EnvelopeKind.ACTION` MUST accept only `ActionPayload`.
+- `EnvelopeKind.CONTROL` MUST accept only `ControlPayload`.
+- `EnvelopeKind.SELECT` MUST accept only `SelectPayload`.
+- The runtime MUST NOT accept legacy raw `str` or weakly-typed `dict` payloads as transport request payloads.
+
+#### Scenario: Message envelope with invalid payload is rejected before execution
+- **WHEN** the runtime receives `TransportEnvelope(kind="message")` whose payload is not a `MessagePayload`
+- **THEN** the envelope is rejected before agent execution begins
+- **AND** the requester receives a deterministic typed error reply
+
+#### Scenario: Action envelope with invalid payload is rejected before dispatch
+- **WHEN** the runtime receives `TransportEnvelope(kind="action")` whose payload is not an `ActionPayload`
+- **THEN** the dispatcher is not invoked
+- **AND** the requester receives a deterministic typed error reply
diff --git a/openspec/specs/typed-transport-replies/spec.md b/openspec/specs/typed-transport-replies/spec.md
new file mode 100644
index 00000000..a3f2ad2d
--- /dev/null
+++ b/openspec/specs/typed-transport-replies/spec.md
@@ -0,0 +1,29 @@
+# typed-transport-replies Specification
+
+## Purpose
+Define the canonical transport reply contract so request and reply envelopes use the same typed payload families without envelope-level subtype aliases.
+
+## Requirements
+
+### Requirement: Transport replies use typed payload families
+The transport layer SHALL return reply envelopes using the same typed payload families as requests, without relying on `event_type` or weakly-typed dictionary wrappers.
+
+- `EnvelopeKind.MESSAGE` replies MUST carry `MessagePayload`.
+- `EnvelopeKind.ACTION` replies MUST carry `ActionPayload`.
+- `EnvelopeKind.CONTROL` replies MUST carry `ControlPayload`.
+- `EnvelopeKind.SELECT` replies MUST carry `SelectPayload`.
+
+#### Scenario: Agent message request returns assistant message payload
+- **WHEN** an agent finishes handling a `TransportEnvelope(kind="message", payload=<MessagePayload>)`
+- **THEN** the reply envelope uses `kind="message"`
+- **AND** the reply payload is one `MessagePayload` representing the assistant-visible result
+
+#### Scenario: Action request returns typed action payload
+- **WHEN** the runtime completes one `TransportEnvelope(kind="action", payload=<ActionPayload>)`
+- **THEN** the reply envelope uses `kind="action"`
+- **AND** the reply payload is one `ActionPayload` containing `ok/result/code/reason`
+
+#### Scenario: Control request returns typed control payload
+- **WHEN** the runtime completes one `TransportEnvelope(kind="control", payload=<ControlPayload>)`
+- **THEN** the reply envelope uses `kind="control"`
+- **AND** the reply payload is one `ControlPayload` containing `ok/result/code/reason`

From fd72bdb9909ed241ee28e39ad1a5448c7925d5bb Mon Sep 17 00:00:00 2001
From: mindfn <lang_c@outlook.com>
Date: Mon, 9 Mar 2026 19:32:43 +0800
Subject: [PATCH 2/2] docs: wire rich media intent PR evidence

Replace the placeholder governance links in the active rich-media message pipeline feature record with the real intent PR and review anchor URLs for PR #206. This makes the docs-only intent branch pass the governance evidence-truth gate and gives PR #204 a merged intent target it can reference for governance-intent-gate.
---
 docs/features/rich-media-message-pipeline.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/features/rich-media-message-pipeline.md b/docs/features/rich-media-message-pipeline.md
index 8f7f7a77..d484d669 100644
--- a/docs/features/rich-media-message-pipeline.md
+++ b/docs/features/rich-media-message-pipeline.md
@@ -80,6 +80,6 @@ caching, compression, resume, and dispatch orchestration.
 
 ### Review and Merge Gate Links
 
-- Intent PR: `TBD`
+- Intent PR: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/206`
 - Implementation PR: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/204`
-- Review request: `TBD`
+- Review request: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/206#issuecomment-4023104454`