chore: Upgrade AI SDK from 4.x to 6.x

Upgrade to AI SDK 6.x to support MCP protocol version 2025-11-25.

Package changes:
- ai: ^4.3.16 → ^6.0.64
- agents: ^0.2.23 → ^0.3.6
- @ai-sdk/anthropic: ^1.2.12 → ^3.0.33
- @ai-sdk/openai: ^1.3.22 → ^3.0.23
- @ai-sdk/react: ^1.2.12 → ^3.0.66
- @ai-sdk/mcp: (new) ^1.0.16
- @modelcontextprotocol/sdk: ^1.21.0 → ^1.25.3

API migrations:
- MCP client imports: "ai" → "@ai-sdk/mcp"
- Type rename: LanguageModelV1 → LanguageModel
- generateText/streamText: maxSteps → stopWhen(stepCountIs(N))
- tool() API: parameters → inputSchema, execute(params) → execute(input)
- Tool call capture: toolCall.args → toolCall.input

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: dcramer

packages/mcp-cloudflare/package.json

@@ -4,9 +4,7 @@
   "private": true,
   "type": "module",
   "license": "FSL-1.1-ALv2",
-  "files": [
-    "./dist/*"
-  ],
+  "files": ["./dist/*"],
   "exports": {
     ".": {
       "types": "./dist/index.ts",
@@ -45,6 +43,7 @@
     "wrangler": "^4.45.0"
   },
   "dependencies": {
+    "@ai-sdk/mcp": "catalog:",
     "@ai-sdk/openai": "catalog:",
     "@ai-sdk/react": "catalog:",
     "@cloudflare/workers-oauth-provider": "catalog:",

packages/mcp-cloudflare/src/server/routes/chat.ts

@@ -1,7 +1,7 @@
 import { Hono, type Context } from "hono";
 import { openai } from "@ai-sdk/openai";
-import { streamText, type ToolSet } from "ai";
-import { experimental_createMCPClient } from "ai";
+import { streamText, type ToolSet, stepCountIs } from "ai";
+import { experimental_createMCPClient } from "@ai-sdk/mcp";
 import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
 import type { Env } from "../types";
 import { logInfo, logIssue, logWarn } from "@sentry/mcp-core/telem/logging";
@@ -326,7 +326,7 @@ Start conversations by exploring what's available in their account. Use tools li
 
 Remember: You're a test assistant, not a general-purpose helper. Stay focused on testing the MCP integration with their real data.`,
       maxTokens: 2000,
-      maxSteps: 10,
+      stopWhen: stepCountIs(10),
       experimental_telemetry: {
         isEnabled: true,
       },

packages/mcp-cloudflare/src/server/routes/metadata.ts

@@ -5,7 +5,7 @@
  * without requiring a chat stream to be initialized.
  */
 import { Hono } from "hono";
-import { experimental_createMCPClient } from "ai";
+import { experimental_createMCPClient } from "@ai-sdk/mcp";
 import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
 import type { Env } from "../types";
 import { logIssue, logWarn } from "@sentry/mcp-core/telem/logging";

packages/mcp-core/package.json

@@ -11,19 +11,15 @@
   "author": "Sentry",
   "description": "Sentry MCP Core - Shared code for MCP transports",
   "homepage": "https://github.com/getsentry/sentry-mcp",
-  "keywords": [
-    "sentry"
-  ],
+  "keywords": ["sentry"],
   "bugs": {
     "url": "https://github.com/getsentry/sentry-mcp/issues"
   },
   "repository": {
     "type": "git",
     "url": "git@github.com:getsentry/sentry-mcp.git"
   },
-  "files": [
-    "./dist/*"
-  ],
+  "files": ["./dist/*"],
   "exports": {
     "./api-client": {
       "types": "./dist/api-client/index.ts",
@@ -144,6 +140,8 @@
     "validate-skills": "tsx scripts/validate-skills-mapping.ts"
   },
   "devDependencies": {
+    "@ai-sdk/provider": "^3.0.6",
+    "@ai-sdk/provider-utils": "^4.0.11",
     "@sentry/mcp-server-mocks": "workspace:*",
     "@sentry/mcp-server-tsconfig": "workspace:*",
     "msw": "catalog:",
@@ -153,6 +151,7 @@
   },
   "dependencies": {
     "@ai-sdk/anthropic": "catalog:",
+    "@ai-sdk/mcp": "catalog:",
     "@ai-sdk/openai": "catalog:",
     "@logtape/logtape": "^1.1.1",
     "@logtape/sentry": "^1.1.1",

packages/mcp-core/src/internal/agents/anthropic-provider.ts

@@ -1,5 +1,5 @@
 import { createAnthropic } from "@ai-sdk/anthropic";
-import type { LanguageModelV1 } from "ai";
+import type { LanguageModel } from "ai";
 import { USER_AGENT } from "../../version";
 
 // Default configuration constants
@@ -24,7 +24,7 @@ export function setAnthropicBaseUrl(baseUrl: string | undefined): void {
  * - ANTHROPIC_MODEL: Model to use (default: "claude-sonnet-4-5") - env var OK
  * - Base URL: Must be set via setAnthropicBaseUrl() - NOT from env vars (security risk)
  */
-export function getAnthropicModel(model?: string): LanguageModelV1 {
+export function getAnthropicModel(model?: string): LanguageModel {
   const defaultModel = process.env.ANTHROPIC_MODEL || DEFAULT_ANTHROPIC_MODEL;
 
   const factory = createAnthropic({

packages/mcp-core/src/internal/agents/callEmbeddedAgent.ts

@@ -1,4 +1,4 @@
-import { generateText, Output, type Tool, APICallError } from "ai";
+import { generateText, Output, type Tool, APICallError, stepCountIs } from "ai";
 import { getAgentProvider } from "./provider-factory";
 import { UserInputError, LLMProviderError } from "../../errors";
 import type { z } from "zod";
@@ -45,7 +45,7 @@ export async function callEmbeddedAgent<
     system,
     prompt,
     tools,
-    maxSteps: 5,
+    stopWhen: stepCountIs(5),
     // Only include temperature if provider specifies one (e.g., GPT-5 requires temperature=1)
     ...(provider.getTemperature() !== undefined && {
       temperature: provider.getTemperature(),
@@ -63,7 +63,7 @@ export async function callEmbeddedAgent<
         for (const toolCall of event.toolCalls) {
           capturedToolCalls.push({
             toolName: toolCall.toolName,
-            args: toolCall.args,
+            args: toolCall.input,
           });
         }
       }

packages/mcp-core/src/internal/agents/openai-provider.test.ts

@@ -1,4 +1,5 @@
 import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import type { LanguageModelV3 } from "@ai-sdk/provider";
 import { getOpenAIModel, setOpenAIBaseUrl } from "./openai-provider.js";
 
 describe("openai-provider", () => {
@@ -21,7 +22,7 @@ describe("openai-provider", () => {
 
   describe("base URL configuration", () => {
     it("uses default base URL when not configured", () => {
-      const model = getOpenAIModel();
+      const model = getOpenAIModel() as LanguageModelV3;
 
       expect(model).toBeDefined();
       expect(model.modelId).toBe("gpt-5");
@@ -30,7 +31,7 @@ describe("openai-provider", () => {
     it("uses configured base URL", () => {
       setOpenAIBaseUrl("https://custom-openai.example.com");
 
-      const model = getOpenAIModel();
+      const model = getOpenAIModel() as LanguageModelV3;
 
       expect(model).toBeDefined();
       expect(model.modelId).toBe("gpt-5");
@@ -39,21 +40,21 @@ describe("openai-provider", () => {
 
   describe("model override", () => {
     it("uses default model when not specified", () => {
-      const model = getOpenAIModel();
+      const model = getOpenAIModel() as LanguageModelV3;
 
       expect(model.modelId).toBe("gpt-5");
     });
 
     it("uses specified model when provided", () => {
-      const model = getOpenAIModel("gpt-4");
+      const model = getOpenAIModel("gpt-4") as LanguageModelV3;
 
       expect(model.modelId).toBe("gpt-4");
     });
 
     it("uses OPENAI_MODEL env var when set", () => {
       process.env.OPENAI_MODEL = "gpt-4-turbo";
 
-      const model = getOpenAIModel();
+      const model = getOpenAIModel() as LanguageModelV3;
 
       expect(model.modelId).toBe("gpt-4-turbo");
     });

packages/mcp-core/src/internal/agents/openai-provider.ts

@@ -1,5 +1,5 @@
 import { createOpenAI } from "@ai-sdk/openai";
-import type { LanguageModelV1 } from "ai";
+import type { LanguageModel } from "ai";
 import { USER_AGENT } from "../../version";
 
 // Default configuration constants
@@ -33,7 +33,7 @@ export function setOpenAIBaseUrl(baseUrl: string | undefined): void {
  * - Vercel AI Gateway: "openai/gpt-4o", "anthropic/claude-sonnet-4.5", etc.
  * - Other providers: Check their documentation
  */
-export function getOpenAIModel(model?: string): LanguageModelV1 {
+export function getOpenAIModel(model?: string): LanguageModel {
   const defaultModel = process.env.OPENAI_MODEL || DEFAULT_OPENAI_MODEL;
 
   const factory = createOpenAI({

packages/mcp-core/src/internal/agents/tools/utils.ts

@@ -126,12 +126,12 @@ export function agentTool<TParameters, TResult>(config: {
 
   return tool({
     description: config.description,
-    parameters: config.parameters,
+    inputSchema: config.parameters,
     execute: async (
-      params: TParameters,
+      input: TParameters,
     ): Promise<AgentToolResponse<InferredResult>> => {
       try {
-        const result = await config.execute(params);
+        const result = await config.execute(input);
         return { result };
       } catch (error) {
         return handleAgentToolError<InferredResult>(error);

packages/mcp-core/src/internal/agents/types.ts

@@ -1,4 +1,4 @@
-import type { LanguageModelV1, JSONValue } from "ai";
+import type { LanguageModel, JSONValue } from "ai";
 
 /**
  * Provider options type matching AI SDK's ProviderOptions (LanguageModelV1ProviderMetadata)
@@ -19,7 +19,7 @@ export interface EmbeddedAgentProvider {
   readonly type: AgentProviderType;
 
   /** Get a language model instance, optionally with a model override */
-  getModel(modelOverride?: string): LanguageModelV1;
+  getModel(modelOverride?: string): LanguageModel;
 
   /** Get provider-specific options for generateText calls */
   getProviderOptions(): ProviderOptions;