Langchain adapter updates and x402 client update by dixitaniket · Pull Request #181 · OpenGradient/OpenGradient-SDK

dixitaniket · 2026-03-12T09:09:08Z

langchain adapter to support x402
ssl cert refesh on errors (tee registry update)
x402 client update to support preinstalled permit2 address

Copilot

Pull request overview

This PR updates the LangChain adapter and LLM client behavior to better support async/streaming usage and to automatically recover from a known x402 “Invalid payment required response” failure mode, along with dependency lockfile updates.

Changes:

Add “retry once after x402 stack reset” behavior for non-streaming and streaming LLM requests when the known invalid-payment error occurs.
Expand the LangChain adapter to support client injection, async methods, streaming chunk conversion, and improved tool-call parsing/serialization.
Update pinned dependency versions (including og-test-v2-x402==0.0.12.dev3) and refresh uv.lock.

Reviewed changes

Copilot reviewed 6 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
`src/opengradient/client/llm.py`	Adds x402 stack reset + retry-once logic for completion/chat, including streaming retry.
`src/opengradient/agents/og_langchain.py`	Refactors LangChain adapter for async paths, streaming support, tool handling, and client lifecycle.
`src/opengradient/agents/__init__.py`	Extends `langchain_adapter` factory to accept client + connection overrides and new params.
`tests/llm_test.py`	Adds tests asserting a single retry + reset on the invalid-payment error (streaming and non-streaming).
`tests/langchain_adapter_test.py`	Adds coverage for injected client init, missing-key validation, identifying params, and async/stream paths.
`pyproject.toml`	Bumps pinned `og-test-v2-x402` dependency.
`requirements.txt`	Bumps pinned `og-test-v2-x402` dependency.
`uv.lock`	Updates locked versions (including `opengradient` metadata and `og-test-v2-x402`).

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Copilot · 2026-03-12T18:51:39Z

src/opengradient/agents/og_langchain.py

+    def _stream(
+        self,
+        messages: List[BaseMessage],
+        stop: Optional[List[str]] = None,
+        run_manager: Optional[CallbackManagerForLLMRun] = None,
+        **kwargs: Any,
+    ) -> Iterator[ChatGenerationChunk]:
+        sdk_messages = self._convert_messages_to_sdk(messages)
+        chat_kwargs = self._build_chat_kwargs(sdk_messages, stop, stream=True, **kwargs)
+        queue: Queue[Any] = Queue()

-        return ChatResult(generations=[ChatGeneration(message=ai_message, generation_info={"finish_reason": finish_reason})])
+        def _runner() -> None:
+            async def _run() -> None:
+                stream = await self._llm.chat(**chat_kwargs)
+                async for chunk in cast(AsyncIterator[StreamChunk], stream):
+                    queue.put(self._stream_chunk_to_generation(chunk))
+
+            try:
+                asyncio.run(_run())
+            except BaseException as exc:  # noqa: BLE001
+                queue.put(exc)
+            finally:
+                queue.put(_STREAM_END)
+
+        thread = Thread(target=_runner, daemon=True)
+        thread.start()


_stream always spawns a new thread and runs self._llm.chat() inside asyncio.run(). Since the SDK client’s underlying async HTTP client is created on the main thread, using it from another thread/event loop is not safe. Consider implementing sync streaming by driving an event loop in the current thread (e.g., create a dedicated loop and iterate the async generator via run_until_complete on __anext__()), or otherwise ensure the HTTP client is created/used within the same thread+loop.

Copilot · 2026-03-12T18:51:40Z

src/opengradient/agents/og_langchain.py

    ):
+        resolved_model_cid = model_cid or model
+        if resolved_model_cid is None:
+            raise ValueError("model_cid (or model) is required.")


OpenGradientChatModel now accepts model_cid / model as str, but the underlying SDK client expects models in the provider/model form (LLM.chat does model.split("/")[1]). Passing a plain model name like "gpt-5" would raise IndexError at runtime. Consider validating the string format here (or normalizing to the required format) and raising a clear ValueError when it’s not supported.

Suggested change

raise ValueError("model_cid (or model) is required.")

raise ValueError("model_cid (or model) is required.")

# When a plain string is provided, ensure it matches the expected "provider/model" format

if isinstance(resolved_model_cid, str) and "/" not in resolved_model_cid:

raise ValueError(

f"Invalid model identifier '{resolved_model_cid}'. "

"Expected format 'provider/model', e.g. 'openai/gpt-4o'."

)

Copilot · 2026-03-12T18:51:40Z

src/opengradient/agents/og_langchain.py

+    try:
+        asyncio.get_running_loop()
+    except RuntimeError:
+        return asyncio.run(coro)
+
+    queue: Queue[Any] = Queue(maxsize=1)
+
+    def _runner() -> None:
+        try:
+            queue.put(asyncio.run(coro))
+        except BaseException as exc:  # noqa: BLE001
+            queue.put(exc)
+
+    thread = Thread(target=_runner, daemon=True)
+    thread.start()
+    outcome = queue.get()
+    thread.join()
+
+    if isinstance(outcome, BaseException):
+        raise outcome
+    return outcome
+
+


_run_coro_sync runs the coroutine in a new thread when a loop is already running. Because LLM holds an httpx.AsyncClient (via x402HttpxClient), running its async methods in a different thread/event loop is not thread-safe and can fail with “attached to a different loop” style errors. A safer approach is to either (a) raise a clear error instructing callers to use the async methods when a loop is running, or (b) schedule work onto the existing loop (without creating a second event loop) rather than using asyncio.run in another thread.

Suggested change

try:

asyncio.get_running_loop()

except RuntimeError:

return asyncio.run(coro)

queue: Queue[Any] = Queue(maxsize=1)

def _runner() -> None:

try:

queue.put(asyncio.run(coro))

except BaseException as exc: # noqa: BLE001

queue.put(exc)

thread = Thread(target=_runner, daemon=True)

thread.start()

outcome = queue.get()

thread.join()

if isinstance(outcome, BaseException):

raise outcome

return outcome

"""Run a coroutine synchronously when no event loop is running.

If an event loop is already running in this thread, synchronous execution

is not supported because it may conflict with resources (such as HTTP

clients) that are bound to the existing loop. In that case, callers must

use the async APIs directly.

"""

try:

# Raises RuntimeError if no loop is running in this thread.

asyncio.get_running_loop()

except RuntimeError:

# Safe to create and run a new event loop.

return asyncio.run(coro)

# An event loop is already running; do not create a second loop in

# another thread, as this is not safe for loop-bound resources.

raise RuntimeError(

"Cannot run coroutine synchronously while an event loop is running. "

"Use the async methods of OpenGradientChatModel instead."

)

Signed-off-by: Kyle Qian <[email protected]>

Copilot

Pull request overview

Copilot reviewed 7 out of 9 changed files in this pull request and generated 4 comments.

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pyproject.toml

    "openai>=1.58.1",
    "pydantic>=2.9.2",
-    "og-test-v2-x402==0.0.11"
+    "og-x402==0.0.1.dev2"


src/opengradient/agents/og_langchain.py

+    def _build_chat_kwargs(self, sdk_messages: List[Dict[str, Any]], stop: Optional[List[str]], stream: bool, **kwargs: Any) -> Dict[str, Any]:
+        x402_settlement_mode = kwargs.get("x402_settlement_mode", self.x402_settlement_mode)
+        if isinstance(x402_settlement_mode, str):
+            x402_settlement_mode = x402SettlementMode(x402_settlement_mode)
+        model = kwargs.get("model", self.model_cid)
+        model = _validate_model_string(model)

+        return {
+            "model": model,
+            "messages": sdk_messages,
+            "stop_sequence": stop,
+            "max_tokens": kwargs.get("max_tokens", self.max_tokens),
+            "temperature": kwargs.get("temperature", self.temperature),
+            "tools": kwargs.get("tools", self._tools),
+            "tool_choice": kwargs.get("tool_choice", self._tool_choice),
+            "x402_settlement_mode": x402_settlement_mode,
+            "stream": stream,
+        }


src/opengradient/client/llm.py

adambalogh · 2026-03-19T15:38:13Z

src/opengradient/client/llm.py

        # self-hosted TEE servers commonly use self-signed certificates.
        verify_ssl = llm_server_url is None
        self._tls_verify: Union[ssl.SSLContext, bool] = ssl_ctx if ssl_ctx else verify_ssl
+        self._reset_lock = threading.Lock()


this is incompatible with async coroutines, it only works with threads

adambalogh · 2026-03-19T15:38:33Z

src/opengradient/client/llm.py

+        return False
+
+    @staticmethod
+    def _is_ssl_error(exc: Exception) -> bool:


is this really necessary? why do we need this complex error handling now?

adambalogh · 2026-03-19T15:39:10Z

src/opengradient/client/llm.py

+                    operation_name,
+                    first_error,
+                )
+                await self._refresh_tee_and_reset()


why do we have to rebuild x402 on an exception?

dixitaniket added 3 commits March 12, 2026 14:32

updates

87de120

test updates

591aeea

addr change

bfe7146

adambalogh requested a review from Copilot March 12, 2026 18:47

Copilot started reviewing on behalf of adambalogh March 12, 2026 18:47 View session

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dixitaniket and others added 7 commits March 13, 2026 01:05

updates

6072d20

updates

19a9c47

updates

12e6d3c

test updates

a9edb21

dep updates

2e74a2c

Merge branch 'main' into ani/langchain-adapater

9e96cf7

Signed-off-by: Kyle Qian <[email protected]>

ssl refresh for clients

31ab38d

dixitaniket requested a review from Copilot March 18, 2026 17:28

Copilot started reviewing on behalf of dixitaniket March 18, 2026 17:29 View session

Copilot AI reviewed Mar 18, 2026

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fixes

6e719f9

dixitaniket changed the title ~~Langchain adapter updates~~ Langchain adapter updates and x402 client update Mar 19, 2026

adambalogh reviewed Mar 19, 2026

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Langchain adapter updates and x402 client update#181

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-            raise ValueError("model_cid (or model) is required.")
+            raise ValueError("model_cid (or model) is required.")
+        # When a plain string is provided, ensure it matches the expected "provider/model" format
+        if isinstance(resolved_model_cid, str) and "/" not in resolved_model_cid:
+            raise ValueError(
+                f"Invalid model identifier '{resolved_model_cid}'. "
+                "Expected format 'provider/model', e.g. 'openai/gpt-4o'."
+            )

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dixitaniket commented Mar 12, 2026 •

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