add_langgraph_fastapi_endpoint clones the agent on every request, and
LangGraphAgent.clone() rebuilds it through type(self)(...) forwarding the base
class's own behavior flags. LangGraphAGUIAgent restated a closed keyword-only
signature, so ag-ui-langgraph 0.0.43 - which began forwarding
enable_legacy_on_interrupt_event, emit_interrupt_outcome and emit_raw_events -
made every request 500 on the documented LangGraph + FastAPI quickstart:
TypeError: LangGraphAGUIAgent must override clone() or ensure its __init__
accepts (name, graph, description, config) as keyword arguments:
LangGraphAGUIAgent.__init__() got an unexpected keyword argument
'enable_legacy_on_interrupt_event'
Our dependency is ag-ui-langgraph[fastapi]>=0.0.42 with no upper bound, so a
fresh install already resolves to 0.0.43 and fails on the first message.
__init__ now forwards **kwargs upstream instead of restating the base signature.
That fixes the 500 without waiting on an upstream release, and makes base flags
reachable at all - emit_raw_events=False, the OSS-607 payload opt-out, could not
be set by any CopilotKit user through this subclass.
Also constructs the intercepted-tool-call test double for real rather than via
object.__new__. That helper built an instance with no behavior flags set, so it
raised AttributeError out of the base dispatch path the moment ag-ui-langgraph
started reading one - 4 failures the pinned 0.0.42 lockfile currently hides.
Verified against published ag-ui-langgraph, both versions: 0.0.43 gives 235
passed / 11 skipped (was 4 failed, 226 passed), and 0.0.42 gives 233 passed /
13 skipped (the two flag tests skip by design). End to end, two sequential
POSTs through add_langgraph_fastapi_endpoint on 0.0.43 return HTTP 200 with no
RUN_ERROR, where the published packages raise at endpoint.py:23.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The AG-UI dispatcher's ManuallyEmitToolCall handler rejected non-dict,
non-string args with CopilotKitMisuseError, but all three emitters
(JS, Python LangGraph, Python CrewAI) accept any JSON-serializable
value. This mismatch caused JS-emitted list/number args to crash the
Python dispatcher.
Replace the strict isinstance(dict, str) check with a None guard and
rely on the existing json.dumps try/except for serializability.
Call-site enumeration:
- langgraph_agui_agent.py:129 — changed from isinstance check to None guard
- test_emit_tool_call_optional_id.py — updated test_missing_args_raises match,
test_non_serializable_args_raises match, converted test_list_args_raises and
test_int_args_raises from negative to positive tests
- No other call sites reference the removed isinstance pattern
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The split queue_put calls introduced interleaving risk (6 yield points
vs 2) and the end_attempted flag was set before the END dispatch,
causing the compensating END to be skipped when END itself failed.
- CrewAI: restore single batched queue_put(start, args, end) call;
compensating END is now unconditional on batch failure
- AG-UI agent: rename end_attempted → end_dispatched, set after
successful END dispatch so compensation fires for all failure modes
- Tests: rewrite CrewAI compensating tests for batch semantics,
add test_failure_on_end_emits_compensating_end for AG-UI agent
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Replace JS error.message mutation with wrapped Error + cause chain
(safe for frozen errors, shared references, non-Error throwables)
- Rename dispatched_end → end_attempted, set before END dispatch to
prevent duplicate TOOL_CALL_END when END partially flushes before throwing
- Switch JS randomId() (ck-prefixed) to randomUUID() for cross-SDK parity
with Python's str(uuid.uuid4())
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Wrap JS dispatchCustomEvent in try/catch that enriches error messages
with tool name and ID for debuggability
- Apply asyncio.shield to copilotkit_emit_message's post-dispatch sleep
to match copilotkit_emit_tool_call's behavior under task cancellation
- Reorder validation in LangGraph Python and JS to name → toolCallId →
args, matching CrewAI's order (cheap checks before serialization)
- Narrow AG-UI dispatcher's except clause around json.dumps from
Exception to (TypeError, ValueError), matching sibling SDK variants
- Add CancelledError propagation and warning-log tests for the shielded
sleep path
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Re-raise CancelledError after logging in langgraph copilotkit_emit_tool_call
to honor asyncio cancellation contract (was silently un-cancelling tasks)
- Move dispatched_end flag to after ToolCallEndEvent dispatch in AG-UI agent
so compensating END fires when END itself throws
- Add dispatched_end tracking to CrewAI variant to prevent double-END on
partial failure
- Add JSON.stringify(args) validation in JS SDK matching Python parity
- Add 4 CrewAI compensating-END tests and 1 JS serializability test
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Address code review findings across all three SDK variants:
- Shield asyncio.sleep(0.02) with asyncio.shield() so task cancellation
doesn't prevent returning the tool_call_id after dispatch
- Revert args validation to original permissiveness (JS: undefined-only
check, Python: no isinstance check) to avoid breaking existing callers
- Add upfront json.dumps() serializability check in Python variants
- Fix compensating TOOL_CALL_END double-emit by tracking dispatched_end
- Add compensating action_execution_end to CrewAI variant (queue_put is
non-atomic)
- Use exc_info=True in compensating-END error logging
- Export all exception types from copilotkit package root (__init__.py)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Address code review findings:
- Wrap AG-UI tool call dispatch in try/except with compensating
TOOL_CALL_END to prevent clients hanging on partial emission
- Reject non-dict/non-str args at the dispatch layer (lists, ints, None)
- Guard against None event value before calling .get()
- Fix docstring examples that reuse variable names (won't compile)
- Introduce CopilotKitError base class; all exceptions now inherit from
it; CopilotKitMisuseError inherits from both CopilotKitError and
ValueError
- Add missing validation tests for name and args across LangGraph and
CrewAI Python variants, plus AG-UI dispatch edge cases
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Address code review findings: stop mislabeling dispatch errors as
CopilotKitMisuseError in JS (let them propagate naturally), add
CopilotKitMisuseError(ValueError) to Python SDK, pre-serialize args
in AG-UI handler to prevent partial event emission, align whitespace
validation across all SDKs and the dispatch layer, tighten JS args
type to Record<string, unknown>, and add comprehensive negative tests
for AG-UI dispatch validation.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Restore CopilotKitMisuseError for dispatch failures in JS (was bare Error)
- Rename JS options.id to options.toolCallId for cross-SDK naming parity
- Add name/args validation to Python LangGraph and CrewAI variants
- Add defensive field validation in AG-UI dispatch handler
- Add missing CrewAI whitespace-only ID test
- Add JS dispatch failure test
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Fixes#2066
## Problem
`copilotkit_customize_config(config, emit_messages=False)` does not work -
TEXT_MESSAGE_* events are still emitted despite the configuration.
## Root Causes
1. **Metadata Reading Bug**: In `langgraph_agui_agent.py`, the code uses
`getattr(raw_event, 'metadata', {})` to read metadata, but `raw_event`
is a dict, not an object. This should use `.get()` instead.
2. **Encoder Crash Bug**: When the filtering logic works (after fixing bug #1),
it returns `""` (empty string) to skip dispatching events. However, this
empty string gets yielded to the event encoder which expects event objects
with `model_dump_json()` method, causing an `AttributeError`.
## Fixes
1. Changed metadata reading to handle both dict and object cases.
2. Changed return value from `""` to `None` for filtered events.
3. Added `run()` method override to filter out `None` values before yielding
to encoder.
Adds missing dict_repr() method to LangGraphAGUIAgent class to fix
AttributeError when SDK tries to serialize agent info.
The method was present in the parent LangGraphAgent class but not
overridden in LangGraphAGUIAgent, causing failures when calling
sdk.info() with AGUI agents in FastAPI integrations.
Fixes#2667
Maxim