[Bug]: TypeError: type.__new__() argument 1 must be str, not None in json_schema_to_model (LangGraph Provider)

[madhavhaldia]

SDK Language

Python SDK (composio package)

SDK Version

composio-langgraph=0.10.9

Runtime Environment

Python3.12

Environment

Production Deployment

Describe the Bug

When using the composio-langgraph provider with ToolRouter, calling session.tools() results in a hard crash (TypeError).

The issue occurs during the conversion of a Tool's JSON schema to a Pydantic model. Specifically, when the json_schema_to_model utility encounters a nested object schema (inside an array) that lacks a title or name field, it passes None as the model_name to Pydantic's create_model, which strictly requires a string.

This seems to happen specifically when a tool parameter is a List[Object] where the inner object is anonymous in the schema.

Steps to Reproduce

1. pip install composio composio-langgraph
2. initialise composio client with LanggraphProvider
3. create a session for a user
4. get tools using session.tools()

Minimal Reproducible Example

from composio import Composio
   from composio_langgraph import LanggraphProvider
   
   client = Composio(provider=LanggraphProvider())
   session = client.create(user_id="test-user", toolkits=["slack"])
   tools = session.tools()  # Crashes here

Error Output / Stack Trace

File "/app/.venv/lib/python3.14/site-packages/composio/utils/shared.py", line 194
    return create_model(model_name, **field_definitions)
                        ^
                   model_name is None (should be a string)

File "/app/src/color/agent/tools.py", line 36, in get_tool_router_for_user
    tools = session.tools()
  File "/app/.venv/lib/python3.14/site-packages/composio/core/models/tool_router.py", line 669, in tools_fn
    return t.cast(AgenticProvider, self._provider).wrap_tools(
  File "/app/.venv/lib/python3.14/site-packages/composio_langgraph/provider.py", line 93, in wrap_tools
    return [self.wrap_tool(tool=tool, execute_tool=execute_tool) for tool in tools]
  File "/app/.venv/lib/python3.14/site-packages/composio_langgraph/provider.py", line 69, in wrap_tool
    args_schema=json_schema_to_model(
  File "/app/.venv/lib/python3.14/site-packages/composio/utils/shared.py", line 187, in json_schema_to_model
    updated_name, pydantic_type, pydantic_field = json_schema_to_pydantic_field(
  File "/app/.venv/lib/python3.14/site-packages/composio/utils/shared.py", line 140, in json_schema_to_pydantic_field
    json_schema_to_pydantic_type(
  File "/app/.venv/lib/python3.14/site-packages/composio/utils/shared.py", line 79, in json_schema_to_pydantic_type
    ItemType = json_schema_to_pydantic_type(items_schema)
  File "/app/.venv/lib/python3.14/site-packages/composio/utils/shared.py", line 86, in json_schema_to_pydantic_type
    nested_model = json_schema_to_model(json_schema)
  File "/app/.venv/lib/python3.14/site-packages/composio/utils/shared.py", line 194, in json_schema_to_model
    return create_model(model_name, **field_definitions)  # type: ignore
  File "/app/.venv/lib/python3.14/site-packages/pydantic/main.py", line 1809, in create_model
    return meta(
File "<frozen abc>", line 106, in __new__
TypeError: type.__new__() argument 1 must be str, not None

Reproducibility

• Always reproducible
• Intermittent / Sometimes
• Happened once, can’t reproduce

Additional Context or Screenshots

No response

[Uday-sidagana]

Hey @madhavhaldia, We were able to reproduce the error.

[Pranavtej]

@Uday-sidagana

please let me know once this issue resolved.
Thanks !

[madhavhaldia]

Hey @Uday-sidagana, I opened a PR with a fix that works for our application. Feel free to check if this solution makes sense for the project. Basically it generates a fallback name when title=None by hashing the property names to ensure the same schema always produces the same model name.

[Pranavtej]

Hey @Uday-sidagana is this issue resolved ?
please let me know once this issue resolved.
Thanks !

[Uday-sidagana]

Hey @Pranavtej, we've fixed the issue. Can you update your composio and composio_langgraph versions to 0.11.0(latest) and lmk?

[Uday-sidagana]

Hey @Uday-sidagana, I opened a PR with a fix that works for our application. Feel free to check if this solution makes sense for the project. Basically it generates a fallback name when title=None by hashing the property names to ensure the same schema always produces the same model name.

We had a minor schema conversion issue on 0.10.9 and it's resolved now, really appreciate the contribution! Thanks @madhavhaldia