ComposioHQ/composio · error · ValueError

Provider is required for tool router. Please initialize Tool

Error message

Provider is required for tool router. Please initialize ToolRouter with a provider.

What it means

Raised by ToolRouter.create() when the ToolRouter instance was constructed without a provider (self._provider is None). The provider is mandatory because it drives session creation semantics; the error is a plain ValueError at the point the API call would be made.

Source

Thrown at python/composio/core/models/tool_router.py:1075

            custom_toolkits=custom_toolkits,
            default_preload=default_custom_preload,
            preload_tools=preload.get("tools") if preload is not None else None,
        )
        if inline_custom_tools_payload:
            if "custom_tools" in inline_custom_tools_payload:
                experimental_payload["custom_tools"] = inline_custom_tools_payload[
                    "custom_tools"
                ]
            if "custom_toolkits" in inline_custom_tools_payload:
                experimental_payload["custom_toolkits"] = inline_custom_tools_payload[
                    "custom_toolkits"
                ]

        if experimental_payload:
            create_params["experimental"] = experimental_payload

        if self._provider is None:
            raise ValueError(
                "Provider is required for tool router. "
                "Please initialize ToolRouter with a provider."
            )

        # Make API call to create session
        session = self._client.tool_router.session.create(**create_params)

        # Build custom tools routing map from backend response
        custom_tools_map: t.Optional[CustomToolsMap] = None
        if custom_tools or custom_toolkits:
            custom_tools_map = build_custom_tools_map_from_response(
                tools=custom_tools or [],
                toolkits=custom_toolkits,
                experimental=session.experimental,
            )
        preloaded_custom_tool_slugs = get_preloaded_custom_tool_slugs(
            custom_tools_map,
            default_preload=default_custom_preload,

View on GitHub (pinned to 64b1b85502)

Solutions

1. Construct ToolRouter with a provider: ToolRouter(api_key=..., provider=provider)
2. If migrating, pass the same provider you give to Composio(...)

Example fix

# before
router = ToolRouter(api_key=key)
session = router.create(...)

# after
router = ToolRouter(api_key=key, provider=provider)
session = router.create(...)

assert router._provider is not None or construct with provider

When it happens

Trigger: ToolRouter(api_key=...) without a provider, then router.create(...) — the missing provider is only detected at create time, not at construction.

Common situations: Migrating from an older ToolRouter signature where provider was optional, or constructing ToolRouter from a partial config object that omitted the provider field.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

• Provider is required for tool router. Please initialize Tool
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AI-assisted analysis of ComposioHQ/composio@64b1b85502 (2026-08-28). Data as JSON: /api/errors/b6f33d537b8701cb. Report an issue: GitHub.