Skip to content

strands.vended_tools.a2a_client.a2a_client

A2A client tool for communicating with remote A2A-protocol agents.

Provides :func:make_a2a_client, a factory that requires an explicit mapping of permitted endpoints to their :class:~a2a.client.ClientConfig, plus optional size limits.

The tool is a stateless shim over :class:~strands.agent.a2a_agent.A2AAgent. A fresh A2AAgent is constructed on every call so the tool carries no session state between invocations. Each endpoint may carry its own :class:~a2a.client.ClientConfig to support per-endpoint authentication (bearer tokens, SigV4, OAuth).

A2AClientError

Section titled “A2AClientError”
class A2AClientError(RuntimeError)

Defined in: src/strands/vended_tools/a2a_client/a2a_client.py:41

Raised when an A2A operation fails.

make_a2a_client

Section titled “make_a2a_client”
def make_a2a_client(
        *,
        name: str = "a2a_client",
        description: str | None = None,
        allowed_endpoints: dict[str, ClientConfig | None],
        max_bytes: int = _DEFAULT_MAX_BYTES) -> DecoratedFunctionTool

Defined in: src/strands/vended_tools/a2a_client/a2a_client.py:45

Create an A2A client tool.

Arguments:

  • name - Tool name shown to the model.
  • description - Tool description shown to the model. When None, generated from DEFAULT_A2A_CLIENT_DESCRIPTION plus the permitted endpoints list.
  • allowed_endpoints - Mapping of permitted base URLs to their :class:~a2a.client.ClientConfig. Use None as the value for endpoints that need no custom configuration. Any endpoint not in this mapping is rejected before a network connection is made.
  • max_bytes - Maximum size in bytes of the result dict returned to the model. Does not cap the network transfer or binary parts. Results larger than this cap are rejected with an error.

Returns:

A decorated tool that communicates with A2A agents.