AgentMiddleware

The schema for state passed to the middleware nodes.

Additional tools registered by the middleware.

The name of the middleware instance.

Defaults to the class name, but can be overridden for custom naming.

Logic to run before the agent execution starts.

Async logic to run before the agent execution starts.

Logic to run before the model is called.

Async logic to run before the model is called.

Logic to run after the model is called.

Async logic to run after the model is called.

Intercept and control model execution via handler callback.

Async version is awrap_model_call

The handler callback executes the model request and returns a ModelResponse. Middleware can call the handler multiple times for retry logic, skip calling it to short-circuit, or modify the request/response. Multiple middleware compose with first in list as outermost layer.

Intercept and control async model execution via handler callback.

The handler callback executes the model request and returns a ModelResponse.

Middleware can call the handler multiple times for retry logic, skip calling it to short-circuit, or modify the request/response. Multiple middleware compose with first in list as outermost layer.

Logic to run after the agent execution completes.

Async logic to run after the agent execution completes.

Intercept tool execution for retries, monitoring, or modification.

Async version is awrap_tool_call

Multiple middleware compose automatically (first defined = outermost).

Exceptions propagate unless handle_tool_errors is configured on ToolNode.

Intercept and control async tool execution via handler callback.

The handler callback executes the tool call and returns a ToolMessage or Command. Middleware can call the handler multiple times for retry logic, skip calling it to short-circuit, or modify the request/response. Multiple middleware compose with first in list as outermost layer.