v3
latestOpenAPI 3.0.02026-08-081996601.2 MBA2A Protocol
Cancel A2A v0.3 task
Cancels a running task. Returns the canonical state of the task after cancellation. If the task is already terminal, returns 409.
post/v2/agents/{agent_key}/v1/tasks/{task_id}:cancel
Path parameters
agent_keystring required
A unique key that identifies an agent.
Example:customer_support
The unique key of the agent.
task_idstring required
The A2A task id, as returned in task.id. Opaque — do not construct or parse.
Headers
Request-Timeoutinteger
The platform makes a best effort to complete the request in the specified seconds, or it times out.
Request-Timeout-Millisinteger
The platform makes a best effort to complete the request in the specified milliseconds, or it times out.
Response
The task state after cancellation.