progress/v1

The A2A extension that carries an Agent's whole plan, step by step, on each status update.

URI: https://docs.nylorun.com/a2a/progress/v1

{
  "statusUpdate": {
    "taskId": "t1.…",
    "contextId": "ticket-4821",
    "status": { "state": "TASK_STATE_WORKING", "timestamp": "2026-11-02T09:12:40.031Z" },
    "metadata": {
      "https://docs.nylorun.com/a2a/progress/v1": {
        "steps": [
          { "label": "Inspect wikis and toolchain", "state": "done", "note": "Node 22, pnpm 9" },
          { "label": "Build in parts", "state": "active" },
          { "label": "Package zip and write summary", "state": "pending" }
        ]
      }
    }
  }
}

An agent keeps its plan with update_plan, a built-in tool of our harness that is off by default. Turn it on in the agent's AGENT.md:

AGENT.md

---
name: coder
description: Writes and ships changes to the team's repositories.
loop:
  plan: true
---

The session's root agent then gets the tool, unless it declares its own tool of that name. Each call takes { steps: [...] }, records a durable plan.updated event in the session, and answers Plan updated. The A2A endpoint sends each one as a status update with this extension, and GetTask and ListTasks carry the latest plan in the task's metadata. A caller gets the whole plan each time, never a diff: replace the plan you show with the latest one.

Field	Type	Meaning
`steps`	array, at most 20	The plan, in order.
`steps[].label`	string, at most 120 characters	What the step does.
`steps[].state`	`pending`, `active`, `done`, `blocked`, or `skipped`	Where the step is.
`steps[].note`	string, at most 280 characters, optional	A short note, such as what the step found.

A longer label or note is cut to its limit, ending in …, and steps past the 20th are dropped; the call does not fail for length. A plan of the wrong shape is a failed tool result the model sees. Labels and notes are short text the agent writes. They never carry tool arguments or results.

Status updates can arrive more than once or out of order. Order them by status.timestamp, and keep the plan from the latest. An agent without update_plan sends no plan; its status updates carry states and step text only. See AGENT.md.