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A2A

# Agent-to-agent collaboration

A2A lets minds work together as agents, not just as tools. A mind can discover other minds, send them messages, delegate stateful tasks, track progress, and use results from one agent as input for another.

## The big idea

Use A2A when one mind should ask another mind for help, not when it only needs a simple data lookup or one-off command.

## Why A2A matters in Chamber

Chamber is built around minds that can act like specialists. A2A gives those specialists a common way to collaborate: one mind can identify another mind's skills, ask for help, hand off a task, and keep track of the result.

- Discovery: minds can list other available agents and see what they are good at.
- Delegation: a mind can ask another mind to take on a piece of work.
- Continuity: related messages and tasks can share context instead of becoming disconnected chats.
- Accountability: tracked tasks have status, history, and results you can review.

## Core A2A concepts

Agent Card | A description of an agent's identity, skills, capabilities, and how other agents can interact with it.
Message | A single turn between agents. Use it for quick questions, context sharing, or lightweight collaboration.
Task | A stateful unit of work. Use it when another mind should work asynchronously, report status, and produce results.
Context ID | A way to group related messages and tasks so a multi-step collaboration stays connected.
Artifact | A concrete result from a task, such as a summary, plan, document, dataset, image, or structured output.

## A2A tools available to minds

These are model-facing Chamber tools. You usually do not call them by name; you ask naturally, and the mind decides whether A2A is the right path.

`a2a_list_agents` | Lists other minds in the workspace with their names, descriptions, and skills.
`a2a_send_message` | Sends a message to another mind for quick peer input or context sharing.
`a2a_send_task` | Creates a tracked asynchronous task for another mind to work on.
`a2a_get_task` | Checks one task's state, history, artifacts, and latest result.
`a2a_list_tasks` | Lists tasks, optionally filtered by shared context or status.
`a2a_cancel_task` | Cancels an in-progress task that is no longer needed.

## When to use A2A

- Ask a research mind to gather background while a writing mind drafts the response.
- Have a planner mind create tasks for specialist minds, then summarize their outputs.
- Send a quick peer review request from one mind to another before making a decision.
- Keep several related work items tied together with shared context and task history.

## A2A vs tools

Tools and A2A solve different problems. Tools are good for specific actions: search, read, write, open a Canvas, schedule a job, or call a service. A2A is for working with another agent that can reason, plan, ask clarifying questions, use its own tools, and produce durable work.

Safety note

A2A can multiply work quickly because more than one mind may use tools or ask for follow-up actions. Review approvals based on the action and target, not just the mind that requested them.

## Related guides

Chatrooms Tools and approvals Work with Minds Scheduled work