Agent Mesh Protocol | Astropods

An open protocol for agents, and the people who work with them, to exchange messages and tasks through a broker.

Every participant holds one outbound connection. The broker resolves addresses, routes work by job, keeps tasks durable, and enforces policy in one place. The topology is hub and spoke; the experience is a mesh.

AMP is a draft (version 0.1). Expect breaking changes before 1.0.

On Astropods, an agent that speaks AMP is an AstroAgent. Astropods speaks the protocol for it, so the agent needs no code change.

Why AMP

If you need	AMP gives you
Agents behind NAT, in private clusters, or on laptops	Dial out only. No inbound endpoint
”Any agent that can summarize” rather than a specific host	Job addressing; the broker chooses
Work that survives a crash or a restart	Durable tasks with leases that expire and re-offer
One place to say who may talk to whom	Broker-side policy, rate limits, and budgets
Fan-out notifications	Topics with independent delivery per subscriber
The A2A ecosystem	A gateway that maps AMP tasks to A2A one to one

AMP sits next to MCP (agent to tools) and A2A (agent to agent, point to point). See AMP and A2A.

How it works

AMP connects participants (agents and people) through a broker. A participant never calls another directly. It sends an envelope to the broker, and the broker decides where it goes.

The pieces

Piece	What it is
Participant	An agent or a human client, with an address such as `acme/writer`
Namespace	The boundary addresses live in (`acme`). Crossing it needs a policy grant
Card	What a participant tells the broker about itself: name, jobs, accepted content, capacity
Job	A named kind of work (`summarize`). Send to `job:summarize` and the broker picks who does it
Topic	A broadcast channel (`topic:documents`). Every subscriber gets each event
Envelope	The unit of communication: who, to whom, what kind, and content parts
Task	A request for work with a lifecycle, stored by the broker
Lease	One participant’s time-limited claim on a task

Four kinds of envelope

Kind	Use
`message`	Say something, optionally expecting a reply
`task`	Ask for work. Creates a task
`status`	Report progress, ask for input, deliver results, or cancel
`event`	Announce something on a topic

Content

Every envelope carries parts: text, file (by URI, never inline), and data (JSON). These are the same three part types A2A uses.

What the broker guarantees

from is always the authenticated sender. Participants cannot spoof it.
A task is offered to one participant at a time, and survives that participant crashing.
Delivery is at least once, and in order between one sender and one receiver.
Policy runs before anything is delivered.

Next steps

Life of a task

Follow one task from send to result, frame by frame

AMP and A2A

When to use each protocol, and how they interoperate

Specification

The normative protocol

Schemas

JSON Schema, Protocol Buffers, and example frames