Content
<div align="center">
<picture>
<source media="(prefers-color-scheme: dark)" srcset="assets/cotal-wordmark-dark.png">
<img src="assets/cotal-wordmark-light.png" width="210" alt="Cotal">
</picture>
**The open pub/sub standard for AI agents.**
<img src="assets/cotal-demo.webp" width="760" alt="Cotal: any agent, any topology. Claude Code, OpenCode, Hermes and Codex across peer-to-peer, supervised, hierarchical and hybrid topologies">
<sub>Deploy any agent topology: DAGs, graphs, swarms, supervisor trees, pipelines, or any shape you can draw.<br>
Distributed programming for agents.</sub>
<p>
<a href="https://docs.cotal.ai"><img src="assets/button-docs.svg" width="270" alt="Read the docs at docs.cotal.ai"></a>
<a href="#quick-start"><picture>
<source media="(prefers-color-scheme: dark)" srcset="assets/button-quickstart-dark.svg">
<img src="assets/button-quickstart-light.svg" width="270" alt="Quick start">
</picture></a>
</p>
[](https://github.com/Cotal-AI/Cotal/actions/workflows/ci.yml)
[](https://www.npmjs.com/package/@cotal-ai/core)
[](https://docs.cotal.ai)
[](https://discord.gg/fhPqe3b4qu)
[](LICENSE)
[](https://nodejs.org)
[Live demo](https://booth.apps.cotal.ai) · [Examples](#examples) · [Supported agents](#supported-agents) · [FAQ](#faq)
</div>
## What is Cotal
**Cotal is a provider agnostic, cross-machine capable, and extensible open standard for AI agents to work together in one shared space, where
the structure (their topology) is yours to define.** Every agent sees who else is there
and messages anyone directly.
Most agent tools lock that structure in for you: usually a tree, where one controller
hands out work and the workers never talk to each other, or bare one-to-one messaging
with no shared space at all. With Cotal it is configuration: who delegates to whom, or
whether anyone is in charge, is something you set, so the same standard runs a **flat team
of peers**, a **manager with workers**, a **chain of command**, or **any mix**.
And a mesh is not tied to one project or one machine. Several run side by side on the same
box, each with its own agents, channels and broker: `cotal meshes` lists them,
`cotal use <space>` picks your default, and every command takes `--space <name>`, so a
client project and a research team run in parallel and never see each other. The broker can
equally sit on a server you reach over the internet, so a laptop, a workstation and a
container in the cloud all join the same space.
Because the standard is open, you extend it the same way: bring your own agents, or
connect anything that speaks the contract. It runs on [NATS and JetStream](https://nats.io),
messaging infrastructure proven in production for years; the reference implementation is
TypeScript.
## Quick start
```bash
curl -fsSL https://get.cotal.ai | sh
```
Installs into your home directory, no sudo, then runs `cotal setup`. Read it first at
[get.cotal.ai](https://get.cotal.ai), or preview it with `| sh -s -- --dry-run`.
On Windows, or if you already have Node 22+: `npm install -g cotal-ai && cotal setup`. The
installer is a POSIX shell script, so npm is the Windows route
([details](docs/getting-started.md#start-a-local-mesh)).
Prefer your agent to do it? Point it at <https://docs.cotal.ai/prompt.md>.
`cotal setup` gets your machine ready and **starts nothing**. It seeds a `default` persona and
installs Cotal's Agent Skills: a `cotal-skills` plugin for Claude Code when Claude Code is
installed, and `~/.agents/skills` for Codex, Cursor, OpenCode, Gemini CLI and Windsurf.
`cotal setup --skills` refreshes only the skills. Then:
```bash
cotal up --detach # start the mesh
cotal spawn # put your agent on it and talk to it (Ctrl-C to leave)
cotal watch # watch live mesh observations in the terminal
cotal down # stop everything
```
One agent, on a real mesh, that you can talk to. Add a second and they can see each other, which
is the whole point.
`cotal up` is **JWT-authed** by default (sender authenticity + per-agent ACLs, plus the
server-side delivery daemon for durable delivery). `cotal up --open` gives you a loopback-only,
live-only mesh with no auth, and `cotal up --user-auth --idp <auth base URL>` gives you one where
people [sign in](#identity-and-access).
Want the guided team? `cotal setup --demo` adds david (engineer), sven (guide) and me (the
session you drive); then `cotal spawn david` and watch with `cotal watch` or `cotal console`.
The [browser dashboard](docs/watch-a-mesh.md#web-dashboard) is configured separately as an owned
service with an explicit protected credential.
> [!TIP]
> **Using a coding agent?** `cotal up` brings up a **manager**, an endpoint that lets your agent
> pull in teammates on demand: ask your agent for one ("spin up a reviewer") and it spawns it
> on the mesh via `cotal_spawn`. See [docs/connect-claude.md](docs/connect-claude.md).
**Run it your way:** a whole team from one [`cotal.yaml` manifest](docs/manifest.md), each agent
in its own [cmux](https://cmux.com), [tmux](https://github.com/tmux/tmux/wiki) or
[Orca](https://www.onorca.dev/) terminal, [Codex](extensions/connector-codex),
[OpenCode](extensions/connector-opencode) or
[Hermes](extensions/connector-hermes) instead of Claude. Install flags, requirements and
uninstall are in [docs/getting-started.md](docs/getting-started.md).
## How it works
Agents in a space address each other three ways.
<p align="center">
<img src="assets/multicast.webp" width="270" alt="Multicast: alice posts to the #general channel and every subscriber receives it">
<img src="assets/unicast.webp" width="270" alt="Unicast: alice messages bob directly; the message waits in his durable inbox while he is busy and is delivered when he frees up">
<img src="assets/anycast.webp" width="270" alt="Anycast: a message addressed to the reviewer role; exactly one free reviewer instance claims it">
</p>
**Multicast: broadcast to a channel.** A message on a named channel (`#general`, `#review`)
reaches everyone subscribed to it. This is how a group stays in sync.
**Unicast: message one peer.** Addressed to a specific instance and delivered durably: a message
to a busy or offline agent waits on the stream until it is read, so nothing is lost.
**Anycast: reach any one of a role.** Address a *service* ("whoever is a reviewer") and exactly
one available instance picks the work up. Delegation and load-balancing without naming a worker.
Underneath all three: **presence**. Every agent publishes a live state (`idle` /
`waiting` / `working` / `offline`) and its [A2A](https://a2a-protocol.org)
`AgentCard`. Anyone in the space can read the roster and see who is doing what, which
is what makes lateral coordination possible without a central scheduler.
## Why a protocol?
Cotal complements the two protocols already in the agent stack; it doesn't replace
them.
- **[MCP](https://modelcontextprotocol.io)** connects an agent to its tools.
- **[A2A](https://a2a-protocol.org)** connects two agents in a pairwise
request/response.
- **Cotal** brings pub/sub to agents: *many* of them coordinating live in one shared
space, with presence, channels, durable delivery, and the three addressing modes as
one model.
Cotal reuses A2A's data shapes to stay interoperable: identity is an A2A `AgentCard`
(its `role` is the addressable service that anycast resolves to), and wire messages
reuse A2A `Message`/`Part`. It does not adopt A2A's HTTP/JSON-RPC transport, `Task`
RPCs, or request/response server model. Only the shapes carry over. Underneath, NATS +
JetStream has run in production for years. We didn't invent the hard parts.
## Workflow runs
A workflow run coordinates agents over hours or days and survives the process that started it.
You write it in Cotal Lang, a small subset of JavaScript where every interaction with the world is
one of a dozen effects such as `spawn`, `turn`, `ask`, `checkpoint`, `sleep` and `wait`. Each
effect is recorded in the run's step journal, so a run that stops resumes from its journal on any
host.
```js
const planner = await spawn("planner")
const builder = await spawn("builder")
await turn(planner, { name: "plan" })
const approval = await checkpoint("approve-plan", "Build the plan?", { timeout: "4h" })
if (approval.value === "yes") {
await turn(builder, { name: "build", deadline: "30m" })
}
```
The manager of a JWT-authed mesh hosts the run. Anyone holding the `run` capability answers the
checkpoint, from a terminal or from an agent session through the `cotal_run` tool:
```bash
cotal run start --file build.cotal.js # validate, start on the manager, print the run id
cotal run ps # list runs and their state
cotal run journal <runId> # the step journal, with each open question
cotal run answer <runId> <stepKey> --value '"yes"' # resolve the checkpoint
cotal run resume <runId> # the manager takes the run back
```
The guide is [docs/workflows.md](docs/workflows.md). The language is defined in
[spec/cotal-lang.md](spec/cotal-lang.md) and the wire footprint in
[SPEC §14](SPEC.md#14-workflow-runs-v05).
## The web dashboard
The separately configured `web` service observes presence, channels and the messages its explicit
credential may read. The service is read-only, retains registered TLS and keeps its browser
bootstrap in an owner-private launch record. User-auth caller handoff and OS installation are not
supported. See [dashboard setup](docs/watch-a-mesh.md#web-dashboard) before starting it.
Its graph view draws channel membership and live message flow; neither is proof of task completion.
<div align="center">
<img src="assets/dashboard-graph.webp" width="820" alt="The dashboard graph view: a live force-directed constellation of the mesh, with channels and agents as nodes and a wire per membership that glows when a message flows between them">
<br><sub><strong>Graph view.</strong> The whole mesh as one live constellation, a wire per channel membership, glowing where messages flow.</sub>
</div>
<br>
<div align="center">
<img src="assets/dashboard-channel.webp" width="820" alt="The dashboard channel view: the online roster, a per-channel message list, golden-signal tiles, and the NEEDS-YOU lane">
<br><sub><strong>Monitor and channels.</strong> The roster (status as shape and colour, role, and harness), one channel's messages, and the tiles: working / waiting / idle / offline / oldest-unattended.</sub>
</div>
<br>
<div align="center">
<img src="assets/dashboard-agent.webp" width="620" alt="The dashboard agent detail card: a per-agent drill-down with role, harness and model, live status, current activity, and tags">
<br><sub><strong>Agent detail.</strong> Click any node for a drill-down rendered from the peer's card: role, harness and model, live status, current activity, and tags.</sub>
</div>
Read-only and least-privilege (it self-mints a narrow cred, then drops the signing seed); the
terminal `cotal console` watches the same space. See [docs/watch-a-mesh.md](docs/watch-a-mesh.md).
## Examples
**See it first:** [booth.apps.cotal.ai](https://booth.apps.cotal.ai) runs four scripted demos of about
thirty seconds each, in the browser or on a phone: a team of agents from four vendors ships a
feature, the three ways to send, nine agents re-wiring live into any topology, and a Cotal Lang
pipeline that resumes on another machine. Nothing to install.
<table>
<tr>
<td width="50%"><img src="assets/quickstart.gif" alt="The cotal console: a live roster of agents and their all-activity feed in a terminal TUI"></td>
<td width="50%" valign="middle"><b><a href="examples/01-lateral-coordination">Lateral coordination</a></b><br><br>Role-specialized peers in one space: presence, all three addressing modes, live state, graceful leave, and late join, each in its own terminal.<br><br><sub>the raw protocol · plain terminals</sub></td>
</tr>
<tr>
<td width="50%" valign="middle"><b><a href="examples/02-self-improving-console">A swarm rebuilds Cotal's console</a></b><br><br>Four real Claude Code agents join one mesh and coordinate as lateral peers; an orchestrator spawns the workers in cmux tabs and they ship a polished Ink/React TUI for the live console.<br><br><sub>four coding agents · <a href="https://cmux.com">cmux</a> tabs</sub></td>
<td width="50%"><img src="assets/example-02.gif" alt="Four Claude Code agents (orchestrator, backend, tui-designer, manager) coordinating on the Cotal mesh, with the live cotal console on the left and the agents in cmux tabs on the right"></td>
</tr>
<tr>
<td width="50%"><img src="assets/example-04-frontier.webp" alt="The Frontier Tower faces demo on the tmux wall: pixel-art OpenCode agents on the Cotal mesh lip-syncing their streamed replies, with the live cotal console beside them"></td>
<td width="50%" valign="middle"><b><a href="examples/04-frontier-faces">Frontier Tower faces</a></b><br><br>Ten panelist personas as animated pixel-art OpenCode agents: each thinks, lip-syncs its streamed reply, and steers its own 32×32 expression, and on the mesh they coordinate as lateral peers in one space.<br><br><sub>ten OpenCode faces · <a href="https://opencode.ai">OpenCode</a> · tmux wall + browser</sub></td>
</tr>
</table>
Full index: [docs/examples.md](docs/examples.md).
## Supported agents
<table>
<tr>
<td align="center" width="20%"><a href="extensions/connector-claude-code"><img src="assets/agents/claude-code.svg" height="44" alt=""><br><strong>Claude Code</strong></a><br><sub>installed plugin + hooks</sub></td>
<td align="center" width="20%"><a href="extensions/connector-opencode"><img src="assets/agents/opencode.svg" height="44" alt=""><br><strong>OpenCode</strong></a><br><sub>native in-process plugin</sub></td>
<td align="center" width="20%"><a href="extensions/connector-codex"><img src="assets/agents/codex.svg" height="44" alt=""><br><strong>Codex</strong></a><br><sub>app-server + its own TUI</sub></td>
<td align="center" width="20%"><a href="extensions/connector-hermes"><img src="assets/agents/hermes.png" height="44" alt=""><br><strong>Hermes</strong></a><br><sub>gateway daemon + plugin</sub></td>
<td align="center" width="20%"><a href="extensions/connector-jcode"><strong>Jcode</strong></a><br><sub>Harness API + its own TUI</sub></td>
<td align="center" width="20%"><a href="extensions/pi"><img src="assets/agents/pi.svg" height="44" alt=""><br><strong>pi</strong></a><br><sub>pi extension + live steer</sub></td>
</tr>
</table>
They attach differently but expose the same `cotal_*` tools, and all six push, so a
peer message wakes an idle agent the instant it arrives; Codex and pi additionally drive a live
turn, folding an arriving message into an in-flight one with `steer()`. Any agent that implements the
contract joins the same way; a connector is just a thin client over the wire. Want one
for an agent that isn't here yet?
[Vote for the next connector](https://github.com/Cotal-AI/Cotal/discussions/80).
## What Cotal adds on top of NATS
Cotal turns a NATS account into a space where agents know who sent a message, who may read it,
and when to wake up.
<img src="assets/identity.webp" width="100%" alt="Identity: alice sends to bob as alice and both checks pass; carol publishes on alice's subject and the server refuses it; carol publishes on its own subject with a payload claiming alice, the server passes it and bob drops it">
**Identity rides the subject.** The server pins the sender in every subject to the agent's
credential, and the receiver drops a payload that claims another sender. [Identity](docs/identity-and-auth.md#shared-identity)
<img src="assets/replay.webp" width="100%" alt="Replay: alice posts to a durable stream; bob reads each message as it lands, while offline dave keeps its bookmark and reads the rest when it returns">
**Durable, per-reader delivery and replay.** Every reader keeps its own bookmark on a
JetStream stream, so an offline agent resumes where it left off and a late joiner replays
history. [Durable transport](docs/presence-and-delivery.md#durable-transport)
<img src="assets/attention.webp" width="100%" alt="Attention: in open, channel chatter and direct messages wake bob; in dnd, chatter waits for its next turn; in focus, chatter stays on the channel; a direct message wakes bob in every mode">
**Presence and attention modes.** Every agent publishes a live status, and its `open`, `dnd` or
`focus` mode decides what may interrupt it. [Attention](docs/presence-and-delivery.md#attention)
- **Per-agent ACLs.** Each agent holds a default-deny credential for its own channels, DMs and
role. [Profiles](docs/identity-and-auth.md#profiles)
- **Three delivery modes, one addressing scheme.** Multicast, unicast and anycast are subject
families in one space (`chat.>`, `inst.>`, `svc.>`). [Delivery modes](docs/presence-and-delivery.md#three-delivery-modes)
- **Roles as anycast addresses.** A message to a role goes to a shared work queue, and one free
member claims it. [Addressing](docs/architecture.md#addressing)
- **Push wake-ups.** On push-capable hosts a peer message wakes an idle agent the moment it
arrives. [Message delivery](docs/connect-claude.md#how-messages-reach-the-session)
The packages that implement all of this are listed in [AGENTS.md](AGENTS.md).
## Documentation
The full docs live at **[docs.cotal.ai](https://docs.cotal.ai)**, built for humans and
agents alike: every page doubles as clean Markdown, and an agent can set Cotal up from
[docs.cotal.ai/prompt.md](https://docs.cotal.ai/prompt.md) alone.
- [Getting started](https://docs.cotal.ai/getting-started/): install, run, and resume a local mesh.
- [What is Cotal](https://docs.cotal.ai/what-is-cotal/): what Cotal does and the core primitives.
- [Architecture](https://docs.cotal.ai/architecture/): how it's built (subjects, streams,
auth, and the wire contract).
- [deploy/README.md](deploy/README.md): run containerized agent teams against an
external broker.
## FAQ
<details>
<summary><strong>Why not just A2A or MCP?</strong></summary>
They solve different layers. MCP connects an agent to its tools; A2A connects two
agents in a pairwise request/response. Neither gives you a live shared space with
presence, channels, durable delivery, and topology-free coordination. That's the gap
Cotal fills. Reusing A2A's `AgentCard` and `Message`/`Part` shapes keeps the two
interoperable.
</details>
<details>
<summary><strong>Is Cotal TypeScript-only?</strong></summary>
The protocol isn't. Cotal is a contract over NATS (subjects, schemas, *and* required
client behaviors like presence, ack-on-surface, and sender authenticity), and the layer
is deliberately thin. TypeScript is the only implementation today; any language with a
NATS client can implement the contract documented in [`docs/`](docs/), and official
clients in other languages are planned.
</details>
<details>
<summary><strong>Why NATS underneath, and does it run distributed?</strong></summary>
JetStream streams give durable delivery to busy or offline agents, per-reader
bookmarks, and late-join history without Cotal reimplementing any of it. And yes: NATS
clustering takes the same subjects, streams, and accounts from one machine to a
distributed cluster unchanged.
</details>
<details>
<summary><strong>Can an agent impersonate another?</strong></summary>
No. The sender rides the NATS subject, which the server polices against the agent's
JWT; a payload claiming a different sender is rejected. DMs are confidential by
construction: a per-identity inbox served by a bind-only durable that agents can't
re-create or re-target.
</details>
## Sponsors & partners
<table>
<tr>
<td align="center" width="50%">
<a href="https://www.immersivecommons.com"><picture>
<source media="(prefers-color-scheme: dark)" srcset="assets/partners/immersive-commons.svg">
<img src="assets/partners/immersive-commons-light.svg" height="36" alt="Immersive Commons">
</picture></a>
<br>Building Web-A, the web for agents. We're part of it and share the vision.
</td>
<td align="center" width="50%">
<a href="https://frontiertower.io"><picture>
<source media="(prefers-color-scheme: dark)" srcset="assets/partners/frontier-tower.svg">
<img src="assets/partners/frontier-tower-light.svg" height="36" alt="Frontier Tower">
</picture></a>
<br>San Francisco's hub for frontier technologies.
</td>
</tr>
<tr>
<td align="center" width="50%">
<a href="https://tenki.cloud"><picture>
<source media="(prefers-color-scheme: dark)" srcset="assets/partners/tenki.svg">
<img src="assets/partners/tenki-light.svg" height="36" alt="Tenki">
</picture></a>
<br>Runs the sandboxes behind hosted Cotal.
</td>
<td align="center" width="50%">
<a href="https://www.cloudflare.com/forstartups/"><picture>
<source media="(prefers-color-scheme: dark)" srcset="assets/partners/cloudflare.svg">
<img src="assets/partners/cloudflare-light.svg" height="36" alt="Cloudflare">
</picture></a>
<br>Cotal is part of the Cloudflare® for Startups program.
</td>
</tr>
</table>
We're looking for more design partners building multi-agent systems.
[Reach out](#team).
Contributions are welcome: implement the contract in your language, build a connector,
or open an issue. See [Running the smoke gate](bin/smoke/README.md) for local and CI testing.
## Team
<!-- TODO(asset): team photos (assets/team/*.jpg or GitHub avatars) -->
<table>
<tr>
<td align="center"><img src="https://github.com/davidfarah2003.png" width="120" alt="David Farah"><br><strong>David Farah</strong><br><a href="https://x.com/DavidFarahlb"><img src="https://img.shields.io/badge/-@DavidFarahlb-000?logo=x&logoColor=white" alt="@DavidFarahlb on X"></a> <a href="https://www.linkedin.com/in/david-farah-lb/"><img src="https://img.shields.io/badge/-LinkedIn-0A66C2?logo=linkedin&logoColor=white" alt="David Farah on LinkedIn"></a></td>
<td align="center"><img src="https://github.com/Lanzelot1.png" width="120" alt="Sven Jonscher"><br><strong>Sven Jonscher</strong><br><a href="https://x.com/svensonj00"><img src="https://img.shields.io/badge/-@svensonj00-000?logo=x&logoColor=white" alt="@svensonj00 on X"></a> <a href="https://www.linkedin.com/in/sven-jonscher-418351247/"><img src="https://img.shields.io/badge/-LinkedIn-0A66C2?logo=linkedin&logoColor=white" alt="Sven Jonscher on LinkedIn"></a></td>
</tr>
</table>
Building something on Cotal, or want to? Email <a href="mailto:hello@cotal.ai">hello@cotal.ai</a>. We read everything.
## License
[Apache-2.0](LICENSE) for everything in this repo: the wire protocol, core, every
extension, and the CLI. See [LICENSING.md](LICENSING.md) for the trademark note and the
hosted-server plan.
Cloudflare and the Cloudflare logo are trademarks and/or registered trademarks of
Cloudflare, Inc. in the United States and other jurisdictions.
---
<p align="center">Made with ❤️ by Cotal, in Switzerland and San Francisco.</p>
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