Agents talk. No polling.

Reactive pub/sub for AI agents. MQTT under the hood. Every agent is a peer — no orchestrator, no framework lock-in.

5-min quickstart For agents: skills.md GitHub

agents @ tailnet

$ planner

$ swarmbus send --to coder --subject plan --body "build it"

sent · msg_id=01J...

$ coder

$ swarmbus tail --follow

← from=planner subject=plan

body: build it

No orchestrator No polling Runs on your laptop, your Pi, or your tailnet

Outbox → broker → inbox

Each agent has an outbox and an inbox. Outbox messages are published to the broker; the broker delivers subscriptions into the peer's inbox. Nothing in the middle coordinates; the broker only routes.

5-minute quickstart

Install the broker. On macOS: brew. On Linux: your package manager.

bash

brew install mosquitto          # macOS
sudo apt install mosquitto      # Debian/Ubuntu

Install swarmbus and initialize an agent.

bash

pip install swarmbus-py
swarmbus init --agent-id planner
swarmbus init --agent-id coder

Send a message from planner to coder.

bash

swarmbus send --agent-id planner --to coder --subject hi --body "ping"

How swarmbus compares

Honest trade-offs. If you need cloud-scale horizontal broker clustering, use NATS. If you need one binary running between your agents on your box, swarmbus is the shorter path.

	Reactive	Agent-first	Local single-binary	MQTT wire	Python + MCP tooling	Tailscale-ready
swarmbus	✓	✓	✓	✓	✓	✓
MQTT (protocol)	✓	✗	needs broker	✓	DIY glue	✓
Google A2A	✓	✓	cloud only	HTTP/JSON	cloud SDK	cloud only
NATS Better pick for cloud-scale horizontal broker clustering.	✓	✗	NATS server	NATS proto	NATS client	✓
Redis Streams	polling	✗	Redis server	RESP proto	Redis client	✓
AutoGen / CrewAI Role/dialog frameworks. Messaging is in-process.	in-process	✓	no broker	in-process	framework-locked	single process
LangGraph state channels Graph state passed between nodes, not pub/sub.	graph ticks	✓	no broker	in-process	framework-locked	single process

✓ supported · ✗ not supported · short notes describe the specific trade-off

Building an agent host? Point it at swarmbus.dev/skills.md.

A plain-markdown runbook your agent can read and act on. Install, configure, verify — in one file.

bash

curl -fsSL https://swarmbus.dev/skills.md

Integration paths

Peer messages are untrusted data. swarmbus never executes body content; its behavioral skill teaches receivers the same. → /docs#security