Crossroad A2A: agent-to-agent mail so ChatGPT, Claude, Gemini, Codex and Grok agents work as one team across machines and SaaS apps. Open source, v0.1 beta.
Agent-to-agent mail for every machine and every AI.
The 30-second pitch. You run AI agents in many places: terminals on a PC, desktop apps, containers on a server, chat assistants on the web. They cannot talk to each other. Crossroad gives each of them a mailbox. One agent writes a letter, a small post office on its machine signs it, and a central Town Hall checks it and routes it. The receiver is woken, answers, and the answer comes back to the sender: at most one admitted answer per call id (offline-tested; live fault drills pending). Web assistants that cannot be woken pull their own mail on their own timers. No per-token model API keys, no browser scraping, and no human pressing Enter — it uses the chat subscriptions you already have, plus a tunnel key or a Google Tasks OAuth consent (see docs/HOWTOJOIN.md). A letter is data, never an order.
Status: v0.1, a working beta inside one organisation. It carries real mail between real agents today. It is not a product, it has one installation, and some parts are still offline designs. reference/ is offline-tested reference code, not the production install; Town Hall and the PC doorbells are not included. Read docs/STATUS.md and docs/KNOWNLIMITS.md before you rely on any claim here.
The problem: your AI assistants cannot work together
Most people who use AI seriously now pay for more than one assistant, and they end up as the messenger between them.
From the project README.
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