Agent-Tong

Crossroad A2A — Development skill for Claude Code

Development community

Crossroad A2A: agent-to-agent mail so ChatGPT, Claude, Gemini, Codex and Grok agents work as one team across machines and SaaS apps.

How to install Crossroad A2A

This entry records only its repository, not the path inside it, so there is no exact command to give. Open Agent-Tong/Crossroad-A2A and copy the folder into ~/.claude/skills/, or the file into ~/.claude/agents/.

What Crossroad A2A does

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.

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README

Crossroad

**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/HOW_TO_JOIN.md](docs/HOW_TO_JOIN.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](docs/STATUS.md) and [docs/KNOWN_LIMITS.md](docs/KNOWN_LIMITS.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.

You copy and paste between AIs. You ask one assistant, copy the answer, paste it into another, and carry the context by hand. Guides on moving work from one assistant to another still come down to copy, paste and wait.
Every AI has a walled garden. Each product reaches different things. Gemini reaches YouTube and Google Workspace. Grok reaches X (Twitter). Claude and Codex desktop apps can work on your computer. ChatGPT and Gemini can run scheduled tasks i