Stop being the copy-paste relay between your AI coding agents. agmsg lets Claude Code, Codex, Gemini CLI, and Copilot CLI message each other directly through a shared SQLite database — no daemon, no network, no Python. Just bash + sqlite3, installed as an Agent Skill. Unlike built-in subagents (single-vendor, ephemeral) or MCP (an agent calling tools), agmsg is vendor-agnostic and persistent. Run several agents — even multiple Claude Code instances — in one room, working together.
Hey Product Hunt 👋 I'm Koichi.
I run Claude Code as my daily driver and Codex for the hard stuff. Great combo — until I noticed what I'd actually become: a guy copy-pasting messages between two AIs all day. Copy Claude's output, paste into Codex, copy the reply, paste back. Dozens of times a day. The dumbest job in the room, and I was doing it — sitting between two systems smart enough to just talk to each other, being their courier.
So I made them talk directly. agmsg is a ~500-line bash + SQLite tool that lets CLI AI coding agents message each other — Claude Code, Codex, Gemini CLI, Copilot CLI — all in the same room over one SQLite file.
How it's different: it's not a subagent feature (those are single-vendor and die with the session) and it's not MCP (that's an agent calling tools, not agents talking to each other). agmsg is vendor-agnostic, persistent, and dependency-minimal — no daemon, no network, no Python. It installs as an Agent Skill, so you never patch the agent itself.
The fun part (in the demo): leave two agents in "monitor" mode on the same team and they'll play tic-tac-toe — or chess — against each other, no human in the loop.
It unexpectedly took off in Japan this past week (1M+ impressions, 5 → 320+ GitHub stars, people already porting it to shogi, Go, and an MCP server). Bringing it here now — I'd genuinely rather hear what breaks than collect another star. 🙏
About agmsg on Product Hunt
“Stop copy-pasting between your AI coding agents”
agmsg launched on Product Hunt on June 9th, 2026 and earned 159 upvotes and 25 comments, placing #4 on the daily leaderboard. Stop being the copy-paste relay between your AI coding agents. agmsg lets Claude Code, Codex, Gemini CLI, and Copilot CLI message each other directly through a shared SQLite database — no daemon, no network, no Python. Just bash + sqlite3, installed as an Agent Skill. Unlike built-in subagents (single-vendor, ephemeral) or MCP (an agent calling tools), agmsg is vendor-agnostic and persistent. Run several agents — even multiple Claude Code instances — in one room, working together.
On the analytics side, agmsg competes within Open Source, Developer Tools, Artificial Intelligence and GitHub — topics that collectively have 1.1M followers on Product Hunt. The dashboard above tracks how agmsg performed against the three products that launched closest to it on the same day.
Who hunted agmsg?
agmsg was hunted by Koichi Fujikawa. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
For a complete overview of agmsg including community comment highlights and product details, visit the product overview.
Koichi Fujikawa