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hcom-agent-messaging — Claude Code skill: use and install

Connects AI agents running in separate terminals so they can exchange messages, watch work, and start other sessions. Use it for multi-agent coordination.

Install into Claude Code · Skills CLI (Vercel) All methods and platforms ↓
npx skills add aannoo/hcom --skill hcom-agent-messaging -a claude-code
Open on GitHub

What hcom-agent-messaging does

This skill explains how to use hcom with AI agents running in separate terminals. Hooks and a shared database let agents exchange messages, inspect status, transcripts, file edits, live screens, and command history. They can subscribe to events and start, fork, resume, or stop sessions.

Launch a tool with hcom <tool> and open the terminal dashboard with hcom. Setup begins with hcom status, followed by hcom list. If the command is missing, install hcom with uv tool install hcom before checking the connection.

For diagnosis, the skill points to hcom hooks status, hcom relay status, and hcom reset all. A project-local state directory is available with HCOM_DIR=$PWD/.hcom hcom <tool>. Without hcom installed, hcom status cannot run.

What it helps with

  • coordinate agents across terminals
  • send work from one AI CLI to another
  • watch file edits and session status
  • start or resume another agent
  • check hcom hooks and relay state

Example prompts for the agent

  • Start Claude Code and Codex with hcom claude and hcom codex, then ask one agent to send its review to the other.
  • Tell an agent to watch Gemini’s file edits and report any bugs it finds.
  • Run hcom status, then use hcom list to inspect the connected participants.

How to install hcom-agent-messaging

1Skills CLI (Vercel)

npx skills add aannoo/hcom --skill hcom-agent-messaging -a claude-code

2Manually: put the files in place

~/.claude/skills/hcom-agent-messaging/SKILL.md

Copy the whole skill folder; for one project use .claude/skills/hcom-agent-messaging/

Step by step, with commands for each platform: How to install skills in Claude Code: five ways

Questions about hcom-agent-messaging

How do I install hcom-agent-messaging in Claude Code?

Run npx skills add aannoo/hcom --skill hcom-agent-messaging -a claude-code. Then check ~/.claude/skills/hcom-agent-messaging/SKILL.md.

What does hcom-agent-messaging do?

It connects agents in separate terminals through hcom. They can message one another, observe sessions, and start or resume other terminals.

Can hcom use a project-local state directory?

Yes. Run HCOM_DIR=$PWD/.hcom hcom <tool> when the normal hcom directory is unavailable or a sandbox blocks it.

Source text

SKILL.md · MIT
---
name: hcom-agent-messaging
description: >
  Multi-agent communication for AI coding tools. Agents message, watch,
  and spawn each other across terminals. Use when setting up hcom or
  troubleshooting.
---

# hcom — multi-agent communication for AI coding tools

AI agents running in separate terminals are isolated. hcom connects them via hooks and a shared database so they can message, watch, and spawn each other in real-time.

Start an agent with `hcom` in front, then prompt normally.

Use hcom to:

- coordinate multi-agent pipelines
- run different AI CLIs as each other's subagents
- avoid copy-pasting

```bash
uv tool install hcom
hcom claude       # or: hcom gemini, hcom codex, hcom opencode, hcom kilo, hcom pi, hcom omp, hcom agy, hcom cursor, hcom kimi, hcom copilot, hcom qoder, hcom grok, hcom hermes
hcom              # TUI dashboard
```

Quickstart:

```bash
# terminal 1
hcom claude

# terminal 2
hcom codex
```

Prompt normally — e.g. `review what claude did and send it fixes`

---

## what humans can do

tell any agent:

> send a message to claude

> when codex goes idle send it the next task

> watch gemini's file edits, review each and send feedback if any bugs

> fork yourself to investigate the bug and report back

> find which agent worked on terminal_id code, resume them and ask why it sucks

---

## what agents can do

**Message** each other in real time: mid-turn or wake immediately when idle

**Observe** each other: status, transcripts, file edits, live terminal screens, command history.

**Subscribe** and notify on status changes, file edits, collisions, specific events. React automatically.

**Spawn**, **fork**, **resume**, **kill** in any terminal emulator or headless.

run `hcom --help` for full command syntax and flags.

---

Works with Claude Code, Gemini CLI, Codex, OpenCode, Kilo Code, Pi, Oh My Pi, Antigravity, Cursor, Kimi, Copilot, Qoder CLI, Grok Build, Hermes Agent, and other tools

---

## setup

When this skill is invoked, first run:

```bash
hcom status
```

If hcom status works: run `hcom list`

If hcom list shows "Your name: <name>" where `<name>` is not "(not participating)": congratulations!

If running `hcom status` returns "command not found", install first:
```bash
uv tool install hcom
```

See the [hcom README](https://github.com/aannoo/hcom#install) for other install options.

If hcom status shows a list of CLI tools and you are not any of them, run `hcom start` to connect to hcom.

If you've just installed hcom now or if hcom list shows "Your name: (not participating)" and you are a tool in the hcom status list of CLI tools:

Relaunch into hcom properly for automatic message delivery and full hcom functionality. User should exit and run `hcom <tool>`.
Or if you know your sessionID/ses_/thread_name: user can exit and run `hcom r <session-id>` to resume you inside hcom. See `hcom r --help`.

---

## troubleshooting

### "hcom not working"

```bash
hcom status          # check installation
hcom hooks status    # check hooks specifically
hcom relay status    # check cross-device relay
```

still broken?
```bash
hcom reset all # backup config/db + reset it
hcom claude          # fresh start
```

still broken after that?
```bash
git clone https://github.com/aannoo/hcom.git
cd hcom
```
Read code and figure out what is going on.


### sandbox / permission issues

Use project-local hcom state when the normal hcom directory is unavailable:

```bash
HCOM_DIR=$PWD/.hcom hcom <tool>
```

## files

| what | location |
|------|----------|
| database | `~/.hcom/hcom.db` |
| config | `~/.hcom/config.toml` |
| env | `~/.hcom/env` |
| logs | `~/.hcom/.tmp/logs/` |
| user scripts | `~/.hcom/scripts/` |

---

## more info

```bash
hcom --help
hcom <command> --help
hcom run docs --scripts   # script authoring info
```

Github: https://github.com/aannoo/hcom

© aannoo · MIT · aannoo/hcom

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