HC

hcom-agent-messaging

Connects independent AI coding agents to enable them to communicate, watch, and spawn tasks.

Install

mkdir -p .claude/skills/hcom-agent-messaging && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/19415" && unzip -o skill.zip -d .claude/skills/hcom-agent-messaging && rm skill.zip

Installs to .claude/skills/hcom-agent-messaging

Activation

This is the description your AI agent reads to decide when to run this skill — the better it matches your request, the more reliably it fires.

Multi-agent communication for AI coding tools. Agents message, watch, and spawn each other across terminals. Use when setting up hcom, troubleshooting delivery, or writing multi-agent scripts.
192 chars✓ has a “when” trigger
Advanced

Key capabilities

  • Message between AI agents in real-time
  • Observe agent transcripts, file edits, and terminal screens
  • Subscribe to agent status changes and events
  • Spawn, fork, resume, and kill agents across terminals
  • Bundle context for agent handoffs

How it works

It connects isolated terminal sessions via hooks and a shared database, allowing agents to communicate, monitor, and control each other's execution.

Inputs & outputs

You give it
Agent commands, terminal session IDs, or task descriptions
You get back
Inter-agent communication, event logs, or spawned agent processes

When to use hcom-agent-messaging

  • Messaging between agents
  • Observing agent terminal activity
  • Forking tasks to sub-agents
  • Coordinating multi-agent workflows

About this skill

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.

curl -fsSL https://github.com/aannoo/hcom/releases/latest/download/hcom-installer.sh | sh
hcom claude       # or: hcom gemini, hcom codex, hcom opencode, hcom kilo, hcom pi, hcom omp, hcom agy, hcom cursor-agent, hcom kimi, hcom copilot
hcom              # TUI dashboard

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, bundle context for handoffs.

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

Subscribe to each other: notify on status changes, file edits, specific events. React automatically.

Spawn, fork, resume, kill each other, in any terminal emulator.

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


tool support

tooldeliveryconnect
claude code (incl. subagents)automatichcom claude
gemini cli (>= 0.26.0)automatichcom gemini
codexautomatichcom codex
opencodeautomatichcom opencode
kilo codeautomatichcom kilo
antigravityautomatichcom agy
cursorautomatichcom cursor-agent
any other ai toolmanual via hcom listenhcom start (run inside tool)

session binding (hcom transcript, hcom r/f by session id) happens on first message or first prompt for all hcom-launched tools.


setup

if the user invokes this skill without arguments:

  1. run hcom status — if "command not found", install first:
    curl -fsSL https://github.com/aannoo/hcom/releases/latest/download/hcom-installer.sh | sh
    
  2. run hcom hooks add to install hooks for all detected tools
  3. restart the AI tool for hooks to activate
status outputmeaningaction
command not foundnot installedinstall via brew install aannoo/hcom/hcom, the curl installer above, or pip install hcom
[~] claudetool exists, hooks not installedhcom hooks add then restart
[✓] claudehooks installedready
[✗] claudetool not foundinstall the AI tool first

troubleshooting

"hcom not working"

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

hooks missing? hcom hooks add then restart tool.

still broken?

hcom reset all && hcom hooks add
# close all ai tool windows
hcom claude          # fresh start

"messages not arriving"

symptomdiagnosisfix
agent not in hcom listagent stopped or never boundrelaunch or wait for binding
message sent but not deliveredcheck hcom events --last 5verify @mention matches agent name/tag
message reaches more than one agentduplicate base name across tagstarget the full @tag-name to hit exactly one
messages leaking between workflowsno thread isolationalways use --thread

intent system

agents follow these rules from their bootstrap:

  • --intent request -> agent always responds
  • --intent inform -> agent responds only if useful
  • --intent ack -> agent does not respond

sandbox / permission issues

export HCOM_DIR="$PWD/.hcom"     # project-local mode
hcom hooks add                   # installs to project dir

workflow scripting

place scripts in ~/.hcom/scripts/ as .sh or .py. run with hcom run <name> "task". see references/script-template.md for the full annotated template, or run hcom run docs --scripts inside an agent.

key rules

  • never use sleep — use hcom events --wait or hcom listen
  • never hardcode agent names — parse from grep '^Names: ' in launch output
  • always use --thread — without it, messages leak across workflows
  • always use trap cleanup ERR INT TERM — orphan headless agents run indefinitely
  • always use hcom kill for cleanup (not stop) — kill also closes the terminal pane
  • always forward --name — hcom injects it, scripts must propagate it
  • always use --go on launch commands — without it, scripts hang on confirmation prompt (hcom kill never prompts, so --go is optional there)

agent topologies

topologyagentspattern
worker-reviewer2worker sends result, reviewer reads transcript, sends APPROVED/FIX
pipelineN sequentialeach stage reads previous via hcom transcript, signals via thread
ensembleN+1 (judge)N agents answer independently, judge reads all via hcom events --sql
hub-spoke1+Ncoordinator broadcasts to @tag-, workers report back
reactiveNhcom events sub triggers agent actions on file edits/status changes

files

whatlocation
database~/.hcom/hcom.db
config~/.hcom/config.toml
logs~/.hcom/.tmp/logs/
user scripts~/.hcom/scripts/

with HCOM_DIR set, uses that path instead of ~/.hcom.


reference files

filewhen to read
references/patterns.mdwriting multi-agent scripts — 6 tested patterns with full code and real event JSON
references/cross-tool.mdclaude + codex + gemini + opencode + kilo + pi + omp + antigravity + cursor + kimi + copilot collaboration details and per-tool quirks
references/gotchas.mddebugging scripts — timing, message delivery, intent system, cleanup
references/script-template.mdwriting a new script from scratch — full template with commentary
references/scripts/6 tested, working example scripts

more info

hcom --help              # all commands
hcom <command> --help    # command details

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

When not to use it

  • Using sleep commands in scripts
  • Hardcoding agent names in scripts
  • Running headless agents without cleanup traps

Prerequisites

hcom CLI tool

Limitations

  • Requires hooks for automatic delivery
  • Messages can leak across workflows without thread isolation
  • Orphaned headless agents run indefinitely without proper cleanup

How it compares

It enables cross-terminal agent orchestration that is otherwise impossible due to terminal isolation.

Compared to similar skills

hcom-agent-messaging side by side with the closest alternatives in the catalog.

SkillInstallsUpdatedSafetyDifficulty
hcom-agent-messaging (this skill)021dReviewAdvanced
agent-protocol11moNo flagsIntermediate
messaging-agents03moReviewIntermediate
agent-collective-intelligence-coordinator05moNo flagsAdvanced

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