hcom-agent-messaging

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

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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

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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.

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tool support

tool	delivery	connect
claude code (incl. subagents)	automatic	hcom claude
gemini cli (>= 0.26.0)	automatic	hcom gemini
codex	automatic	hcom codex
opencode	automatic	hcom opencode
kilo code	automatic	hcom kilo
antigravity	automatic	hcom agy
cursor	automatic	hcom cursor-agent
any other ai tool	manual via hcom listen	hcom 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.

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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 output	meaning	action
command not found	not installed	install via brew install aannoo/hcom/hcom, the curl installer above, or pip install hcom
[~] claude	tool exists, hooks not installed	hcom hooks add then restart
[✓] claude	hooks installed	ready
[✗] claude	tool not found	install the AI tool first

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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"

symptom	diagnosis	fix
agent not in hcom list	agent stopped or never bound	relaunch or wait for binding
message sent but not delivered	check hcom events --last 5	verify @mention matches agent name/tag
message reaches more than one agent	duplicate base name across tags	target the full @tag-name to hit exactly one
messages leaking between workflows	no thread isolation	always 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

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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

topology	agents	pattern
worker-reviewer	2	worker sends result, reviewer reads transcript, sends APPROVED/FIX
pipeline	N sequential	each stage reads previous via hcom transcript, signals via thread
ensemble	N+1 (judge)	N agents answer independently, judge reads all via hcom events --sql
hub-spoke	1+N	coordinator broadcasts to @tag-, workers report back
reactive	N	hcom events sub triggers agent actions on file edits/status changes

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files

what	location
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.

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reference files

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

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more info

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

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