A communication helper for sending messages between separate Claude Code or Codex sessions through tmux, a terminal tool that keeps sessions running and lets them share terminal interaction.

Use it to list sessions, identify their working directories, send debugging details or handoffs, and read responses from other coding agents.

It makes it easier to coordinate work across multiple agent sessions without copying technical context by hand. You can also inspect available sessions and read their terminal output.

agent-comms — Skill for Claude Code and Codex by buddyh/agent-skills

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add buddyh/agent-skills --skill agent-comms

Clone the repo

git clone --depth 1 https://github.com/buddyh/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/buddyh/agent-skills/agent-comms/github.svg)](https://agentmods.dev/skills/buddyh/agent-skills/agent-comms)

Your own site

<a href="https://agentmods.dev/skills/buddyh/agent-skills/agent-comms"><img src="https://agentmods.dev/badge/skills/buddyh/agent-skills/agent-comms/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/buddyh/agent-skills/agent-comms"><img src="https://agentmods.dev/badge/skills/buddyh/agent-skills/agent-comms.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,126 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00035	$0.01126
Opus 5.5	$0.00014	$0.00450
Sonnet 5.5	$0.00007	$0.00225
Haiku 4.5	$0.00003	$0.00113

Measured 2mo ago against content hash 0ccf4a7d548c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agent-comms scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agent-comms/SKILL.md · 139 lines

How it starts

The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Communication

Send messages to and read output from other tmux sessions running Claude Code or Codex. Built for coordination between parallel agent sessions.

Platform Support

Works identically on both platforms -- the underlying mechanism is tmux, not the AI agent. Sessions can communicate across platforms (a Claude Code session can message a Codex session and vice versa).

Setup

Make the script executable (one-time):

chmod +x ~/.claude/skills/agent-comms/scripts/agent-msg

Message Format

Always prefix messages with a header so the receiving session knows it's agent-to-agent:

[AGENT-MSG] From: <your-session-name>
<your actual message here>

Get your session name:

tmux display-message -p '#S'

Commands

SCRIPT=~/.claude/skills/agent-comms/scripts/agent-msg

# List available sessions
$SCRIPT list

# Send message (types into their terminal + Enter)
$SCRIPT send <session> "<message>"

# Read their terminal output
$SCRIPT read <session> --lines 50

# Get their working directory
$SCRIPT info <session>

Workflow

Get your session name for identification:
```
tmux display-message -p '#S'
```

List sessions to find the target:

~/.claude/skills/agent-comms/scripts/agent-msg list

Read their context before sending:

~/.claude/skills/agent-comms/scripts/agent-msg read worker-1 --lines 50

Send your message with identification:

~/.claude/skills/agent-comms/scripts/agent-msg send worker-1 "[AGENT-MSG] From: main-session

Hit a wall on the websocket reconnection logic. Here's where I'm stuck: [detailed context...]"

Read their response:

~/.claude/skills/agent-comms/scripts/agent-msg read worker-1 --lines 30

Example: Complex Debug Handoff

You've been debugging a native module issue for 20 minutes. It's a multi-layered problem involving Node versions, native rebuilds, and cross-project dependencies. You want another agent to take a look with full context:

Read the full file on GitHub · 139 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

scripts/agent-msg 4.3 KB

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 139 lines · 35 tokens per session scan A 0ccf4a7d548c

Subscribe to this mod's changes

agent-comms is a skill published in the GitHub repository buddyh/agent-skills (5 stars, last pushed 3mo ago), licensed MIT. It adds 35 tokens to every session and 1,126 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Building agents Claude Code ai-agents claude skills

agent-comms next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
agent-commsbuddyh/agent-skills	Skill	5	3mo ago	MIT	A	35	Claude Code, Codex
claude-md-improveranthropics/claude-plugins-official	Skill	46k	yesterday	Apache-2.0	A	82	Claude Code
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gke-workload-securitygoogle/skills	Skill	23k	today	Apache-2.0	A	171	Claude Code, Codex
google-cloud-solution-agentic-analytics-spark-knowledge-cataloggoogle/skills	Skill	23k	today	Apache-2.0	A	132	Claude Code, Codex
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