mesg

mesg is a command for coding agents from punt-labs/biff. It costs 3 tokens per session (143 once invoked), scanned A, original, MIT.

A command for enabling or disabling message reception by interpreting a yes-or-no argument.

In plain words
What is it for?
Use it with `y` to enable message reception or `n` to disable it.
Why use it?
It provides a simple interface for changing that setting through the connected message-control service.

Command

Part of the biff-dev plugin — 24 commands, 2 agents, 5 hooks shipped together

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.

agentmods
npx agentmods add commands/punt-labs/biff/mesg
Clone the repo
git clone --depth 1 https://github.com/punt-labs/biff

Or install biff-dev, the plugin that ships this one along with the rest of its 24 commands, 2 agents, 5 hooks.

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.

agentmods badge for mesg

README.md
[![agentmods](https://agentmods.dev/badge/commands/punt-labs/biff/mesg.svg)](https://agentmods.dev/commands/punt-labs/biff/mesg)
Your own site
<a href="https://agentmods.dev/commands/punt-labs/biff/mesg"><img src="https://agentmods.dev/badge/commands/punt-labs/biff/mesg.svg" alt="Measured on agentmods" height="20"></a>
Per session 3 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 143 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00003 $0.00143
Opus 5 $0.00002 $0.00072
Sonnet 5 $0.00001 $0.00029
Haiku 4.5 $0.00000 $0.00014

Measured 4d ago against content hash 9fd68edba95a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mesg 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 4d 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.

plugin/commands/mesg.md · 17 lines

What it actually says

Input

Arguments: $ARGUMENTS

Parse the argument as y or n. Map y to enabled=true, n to enabled=false.

Task

Call mcp__plugin_biff_tty__mesg with enabled set to the parsed value. The result is already formatted by a PostToolUse hook and displayed above. Do not repeat or reformat the data. Do not send any text after the tool call.

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.

  1. 4d ago First seen · 17 lines · 3 tokens per session scan A 9fd68edba95a

Subscribe to this mod's changes

mesg is a command published in the GitHub repository punt-labs/biff (2 stars, last pushed yesterday), licensed MIT. It adds 3 tokens to every session and 143 once invoked, about $0.0000 per session on Opus 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.