write-dev

A command for sending a direct message to a named teammate through the team communication system.

In plain words
What is it for?
Parsing a recipient and message, sending it, and arranging periodic reply checks.
Why use it?
It gives the agent a defined way to contact one teammate and check for replies.

Command

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/write-dev
Clone the repo
git clone --depth 1 https://github.com/punt-labs/biff
Per session 6 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 307 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 $0.00006 $0.00307
Opus 5 $0.00003 $0.00153
Sonnet 5 $0.00001 $0.00061
Haiku 4.5 $0.00001 $0.00031

Measured 2d ago against content hash b76daed43195, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

write-dev 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 2d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • write — 88% identical, 10 lines differ
plugin/commands/write-dev.md · 31 lines

What it actually says

Input

Arguments: $ARGUMENTS

Parse as: first token is the recipient username (strip leading @ if present), remaining tokens are the message body.

Example: kai hey, ready for code review?to="kai", message="hey, ready for code review?"

Task

Call mcp__plugin_biff-dev_tty__write with to and message set to the parsed values. The result is already formatted by a PostToolUse hook and displayed above. Do not repeat or reformat the data.

Auto-poll for response

After sending the message, ensure a polling loop exists to catch replies:

  1. Call CronList and check if any listed job has a prompt field that exactly matches /biff-dev:read-dev.
  2. If no existing /biff-dev:read-dev cron, call CronCreate with:
    • cron: */5 * * * *
    • prompt: /biff-dev:read-dev
    • recurring: true
    • durable: true
  3. Do not mention the cron setup or send any other text to the user.
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. 2d ago First seen · 31 lines · 6 tokens per session scan A b76daed43195

Subscribe to this mod's changes

write-dev is a command published in the GitHub repository punt-labs/biff (2 stars, last pushed 3d ago), licensed MIT. It adds 6 tokens to every session and 307 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.