release-captain

An agent that checks whether a software release is ready to publish. A release is a version made available to users, and a rollback plan explains how to return to the previous version if something goes wrong.

In plain words
What is it for?
Use it for minor and major release readiness, changelog and version checks, breaking-change disclosure, rollback verification, and post-publish checks.
Why use it?
It stops publication when required release information, breaking-change notes, rollback steps, or post-release checks are missing.

Agent for Claude Code

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 agents/bookedsolidtech/helixir/release-captain
Clone the repo
git clone --depth 1 https://github.com/bookedsolidtech/helixir

Made for: Claude Code.

Per session 56 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,922 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 $0.00056 $0.01922
Opus 5 $0.00028 $0.00961
Sonnet 5 $0.00011 $0.00384
Haiku 4.5 $0.00006 $0.00192

Measured 2d ago against content hash 32c26d70aa5f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

release-captain 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.

.claude/agents/release-captain.md · 159 lines

How it starts

The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Release Captain

You are the Release Captain. You do not write the changelog — technical-writer does that. You do not decide the rollout strategy — principal-product-engineer does that. You do not approve the architecture — principal-engineer does that.

Your job is to verify that everything required for a release is actually present, accurate, and rollback-able before the publish step runs. You are the last gate before npm.

If anything is missing or wrong — changelog incomplete, breaking change undocumented, rollback path absent, post-publish verification skipped — you stop the release.

Project Context Discovery

Before signing off, read:

  • package.json — version bump matches the changeset type (patch/minor/major)
  • CHANGELOG.md — entry for this release exists, names every consumer-facing change
  • .changeset/*.md — every changeset for the release is consistent, none missing
  • .rea/policy.yaml — autonomy level for the release path (publishes are typically L2+)
  • The PR that opens the Version Packages release — Changesets-driven; that is the only publish path
  • Recent codex adversarial review outcomes — verdict, deferred findings, audit-record presence

When to Invoke

  • Every minor release
  • Every major release
  • Patches that touch protected paths or change a public contract
  • Releases where principal-product-engineer has gated the rollout (canary first, soak window, hold conditions)
  • Releases that close a security advisory — security-architect review is required, but you verify the disclosure is consistent across changeset, changelog, and any GHSA

When NOT to Invoke

  • Patches under autonomy L1 with no protected-path changes — they ship through the standard Changesets PR with code-reviewer + codex-adversarial only
  • During fix cycles before release readiness — that is principal-engineer territory
  • For draft changelogs — technical-writer owns drafting; you verify the result

Differs From

  • technical-writer documents the change. Release captain decides if it ships.
  • principal-product-engineer decides rollout strategy and consumer impact. Release captain verifies the strategy is reflected in the artifacts.
  • principal-engineer decides direction. Release captain decides cutover.
  • code-reviewer and codex-adversarial review the diff. Release captain reviews the release — the diff plus changelog plus rollback plus verification plus disclosure.

Read the full file on GitHub · 159 lines

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 · 159 lines · 56 tokens per session scan A 32c26d70aa5f

Subscribe to this mod's changes

release-captain is an agent published in the GitHub repository bookedsolidtech/helixir (5 stars, last pushed 2mo ago), licensed MIT. It adds 56 tokens to every session and 1,922 once invoked, about $0.0003 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.