mutex

Newest release first. Each says what changed, and the choices behind it.

Everything up to 0.4.1 was read back out of the commits, because the plugin shipped four releases before it kept a changelog.

0.4.2 - 2026-09-18

The plugin carries this changelog. Nothing about running it changed: the entries below were reconstructed so that somebody on an older version can see what they are missing, and so that every release from here on has to say.

0.4.1 - 2026-09-11

The marketplace answers to release-tools, so installing is claude plugin install mutex@release-tools or codex plugin add mutex@release-tools. The ReleaseTools handle from 0.3.2 no longer resolves.

0.4.0 - 2026-09-11

• Gemini is no longer recognised as a host, and GEMINI_*_ID is no longer read as a session id. A lock owner there is the agent and the machine alone, so every session on that machine shares one owner and can release the others' locks. Export MUTEX_SESSION_ID to give a session a name of its own. /mutex:status says when the session id is missing.
• Hermes and Antigravity install the plugin from the repository. plugins/mutex/plugin.json is the portable manifest both read, so agy plugin install https://github.com/releasetools/agent-plugins registers mutex through the host's own install, update and uninstall instead of a script copying files into a home directory.
• An Antigravity session gets a lock owner of its own. Its id is ANTIGRAVITY_CONVERSATION_ID, a spelling the owner rule did not accept, so sessions there had been sharing one name.

Choices

• The portable manifest is generated from .claude-plugin/plugin.json and compared byte for byte, rather than maintained beside it. It carries only the fields the schema names, because an unknown field there fails validation instead of being ignored.
• Gemini CLI still installs by copy. Its extensions have to sit at the root of a repository or a release archive, and it has no notion of one inside a monorepo.

0.3.2 - 2026-08-23

The marketplace answers to ReleaseTools rather than releasetools, so installing is mutex@ReleaseTools.

0.3.1 - 2026-08-21

/mutex:callsign stops short of naming a lock for an operation. Asked which lock reviewing or deploying something takes, it points at the naming skill rather than composing an id, because which lock an operation needs is a judgment rather than a derivation.

0.3.0 - 2026-08-21

A naming skill decides which lock an operation takes and what that lock is called, before any lock exists. It covers whether an operation needs a lock at all, and what an issue, a pull request, a branch or an environment would be called.

0.2.0 - 2026-08-21

/mutex:callsign derives a resource's lock id and prints it alone, so two agents guarding the same thing compute the same id instead of inventing one each. It takes a resource kind and its arguments, reads the repository from origin or from --repo owner/name, and exits 2 naming the rule the input broke.

0.1.0 - 2026-08-19

The first release: a distributed lock for a shared resource, held in a PostgreSQL table that the mutex CLI and the releasetools/mutex GitHub Action use as well, so a lock taken by an agent blocks CI and one taken by CI blocks the agent.

• /mutex:lock takes a lock for the work that follows, /mutex:unlock hands it back, and /mutex:renew extends one before it expires.
• /mutex:status shows what you hold, or who holds a lock you name.
• /mutex:preflight answers whether the lock table is reachable from where you are, and says what is missing when it is not.
• A hook warns before a lock taken through the skill runs out.
• The plugin runs the mutex command and does not contain it. Installing the plugin installs nothing else, and MUTEX_DATABASE_URL is yours to set: the plugin never reads its value or repeats it back.