Interlock

Spec-driven development for Claude Code. You read one spec; parallel agents ship it to a tested commit.

_{One real run, cut to 34 s. spec asks one question, writes 11 specs and 12 tasks, then stops. ship runs three agents in parallel across two waves and ends in a commit with the suite green, 180 of 180.}

12 tasks · 2 waves · 19 agents · 13m 54s · 57 files · 2,881 lines · 180 of 180 pass · 1 commit

_{The whole run, uncut and captioned: 2:34, mp4, 9 MB.}

/interlock:spec "<idea>"   # explores your repo, writes a reviewed spec, then stops
                           # ← you read it. The only place a human is required.
/interlock:ship            # parallel agents implement → your tests pass → commit. Nobody is asked.

• One human checkpoint. A spec is the cheapest place to catch a wrong idea, so that is the one place you must look. Everything after it is automatic.
• Zero-touch by construction. ship is a Claude Code workflow, and the workflow runtime has no channel for mid-run input. It cannot ask you anything, so it never does.
• Caps and gates are code, not prose. Parallelism, retry budgets and review thresholds are CLI exit codes a model cannot argue with, and during remediation an agent cannot even edit a test. Re-run any decision yourself, with no model and no network.

Install

Interlock is a Claude Code plugin layered on OpenSpec, which owns the spec format. You need:

The full table, including two environment variables that must stay unset, is in the first hour.

1. Install the OpenSpec CLI. In your terminal, once per machine:

npm install -g @fission-ai/openspec@latest
openspec --version        # prints a version when it worked

2. Install the plugin. In Claude Code, once per machine:

/plugin marketplace add renzrollon/interlock
/plugin install interlock@interlock

3. Onboard your project. Start a new session in the project from your terminal (cd your-project && claude), then in Claude Code, once per repo:

/interlock:bootstrap

Bootstrap runs openspec init if the repo has never been initialized. It reads your code, asks you to confirm the list of features it found, then writes one spec per feature describing what the code does today, and builds the graph agents navigate by. It never changes source code.

4. Read the first line of each session. Every time a session starts in your project, the plugin checks that an unattended run could finish and prints either interlock preflight OK or a list of problems, each with its fix. The most common problem is a command your permission settings do not allow yet. During ship nobody is there to approve a prompt, so the run would stop at it. /permissions is the quickest way to add what the check names.

interlock doctor is optional. The session-start check is interlock doctor, run for you. Run it yourself only for the full report, which includes a ready-to-paste settings snippet that allowlists every command a run needs:

! interlock doctor

The ! runs it from the Claude Code prompt, because the plugin puts the CLI on the PATH of Claude Code's shell, not your own terminal's. For your terminal too, install the npm package (07), and keep that copy at the plugin's version: doctor says when it is not (16). It exits 1 when it finds something that would stop a zero-touch run.

Your first shipped change, step by step: 01 — The first hour.

The flow

You type two commands for every change and read the spec between them. The rest is there when you want it.

After a ship, /interlock:settle --create --review pushes the branch, opens the pull request as a draft, reviews it (the lean default set of review dimensions, or the wider set with --strict, with the blast-radius dimension when the repository has a graph; it is skipped, and says so, without one), posts the findings as a comment, remediates what it can, posts a reply comment saying which findings are fixed, open or new, and marks it ready with the merge verdict and the head-bound evidence in its description. It never merges and never approves; a person still presses the button. The GitHub loop is not exercised end to end until a first run on a real pull request is recorded. Details.

_{The same run, drawn inside Claude Code while it ran: every wave, batch and lane as the CLI reported them.}

On Claude Code 2.1.287 and later the plugin draws both runs live: a status line that stops at the checkpoint, a pane of every wave, lane and agent, and each degradation banner as a toast the moment it is raised. The pane observes; the CLI decides. On an older host the run is the same, without the pane. The ship meter →

Turn the gates up

Default ship trusts your test suite: a green suite, one commit, nothing else. None of the rows below is needed for your first change. Add them one at a time as the loop earns it; each costs what its last column says.

Why Interlock

Most of the category competes on how much structure you write before coding: Spec Kit adds phases, BMAD adds roles, Kiro adds an IDE. Interlock competes on how many decisions the model is not allowed to make.

• Parallel agents cannot overwrite each other. The planner separates tasks that would touch the same file. With --isolate-waves, every parallel task runs in its own git worktree and a collision is a named halt, never a lost write.
• An agent cannot make the suite smaller to make it green. During remediation a hook denies test edits, task ticks and commits outside the commit stage. They are PreToolUse hooks, inert outside a run. 13
• A dismissal needs evidence. A reviewer who says "not real" must cite a file:line in the diff, or it dismisses nothing. 06
• Specs do not quietly rot. interlock drift reports unarchived changes, specs citing missing files and code no spec describes, each at its own confidence, and never blocks. 03
• Degradation is spoken, never silent. A missing graph, an overridden model, a failed push: each is a named banner in the summary. 04
• Built with itself. Every feature here started as a spec and went through the same checkpoint and ship. The archive is the record, one folder per change.

It composes OpenSpec rather than replacing it: /interlock:spec drives the openspec CLI, and the stock OpenSpec skills stay available for the plain artifact loop. 03 says when each is the right call; 08 sets the harness beside OpenClaw, Hermes Agent and DeepSeek Harness. The trade is portability: Claude Code is the default and supported host, and Cursor and Copilot are not supported, because the guarantees come from Claude Code's workflow runtime.

Docs

New here? Start with 01 — The first hour, and keep 04 — When it stops open during your first ship. Only ever prompted a coding agent? 09 defines every term once, ending at why ship is a script and not a prompt.

Development

git clone https://github.com/renzrollon/interlock && cd interlock
npm test                      # no dependencies to install first
claude --plugin-dir .         # load it without installing

More in CONTRIBUTING.md. Report vulnerabilities privately (SECURITY.md); ACCESSIBILITY.md and the code of conduct cover the rest. Built on OpenSpec by Fission AI, and on the wave-execution pattern for parallel task application. MIT.