Circuit is a workflow engine at its core, with a plain CLI for direct use. The Claude Code plugin teaches its host to drive that CLI. The Codex plugin uses a small MCP lifecycle so Circuit can start outside Codex's restricted task shell. Both plugins are also fast ways to install and try Circuit.

Go from this:

• Remember which chat thread has the latest state
• Remember which skill to use and when
• Ask for routine planning, checking, and review steps by hand
• Wonder whether the agent took shortcuts or repeated an old mistake
• Keep nudging the process forward yourself

To this:

• /circuit:run build the thing

Circuit puts the process into a repeatable flow:

• Records the chosen flow, built-in or custom
• Moves through each step in sequence and/or parallelizes non-dependent steps
• Applies your preferred skills at the appropriate steps
• Uses your preferred model(s) and thinking power for particular steps
• Checks step outputs before continuing, including deterministic relay acceptance criteria where a flow declares them, with traces, reports, and evidence that show what passed

Ready to try it? Pick a host below, or point your coding agent at the setup prompt. For the full docs map, see docs/README.md.

Start Here

Pick the path that matches where you want to use Circuit. Claude Code and Codex reach the same workflow engine through a plugin; Local CLI runs that engine directly. If you want a coding agent to set this up for you, skip to Give This To A Coding Agent.

Claude Code

Install the host plugin:

/plugin marketplace add petekp/circuit
/plugin install circuit@circuit
/reload-plugins

Then ask Circuit to handle a task:

/circuit:run the checkout total is wrong when discounts and tax both apply

A real run spawns worker agents that spend model time: a small task typically takes several minutes end to end and costs a few dollars at the default dials. The power dial spends less: --power low on a CLI run, or defaults.power in config.

If you would rather see the whole shape before pointing Circuit at your own work, circuit demo builds a small throwaway project with one real bug and a failing test, then runs Fix against it. Your checkout is untouched, the run is real, and the ending is checkable: the test failed before the change and passes after it, which is the proof Fix cannot close without.

The installed plugin bundles the whole engine, so you do not need to clone this repo, run npm install, install a separate circuit binary, or create a symlink to get started this way.

Codex

The MCP-based Codex path in this checkout supports macOS. It requires Node.js 22.18 or newer and Codex 0.146.0 or newer.

The public tag circuit--v0.1.5 includes the MCP path and is the first tag to carry the fix for a first-launch race in earlier releases. A paid first-attempt Review has passed through real headless Codex at the exact commit this tag points at, with every artifact digest-bound to that commit. The remaining tracked gap is an Intel Mac capture of the same Review.

After installing an MCP-capable build, restart Codex. A single MCP approval is normal. Any shell fallback or sandbox escalation means the setup failed. Stop rather than working around it.

Working from this checkout instead? Refresh the local plugin package and installed host caches:

npm run plugins:refresh-local

Then ask Codex to use Circuit:

Use Circuit to list recent Circuit runs for this workspace. Do not start a run.

That readiness check is free. If it succeeds, start with the read-only Review flow:

/circuit:run review my current diff for obvious problems

Codex can recommend the right Circuit flow from your natural-language request.

Local CLI

Install the CLI directly from npm:

npm install -g @petepetrash/circuit
circuit doctor
circuit run <flow> --goal '<your task>'

Circuit does the work through connector CLIs (claude by default), so a signed-in Claude Code install is a prerequisite. circuit doctor confirms the connectors your runs would actually use are ready, before a run spends anything on a broken one, and lists any other connector CLI as optional.

Working from this checkout instead?

npm install
npm run build
./bin/circuit run <flow> --goal '<your task>'

The flow name is required: one of build, fix, review, explore, or prototype. The CLI runs from any directory: it prefers compiled flows in the current project and falls back to its own bundled copies. The operator guide covers pointing at a specific flow folder with --flow-root.

Circuit requires Node.js 22.18.0 or newer.

One scope note: flows that change code (build, fix) will not claim a change works without running something that proves it. In an npm-family project they find that on their own, using the first of your package.json scripts named verify, test, or check. Anywhere else, name the command once:

circuit config set verification.general '{argv: [pytest, -q]}'

circuit doctor reports which command a project resolves to. review, explore, and prototype need no proof command and work in any repo.

For a more careful manual check, use docs/first-run.md. For the repo map, use docs/repository-map.md.

Start From An Intent

/circuit:run is the normal front door on every host. See docs/operator-guide.md for the per-host table, the CLI flow-name rule, and the host-alias status.

Handoff stays available as a visible continuity utility for saving, resuming, clearing, briefing, or installing continuity support. The CLI also has experimental utilities that are not published as host commands: ./bin/circuit create drafts a reusable custom flow after explicit confirmation, ./bin/circuit generate composes a runnable bespoke flow from a plain task description, and ./bin/circuit preview shows which connector, model, and effort each step of a flow would get, without spawning anything. See docs/operator-guide.md for direct commands, flags, checkpoints, verification, and troubleshooting.

Safety Notes

Build, Fix, and Prototype may invoke a write-capable worker. Circuit discloses that before write-capable work starts:

A worker can edit this checkout.

Review collects untracked file paths and sizes by default, but not untracked file contents. Add --include-untracked-content only after you confirm those files are safe to relay.

Built-in worker connectors are claude-code, codex, and cursor-agent. Use claude-code for trusted Claude Code writes, codex for first-class Codex worker writes, and cursor-agent for Cursor CLI implementer work.

Custom connectors use the prompt-file/output-file protocol. stdin is ignored, the process inherits the Circuit process environment and current working directory, and capabilities.filesystem: read-only is a routing signal, not an OS sandbox.

Host And Worker Terms

Codex has two separate roles:

• host/orchestrator behavior: in Codex, use /circuit:run for a task. Codex can recommend the right Circuit flow and invoke the local Circuit engine.
• worker connector behavior: Circuit can relay worker steps through the Codex CLI from any host, including write-capable implementer steps.

See docs/configuration.md for connector routing and worker setup.

Configuration

Circuit reads config at run time from:

1. ~/.config/circuit/config.yaml for your personal defaults across projects.
2. ./.circuit/config.yaml at the repo root for project-specific overrides.

Config can set models, effort, local skills, connector routing, and per-flow overrides. See docs/configuration.md.

Give This To A Coding Agent

Paste this into a coding agent when you want it to set up Circuit from a checkout safely:

You are setting up Circuit in this repo: <repo-path>.

Stay inside that checkout. Read README.md and docs/agent-setup.md, then follow
the setup checklist there. Do not hand-edit generated host output. Preview any
config YAML before writing it. Use Review as the first real run unless I ask
for a write-capable flow. Report commands run, files changed, verification
results, and any blocker.

See docs/agent-setup.md for the full setup checklist.

Where To Go Next

Start:

• docs/first-run.md: manual setup check, the demo run, Review on your own work, and the run folder shape.
• docs/README.md: map of the current docs.
• docs/repository-map.md: repo map, layer ownership, and migration rationale.

Operate:

• docs/operator-guide.md: commands, run flow, checkpoints, verification, and troubleshooting.
• docs/configuration.md: config layers, local skills, Codex worker setup, and connector routing.
• docs/agent-setup.md: copy-paste setup instructions for a coding agent.

Contribute or verify:

• docs/generated-surfaces.md: source map for generated command, skill, schematic, and plugin output.
• src/README.md: source tree map for contributors.
• docs/release/proofs/index.yaml: checked-in proof set covering doing work, deciding, continuity, customization, failure, first run, and plan execution for this release.

License

Circuit is released under the MIT License. You are free to use, modify, and redistribute it, including commercially, as long as you keep the copyright and license notice.