Local dev orchestration

Run every project's dev process at once with one dev. Where the command lives, how to run a single project, how it composes with one run.

one dev starts every project's local dev process at once. Commands are read from one.manifest.json at projects[].domains.dev.command, and a built-in supervisor handles the children — no third-party tool to install.

1. Where the dev command lives

When you one add <template>, the CLI derives a dev command from the template's stack and writes it into the manifest:

{
  "projects": [
    {
      "name": "api",
      "relativeDir": "services/api",
      "toolchain": "node",
      "domains": {
        "dev": { "command": "pnpm run start:dev" }
      }
    },
    {
      "name": "web",
      "relativeDir": "apps/web",
      "toolchain": "node",
      "domains": {
        "dev": { "command": "pnpm run dev" }
      }
    }
  ]
}

Resolution order:

Node projects: scripts.dev → scripts.start:dev (NestJS) → scripts.start (Expo / generic)
Go projects: go run ./cmd/server
Nothing matches: empty string — the project is skipped by one dev

Want to customise? Edit the field directly. There is no auto-sync from package.json — the manifest is the source of truth.

2. Run everything

one dev

The built-in supervisor starts every project in parallel, multiplexes stdout/stderr line-by-line with a <name> | prefix (colored under a TTY), and forwards Ctrl-C to every workload — including grandchildren forked by npm / node (via POSIX process groups).

3. Run just one project

one dev -p api
one dev -p apps/web        # selector also accepts relativeDir

Only the matching project is launched. Use this when:

You want to restart api alone while the rest keeps running in another terminal
You only need part of the stack to avoid port conflicts

4. Dry-run to inspect the resolved commands

one dev --dry-run

Prints the per-project commands that would run without starting any process.

5. Composition with `one run`

Each project's command is internally launched as one run -p <reldir> -- <command> — so one env variables are auto-injected (dotenv or Infisical, per workspace backend). No need to wrap your dev script with one run in the manifest.

To start one project with full control, you can still call one run -p <name> directly; one dev is an orchestrator, not a gate.

Common errors

Code	Symptom	Fix
`SUBPROJECT_NOT_FOUND`	No projects declared a dev command, or `-p` selector didn't match	Run `one -o json` to list projects; edit the manifest's `projects[].domains.dev.command`

Full table: Error codes.

Full flag reference → one dev