Claude Code Plugin

The FastYoke Claude Code plugin turns a one-line description into a working FastYoke app — scaffolded, running on the local runtime, with a first workflow transition already verified — without leaving your terminal.

It is distributed as a Claude Code marketplace from the public built-on-fastyoke gallery, and it drives the same local runtime and SDK you'd use by hand.

What it does

• /fy-new-app — describe an app in one line ("a vacation-approval workflow", "a support-ticket queue") and the plugin scaffolds the entity schema, the FSM, and seed data, boots it on the local runtime, and fires a first transition so you see the state machine actually move before you write any code.
• Authoring skills — bundled guidance Claude pulls in on demand for the four things you'll actually do: authoring FSMs, authoring schema-driven entities and their UI, using the SDK, and writing sandboxed WASM scripts.
• App reviewer — an on-demand reviewer agent that reads a FastYoke app and flags workflow mistakes: unreachable states, transitions pointing at states that were never declared, unbounded self-loops, and guards written as raw strings instead of sandboxed predicates.
• Save-time validation — a hook that validates FSM schema files as you write them, catching the same class of mistakes inline so a broken workflow never reaches the runtime.

Everything runs locally against the real FastYoke engine — no cloud account is required to scaffold, run, and iterate.

Install

1. Add the marketplace:

   /plugin marketplace add fastyoke/built-on-fastyoke
   

2. Install the plugin:

   /plugin install fastyoke
   

3. Scaffold your first app:

   /fy-new-app
   

Already have the gallery checked out locally? Point the marketplace at the path instead: /plugin marketplace add /path/to/built-on-fastyoke.

How the scaffold runs

The generated app installs as data: a seed.json carries the entity kinds, the FSM schema, and a starting job row. npx fastyoke dev boots a local HTTP runtime, and the plugin drives transitions through the standard jobs API — the same shape the SDK and CLI speak. Guards are sandboxed JSONLogic evaluated against the job's data payload, exactly as they are in production, so what you verify locally is what runs in the cloud.

See also

• Built on FastYoke — the open-source gallery of example apps the plugin's marketplace is published from.
• SDK and CLI — the same runtime surface the plugin builds on, for driving apps by hand.
• VS Code Extension — author and preview fy-app.json in your editor.
• Workflows — how FSMs, guards, and transitions fit together.