Formio React

Form.io + React — Framework Implementor

React is where this library's work lands three different ways, so this skill routes before it builds. One request wants a new application stood up around a Form.io project; another wants Form.io CRUD added to a React codebase that already exists and has its own conventions; a third wants a single form on a page. They share a preflight and very little else.

This file is a router. It holds the dispatch table, the shared preflight, and the handoff contracts. Every branch's own steps live in a sibling document, so a reader arriving for one branch never has to read another branch's steps to find their own.

What this skill does not do: choose the framework, design the data model, or import a template. Those belong upstream, to formio-application and formio-resource-planner, and they run before you.

Dispatch — pick the branch first

Determine which branch the request belongs to BEFORE loading any branch document.

The branches are mutually exclusive. When the request does not make the branch obvious, ask which one applies in ONE question round, using the client's structured question mechanism (in Claude Code, AskUserQuestion), before loading anything.

When the workspace contradicts the stated branch, say so and confirm. A greenfield request in a directory that already holds a React application, or an existing-application request in an empty directory, is a mismatch to surface rather than proceed through. Scaffolding over someone's app because they said "new" is not a recoverable mistake.

The embed branch is not an application build: it needs the project URLs and a provider, not a workspace, an auth surface, or a resource hierarchy. It runs none of BOOTSTRAP.md, EXISTING.md, CONFIG.md, or AUTH.md, and does not load formio-react-resources.

When an embed request turns out to want list, create, and edit screens over a resource, re-dispatch to the appropriate CRUD branch and say why the branch changed. Conversely the CRUD branches document no standalone embedding — that guidance lives in the embed branch alone.

Preflight — the Form.io MCP server

Check this when you reach your first Form.io tool call, not when this skill activates. The check is whether form_list is callable by you, under whatever name this client exposes it. If it is, proceed. If it is not, load the formio-mcp-setup skill and use it to help the user connect the server; that skill is the only remedy you offer, and this skill writes no MCP configuration itself.

A missing server blocks that call, not the turn. Reading this skill, answering a question from it, planning, and writing files to the working directory all need no server. Do everything that needs no server first and in full, then raise the gap when you actually reach the call that needs it. Opening with a blocked-on-setup message — or asking for a Project URL before there is anything to write to it — spends the user's turn on a step that was not due.

Never work around missing tools

Do not work around missing tools by making direct HTTP requests against a Form.io deployment, and do not write a throwaway script that makes them for you. This library documents the whole Form.io REST surface, which makes hand-rolling requests tempting and wrong — it bypasses the guardrails the tools enforce and can write to a live deployment unreviewed. Stop and report what is blocking instead.

That ban is on build-time work — the configuring you do in this session. It says nothing about the application you are building: an app is expected to call the Form.io REST API at runtime, to log its users in and to read and write their submissions, and formio-api's runtime-scope references document those endpoints for exactly that code.

Which project the tools target

Available tools are not a configured project. Every Form.io tool resolves which project it targets per working directory, so pass cwd — the user's current working directory — on every Form.io tool call; omitting it resolves against the MCP server's own directory, which is fixed at spawn and may be mapped to a different project. Before the first call that reads from or writes to a deployment, ask the server what this directory resolves to by calling the project_get tool with cwd set to the user's current working directory. Do not shell out for this: the connected server answers it directly, with the same resolver every other tool uses, so what it reports is what the next call targets. If project_get is not callable, the connected server predates it — load the formio-mcp-setup skill, which moves the pinned version forward.

What project_get returns IS the configuration. There is one value to think about — the Project URL, the full URL of the Form.io project this work reads and writes. The Base URL (the deployment hosting it) is normally DERIVED from that project URL rather than supplied, so it is not a second thing to ask for. The values may come from a committed formio.json tracked with the application's own source, from this directory's mapping, or from the environment — the report says which. Do not ask the user to confirm or re-supply either one.

Branch on the status it returns. On ok, proceed. On not-configured — nothing is recorded for this directory — relay that message's own instruction to the user, ask for the single value it names, record it with project_set, and call project_get again. On base-url-unresolved the project IS recorded and one named value is still missing — the Base URL, for a project URL that names no deployment of its own: relay that message the same way, ask the user for that one value, and do exactly what that message names — which record the deployment goes in decides what the fix IS, and the report names it rather than leaving you to compose one. For a project this directory's own mapping holds, that is a project_set call, and the report also carries it as a structured remedy. For a project a committed formio.json holds, it is an EDIT to that file — the report names the path and the key, there is no remedy field to act on, and this server never writes a committed file, so composing a project_set call there is refused. Then call project_get again. Do not re-ask the user for the Project URL there; the report already reported it, and the call it names carries it for you. If the call fails outright instead of returning a status, it could not answer at all (an unreadable ~/.formio/projects.json, a formio.json that will not parse, a malformed URL): do NOT interview, because a project_set would fail for the same unreported reason and the loop would repeat with the cause never named — relay the error and stop until it is fixed. Before the first call that WRITES (form_create, form_update, role_create, action_create, project_import), state the resolved Project URL and Base URL in one line, so a wrong target is caught before anything is written to it.

Never invent a Base URL, never reuse one from another project or an earlier session, and never edit ~/.formio/projects.json by any means — its shape, its 0600 mode, and its merge rules belong to the server, and project_set is how you reach it. The server's own messages carry the URL shapes and the remedy for each; this skill does not restate them.

Greenfield branch — five gated phases

Run these in strict order, each loading its document by path, with a user-approval gate between each. A declined gate stops the flow without writing partial state.

1. SETUP — SETUP.md. Establish the workspace root and resolve the project configuration.
2. BOOTSTRAP — BOOTSTRAP.md. Create the Vite + React + TypeScript workspace, install dependencies, capture versions, stash the design brief.
3. CONFIG — CONFIG.md. Generate src/config.ts and mount FormioProvider.
4. AUTH — AUTH.md. Generate the login, register, and logout routes, the root-loader user, and requireUser.
5. Resources — load formio-react-resources/SKILL.md by path and hand off.

Without the gates a single "build it in React" scaffolds a workspace, writes configuration, and generates an entire authentication surface with no stopping point.

No phase is skipped silently. When a re-run finds a phase already satisfied, say so and move on.

Reset to an earlier phase when the workspace changes underneath you: the project URL is re-pointed (reset to SETUP), dependencies are reinstalled or the router is swapped (reset to BOOTSTRAP), or src/config.ts is edited by hand (reset to CONFIG). State which phase you are resetting to and why.

Existing-application branch

Load EXISTING.md. It inspects the application and reports before changing anything, then backfills ONLY the missing prerequisites. BOOTSTRAP.md never runs on this branch.

Planning and import are not yours

This skill never runs the planner and never imports. formio-resource-planner and template import into a Form.io project both belong to formio-application.

When you are invoked directly by a React-explicit trigger, expect an already-approved template.json and a project the template has been imported into. When neither exists, ask the user to invoke formio-application first rather than planning yourself — that skill runs the planner, imports, and hands off to you. The chain cannot usefully proceed without the plan in any case: BOOTSTRAP sizes the workspace against it, AUTH renders the planner's login and registration forms, and Resources generates from it.

Target stack

Vite + React Router data routers + TypeScript, client-rendered.

React Router's data-router API (createBrowserRouter with RouteObject arrays) is what this skill generates against: loaders, actions, errorElement, and post-action revalidation are what let the generated code drop the service, registry, alert bus, and refresh emitter that @formio/angular needs. React Router is not the only router in React, and the kernel's domain logic is router-agnostic by design — see formio-react-resources/references/app-integration.md for what another router would have to supply. What cannot host the generated resources is a router with no data phase: <BrowserRouter> with <Routes> alone has nowhere to put a loader.

Out of scope: Next.js App Router, and server-rendered React Router framework mode. Both server-render, and @formio/js is DOM-only — a loader that runs on the server cannot feed a server-rendered form screen. Say this plainly rather than generating output that will not run.

Handoff contract with the resources sub-skill

Load ./formio-react-resources/SKILL.md by path as the last step of BOTH CRUD branches. Do not invoke it by frontmatter name.

Payload — the field names formio-angular uses, so formio-application needs no per-framework adaptation, plus two this skill adds for its own two CRUD branches (formio-application sends neither; the sub-skill defaults a missing branch to 'existing' and runs EXISTING.md's inspection itself):

• workspacePath
• templateMdPath and templateJsonPath
• userRequest (extend path)
• newResourceNames (extend path)
• frontendDesignStatus
• branch — 'greenfield' or 'existing'
• On the existing branch: the inspection findings — design conventions, authentication arrangement, current-user source

URLs are deliberately absent, as they are for Angular: the sub-skill resolves them with project_get and reconciles against the workspace's own src/config.ts.

Links

• SETUP.md · BOOTSTRAP.md · EXISTING.md · CONFIG.md · AUTH.md
• formio-react-resources/SKILL.md · formio-react-form/SKILL.md
• project-urls.md — the canonical URL guidance