Fine Structure

Create a new application from a natural language prompt. The AI generates a complete web app with pages, components, styling, and data models. Returns a job_id - poll get_job_status to track progress. When the job is done, the app is ready.

Update an existing application with a new prompt. The AI modifies the app based on your instructions. Creates a Saved Version before the update. Returns a job_id - poll get_job_status to track progress.

Publish an app - freeze current state and make it live at a URL. Also configures whether the public URL is open, app-login gated, private, or inferred from the app.

Return a machine-readable Fine Structure / FSe2 guide for AI agents. Call this at the start of an MCP session to learn app files, entities, safe edit workflows, validation, publishing, A/B testing, secrets, and platform rules.

Return the recommended MCP tool sequence for a task type. Use this before creating apps, editing files, seeding data, publishing, setting up A/B tests, restoring versions, or configuring secrets/integrations.

Poll the status of an async generation job. Use this after create_app or update_app to know when the job is done. Returns status ('running' or 'done'), progress events, and result summary when complete.

Get app overview: files, published state, URL, active jobs.

Return editor, preview, published path, subdomain, and custom-domain links plus whether each works for anonymous visitors, app users, or Studio users based on publish and auth settings.

List an app's platform path, subdomain, and configured custom domain with verification, SSL, primary-domain, redirect, publish, and login-gating status.

Attach or replace the app custom domain through the same Fine Structure Studio custom-domain flow. Returns exact DNS verification and routing records for the user to configure at their DNS provider.

Return the exact DNS records and instructions required to verify and route the app custom domain.

Check Fine Structure custom-domain verification and SSL status for the configured custom domain, then save the latest status.

Set which app host should be treated as primary for generated links and custom-domain redirects.

Remove the configured custom domain from the app and clean up the platform-side hostname registration when possible.

Return SSL/certificate status and pending certificate validation DNS records for the app custom domain.

Configure custom-domain redirect policy: primary domain, optional www/root redirect, and HTTPS enforcement.

List applications owned by the authenticated user, newest activity first. Returns up to `limit` apps per call plus the total count; page with `offset` when the account has more.

Get the file tree for an app with paths and byte sizes.

Read one source file from an app's virtual filesystem.

Read several source files from an app's virtual filesystem.

Create or replace one file in an app's virtual filesystem. Creates a Saved Version before changing content.

Patch one file by replacing exact text. Safer than full overwrite for targeted edits. Creates a Saved Version before changing content.

Rename or move one app source file atomically. Internally stages an upsert at new_path and a delete at old_path, validates the resulting app state, and creates a Saved Version before applying.

Deep introspection of an app: entities, pages, settings, integrations, environment variables, and file structure. Use this to understand what an app contains before updating it.

Get all entity (data model) schemas for an app, with record counts. Each entity has fields, types, and relationships.

Query app data records for one entity with optional exact-match filters.

Compatibility tool for proposing starter-record creation. It never inserts records directly: it creates a pending approval that the app owner must approve or reject in Studio chat. Approval-free initial seed is server-controlled inside create_app and cannot be requested through MCP.

Propose creating/inserting records in one app entity. No records are written until the app owner explicitly approves the frozen request in Studio chat.

Compatibility tool for proposing an update to one record by ID. It returns a pending approval and never changes the record until the app owner approves it in Studio chat.

Propose updates to exact records. Select explicit record_ids or exact-match filters and provide shared changes, or provide per-record updates. The database remains unchanged until the app owner approves the frozen request in Studio chat.

Propose deleting exact records by ID or exact-match filters. It freezes the matched IDs and returns a pending approval; zero records are deleted until the app owner approves in Studio chat.

Get all pages in an app with their file paths and sizes.

Get recent runtime errors for an app (last 20). Useful for diagnosing issues before updating.

Return editor preview and published/public URLs for an app.

List restorable Saved Versions for an app, including versions created by MCP writes.

Compatibility endpoint for full Saved Version restore. MCP cannot execute this operation because it can replace database records without the dedicated in-chat approval flow. Use list_saved_versions and compare_current_to_version for read-only inspection, then ask the authenticated app owner to resto

Create a staged file change set. Add multiple file changes, validate them as one app state, then apply atomically.

Stage one file upsert or delete inside a change set. Does not modify the live app until apply_change_set.

Validate current app files plus staged change set files before applying.

Apply a staged change set to the app. Creates a Saved Version before applying. Blocks on validation errors unless force=true.

Discard a pending staged change set without changing app files.

Run deterministic app checks: syntax, imports, routes/pages, entity schemas, missing entities, and recorded runtime errors.

Return server-side preview context: URLs, persisted runtime/network errors, static clickable candidates, pages, and explicit live-browser availability.

Return safe security context for one owned app: owner id/email, Studio collaborators, generated-app members, route policies, entity policies, and recent security audit entries. Does not return secrets and does not grant access to other apps.

Create or update a server-owned route policy for a generated app route.

Create or update server-side read/write role policy for an app entity.

List generated-app runtime users/members for an app. This is separate from Studio project collaborators.

Provision a generated-app runtime member with a role. This does not create a Studio collaborator. The owner role cannot be assigned. If password is omitted, a temporary password is generated and returned once.

Update a generated-app runtime member role. This cannot assign owner and cannot change the Fine Structure account owner.

Remove a generated-app runtime member.

Read recent server-side security audit events for an app.

Compare two Saved Versions and return per-file additions, removals, modifications, and compact diffs.

Compare the current app files to a Saved Version and return compact per-file diffs.

Restore one file from a Saved Version instead of restoring the entire app. Creates a Saved Version before changing the file.

Create an entity schema file in entities/<Entity>.json. Creates a Saved Version before writing.

Replace or shallow-merge an existing entity schema file. Creates a Saved Version before writing.

Validate entity relationship metadata and *_id references against existing entity schemas.

Set relationship/index metadata on an entity schema. This stores metadata in the schema file; DB index creation is automatic where supported by the platform.

List secret key names for an app. Secret values are never returned.

Create or update one encrypted app secret. The secret value is never returned.

Delete one app secret by key.

List supported integrations and safe connected integration metadata for an app. Tokens/secrets are never returned.

Store safe non-secret integration metadata for an app. Use set_secret for API keys/tokens.

List the platform A/B tests configured for an app.

Create a native Fine Structure A/B test between existing app pages. Use update_app first if a variant page still needs to be generated. Creates a Saved Version before the change.

Update a native A/B test, including active state, variants, traffic, and conversion goal. Creates a Saved Version before the change.

Delete a native A/B test from an app. Creates a Saved Version before the change.

Get views, unique visitors, conversions, and conversion rates for an A/B test.