Type Generation

Type Generation Workflow

Use this skill when the API shape has changed and the frontend needs updated types, or when the user asks to sync types between backend and frontend.

Overview

The type flow is:

1. Backend (Encore.ts or Rust daemon) defines API endpoints
2. OpenAPI spec is generated from the running API
3. openapi-typescript converts the spec to TypeScript types
4. Frontend imports types from ui/src/lib/api-types.ts

Option A: Generate from existing openapi.json file

If openapi.json at the repo root is already up to date:

cd ui && npm run generate-types:file

This reads ../openapi.json and writes src/lib/api-types.ts.

Option B: Generate from running daemon

If the Rust daemon is running locally (port 3000):

cd ui && npm run generate-types

This fetches from http://localhost:3000/api/openapi.json.

Option C: Full sync (daemon → openapi.json → types)

If you need to update both the spec file and types:

./scripts/sync-openapi.sh

This script:

1. Detects a running daemon or starts one temporarily
2. Fetches the live OpenAPI spec
3. Normalizes JSON for stable diffs
4. Writes openapi.json at repo root
5. Runs openapi-typescript to generate ui/src/lib/api-types.ts

After generating types

1. Check for new types to re-export in ui/src/lib/api.ts:

// In ui/src/lib/api.ts — add re-exports for new schema types
export type NewEntity = Schemas['NewEntity'];
export type NewEntityResponse = Schemas['NewEntityResponse'];

2. Add fetch helpers if needed:

export async function getNewEntities(): Promise<NewEntity[]> {
  const res = await fetch(`${API_BASE}/internal/new-entities?org_id=${getOrgId()}&project_id=${getProjectId()}`);
  if (!res.ok) throw new Error(res.statusText);
  const data = await res.json();
  return data.items;
}

3. Run svelte-check: cd ui && npm run check

Makefile shortcuts

make sync-openapi      # Full sync (Option C)
make generate-types    # From file (Option A)

When to regenerate

• After adding/modifying Encore.ts API endpoints
• After changing Rust daemon API routes or response types
• After modifying request/response interfaces in backend/app/*/types.ts
• Before starting UI work that consumes new API endpoints