# API Module

> Add a new API endpoint module to packages/api-client from an OpenAPI schema. Use when adding new backend endpoints, creating API client modules, or when an openapi.yml is provided.

- Skill: `mystic-stars/api-module` (Agent Skill)
- Install (CLI): `npx skillmds@latest add mystic-stars/api-module`
- Raw SKILL.md: https://api.skillmd.com/api/skills/mystic-stars/api-module/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: mystic-stars (https://skillmd.com/u/mystic-stars)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/mystic-stars/api-module

---


Refer to the standard: @standards/frontend/ADDING_API_MODULES.md

## Steps

1. **Read the OpenAPI schema** at `$ARGUMENTS` — identify the endpoints, request/response shapes, and path parameters.
2. **Read the standard above** for naming conventions, type rules, and the module registration pattern.
3. **Determine the service and version** — the URL path prefix tells you which service directory and version namespace to use (e.g. `/v3/projects` → `labrinth/v3/`).
4. **Define types in `types.ts`** — types must match the API response 1:1. Use the OpenAPI schema as the source of truth. Do not reshape or rename fields.
5. **Create the module class** — extend `BaseModule`, implement each endpoint as a method. Use the correct HTTP verb and request options pattern from the standard.
6. **Register in `MODULE_REGISTRY`** — add the module entry so it's auto-instantiated on the client.
7. **Export types** from the service's barrel `index.ts`.
8. **Verify** — check that the module compiles and the types are accessible from `@modrinth/api-client`.