Guide · Agent skill
How to use the API Documentation Generator agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The API Documentation Generator is an agent skill, a packaged set of instructions that an AI agent such as Claude loads when it is relevant to your request. Once installed, it tells the agent how to read your API source code and produce structured documentation for endpoints, parameters, request and response examples, and error lists. This guide explains what the skill does, how to install it, how to trigger it, and what to check before you publish the output.
API Documentation Generatorsickn33/agentic-awesome-skills · MIT Download the skill Quick start
- 1Download the skill. Download the ZIP for api-documentation-generator from this page.
- 2Unzip it into the right folder. Unzip into ~/.claude/skills/ for personal use, or into your project's .claude/skills/ folder for one project.
- 3Or upload it in the Claude apps. Go to Settings → Capabilities → Skills and upload the skill there.
- 4Describe the documentation task. Ask in plain language, naming the routes or endpoints you want documented.
- 5Review the draft. Check each endpoint, example and error against the code and the running system, especially anything marked as inferred.
- 6Validate and test. Run any OpenAPI spec through a validator and test examples in an approved sandbox before publishing.
What the skill makes the agent do
The skill's workflow starts by analysing the API structure: available endpoints and routes, HTTP methods, request parameters and body structure, response formats and status codes, authentication and authorization requirements, and error handling patterns. It then generates documentation for each endpoint, covering the method and path, a short description, authentication requirements, path, query and header parameters, request body schema, success and error responses, and code examples.
The skill also covers usage guidelines such as getting started, authentication setup, pagination, and filtering, plus error troubleshooting and, where possible, a Postman collection or OpenAPI/Swagger specification.
- Works for REST, GraphQL and WebSocket APIs, according to the skill's description.
- Code examples are written in cURL, JavaScript (fetch or axios) and Python (requests), and other languages when needed.
- Anything the agent cannot verify from the code should be marked as missing or inferred rather than guessed. The skill specifically says not to invent rate limits, password policy, token expiry or exhaustive error coverage.
- Examples use synthetic data and secret placeholders such as YOUR_TOKEN instead of real credentials.
How to install the API Documentation Generator skill
You can install the skill in one of two ways. Download the ZIP file for api-documentation-generator from this page and unzip it. For a personal install, place the skill folder in ~/.claude/skills/. For a single project, place it in the project's .claude/skills/ folder. The skill's main file is SKILL.md.
If you use the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.
- Personal install: unzip into ~/.claude/skills/
- Project install: unzip into the project's .claude/skills/ folder
- Claude apps: upload via Settings → Capabilities → Skills
How to trigger the skill with natural requests
You do not need a special command. Describe the documentation task in plain language and point the agent at your API code. The skill is written for requests about documenting a new API, updating existing docs, onboarding developers, preparing docs for external users, and creating OpenAPI or Swagger specifications.
Being specific about the scope helps, for example naming the routes folder or a single endpoint.
- "Document the user endpoints in this Express app, with cURL and Python examples."
- "Draft an OpenAPI spec from our routes and schemas in src/api."
- "Our API has no docs. Write error catalogue for the orders endpoints."
- "Update the docs for POST /api/v1/users after the validation change."
Examples of what you get back
The skill's own examples show the expected format. A typical endpoint section lists the method and path, the authentication requirement, a JSON request body with field notes, a success response with its status code, error responses with error codes and messages, and cURL, JavaScript and Python snippets.
The skill also includes a GraphQL example with a query, variables, a response and an errors block, and an authentication example covering login, using a bearer token, and refreshing an expired token. Treat these as formatting templates: the values in them are illustrative and must be replaced with what your code actually does.
curl -X POST https://api.example.com/api/v1/users \
-H "Authorization: Bearer YOUR_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"email": "user@example.com",
"password": "SecurePass123!",
"name": "John Doe"
}'What the skill needs and what it does not need
The skill lists no requirements. It does not run scripts and does not use the network, according to its listing. Its practical requirement is access to the API source code, because the skill works by reading routes, middleware and schemas. Without the code, it can only work from what you paste in, and most of its value is lost.
- Access to the API source code in the workspace the agent can read
- No listed dependencies or runtime requirements
- Does not run scripts and does not use the network (per the listing)
Safety notes before you use the output
The 'Try It' or interactive calls the skill mentions are real operations. The skill states they need an approved sandbox, so do not point them at production. Generated examples also still need checking against the running system, because the skill only reads what it can see and labels inferred behaviour.
The skill's instructions say that public user creation must not accept a client-supplied admin role unless a separately authorized admin endpoint validates that capability. Generated OpenAPI fragments should also include complete referenced schemas and responses and pass spec validation.
- Do not run interactive examples against production; use an approved sandbox.
- Replace secrets with placeholders and never paste real tokens or passwords into docs.
- Check every example and every rate limit, token expiry or password rule against the actual system.
- Validate generated OpenAPI specs with a spec validator before sharing them.
Tips for better results
Give the agent a bounded scope, one module or a set of routes, so the output stays checkable. Ask it to list anything it could not verify. Then review the draft against your tests and the running service before publishing.
- Ask for a list of unverified or inferred items alongside the draft.
- Work one resource at a time and review each before moving on.
- Keep the generated OpenAPI file in version control so future edits are tracked.
- Use the Postman collection or spec as a starting point for partner testing in a sandbox.
What people use it for
- Drafting endpoint reference pages for a REST API that has little or no documentation.
- Producing an OpenAPI/Swagger starting draft that an engineer then verifies and edits.
- Writing an error catalogue that lists error codes and messages for an endpoint group.
- Preparing onboarding material for new developers joining a backend team.
- Creating a first-pass GraphQL query and response reference from a schema.
Frequently asked questions
Is the API Documentation Generator skill free?
This page does not state a price or licence beyond the item's listed MIT licence. The MIT licence generally permits use and modification, but check the repository's licence file for the exact terms before you rely on it.
What do I need to use the api-documentation-generator skill?
The listing shows no required dependencies. It does not run scripts or use the network. In practice you need access to your API source code, since the skill reads routes, middleware and schemas.
Where do I install the skill?
Unzip the downloaded ZIP into ~/.claude/skills/ for personal use or into a project's .claude/skills/ folder. In the Claude apps, you can upload it under Settings → Capabilities → Skills.
Can it generate an OpenAPI spec?
Yes, the skill covers creating OpenAPI/Swagger specifications and optionally a Postman collection. The skill says generated fragments need complete referenced schemas and spec validation before use.
Will the generated docs be accurate?
Not automatically. The skill only reads what it can see and labels inferred behaviour, so every example needs checking against the running system. It is designed to avoid inventing rate limits and token expiry, and to mark them as unknown instead.
Can I use the Try It calls against production?
The skill says interactive Try It calls are real operations that need an approved sandbox. Do not point them at production.
How does it compare with writing docs by hand or using other tools?
The listing does not compare it with other tools. Its advantage is that it works from your code and drafts several formats at once; its limit is that a person still has to verify the output.
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Our verdict
Use this skill if you are a backend developer or team with an API that has little documentation and you want a structured, code-based first draft, including an OpenAPI starting point. Pick something else if you need fully automatic, verified docs, if you have no access to the API source, or if you plan to test interactive calls directly against production.
Download the skill