API Documentation Writer
Generates developer-grade API references from code: endpoints, parameters, auth, errors and copy-paste request examples.
Overview
API Documentation Writer converts routes, handlers or OpenAPI fragments into documentation developers actually enjoy reading. It documents every endpoint with method, path, purpose, parameters, request/response schemas, auth requirements and error codes.
The skill writes in a consistent, minimal voice, includes ready-to-run curl and fetch examples, and flags undocumented or inconsistent behavior it notices in the code — such as params that are validated but never described.
It fits teams that keep docs drifting behind code: paste a handler, get a reference section that drops straight into README, docs sites or an OpenAPI description block.
System prompt
Preview redactedThe instruction block that defines the agent's role, rules and output format.
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████████████████████████████████████████████████████████████████User prompt template
Fill in the variables and send it to run the skill: {{variables}}
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████████████████████████████████████████████████████████████████Variables
| Name | Required | Description | Example |
|---|---|---|---|
| {{code_sample}} | Yes | Route handler(s), controller(s) or OpenAPI fragment to document. | — |
| {{framework}} | Yes | Framework and language, e.g. "Express + TypeScript" or "FastAPI". | FastAPI + Python |
| {{audience}} | Optional | Who reads the docs, e.g. "external API consumers". | external API consumers |
Full skill configuration
Redacted previewThe standard .aiskill file in JSON and YAML.
{
"format": "aiskill/v1",
"skill": {
"name": "API Documentation Writer",
"slug": "api-docs-writer",
"version": "2.0.1",
"description": "Generates developer-grade API references from code: endpoints, parameters, auth, errors and copy-paste request examples.",
"category": "Development",
"tags": [
"api",
"documentation",
"openapi",
"technical-writing"
],
"platforms": [
"claude-code",
"cursor",
"chatgpt",
"dify",
"langgraph"
],
"tested_environment": "GPT-5, Claude Sonnet 4.5; Express, FastAPI, Spring handlers",
"license": "CC-BY-4.0"
},
"prompts": {
"system": "████████████████████████████████████████████████████████████████████████████████████████████████",
"user_template": "████████████████████████████████████████████████████████████████████████████████████████████████"
},
"variables": [
{
"name": "code_sample",
"description": "Route handler(s), controller(s) or OpenAPI fragment to document.",
"required": true
},
{
"name": "framework",
"description": "Framework and language, e.g. \"Express + TypeScript\" or \"FastAPI\".",
"required": true,
"example": "FastAPI + Python"
},
{
"name": "audience",
"description": "Who reads the docs, e.g. \"external API consumers\".",
"required": false,
"example": "external API consumers"
}
],
"install": {
"steps": [
{
"title": "Copy the system prompt",
"detail": "Copy the full system prompt from the skill page."
},
{
"title": "Add to your platform",
"detail": "Paste as a custom GPT instruction, a Cursor rule for docs files, or a Claude Code skill."
},
{
"title": "Feed it a handler",
"detail": "Paste one or more endpoint implementations into the user template with the framework name."
},
{
"title": "Review and publish",
"detail": "Check the \"Gaps noticed\" section, then merge the reference into your docs."
}
]
},
"usage": {
"steps": [
"Paste the endpoint code and specify the framework and target audience.",
"Send the template; you get a complete reference block per endpoint.",
"Address the \"Gaps noticed\" list — those are real doc/code mismatches.",
"Repeat per module and assemble the sections into your docs site."
]
},
"metadata": {
"author": "SkillVault",
"source": "https://skillvault.top/skills/api-docs-writer",
"exported_at": "2026-11-03T07:41:22.221Z"
}
}format: aiskill/v1
skill:
name: API Documentation Writer
slug: api-docs-writer
version: 2.0.1
description: >-
Generates developer-grade API references from code: endpoints, parameters, auth, errors and
copy-paste request examples.
category: Development
tags:
- api
- documentation
- openapi
- technical-writing
platforms:
- claude-code
- cursor
- chatgpt
- dify
- langgraph
tested_environment: GPT-5, Claude Sonnet 4.5; Express, FastAPI, Spring handlers
license: CC-BY-4.0
prompts:
system: ████████████████████████████████████████████████████████████████████████████████████████████████
user_template: ████████████████████████████████████████████████████████████████████████████████████████████████
variables:
- name: code_sample
description: Route handler(s), controller(s) or OpenAPI fragment to document.
required: true
- name: framework
description: Framework and language, e.g. "Express + TypeScript" or "FastAPI".
required: true
example: FastAPI + Python
- name: audience
description: Who reads the docs, e.g. "external API consumers".
required: false
example: external API consumers
install:
steps:
- title: Copy the system prompt
detail: Copy the full system prompt from the skill page.
- title: Add to your platform
detail: Paste as a custom GPT instruction, a Cursor rule for docs files, or a Claude Code skill.
- title: Feed it a handler
detail: Paste one or more endpoint implementations into the user template with the framework name.
- title: Review and publish
detail: Check the "Gaps noticed" section, then merge the reference into your docs.
usage:
steps:
- Paste the endpoint code and specify the framework and target audience.
- Send the template; you get a complete reference block per endpoint.
- Address the "Gaps noticed" list — those are real doc/code mismatches.
- Repeat per module and assemble the sections into your docs site.
metadata:
author: SkillVault
source: https://skillvault.top/skills/api-docs-writer
exported_at: "2026-11-03T07:41:22.221Z"
Installation guide
- 1
Copy the system prompt
Copy the full system prompt from the skill page.
- 2
Add to your platform
Paste as a custom GPT instruction, a Cursor rule for docs files, or a Claude Code skill.
- 3
Feed it a handler
Paste one or more endpoint implementations into the user template with the framework name.
- 4
Review and publish
Check the "Gaps noticed" section, then merge the reference into your docs.
How to use
- Paste the endpoint code and specify the framework and target audience.
- Send the template; you get a complete reference block per endpoint.
- Address the "Gaps noticed" list — those are real doc/code mismatches.
- Repeat per module and assemble the sections into your docs site.
Platform compatibility
Claude Code
Anthropic
Save the exported .aiskill JSON as a skill file in your project or paste the system prompt into CLAUDE.md / a slash-command markdown file.
Official docsCursor
Anysphere
Copy the system prompt into .cursor/rules/*.mdc (or Project Rules in Settings) and reference the user template in your agent prompts.
Official docsChatGPT GPTs
OpenAI
Paste the system prompt into the GPT "Instructions" field and keep the user template as your starter message.
Official docsDify
LangGenius
Create a new Agent/App, paste the system prompt as the system prompt, and register template variables as input fields.
Official docsLangGraph
LangChain
Load the JSON config into your graph state: use prompts.system for the system message and prompts.user_template as a runnable template.
Official docsPreview gallery
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