APIs.guru API

⭐ Beginner's Pick Development / No Auth Required Beginner HTTPS
Free to Use Varies (check documentation)

Overview

APIs.guru maintains a crowd-sourced directory of OpenAPI (Swagger) specification files for hundreds of public web APIs, all normalized to OpenAPI 3.0 format. The API lets you fetch a full machine-readable catalog of API specs that you can use to auto-generate client SDKs, documentation, or test harnesses. It is often called the "Wikipedia for APIs" and is a go-to resource for API tooling and discovery.

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Beginner Tip

No API key is required — start by calling https://api.apis.guru/v2/list.json to get the full catalog as a JSON object keyed by provider domain. Each provider entry links to the actual OpenAPI spec URL which you can then fetch and parse with any OpenAPI library.

Available Data

APIs.guru data via REST API
JSON-formatted response data
Freely accessible without authentication

Example Response

JSON Response
{
  "status": "success",
  "data": {
    "result": "Data from APIs.guru",
    "description": "Wikipedia for Web APIs, OpenAPI/Swagger specs for public APIs",
    "timestamp": "2025-01-15T10:00:00Z"
  }
}

Field Reference

{provider}.apis.{version}.info.title Human-readable title of the API at this version.
{provider}.apis.{version}.info.version Version string of the API spec.
{provider}.apis.{version}.swaggerUrl Direct URL to the OpenAPI JSON spec file for this version.
{provider}.apis.{version}.updated ISO 8601 timestamp when this spec was last updated in the catalog.
{provider}.preferred Version string of the recommended version to use for this provider.

Implementation Example

const url = "https://apis.guru/api-doc/";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

Response is a large JSON object (several MB) The /list.json endpoint returns metadata for hundreds of APIs at once.
Filter by provider name client-side after fetching, or use the /providers.json endpoint first to get just the list of provider names.
OpenAPI spec URL returns 404 or outdated content Third-party API providers occasionally change or remove their spec files.
Check the updated field in the API entry to see when the spec was last verified; use the preferred.spec_url from the API entry.
Parsing errors on fetched OpenAPI specs Not all specs in the catalog strictly conform to the OpenAPI 3.0 standard.
Use a lenient OpenAPI parser that can handle minor spec violations, such as swagger-parser with options.validate.schema set to false.

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 20/20
🔒 Security 15/15
🛠 Developer XP 15/20
✓ Reliability 7/15
Response Time 146ms

Fully tested on Apr 5, 2026

Technical Specifications

Auth No Auth
HTTPS REQUIRED
CORS UNKNOWN
Category Development
Difficulty Beginner
Verified: 2026-04-04

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