APIs.guru
APIs.guru is the world's largest open directory of publicly available REST API specifications, providing machine-readable OpenAPI (formerly Swagger) specifications for over 2,000 public APIs in a single, freely accessible catalog. It is the foundation layer for API discovery tools, SDK generators, documentation platforms, and developer portals that need a comprehensive, well-maintained catalog of public API definitions.
The dataset is maintained as an open source project on GitHub, with contributors adding and updating specifications for public APIs from major providers — Google, Microsoft, AWS, Stripe, Twilio, SendGrid, and hundreds of smaller services. The specifications are validated, normalized, and converted to current OpenAPI 3.0 format where possible, ensuring consistency across the catalog.
The REST API provides programmatic access to the catalog. Developers can list all API providers, retrieve the list of APIs offered by a specific provider, fetch the full OpenAPI specification for any API, and access metadata about each API including its version, documentation URL, and last-update timestamp. This programmatic access is what enables building tools on top of the catalog rather than only browsing it manually.
OpenAPI specifications are the foundation for a wide range of developer tools. API client code generators use OpenAPI specs to automatically produce SDK code in multiple programming languages — eliminating the need for manual client library development. Documentation generators transform OpenAPI specs into interactive API reference documentation. API testing tools use specs to generate test cases and validate response schemas. Contract testing tools use specs to verify that API implementations match their documented interface.
For Nigerian developer tools companies and developer advocacy programs, APIs.guru provides a rich dataset for building API discovery experiences. A Nigerian developer portal that wants to help developers discover and compare public APIs for their projects can use APIs.guru as its catalog backend — providing machine-readable, up-to-date API information without the effort of maintaining a proprietary catalog.
Nigerian development teams building internal tooling around external APIs can use APIs.guru to fetch current OpenAPI specs for the APIs they use — feeding those specs into code generation tools, testing frameworks, or documentation systems to stay in sync with the latest API definitions.
Nigerian API training and education providers can use the APIs.guru catalog to build practical API exploration tools for students — allowing learners to browse, inspect, and experiment with real-world API specifications as part of API development coursework.
The service is completely free with no API key required. Requests are standard HTTP GET calls to the APIs.guru REST endpoint. The open source nature means it will never be paywalled or discontinued without community alternatives emerging.
APIs.guru also provides a metrics endpoint showing statistics about the catalog — total provider count, total API count, and historical growth data. Nigerian developer platforms and API marketplace projects that want to cite catalog coverage statistics for marketing or research purposes can pull these metrics programmatically.
The catalog is continuously updated through community contributions via the GitHub repository. Nigerian developers who discover public APIs with well-documented OpenAPI specs can contribute them to the APIs.guru catalog, making them discoverable to the global developer community and supporting the shared resource that benefits all developers.
APIs.guru's search and filter capabilities through the REST API allow querying the catalog by specific criteria — finding all APIs from a specific provider, filtering by API category, or locating APIs with a specific authentication type. Nigerian developer tools that provide curated API recommendations can use this filtering to surface relevant APIs based on user context.