# OpenAPI

[OpenAPI](https://www.openapis.org) is an industry-standard format for describing RESTful APIs. [Twilio OpenAPI 3.0 specification files](https://github.com/twilio/twilio-oai) allow you to integrate the Twilio API with a wide variety of community tools. They also turn on API mocking and testing, the generation of client libraries, integrations with Postman, and more.

## Build with the Twilio OpenAPI Spec

Get inspired with guides on common use cases to improve your developer experience:

* [Explore the Twilio API without writing code using Postman Collections](/docs/openapi/using-twilio-postman-collections)
* [Mock the Twilio API for testing with Prism](/docs/openapi/mock-api-generation-with-twilio-openapi-spec)
* [Auto-generate a Twilio client in the Rust programming language](/docs/openapi/generating-a-rust-client-for-twilios-api)