OpenAPI spec

How to fetch the OpenAPI specifications for the DeepL API

The DeepL API is described by an OpenAPI specification for the REST endpoints and an AsyncAPI specification for the streaming Voice API. Both are published in YAML and JSON.

Fetch them from this documentation site at a stable URL:

Spec	Format	URL
REST API (source of truth)	YAML	/api-reference/openapi.yaml
REST API	JSON	/api-reference/openapi.json
Voice WebSocket API (source of truth)	YAML	/api-reference/voice/voice.asyncapi.yaml
Voice WebSocket API	JSON	/api-reference/voice/voice.asyncapi.json

The JSON files are generated from the YAML sources, so treat the YAML as authoritative.

The same files are available on GitHub if you prefer to pin a revision.

You can use these specs to explore the API in tools like Postman, or to auto-generate SDKs and code libraries using tools such as Swagger Editor or OpenAPI Generator.

Swagger’s “Try it out” in-browser simulator creates valid curl requests, but requests will fail due to CORS restrictions.

If you encounter issues or have feature requests, create an issue.