The data-plane-api repository serves as a read-only mirror of Envoy's REST and Protocol Buffer API definitions and documentation. While the canonical read-write home for these APIs resides in the main Envoy repository at envoyproxy/envoy/tree/main/api, this dedicated mirror enables users to consume the data plane APIs independently without requiring the full Envoy implementation. This separation of concerns allows developers and organizations to integrate with Envoy's configuration standards without adopting the entire proxy codebase.
The repository is classified across multiple domains reflecting its broad applicability in modern infrastructure: load balancing, proxy services, service mesh implementations, middleware, microservices architectures, network proxying, HTTP/2 and gRPC support, performance optimization, traffic management, API gateway functionality, and protocol buffer communication standards. These classifications underscore the repository's role as a foundational specification for data plane interactions across diverse networking contexts.
The primary purpose of this repository is to establish what the project terms universal data plane APIs. Rather than being Envoy-specific, these APIs are designed to be consumed by other proxy solutions and management systems that aim to interoperate with configuration generators built against this standard. This universality is intentional and documented in a referenced blog post on the concept, positioning the data plane API as a lingua franca for proxy configuration across the ecosystem.
The repository is written primarily in Starlark, a language commonly used for build configuration and code generation tasks. This choice reflects the repository's focus on API definitions and build-time code generation rather than runtime implementation. The structure includes comprehensive documentation and guidance materials for developers working with these APIs.
The repository provides several key resources for users and contributors. The API style guide establishes conventions for API design within the project. The API versioning guide documents how the APIs evolve while maintaining compatibility. An API overview for users is available through the Envoy documentation, offering practical guidance on configuration. The xDS protocol overview explains the dynamic service discovery and configuration protocol that underpins Envoy's data plane interactions. A contributing guide establishes expectations for those wishing to modify or extend the APIs.
By maintaining this read-only mirror, the Envoy project acknowledges that the data plane API specification has value independent of the Envoy proxy implementation itself. Organizations building management planes, configuration systems, or alternative proxy implementations can reference and build against these APIs without maintaining a dependency on the full Envoy codebase. This architectural decision reflects a maturation of the Envoy ecosystem, where the APIs themselves have become a standardized interface that transcends any single implementation.
The repository's existence as a separate entity demonstrates the project's commitment to establishing industry standards for data plane configuration and communication, making it a critical resource for anyone building infrastructure tooling that needs to interoperate with Envoy or Envoy-compatible proxies.
