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2025-12-02 3 min · 542 words

Why Connect RPC is a great choice for building APIs

gRPC authentication security software development developer tools apis

Connect RPC is a suite of libraries which enable you to build HTTP based APIs which are gRPC compatible. It provides a bridge between gRPC and HTTP/1.1, letting you leverage HTTP/2’s multiplexing and performance benefits while still supporting HTTP/1.1 clients. This makes it a great solution for teams looking to get the performance benefits of gRPC, while maintaining broad client compatibility.

HTTP/2’s multiplexing and binary framing make it significantly more efficient than HTTP/1.1, reducing latency and improving throughput. Connect RPC lets you harness these benefits while maintaining broad client compatibility for services that can’t yet support HTTP/2.

Connect RPC can be used to build both internal and external APIs, powering frontends, mobile apps, CLIs, agents and more. See the list of supported languages .

Core Features

Connect RPC provides a number of features out of the box, such as:

  • Interceptors which make it easy to extend Connect RPC and are used to add authentication, logging, metrics, tracing and retries.
  • Serialization & compression , with pluggable serializers, and support for asymmetric compression reducing the amount of data that needs to be transmitted, or received.
  • Error handling , with a standard error format, with support for custom error codes to allow for more granular error handling.
  • Observability , with in built support for OpenTelemetry enabling you to easily add tracing, or metrics to your APIs.
  • Streaming , which provides a very efficient way to push or pull data without polling.
  • Schemas , which enable you to define and validate your API schemas, and generate code from them.
  • Code generation for Go , TypeScript , Kotlin , Swift and Java .

Ecosystem

In addition to these features, Connect RPC is built on top of the Buf ecosystem, which offers notable benefits:

  • Connect RPC joins CNCF , entering the cloud-native ecosystem, which is great for the long term sustainability of the project.
  • Buf Schema Registry , which is a great tool for managing, sharing and versioning your API schemas.
  • Buf CLI , a handy all in one tool for managing your APIs, generating code and linting.

Some handy Go packages that provide pre-built Connect RPC interceptors worth exploring or using as a starting point:

  • authn-go , provides a rebuilt authentication middleware library for Go. It works with any authentication scheme (including HTTP basic authentication, cookies, bearer tokens, and mutual TLS).
  • validate-go provides a Connect RPC interceptor that takes the tedium out of data validation. This package is powered by protovalidate and the Common Expression Language .
  • rpclog provides a structured logging interceptor for Connect RPC with support for both unary and streaming RPCs.

Summary

  1. Connect RPC provides a paved and well maintained path to building gRPC compatible APIs, while maintaining compatibility for HTTP/1.1 clients. This is invaluable for product teams that need to support multiple client types without building custom compatibility layers.

  2. Using a mature library like Connect RPC, you get to benefit from all the prebuilt integrations, and the added capabilities of the Buf ecosystem. This makes publishing and consuming APIs a breeze.

  3. Protobuf schemas, high performance serialisation and compression ensure you get robust and efficient APIs.

Conclusion

Connect RPC makes it easy to build high-performance, robust APIs with gRPC compatibility, while avoiding the complexity of building and maintaining custom compatibility layers.