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Buf Schema Registry (BSR) overview

Welcome to the Buf Schema Registry (BSR)! This overview covers what the BSR is and the challenges it aims to solve within the Protobuf ecosystem. If you just want to see the BSR in action with code examples, check out the BSR tour.

What is the BSR?

The BSR stores and manages Protobuf files as versioned modules so that individuals and organizations can consume and publish their APIs without friction.

The BSR comes with a browsable UI, dependency management, API validation, versioning, generated documentation, and an extensible plugin system that powers remote code generation.

BSR goals

  • Centralized registry: The BSR is the source of truth for tracking and evolving your Protobuf APIs. A centralized registry enables you to maintain compatibility and manage dependencies, while enabling your clients to consume APIs reliably and efficiently. Having a centralized, Protobuf-aware, registry has the added benefit of protecting against broken builds.

  • Dependency management: The BSR finally introduces dependency management to the Protobuf ecosystem. You can now declare, resolve and use hosted BSR modules as dependencies in your projects. Put simply, you don't need to copy your .proto file dependencies around anymore. The Buf CLI interacts directly with the BSR to fetch your dependencies, (analogous to npm for Node.js, pip for Python, cargo for Rust, and Go modules in Go).

  • UI and documentation: The BSR offers complete documentation for your Protobuf files through a browsable UI with syntax highlighting, definitions, and references.

  • Remote plugins: The Buf team manages hosted Protobuf plugins that can be referenced in buf.gen.yaml files. Code generation takes place remotely on the BSR and generated source code is written out to disk.

  • Generated SDKs: The BSR exposes generated artifacts through managed software repositories you fetch like any other library with tools you already know: go get, npm install, mvn, or gradle.

Why the BSR?

You're probably wondering why adopting the Buf Schema Registry (BSR) is an improvement over your existing Protobuf workflows. We've highlighted available features above, but let's break down how the BSR aims to solve existing problems.

The Protobuf ecosystem deserves build guarantees

Traditional workflows push Protobuf files to version control systems, but these systems lack Protobuf-awareness and thus consumers often waste time working with Protobuf files that don't compile. Yes, some organizations add checks to catch broken Protobuf files, but these are error-prone and don't scale well because each repository needs to be configured, setup and maintained.

Since the BSR is a Protobuf-aware registry, it prevents Protobuf files that don't compile from being pushed to the origin in the first place. Your consumers will have confidence that Protobuf files consumed from the BSR are not broken and can compile. Everyone in the ecosystem benefits because compilation guarantees are pushed from the individual to the BSR.

Generated documentation for all

Sadly, readily consumable and up-to-date documentation is rarely available for Protobuf files. Some organizations setup workflows to generate documentation, but this is yet another manual step that has to be configured and maintained. Furthermore, much of the tooling and plugins are unsupported and generate incomplete documentation.

The BSR comes built-in with generated documentation. You get live documentation for every commit to the BSR. Which means live and up-to-date documentation for latest and historic commits. Even better, the documentation the BSR provides has syntax highlighting, definitions, and references.

Keeping Protobuf files synced

Every organization that adopts Protobuf needs to solve distribution, whether internally across teams or externally exposed to the public. Protobuf files are usually checked into repositories, often dispersed, and it becomes challenging to keep Protobuf files synced across projects. API drift is a common issue and even worse, forked Protobuf repositories accidentally get consumed by downstream dependents (instead of the upstream). It's a mess.

The BSR solves this by offering a centralized registry to store all your Protobuf files, simplifying the process of publishing and consuming. By making the BSR the single source of truth it is possible to power developer workflows and business processes around Protobuf without worrying how to keep everything in-sync.

Client SDKs should not be an afterthought

Define. Generate. Consume.

Defining a Protobuf-based API enforces a contract between producer and consumers, however consumers are typically an afterthought in the process.

Before a client can consume a Protobuf-based API they need to generate an SDK for their language of choice. Traditionally consumers are left to figure out how to build and generate clients, but this is often cumbersome as little guidance is provided and not all Protobuf files correctly encode options for a given language.

Fetching a client SDK from the BSR is a single npm install or go get command.

Start using the BSR

Once you've installed the latest version of the Buf CLI, you're ready to use the BSR! We recommend starting with the BSR tour, if you haven't already done it. The tour provides an overview of the BSR and takes approximately 10 minutes to complete.