Buf Schema Registry (BSR)


The Buf Schema Repository (BSR) provides generated SDKs for Rust in the form of a Crate registry. You can consume generated SDKs from modules and plugins using cargo. It generates SDKs automatically when you push schema changes, which eliminates the need to manage a Protobuf toolchain or generate code locally.


cargo is configured to use crates.io by default. To use Buf's Cargo registry, you must configure it in your .cargo/config.toml file:

index = "sparse+https://buf.build/gen/cargo/"
credential-provider = "cargo:token"

You then need to configure a token for the registry. See the Authentication page for instructions on creating a token, and then run:

$ cargo login --registry buf "Bearer {token}"

Installing generated SDKs

To install a generated SDK, use cargo add and reference the SDK name. For example, to install the connectrpc/eliza Protobuf module using the community/neoeinstein-prost plugin, run this command:

$ cargo add --registry buf connectrpc_eliza_community_neoeinstein-prost

See the names and versions section for syntax specifics.

Eager generation

Unlike our other generated SDKs, which generate SDKs lazily, Rust crates are generated eagerly to populate the checksum of the generated crate in the package index. Once you've run cargo add on a crate, future pushes to the default label for the crate's repository will be automatically generated.

To eagerly generate a version for a particular label or commit, go to the module you want to generate for, then choose a label from the dropdown or enter a commit ID:

This repository has two labels, 'main' and 'demos'. 'main' is the default label

Future pushes to the label will be automatically generated.

Names and versions

The BSR Cargo registry has a special syntax for SDK names:


For example, the SDK name connectrpc_eliza_community_neoeinstein-prost contains code for the connectrpc/eliza module using the community/neoeinstein-prost plugin.


To discover SDK versions for the Cargo registry, you can browse a repository's generated SDK page, which has installation instructions and an interactive UI for selecting SDK versions.

Full syntax


As an example:


That represents:

  • Plugin version: 0.3.1
  • Plugin revision: 1
  • Commit timestamp: 20240523144506
  • Commit short name: ce529d32d80c

The BSR supports commits on labels. This feature enables you to push unreleased Protobuf file changes and consume generated code without affecting the default label.

Only commits that are on the default label at the time they're pushed to the BSR have populated timestamps. Timestamps on commits pushed to other labels are set to 00000000000000 to easily distinguish them as changes in labels that are still in development.

Available plugins

For a full list of supported plugins, navigate to the BSR plugins page and search for Rust.

To learn more about how these plugins are packaged and distributed, go to the bufbuild/plugins repository. If you find a useful plugin that should be added, please file an issue!