Rust crates

There are 3 crates: mediasoup, mediasoup-sys and mediasoup-types:

• mediasoup-sys crate wraps C++ worker into Rust.
• mediasoup-types crate defines and exposes mediasoup Rust types.
• mediasoup crate uses mediasoup-sys and mediasoup-types and it exposes nice user API in idiomatic Rust.
• mediasoup-sys is the only one that needs updating if changes are purely inside the worker or inside the mediasoup-sys crate. You can bump them all, but it is not required.
• If mediasoup-sys's API changes in a breaking way, then its minor version needs to be changed, otherwise patch version needs to be changed. Same for mediasoup-types crate.

Important: Adding new APIs that mediasoup crate has to understand to continue working normally is a breaking change because it'll start crashing/printing errors if unexpected things happen.

Publishing crates

Each crate is published through an automated flow (mirroring how the NPM package is released): npm run release:rust <crate> X.Y.Z bumps the version, commits and pushes, and the mediasoup-crate-publish.yaml workflow then publishes the crate to crates.io via OIDC trusted publishing.

Because mediasoup depends on mediasoup-sys and mediasoup-types, when more than one crate needs a new version, publish the dependencies first (mediasoup-types and/or mediasoup-sys) and mediasoup last, so each crate's dependencies are already on crates.io when it is published. Each release updates only the released crate's own resolved version in Cargo.lock (within that crate's release commit), so releasing a dependency is what refreshes its Cargo.lock entry, and the later mediasoup release only touches mediasoup's own entry.

You do not bump the crate's [package].version, edit rust/CHANGELOG.md, nor edit the sibling version requirements in rust/Cargo.toml yourself; npm run release:rust does all that. For each crate to publish:

1. Have the crate's code changes merged on the main branch. When publishing the mediasoup crate, the changes for the new version must be under the ### NEXT heading of rust/CHANGELOG.md.
2. You do not edit the version of [dependencies.mediasoup-sys] / [dependencies.mediasoup-types] in rust/Cargo.toml yourself: that requirement is what the published mediasoup crate depends on (its path is only used for local builds and is dropped when published). Releasing mediasoup-sys / mediasoup-types automatically bumps that requirement to the just-released version and commits it together with the release, so the mediasoup crate always depends on the latest version of its siblings (and the workspace stays buildable after a breaking minor/major bump, where the requirement must keep accepting the sibling's actual version).
3. Make sure Cargo.lock is already in sync with the merged code, committing it if an earlier change to third-party dependencies left it stale (run cargo build). This is only about pre-existing code changes, not the version bump: npm run release:rust regenerates Cargo.lock for the bumped version itself and commits it within the crate's own release commit. A stale Cargo.lock is harmless for crate consumers (they ignore the packaged lock) but leaves the repo out of sync and breaks the --locked GitHub Actions workflows, and the release aborts on it.
4. On the main branch, with a clean work tree, run:

npm run release:rust mediasoup-types X.Y.Z
# and/or
npm run release:rust mediasoup-sys X.Y.Z
# and finally, when a new mediasoup must depend on the version(s) just released
npm run release:rust mediasoup X.Y.Z

This runs the checks, bumps the crate version in its Cargo.toml (and, for mediasoup-sys / mediasoup-types, the matching version requirement in the mediasoup crate's rust/Cargo.toml) and in Cargo.lock, and then:

• For mediasoup: sets the top ### NEXT heading of rust/CHANGELOG.md to ### X.Y.Z, commits (release rust-X.Y.Z [no-ci]), creates the rust-X.Y.Z tag and pushes the branch and the tag. The tag triggers mediasoup-crate-publish.yaml, which creates the GitHub release from rust/CHANGELOG.md and publishes the crate.
• For mediasoup-sys / mediasoup-types: commits (<crate> X.Y.Z [crate-publish] [no-ci]) and pushes the branch (no tag, no GitHub release). The [crate-publish] marker is what mediasoup-crate-publish.yaml detects on the branch push to publish that crate.

See npm run release:rust in Building.md for more details.