Stability & deprecation

What "1.x" promises, in one place — the consumer-facing copy of the policy CONTRIBUTING.md holds for contributors.

The public surface

The exports subpaths are the public API. Everything reachable through @alexify/wrpc and its subpaths (/ws, /engine, /uws, /fastify, /express, /scaling, /sse, /query, /auth), as typed by the hand-maintained root .d.ts files, is stable under semver. Deep imports into src/ are not addressable and not supported: the module layout may change in any release (and has — rpc/core.js split twice already).

Semver, spelled out

• Patch — fixes; no observable API change.
• Minor — additive API, additive wire fields, new options with safe defaults. Deprecations are announced here: a deprecated API keeps working for at least one minor, with the note in the CHANGELOG and the docs.
• Major — the only place a stable API may break or a deprecated one may be removed.

@experimental carve-outs

Two areas are marked @experimental in the .d.ts files and may change in a minor (described in the CHANGELOG):

• the telemetry writer shapes and metric set (the telemetry option, and the RpcServer#otel getter the fastify adapter brackets delegated routes with) — the signals will keep improving;
• the engine port internals beyond the documented WrpcSocket contract (capabilities in particular).

The wire protocol's own, stronger promise

The wire protocol is frozen at 1.0: packet shapes never break inside a major, new fields are additive and ignorable, and the revision is named on the wire — the wrpc.v1 subprotocol on WebSocket, the reserved wrpc-version response header on HTTP. An independent implementation written against the reference keeps working for the life of the major version.