npm / @connectrpc/connect

@connectrpc/connect

What changed in @connectrpc/connect 2, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-19.

15 breaking2 new APIs and options1 behavior and defaults1 tooling1 fixes and other

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

@connectrpc/connect 220 changes

Bare errors are no longer serialized to the wire.
2.0.0upgrade guide
Headers and trailers are reached through a CallInfo via context APIs.
2.0.0upgrade guide
Metadata moves to context; headers and trailers are reached through a CallInfo via this API.
2.0.0upgrade guide
A function type replaces the three-method Interceptor interface and works for unary and streaming RPCs.
2.0.0upgrade guide
Metadata moves to context; headers and trailers are reached through a CallInfo via this API.
2.0.0upgrade guide
Servers register with connect.NewServer and are mounted with connecthttp.Mount.
2.0.0upgrade guide
The wrapper is gone; unary handlers and clients use plain Protobuf messages.
2.0.0upgrade guide
The wrapper is gone; unary handlers and clients use plain Protobuf messages.
2.0.0upgrade guide
A function type replaces the three-method Interceptor interface and works for unary and streaming RPCs.
2.0.0upgrade guide
Servers are mounted with connecthttp.Mount.
2.0.0upgrade guide
Creates the transport that clients wrap.
2.0.0upgrade guide
The three-method interface is replaced by client and server interceptor function types.
2.0.0upgrade guide
Generated code no longer depends on net/http.
2.0.0upgrade guide
The generator's simple flag has been removed.
2.0.0upgrade guide
Simple signatures are now the default: unary handlers and clients use plain Protobuf messages.
2.0.0upgrade guide

Clients wrap a connect.Transport created by connecthttp.NewTransport.
2.0.0upgrade guide
An in-process transport enables testing without listeners or loopback HTTP.
2.0.0upgrade guide

The migration tool automatically applies many mechanical changes; without -w, it runs a dry run and prints diffs.
2.0.0upgrade guide