# What changed in connectrpc

> 10 changes in connectrpc 0.11 to 0.12 from its official release notes, upgrade guides and advisories: 2 breaking, 2 new APIs and options. Each one cited. Sources checked 2026-10-21. HTML: https://unstale.sh/pypi/connectrpc/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## connectrpc 0.12

### Breaking changes

- The JSON codec now accepts fields unknown to the schema by default; set ignore_unknown_fields=False to preserve the previous behavior. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)
- The default incoming message size limit is now 4MB instead of unlimited; raise it for larger messages or set it to None to disable the limit. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)

### New APIs and options

- ResponseMetadata now exposes the HTTP status code. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)
- A service descriptor is now exposed. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)

### Performance

- The streaming path avoids quadratic buffer copies. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)

### Behavior and default changes

- Metadata interceptors execute at the start of the chain, before the request is parsed. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)
- Implemented protocols now use positional-only parameters. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)

### Fixes and other changes

- The message read limit is checked before compression and applied during decompression. (0.12.0) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.12.0)

## connectrpc 0.11

### Performance

- Avoids unnecessary copies and reuses protocol singletons. (0.11.1) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.11.1)

### Fixes and other changes

- Fixes relative path calculation for generated code, addressing an interop issue that likely prevented most usage. (0.11.1) — [release notes](https://github.com/connectrpc/connect-py/releases/tag/v0.11.1)