# What changed in prometheus-client

> 13 changes in prometheus-client 0.24 to 0.26 from its official release notes, upgrade guides and advisories: 2 breaking, 2 new APIs and options. Each one cited. Sources checked 2026-10-20. HTML: https://unstale.sh/pypi/prometheus-client/

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

## prometheus-client 0.26

### Breaking changes

- A precedence fix prevents exemplars from being allowed on any metric type. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- Float exponents greater than or equal to 10 no longer include a leading zero. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)

### New APIs and options

- TLS version parameters are added to start_wsgi_server. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- The Timer context manager exposes its measured duration, so callers can access the elapsed time. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)

### Fixes and other changes

- Calling clear() on a label-less metric is now a no-op. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- Enum arguments are validated before the collector is registered. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- Duplicate timeseries now use a specific exception. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- The labels() parameters use object instead of Any in their type annotations. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- The native histogram sum is parsed as a float. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)
- Unregistering removes nameless collectors from the registry. (0.26.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.26.0)

## prometheus-client 0.25

### Fixes and other changes

- Spaces in grouping key values are handled correctly when using push_to_gateway. (0.25.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.25.0)
- RestrictedRegistry supports MultiProcessCollector. (0.25.0) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.25.0)

## prometheus-client 0.24

### Fixes and other changes

- Django now passes the correct registry to MultiProcessCollector. (0.24.1) — [release notes](https://github.com/prometheus/client_python/releases/tag/v0.24.1)