# POST /v1/firewalls changes: CIDRs for Firewall rules not allowing host bits

Calls to POST /v1/firewalls on Hetzner Cloud API stopped working on December 10, 2025.

- API: Hetzner Cloud API (api.hetzner.cloud)
- Kind: Behaviour change
- Takes effect: December 10, 2025
- Calls after that day: fail
- Calls it hits: `POST /v1/firewalls`
- Source: [Changelog](https://docs.hetzner.cloud/changelog)
- Verified: November 6, 2026, against Hetzner Cloud API's own pages
- Page: https://www.okapi.bot/providers/hetzner-cloud-api/breaking-changes/post-v1-firewalls-changes-cidrs-for-firewall-rules-not-allowing-host-bits/

## Hetzner Cloud API's words

> Starting on 10 December 2025, CIDRs specified as destination_ips or source_ips for Firewall rules will no longer allow for the host bits to be set.

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent