4.18.0

2026-09-21

minor

Features 2

Publish pgxpool statistics as metrics via OTel

Adds observable counters and gauges for Postgres connection pool statistics, including acquired/idle connections, acquire duration, and connection lifecycle events. Metrics are published under `zitadel.database.pool.*`.

Metrics Database
Auto-detection for Google Cloud Platform telemetry attributes

Automatically detects GCP-specific resource attributes (region, service name, revision, instance ID) to prevent metric collisions in multi-region deployments. This is disabled by default to avoid unintended external calls.

Telemetry

Efficient bulk unique-constraint deletes using owner tags

Introduces an `owners` tag bag to unique constraints to allow efficient bulk deletes by owner (Org, IDP, Project, etc.) without OOM risks. Includes a repeatable setup migration (Step 79) to backfill tags from projections.

Eventstore
Prevent event skipping in projections under high load (#12703, #8509, #10480, #10560, #10710)

Fixes a race condition where simultaneous writes could cause projections to skip events. Uses advisory locks and stable ordering to ensure data consistency.

Eventstore Projections
Forward login_hint to external Identity Providers (#12760, #12080, #12683)

Enables OIDC `login_hint` forwarding to external Identity Providers in Login V2, ensuring users don't have to re-enter their username at the external IdP.

Login V2
Verify API credentials at startup instead of readiness probe

Moves API credential verification from the `/ready` probe to process startup. This prevents unnecessary authenticated API calls and access log entries during routine health checks.

Login V2

Optimized ListUsers equality filters using UNION of index seeks

Rewrites equality lookups for username, email, phone, and login names to use a UNION of index seeks. This significantly improves performance for Login V2 search trees by avoiding slow view-based filters on large datasets.

Query