●Change8

Migrating to Prometheus v3.13.0-rc.1

Version v3.13.0-rc.1 introduces 2 breaking changes. This guide details how to update your code.

Released: 6/22/2026

2
Breaking Changes
2
Migration Steps
14
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

min()max()min_of()max_of()prometheus_engine_query_samples_read_total__convert_classic_histograms_to_nhcb____always_scrape_classic_histograms____scrape_native_histograms__storage.tsdb.chunk_encoding.floatspredict_linearfill_leftfill_rightresets()changes()

Breaking Changes

●Issue #1

HTTP clients no longer forward credentials (Authorization header, basic auth, bearer token, OAuth2, configured headers) when following a redirect to a different host. This affects scraping, remote read/write, alerting, and service discovery. Users relying on credentials being forwarded across host redirects must update their configuration or client logic.

●Issue #2

Relative file paths in the file passed to `promtool --http.config.file` are now resolved relative to that config file's directory instead of its parent directory. Users relying on the old behavior must update their paths.

Migration Steps

  1. 1
    If you relied on credentials being forwarded across host redirects for HTTP clients (scraping, remote read/write, alerting, service discovery), update your configuration as credentials are no longer forwarded.
  2. 2
    If you used relative file paths with `promtool --http.config.file`, ensure paths are now relative to the config file's directory, not its parent directory.

Release Summary

This release candidate focuses heavily on CI/build improvements following migration issues, while introducing several PromQL enhancements, performance optimizations in TSDB, and security fixes. Key user-facing changes include embedding third-party licenses in the binary and renaming experimental duration functions.

Need More Details?

View the full release notes and all changes for Prometheus v3.13.0-rc.1.

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