Per-branch RunsOn environments

If you have 2 environments ↗ e.g. production (default) and dev (per-branch), you can target a specific one based on e.g. branch names by dynamically assigning a value to the env ↗ label:

Example:

  example-job:
    name: Example Job
    runs-on:
      - runs-on=${{ github.run\_id }}-${{ github.run\_attempt }}-example-job
      - env=${{ contains(vars.RUNS\_ON\_DEV\_BRANCHES || '', github.ref\_name) && 'dev' || 'production' }}

Then setting a repo var RUNS_ON_DEV_BRANCHES to include branch names you want to specifically run on dev.

Especially useful when you want to test RunsOn upgrades without impacting the main branches: spin-up a new dev stack, update the RUNS_ON_DEV_BRANCHES value, and test your workflows in an isolated branch of your repositories.

---

Last updated: October 22, 2025

View original discussion ↗