Why does Astro Build ID exist?
To provide a simple, reliable way to identify which build is currently deployed, especially on static sites behind CDNs.
Astro Build ID Plugin FAQs
Clear answers explaining how Astro Build ID identifies deployed builds safely and deterministically.
Last Updated: 01 April 2026
What build ID formats are supported?
ISO timestamps (default), Unix timestamps, and a short deterministic identifier.
Can I change the output filename?
Yes. You can configure a custom filename, such as health.txt or version.txt.
Can I use a CI-provided value?
Yes. If a value is provided explicitly, it is written verbatim and overrides any format.
Is the output cache-safe?
Yes. The output is static and can be cached indefinitely by CDNs.
What happens if the file cannot be written?
A warning is logged, the build continues, and the site is not broken.
Does Astro Build ID execute at runtime?
No. It never runs at runtime and introduces zero overhead.
Is Astro Build ID open source?
Yes. Astro Build ID is released under the MIT license.
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