A Gradle build on a GitHub-hosted runner fails with a Maven Central 403: Received status code 403 from server: Forbidden for a file on repo.maven.apache.org . Or it gets 429, Too Many Requests. Nothing is wrong with your build. Maven Central limits the IP addresses that download the most, and GitHub's runners share their addresses with everyone else's jobs. A cache and retries don't fix it. Downloading less from Maven Central does: a Gradle init script that sends the downloads to Google's mirror of Maven Central, keeps Maven Central last for what the mirror doesn't have yet, and closes the path through the Gradle Plugin Portal.

The CI of SMF builds Flutter apps for Android in about 60 parallel jobs every night, and it has used this script since 2 October 2026. Since then it has run at least 3,917 Android jobs without one 403 or 429.…