[groyoh]

Context

The scheduled OpenAPI drift job has failed on every run since 2026-09-09. The drift PR is opened or updated, then the job fails when it requests a review from the developers team: the team is not a collaborator of this repository, and the default GITHUB_TOKEN cannot request team reviews either. Nobody is told about the failure, so the job stayed red and the drift PR stayed without a reviewer.

Description

The team-reviewers input was removed, so the job passes once the drift PR is opened or updated. The team can be requested again once it has access to the repository and SPEC_DRIFT_TOKEN is set.

The review request now goes to Slack instead. When the drift PR is created or gets new drift, the job posts :pr: <url|repo#number> - title, the same format as other PR review requests. A run without new drift posts nothing. When any step fails, the job posts a link to the failed run in the same channel.

Both messages use slackapi/slack-github-action@v4.0.0 and read two repository secrets, which are already set: SLACK_BOT_TOKEN (a bot with chat:write, member of the channel) and SLACK_CHANNEL_ID.

A run from a branch other than main pushes its own automation/openapi-drift-<datetime> branch and opens its own PR into that branch. A manual test run therefore does not overwrite the drift PR of main.

The drift PR body now follows the ## Context / ## Description layout and ends with the fetch time, the spec version, the SHA-256 of the fetched document, and the lago-openapi commit it comes from. The commit is only linked when its openapi.yaml is byte for byte the fetched file; the last 5 commits that changed it are checked, to cover the delay before GitHub Pages serves a new version.

[groyoh]

Thanks @vincent-pochet for the review!