Give schema pull requests their own PlanetScale branch
When a pull request changes the database, we create a matching PlanetScale branch for reviewers and post its name right on the pull request.
PlanetScale
GitHubEngineeringOnboarding AutomationData SyncWhen a pull request is opened in our GitHub repository, provision a matching PlanetScale development branch so reviewers get an isolated database to test schema changes against. Trigger this workflow from a GitHub webhook on the pull request opened event.
Start by fetching the pull request from GitHub with Get a Pull Request so you have its title, body, and head branch name. Our GitHub integration has no per-file pull request diff operation, so you cannot look at a changed files list. Judge whether the change is schema related from the title, body, and head branch name alone. That judgement is the whole point of this workflow, so take it seriously.
Treat it as schema related when there is a concrete signal, for example a head branch named something like add-orders-table, migrate-users, or db/backfill-index; a title or body that mentions a migration, a new or dropped table, a column, an index, a foreign key, or a backfill; or a body that references migration files or an ORM schema file such as a Prisma, Drizzle, or Atlas schema. Do not infer schema work from vague wording alone. If there is no concrete signal, treat the pull request as not schema related.
If the pull request is not schema related, stop immediately and do nothing. Do not create a PlanetScale branch and do not post a comment of any kind, not even one saying it was skipped. Silence on unrelated pull requests is a requirement, not a nicety.
If it is schema related, create the database branch with PlanetScale Create a branch in our organization and database, using our production branch as the parent so the new branch starts from the real production schema. Follow the community convention that the git branch name and the PlanetScale branch name should match: name the new branch after the pull request head branch. If the head branch contains characters PlanetScale will not accept, such as slashes in db/add-index, replace them with dashes and use that as the name. Before creating, call Get a branch for the intended name; if a branch with that name already exists, reuse it rather than creating a duplicate or failing, which keeps reopened pull requests and repeat runs clean.
Branch creation is asynchronous, so confirm the branch actually reached ready state by calling PlanetScale Get a branch and checking its ready status, retrying a few times with a short wait between attempts. If it is still not ready after a reasonable number of attempts, do not claim it is ready; say in the comment that the branch was created and is still preparing.
Once the branch is ready, post a single comment on the pull request with GitHub Create an Issue Comment. Name the new PlanetScale branch exactly, say it was branched from our production branch, and give the next step: apply the migrations to that branch, then open a deploy request to roll the schema change into production once the change has been reviewed. Keep the comment short and useful to a reviewer skimming the thread.
Never put database credentials into the pull request comment. Do not create or request a branch password, and never include a connection string, host, username, or password, even if a PlanetScale response contains one. Pull request comments are visible to everyone with access to the repository, so the comment must carry only the branch name and instructions. Reviewers get their own credentials from PlanetScale directly.
What does this prompt do?
- Watches for new pull requests opened in your GitHub repository
- Reads the title, description, and branch name to judge whether the change actually touches your database
- Creates a matching PlanetScale branch copied from your production branch, named after the git branch, and waits until it is ready to use
- Comments on the pull request with the branch name and the next step, and stays completely silent on pull requests that have nothing to do with the database
What do I need to use this?
- A GitHub account with access to the repository you want to watch
- A PlanetScale account with permission to create branches on the database you want copies of
- The name of the branch new copies should be made from, usually your production branch
- A team habit of naming git branches descriptively, since the branch name is one of the signals used to spot database work
How can I customize it?
- Tighten or loosen what counts as a database change, for example only acting when the branch name starts with migrate or the description mentions a migration
- Copy from a staging branch instead of the production branch
- Reword the comment, or have it tag the reviewers who own the database
FAQs
Does this create a database branch for every pull request?
How does it know a pull request changes the database?
Will database passwords ever end up in the pull request comment?
What happens if a branch with that name already exists?
Does it apply my migrations and update production for me?
Related templates
When you merge a fix in GitHub, this agent checks the matching dead-letter queue, replays the failed messages, and reports back on the pull request and in Slack.
Every night, find the preview databases whose pull request closed days ago, delete only the ones that are safe, and report the savings in Slack.
Every weekday morning, surface the security checks nobody has reviewed yet, file them in the right repository, and post your team one clear summary.
Every morning, find the development branches nobody is using anymore, skip anything with a migration still in flight, delete the rest, and post a Slack recap.
Every Monday we review your production databases, share the top fixes in Slack, and file the high impact ones in Linear.
Checks your PlanetScale database changes every hour on weekdays and posts one Slack alert when something is stuck, errored, or waiting on approval.
Stop hand-building a database branch for every schema review.
Let every schema pull request show up with its own isolated PlanetScale branch already waiting for reviewers.