Frequently asked questions

What does it cost?

Nothing. It is free while in early access — no paid tier, no trial timer, no card required. If pricing is introduced later, existing workspaces get notice and are never charged without opting in.

Does it connect to my production database?

No. The GitHub Action introspects a throwaway database that your CI creates, applies the pull request’s migrations to, and destroys. That is the point of the design: the verdict reflects what the migration would do, rather than what someone wrote in the description.

Can it see my data?

No. Only schema structure is read — table and column names, types, nullability, constraints, enum variants. Row contents are never queried, transmitted, or stored.

What counts as a breaking change?

Anything that can break a reader without the reader’s code changing:

• a dropped column, table, or enum variant
• a narrowed type (varchar(255) → varchar(64))
• a column becoming NOT NULL
• a removed or narrowed API response field

Additive changes are reported as informational and never fail a build.

Which databases and formats are supported?

Postgres, Snowflake, OpenAPI, and JSON Schema. Postgres is the most exercised path. View bodies are only compared within one Postgres major version, because Postgres 16 deparses views differently from 15 and comparing across them reports every view as rewritten.

Which migration tools work?

All of them. You pass your own command — Rails, Flyway, Alembic, Prisma, golang-migrate, dbt, a Makefile target. It runs with DATABASE_URL exported before introspection. This is deliberately not auto-detected: every tool has its own ordering rules, and guessing wrong produces a confidently incorrect baseline.

Will it block my team on day one?

Only if you ask it to. Start with fail-on-drift: false — the Check Run and pull request comment still post, so you see verdicts without merge friction. Switch it on once those verdicts have earned trust.

What does it not do yet?

It tells you the schema broke, not who it broke. Tracing a change through to the dashboards and services that depend on it — the impact graph — is not built. It is the next thing being built, and this answer will change when it ships.

Can I self-host it?

Yes. The whole platform runs on one machine with Docker Compose, and the Action accepts an api-url pointing at your own deployment.

Is it reliable enough to depend on?

It is early-access software with no SLA. The diff engine has a substantial test suite and gates this project’s own schema on every pull request, but treat verdicts as advisory and keep a path to shipping without one. Being told that up front is worth more than a badge.

How do I get help?

Email hello@schemadrift.dev. It reaches a person, not a queue.