Database Migration Sequencer

Validate migration metadata, calculate deterministic forward and rollback order, and identify safe parallel groups without connecting to a database.

Migration definitions

Input format

Definitions (maximum 3 MiB / 5,000 migrations / 50,000 dependency edges)

JSON: an array or {"migrations": [...]}. Fields: id, dependencies, rollback_dependencies, file, rollback_file, description, irreversible.

No SQL execution or interpretation: SQL-comment mode reads only standalone lines beginning with -- migration:, -- depends:, -- rollback-depends:, -- file:, -- rollback-file:, -- description:, or -- irreversible. Every other line is ignored.

Sequence report

Validated migrations

Forward step	Forward level	Rollback step	Rollback level	ID	Dependencies	Rollback prerequisites	File	Rollback	Description

Forward dependency levels

Rollback dependency levels

Dependency graph

Arrows run from prerequisite to dependent. The SVG preview is capped at 100 nodes and 200 edges; exports retain the full validated graph.