shki diff

shki diff [--shadow-database-url URL] [--pg-version 14..18]

Compiles the Declarative Schema in the Shadow Database, snapshots the result, and compares it with the latest Snapshot recorded in the Journal. Prints an object-level summary of the resulting Migration Plan, including rename candidates.

diff writes no files, prints no SQL, and never touches the live database. It is the safe command to run as often as you like.

Options

Flag	Purpose
--shadow-database-url <URL>	Use an external Shadow Database. Env: SHKI_SHADOW_DATABASE_URL.
--pg-version <14…18>	Embedded PostgreSQL major version. Default 18. Env: SHKI_PG_VERSION.
-v, --verbose	More detail about the compile and diff.

Examples

shki diff
shki diff --pg-version 16
shki diff --shadow-database-url postgres://user:pass@localhost:5432/shki_shadow

Notes

• If any Custom Migrations have no Snapshot yet, diff replays them on the Shadow Database first so the baseline is complete.
• “No schema changes detected” means the Declarative Schema and the latest Snapshot agree — nothing to generate.
• An index declared CREATE INDEX CONCURRENTLY diffs exactly like a plain one: the keyword is a creation strategy, not schema state. It only changes what shki generate writes.
• PostgreSQL only: Declarative Schema compilation is not implemented for MySQL, and is planned for SQLite.

See also: shki generate, How It Works.