pgvector

pgvector and Postgres extension requirements

Some plugins need a Postgres extension. claw, for example, needs vector. The plugin says so in its manifest:

"requires": { "postgres_extensions": ["vector"] }

Use the Postgres extension name (vector), not the config spelling pgvector.

What nself plugin install checks

The check runs before anything is downloaded.

Database state	What decides	Result when the extension is missing
Running	pg_available_extensions on the project's postgres container	Error E507
Stopped or not created	The resolved image (POSTGRES_IMAGE, or the version)	Error E507
Stopped, custom image	Unknown	Warning E508, install continues
Running but cannot be queried, or Docker is unreachable	Nothing	A plain error that says so. It is never reported as "missing"

The check only reads. It never creates or enables an extension, and it never changes the image or any env value. It talks to Postgres through the container (docker exec ... psql over the local socket), so no password is placed on a command line. Extension names are validated and are never put into SQL.

Which images have vector

Image	vector	Contrib extensions (pgcrypto, uuid-ossp, pg_trgm, ...)
pgvector/pgvector:pg16 and other pgvector/pgvector:*	yes	yes
postgres:16-alpine and other postgres:*	no	yes
anything else	unknown	unknown

New projects default to the pgvector image. Older projects and production run postgres:16-alpine, which has no vector, so installing claw there is refused with E507.

The fix

Move the project to the pgvector image:

nself db image switch --to pgvector

Then run the install again. For another extension, set POSTGRES_IMAGE to an image that ships it, run nself build, restart, and retry.

See error-codes for E507 and E508.