TL;DR: # Supabase pgvector: enable it correctly before anything else Every pgvector failure agents hit starts with the extension not being enabled where their code expects it. The `vector`

## Fix
1. # Supabase pgvector: enable it correctly before anything else Every pgvector failure agents hit starts with the extension not being enabled where their code expects it.
   Expected: this specific failure stops.
2. Enable the extension with.
   Expected: this specific failure stops.
3. Add the.
   Expected: this specific failure stops.
4. ) after the extension exists, and set a fixed.
   Expected: this specific failure stops.
5. Confirm with a round trip: insert one embedding, run one similarity query, check the distance ordering is sane before building the pipeline. ## Quick test In a fresh database (a branch or local), run your migrations from zero and then insert and query a vector.
   Expected: the value or setting is exactly right, nothing ambiguous.

## Details
The `vector` type, the distance operators, and the index methods all come from the extension. No extension, no vectors. ## Checkable procedure 1. `create extension if not exists vector;` . Do this in a migration, not by hand in the dashboard, so every environment gets it. 2. Be deliberate about the schema. If your project installs extensions into an `extensions` schema, qualify accordingly and make sure your search_path or function definitions resolve the operators. Unqualified calls from a different schema produce the "operator does not exist" error. 3. `vector(1536)` (or your model's dimension) column in the same migration that enables the extension. 4. Write the similarity function ( `match_documents` `search_path` on the function. Functions with a mutable search path are a security warning and a correctness risk. 5. If it works from zero, the extension setup is migration-safe.

## When to use
You hit exactly this: Supabase pgvector: enable the extension in the right schema before writing vector code in Supabase pgvector.

## When not to use
A different error, or the same symptom in a different tool. This page only covers the failure above.

## Compatibility
Supabase pgvector.

## Root cause
The dimension is part of the type; changing it later means rewriting the column.