# 2026-03-01 Session Notes

## UMAP Projection Database Schema Bug

Investigated a critical UMAP projection failure in the signetai daemon deployed on macOS. The error was a SQLiteError indicating the query referenced a non-existent column `e.vector` in the embeddings table schema. The issue occurred in the `computeProjection` function within `packages/daemon/src/umap-projection.ts` when processing embeddings for the memory projection visualization.

The debugging approach involved:
1. Grepping for `e.vector` references across the codebase (found 6 files)
2. Grepping for `computeProjection` function (found 2 files: daemon.ts and umap-projection.ts)
3. Beginning source code inspection of the problematic UMAP projection module

The root cause appeared to be a schema mismatch between the query being executed and the actual database schema, likely a migration gap or column naming inconsistency. Investigation was ongoing at session end.