pgvector-setup

name	pgvector-setup
description	Supabase pgvector setup, RAG pipeline, and vector search for StartupAI. Covers knowledge_chunks schema, HNSW/IVFFlat indexes, search_knowledge + hybrid_search_knowledge RPCs, embedding generation via OpenAI, Edge Function integration, and Gemini web search grounding. **Trigger when user asks to:** - Set up or modify vector search, embeddings, or knowledge base - Ingest documents into knowledge_chunks - Debug search quality or missing results - Tune HNSW parameters or search performance - Wire RAG into edge functions or AI chat - Use Google Search grounding or URL Context with Gemini **This project:** OpenAI text-embedding-3-small (1536 dims), stored in knowledge_chunks, HNSW index, search via search_knowledge() and hybrid_search_knowledge() RPCs.
allowed-tools	Bash, Read, Write, Edit

pgvector for StartupAI

Our Setup (Live DB — audited 2026-03-19)

Component	Value
Extension	pgvector 0.8.0
Embedding model	OpenAI text-embedding-3-small
Dimensions	1536
Table	knowledge_chunks
Index	HNSW (m=16, ef_construction=64, vector_cosine_ops)
FTS	GIN index on fts tsvector column
Total chunks	3,973 (3,865 with embeddings)
Documents	89 (all with content_hash dedup)
Search RPCs	search_knowledge + hybrid_search_knowledge
RLS	Authenticated SELECT; service_role writes

Industry Distribution (problem: 78% AI/ML)

Industry	Chunks	With Embedding
ai_ml	3,106	3,102
fashion	508	508
retail	219	219
GTM	22	22
saas	36	0
7 others	1-2 each	0

Gap: 16 of 19 industries have <3 chunks. healthtech, fintech, ecommerce, education, legal, manufacturing, etc. are essentially empty.

Empty Tables

• industry_playbooks — 0 rows (edge functions query this and get nothing)
• prompt_packs — 0 rows (prompt-pack edge function queries this)

---

Schema

-- knowledge_chunks (main vector table)
CREATE TABLE knowledge_chunks (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  content TEXT NOT NULL CHECK (length(content) >= 20),
  embedding vector(1536),
  source TEXT,
  source_type TEXT,
  year INT,
  confidence TEXT,           -- high/medium/low
  category TEXT,
  industry TEXT,
  document_id UUID REFERENCES knowledge_documents(id),
  page_start INT,
  page_end INT,
  section_title TEXT,
  chunk_kind TEXT,           -- text/table
  chunk_index INT,
  source_path TEXT,
  tags TEXT[],
  fts TSVECTOR,              -- auto-maintained via trigger
  fetch_count INT DEFAULT 0,
  last_fetched_at TIMESTAMPTZ,
  created_at TIMESTAMPTZ DEFAULT now(),
  updated_at TIMESTAMPTZ DEFAULT now()
);

-- knowledge_documents (source tracking)
CREATE TABLE knowledge_documents (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  title TEXT NOT NULL,
  source_type TEXT,
  year INT,
  llama_parse_id TEXT,       -- LlamaCloud job ID for PDFs
  content_hash TEXT NOT NULL, -- SHA-256 dedup
  created_at TIMESTAMPTZ DEFAULT now()
);

Indexes (12 total)

-- Vector search (HNSW)
CREATE INDEX knowledge_chunks_embedding_idx
  ON knowledge_chunks USING hnsw (embedding vector_cosine_ops)
  WITH (m = 16, ef_construction = 64);

-- Full-text search
CREATE INDEX idx_knowledge_chunks_fts ON knowledge_chunks USING gin (fts);

-- Dedup (prevents re-embedding same content)
CREATE UNIQUE INDEX idx_knowledge_chunks_doc_content_hash
  ON knowledge_chunks (document_id, md5(content))
  WHERE document_id IS NOT NULL;

-- Filter indexes
CREATE INDEX idx_knowledge_chunks_category ON knowledge_chunks (category);
CREATE INDEX idx_knowledge_chunks_industry ON knowledge_chunks (industry) WHERE industry IS NOT NULL;
CREATE INDEX idx_knowledge_chunks_source_type ON knowledge_chunks (source_type);
CREATE INDEX idx_knowledge_chunks_year ON knowledge_chunks (year DESC);
CREATE INDEX idx_knowledge_chunks_category_year ON knowledge_chunks (category, year DESC);
CREATE INDEX idx_knowledge_chunks_tags ON knowledge_chunks USING gin (tags);
CREATE INDEX idx_knowledge_chunks_document_id ON knowledge_chunks (document_id) WHERE document_id IS NOT NULL;

---

Search Functions

search_knowledge (semantic only)

search_knowledge(
  query_embedding vector,
  match_threshold float DEFAULT 0.75,
  match_count int DEFAULT 5,
  filter_category text DEFAULT NULL,
  filter_industry text DEFAULT NULL
) RETURNS TABLE(id, content, source, source_type, year, confidence, category, tags, similarity)

hybrid_search_knowledge (semantic + keyword with RRF)

hybrid_search_knowledge(
  query_embedding vector,
  query_text text,
  match_threshold float DEFAULT 0.75,
  match_count int DEFAULT 10,
  filter_category text DEFAULT NULL,
  filter_industry text DEFAULT NULL,
  rrf_k int DEFAULT 50
) RETURNS TABLE(id, content, source, source_type, year, confidence, category, tags, similarity,
                document_id, document_title, section_title, page_start, page_end)

How RRF works: Runs vector search (top 20) and FTS search (top 20) independently, then combines ranks using 1/(k+rank) formula. Captures both semantic meaning and exact keyword matches.

Calling from Edge Functions

// Via service-role client (bypasses RLS for pipeline callers)
const { data } = await supabaseAdmin.rpc('hybrid_search_knowledge', {
  query_embedding: embedding,
  query_text: userQuery,
  match_threshold: 0.5,
  match_count: 10,
  filter_industry: 'healthcare',
});

---

Embedding Generation

File: supabase/functions/_shared/openai-embeddings.ts

// Single embedding
const result = await generateEmbedding(text);
// result.embedding = number[1536]

// Batch (20 at a time, 500ms throttle)
const results = await generateEmbeddings(texts);

Known issue: No Promise.race timeout — OpenAI calls can hang. Add 15s timeout wrapper.

---

RAG Integration Points

Where RAG is wired today

Feature	File	How
AI Chat (coaching modes)	ai-chat/rag.ts	getRAGContext() → injects top-5 chunks into Gemini system prompt
Canvas Coach	lean-canvas-agent/actions/coach.ts	searchCoachingContext() → service-role RPC → citations as badges

Where RAG should be wired (not yet done)

Feature	Integration point	Expected impact
Validator Composer	validator-start/agents/composer.ts Group D	Cite benchmarks in executive summary
Sprint Agent	sprint-agent/index.ts	Industry-specific task prioritization
Pitch Deck Generation	pitch-deck-agent/actions/generation.ts	Market data in slides
Investor Agent	investor-agent/index.ts	Stage-specific fundraising benchmarks

RAG failure pattern (graceful degradation)

try {
  const context = await getRAGContext(supabase, query, filterIndustry);
  // Inject into system prompt if non-empty
} catch (e) {
  console.warn("[RAG] Failed:", e);
  return ""; // Fail open — chat continues without RAG
}

---

Web Search (Not pgvector — Gemini API features)

For live web data, use Gemini's built-in search instead of vectorizing URLs.

Google Search Grounding

const result = await callGeminiChat(model, systemPrompt, messages, {
  useSearch: true, // Gemini searches Google in real-time
  timeoutMs: 45_000,
});
// Citations in result.citations (extracted from groundingMetadata)

Where used: Validator Research Agent, Competitors Agent, AI Chat research mode.

URL Context (read a specific webpage)

const result = await callGemini(model, systemPrompt, userPrompt, {
  useUrlContext: true, // Gemini fetches and reads the URL
});

Where used: profile-import, Research Agent (reads competitor URLs).

When to use which

Content Type	Method	Why
Our curated benchmarks/playbooks	pgvector	Static, authoritative, fast
Market trends, news, competitor data	Google Search	Always fresh
Specific website content	URL Context	Reads actual page
PDF reports we've ingested	pgvector	Already chunked + embedded
External research links (research/links/)	Google Search / URL Context	Live reads get latest data

---

Ingestion Pipeline

Scripts

# Batch ingest all markdown docs
node scripts/ingest-industry-docs-batch.mjs

# Single directory ingest
node scripts/ingest-markdown-knowledge.mjs --dir=research/<path> --industry=<tag>

# Verify vectors after ingest
node scripts/verify-vector-rag.mjs

Edge Function: knowledge-ingest

Auth: X-Internal-Token header (not JWT — used by scripts) Actions: ingest, ingest_from_llamacloud, generate_embeddings, status, test_search

Chunking strategy:

• Heading-based segmentation (## and ### level)
• Table extraction (entire tables as single chunks, 3600-char max)
• Narrative text: 3600-char chunks, 200-char overlap
• SHA-256 content-hash dedup (unique index prevents re-embedding)

---

HNSW Tuning Guide

Parameters

Parameter	Our Value	Range	Effect
m	16	12-48	Higher = better recall, more memory
ef_construction	64	64-256	Higher = better graph quality, slower builds
ef_search	40 (default)	40-400	Higher = better recall, slower queries

When to change

• Poor recall (missing relevant results): Increase ef_search first (cheapest). Then increase m + ef_construction (requires reindex).
• High latency: Decrease ef_search. Check if index fits in memory (pg_size_pretty).
• Filtered search returns too few results: Enable iterative scan:

  SET hnsw.iterative_scan = relaxed_order;
  SET hnsw.max_scan_tuples = 50000;
  

Performance at our scale (3,973 chunks, 1536-dim)

At this data volume, HNSW is massive overkill — queries are <50ms. Tuning only matters at 100K+ vectors. Current config is fine.

Monitoring

-- Index size
SELECT pg_size_pretty(pg_relation_size('knowledge_chunks_embedding_idx'));

-- Query plan (verify index is used)
EXPLAIN (ANALYZE, BUFFERS)
SELECT id, content FROM knowledge_chunks
ORDER BY embedding <=> $1::vector(1536) LIMIT 10;

-- Check for chunks without embeddings
SELECT count(*) FROM knowledge_chunks WHERE embedding IS NULL;

---

Common Issues

Symptom	Cause	Fix
Search returns AI/ML data for non-AI founders	78% of chunks are ai_ml	Ingest more industry-specific content
industry_playbooks queries return empty	0 rows in table	Seed 19 industry playbooks
prompt_packs queries return empty	0 rows in table	Seed prompt pack definitions
108 chunks missing embeddings	saas + null-industry chunks	Run generate_embeddings action
Hybrid search not finding keyword matches	FTS query syntax edge cases	Use websearch_to_tsquery (handles phrases, AND/OR)
Search quality low for non-English content	text-embedding-3-small optimized for English	Consider multilingual model if needed

---

Priority Improvements

P0 — Fill empty industries:

• Ingest research/services/02-12*.md (11 industry guides)
• Ingest research/sports/reports/*.md (5 synthesis reports)
• Seed industry_playbooks table (19 rows)

P1 — Wire RAG into more features:

• Add getRAGContext() to Validator Composer (Group D)
• Add getRAGContext() to Sprint Agent
• Add Promise.race(15s) to openai-embeddings.ts

P2 — Expand knowledge base:

• Ingest remaining PDFs via LlamaCloud
• Generate embeddings for 108 missing chunks
• Seed prompt_packs table

---

Docs: https://supabase.com/docs/guides/ai Version: 2.0.0 Last Updated: 2026-03-19