nate-jones-second-brain
v1.0.2Set up and operate a personal knowledge system using Supabase (pgvector) and OpenRouter. Five structured tables — thoughts (inbox log), people, projects, ideas, admin — with AI-powered classification, confidence-based routing, and semantic search across all categories. Captures thoughts from any sou...
Installation
Nate Jones Second Brain
When intelligence is abundant, context becomes the scarce resource. This skill is context architecture — a persistent, searchable knowledge layer that turns your agent into a personal knowledge manager.
Two opinionated primitives:
- Supabase — your database, and so much more. PostgreSQL + pgvector. Stores thoughts, people, projects, ideas, and tasks as structured data with vector embeddings. REST API built in. Your data, your infrastructure. Models come and go; your context persists. And once you have a Supabase project, you've unlocked the foundation for everything else you'll want to build — the Second Brain is just the beginning.
- OpenRouter — your AI gateway. One API key, every model. Embeddings and LLM calls for classification and routing. Swap models by changing a string. Future-proof by design.
Everything else — how you capture thoughts, how you retrieve them, what you build on top — is application layer. The skill covers the foundation.
If the tables don't exist yet, see
{baseDir}/references/setup.md
Building Blocks
These are the operational concepts behind the system. Understanding them helps you operate correctly.
| Block | What It Does | Implementation |
|---|---|---|
| Drop Box | One frictionless capture point | Everything goes to thoughts first |
| Sorter | AI classification + routing | LLM classifies type, then routes to structured table |
| Form | Consistent data contracts | Each table has a defined schema |
| Filing Cabinet | Source of truth per category | people, projects, ideas, admin tables |
| Bouncer | Confidence threshold | confidence < 0.6 = don't route, stay in inbox |
| Receipt | Audit trail | thoughts row logs what came in, where it went |
| Tap on the Shoulder | Proactive surfacing | Daily digest queries (application layer) |
| Fix Button | Agent-mediated corrections | Move records between tables on user request |
Full conceptual framework: {baseDir}/references/concepts.md
Five Tables
| Table | Role | Key Fields |
|---|---|---|
thoughts |
Inbox Log / audit trail | content, embedding, metadata (type, topics, people, confidence, routed_to) |
people |
Relationship tracking | name (unique), context, follow_ups, tags, embedding |
projects |
Work tracking | name, status, next_action, notes, tags, embedding |
ideas |
Insight capture | title, summary, elaboration, topics, embedding |
admin |
Task management | name, due_date, status, notes, embedding |
Every table has semantic search via its own match_* function. Cross-table search via search_all.
Routing Rules
When a thought is classified:
| Type | Route | Action |
|---|---|---|
person_note |
people |
Upsert: create person or append to existing context |
task |
admin |
Insert new task (status=pending) |
idea |
ideas |
Insert new idea |
observation |
none | Stays in thoughts only |
reference |
none | Stays in thoughts only |
If confidence < 0.6, don't route. Leave in thoughts, tell user.
Quick Start
Capture a thought (full pipeline)
# 1. Embed
EMBEDDING=$(curl -s -X POST "https://openrouter.ai/api/v1/embeddings"
-H "Authorization: Bearer $OPENROUTER_API_KEY"
-H "Content-Type: application/json"
-d '{"model": "openai/text-embedding-3-small", "input": "Sarah mentioned she is thinking about leaving her job to start consulting"}'
| jq -c '.data[0].embedding')
# 2. Classify (run in parallel with step 1)
METADATA=$(curl -s -X POST "https://openrouter.ai/api/v1/chat/completions"
-H "Authorization: Bearer $OPENROUTER_API_KEY"
-H "Content-Type: application/json"
-d '{"model": "openai/gpt-4o-mini", "response_format": {"type": "json_object"}, "messages": [{"role": "system", "content": "Extract metadata from the captured thought. Return JSON with: type (observation/task/idea/reference/person_note), topics (1-3 tags), people (array), action_items (array), dates_mentioned (array), confidence (0-1), suggested_route (people/projects/ideas/admin/null), extracted_fields (structured data for destination table)."}, {"role": "user", "content": "Sarah mentioned she is thinking about leaving her job to start consulting"}]}'
| jq -r '.choices[0].message.content')
# 3. Store in thoughts (the Receipt)
curl -s -X POST "$SUPABASE_URL/rest/v1/thoughts"
-H "apikey: $SUPABASE_SERVICE_ROLE_KEY"
-H "Authorization: Bearer $SUPABASE_SERVICE_ROLE_KEY"
-H "Content-Type: application/json"
-H "Prefer: return=representation"
-d "[{"content": "Sarah mentioned she is thinking about leaving her job to start consulting", "embedding": $EMBEDDING, "metadata": $METADATA}]"
# 4. Route based on classification (if confidence >= 0.6)
Full pipeline with routing logic: {baseDir}/references/ingest.md
Semantic search (single table)
QUERY_EMBEDDING=$(curl -s -X POST "https://openrouter.ai/api/v1/embeddings"
-H "Authorization: Bearer $OPENROUTER_API_KEY"
-H "Content-Type: application/json"
-d '{"model": "openai/text-embedding-3-small", "input": "career changes"}'
| jq -c '.data[0].embedding')
curl -s -X POST "$SUPABASE_URL/rest/v1/rpc/match_thoughts"
-H "apikey: $SUPABASE_SERVICE_ROLE_KEY"
-H "Authorization: Bearer $SUPABASE_SERVICE_ROLE_KEY"
-H "Content-Type: application/json"
-d "{"query_embedding": $QUERY_EMBEDDING, "match_threshold": 0.5, "match_count": 10, "filter": {}}"
Cross-table search
curl -s -X POST "$SUPABASE_URL/rest/v1/rpc/search_all"
-H "apikey: $SUPABASE_SERVICE_ROLE_KEY"
-H "Authorization: Bearer $SUPABASE_SERVICE_ROLE_KEY"
-H "Content-Type: application/json"
-d "{"query_embedding": $QUERY_EMBEDDING, "match_threshold": 0.5, "match_count": 20}"
Returns table_name, record_id, label, detail, similarity, created_at from all tables.
List active projects
curl -s "$SUPABASE_URL/rest/v1/projects?status=eq.active&select=name,next_action,notes&order=updated_at.desc"
-H "apikey: $SUPABASE_SERVICE_ROLE_KEY"
-H "Authorization: Bearer $SUPABASE_SERVICE_ROLE_KEY"
List pending tasks
curl -s "$SUPABASE_URL/rest/v1/admin?status=eq.pending&select=name,due_date,notes&order=due_date.asc"
-H "apikey: $SUPABASE_SERVICE_ROLE_KEY"
-H "Authorization: Bearer $SUPABASE_SERVICE_ROLE_KEY"
Ingest Pipeline
When content arrives from any source:
- Embed the text via OpenRouter (1536-dim vector)
- Classify via OpenRouter LLM (type, topics, people, confidence, suggested route)
- Log in
thoughts(the Receipt — always, regardless of routing) - Bounce check — if confidence < 0.6, stop here
- Route to structured table based on type (the Sorter)
- Confirm to the user what was captured and where it was filed
Full pipeline details: {baseDir}/references/ingest.md
Metadata Schema
Every thought gets classified with:
| Field | Type | Values |
|---|---|---|
type |
string | observation, task, idea, reference, person_note |
topics |
string[] | 1-3 short topic tags (always at least one) |
people |
string[] | People mentioned (empty if none) |
action_items |
string[] | Implied to-dos (empty if none) |
dates_mentioned |
string[] | Dates in YYYY-MM-DD format (empty if none) |
source |
string | Where it came from: slack, signal, cli, manual, etc. |
confidence |
float | LLM classification confidence (0-1). The Bouncer uses this. |
routed_to |
string | Which table the thought was filed into (null if unrouted) |
routed_id |
string | UUID of the record in the destination table (null if unrouted) |
References
- Conceptual framework:
{baseDir}/references/concepts.md - First-time setup:
{baseDir}/references/setup.md - Database schema (SQL):
{baseDir}/references/schema.md - Ingest pipeline details:
{baseDir}/references/ingest.md - Retrieval operations:
{baseDir}/references/retrieval.md - OpenRouter API patterns:
{baseDir}/references/openrouter.md
Env Vars
| Variable | Service |
|---|---|
SUPABASE_URL |
Supabase project REST base URL |
SUPABASE_SERVICE_ROLE_KEY |
Supabase auth (full access) |
OPENROUTER_API_KEY |
OpenRouter API key |
Security Notes
Why service_role key? Supabase provides two keys: anon (public, respects RLS) and service_role (full access, bypasses RLS). This skill uses service_role because:
- This is a single-user personal knowledge base, not a multi-tenant app
- Your agent IS the trusted server-side component
- The RLS policy restricts access to
service_roleonly — the most restrictive option - Using the
anonkey would require loosening RLS to allow anonymous access to your thoughts, which is worse
Data sent to OpenRouter: All captured text (thoughts, names, action items) is sent to OpenRouter for embedding and classification. This is inherent to the design — you need AI to understand meaning. Don't capture highly sensitive information unless you accept OpenRouter's data handling policies.
Key handling: Store SUPABASE_SERVICE_ROLE_KEY and OPENROUTER_API_KEY securely. Never commit them to public repos. Rotate periodically. In OpenClaw, store them in openclaw.json under skills.entries or as environment variables.
Built by Limited Edition Jonathan • natebjones.com