# SurrealDB Cache Authentication Fix

## Problem

Node publishing was showing a yellow warning notification:
```
Node published to Bluesky, but cache update failed. Advanced features may be unavailable.
```

Server logs showed:
```
[POST /api/nodes] ⚠ SurrealDB cache write failed (non-critical):
Error [ResponseError]: There was a problem with the database: There was a problem with authentication
```

## Root Cause

The `connectToDB()` function in `lib/db.ts` was attempting to authenticate with SurrealDB using our application's custom JWT token:

```typescript
await db.authenticate(token);
```

However, SurrealDB doesn't know how to validate our custom JWT tokens. The `db.authenticate()` method is for SurrealDB's own token-based authentication system, not for validating external JWTs.

## Solution

Changed `connectToDB()` to use root credentials instead:

### Before:
```typescript
export async function connectToDB(token: string): Promise<Surreal> {
  const db = new Surreal();
  await db.connect(SURREALDB_URL);
  await db.authenticate(token); // ❌ This fails
  await db.use({ namespace, database });
  return db;
}
```

### After:
```typescript
export async function connectToDB(): Promise<Surreal> {
  const db = new Surreal();
  await db.connect(SURREALDB_URL);
  await db.signin({
    username: SURREALDB_USER, // ✅ Use root credentials
    password: SURREALDB_PASS,
  });
  await db.use({ namespace, database });
  return db;
}
```

## Data Security

Since we're now using root credentials instead of JWT-based authentication, we maintain data isolation by:

1. **Extracting user_did from the verified JWT** in API routes
2. **Filtering all queries by user_did** to ensure users only access their own data

Example from `/app/api/nodes/route.ts`:
```typescript
// Verify JWT to get user's DID
const userSession = verifySurrealJwt(surrealJwt);
const { did: userDid } = userSession;

// Create node with user_did field
const nodeData = {
  user_did: userDid, // ✅ Enforces data ownership
  atp_uri: atp_uri,
  title: title,
  body: body,
  embedding: embedding,
};
await db.create('node', nodeData);
```

Example from `/app/api/suggest-links/route.ts`:
```typescript
// Query filtered by user_did
const query = `
  SELECT * FROM node
  WHERE user_did = $user_did  // ✅ Only user's own nodes
  ORDER BY score DESC
  LIMIT 5;
`;
await db.query(query, { user_did: userDid });
```

## Files Changed

1. `/lib/db.ts` - Changed authentication method
2. `/app/api/nodes/route.ts` - Removed JWT parameter from `connectToDB()` call
3. `/app/api/suggest-links/route.ts` - Updated to use root credentials and filter by `user_did`

## Test

Created `/tests/magnitude/cache-success.mag.ts` to verify:
- Node publishes successfully
- GREEN success notification (not yellow warning)
- No "cache update failed" message

## Verification

After the fix, server logs show:
```
[POST /api/nodes] ✓ Published to ATproto PDS
[POST /api/nodes] ✓ Generated embedding vector
[POST /api/nodes] ✓ Cached node in SurrealDB
POST /api/nodes 200 in 1078ms
```

No more authentication errors! 🎉

## Architecture Note

This implements the "App View Cache" pattern where:
- **ATproto PDS** is the source of truth (decentralized, user-owned)
- **SurrealDB** is a performance cache (centralized, app-managed)

The cache uses root credentials but enforces data isolation through `user_did` filtering in application code, similar to how the OAuth session store works (`lib/auth/oauth-session-store.ts`).