knowledge-persistence

Knowledge Persistence

Knowledge persistence is about capturing what you learn during sessions so future sessions start smarter. This includes corrections, discovered patterns, user preferences, and debugging insights.

When to Use

• User corrects a mistake originating from stored memory
• You discover a pattern that applies broadly to the project
• A debugging session reveals a non-obvious root cause
• User states a preference ("always do X", "never use Y")
• You solve a problem that is likely to recur

Core Patterns

Learning from Corrections

When the user corrects you, the correction invalidates stored knowledge. Fix the source immediately:

User: "We don't use Express anymore, we migrated to Fastify"

# WRONG: Just acknowledge and continue
"Got it, I'll use Fastify."

# RIGHT: Update memory, then continue
1. Edit memory/MEMORY.md:
   Old: "Framework: Express"
   New: "Framework: Fastify (migrated from Express)"

2. Check topic files for stale Express references:
   Edit memory/architecture.md if it mentions Express

3. Then continue with correct context

The correction means the stored memory is wrong. Fix it at the source before continuing, so the same mistake does not repeat.

Instinct Capture

When you notice yourself repeatedly making the same decision, capture it:

# memory/patterns.md

## Project-Specific Instincts

### Error Handling
- This project always wraps service calls in try/catch at the route level
- Errors are logged with structuredLogger.error(), not console.error()
- All error responses use the AppError class from src/errors.ts

### Naming
- Database functions: findX, createX, updateX, deleteX (not getX, setX)
- Route handlers: handleGetUser, handleCreateUser (not getUser, createUser)
- Test files: same name with .test.ts suffix, same directory

Pattern Extraction

After seeing a pattern in 3+ locations, extract it to memory:

# Observation across multiple files:
# - src/routes/users.ts uses Zod schema + validate middleware
# - src/routes/posts.ts uses Zod schema + validate middleware
# - src/routes/comments.ts uses Zod schema + validate middleware

# Extract to memory/patterns.md:
## Input Validation Pattern
All route handlers use Zod schemas for request validation:
1. Schema defined in src/schemas/{resource}.ts
2. validate(schema) middleware applied to route
3. Handler receives typed, validated body via req.validated

Example:
  const schema = z.object({ title: z.string().min(1) })
  router.post('/', validate(schema), handleCreatePost)