Memory System — Persistent Cross-Session Memory
Enables agents to remember across sessions. Never re-discover what was already learned.
Overview
The Memory System provides persistent, searchable memory that survives across sessions. Instead of re-explaining preferences, conventions, and past decisions every time, agents read a structured MEMORY.md index and topic files.
Token Impact: +1,000 tokens to load index, but saves 3,000-10,000 tokens by eliminating re-discovery.
Architecture
.agents/memory/
├── MEMORY.md ← Lightweight index (max 200 lines)
├── user-preferences.md ← Topic file: user role, style, tools
├── project-conventions.md ← Topic file: coding standards, patterns
├── tech-decisions.md ← Topic file: past architectural decisions
├── feedback-history.md ← Topic file: what user liked/disliked
└── [topic-name].md ← Additional topic files as needed
MEMORY.md Index Format
The index is a lightweight pointer file — short entries that reference topic files for details.
Rules:
- Maximum 200 lines total
- Each entry: ~150 characters max
- Format:
- [type] summary → topic-file.md - Types:
[user][feedback][project][reference]
Example:
# Memory Index
## User
- [user] Prefers dark mode, uses Windows 11, PowerShell → user-preferences.md
- [user] Senior DevOps engineer, 8 years experience → user-preferences.md
- [user] Primary language: English, sometimes Turkish → user-preferences.md
## Project
- [project] Always use bun instead of npm → project-conventions.md
- [project] Tailwind v4 preferred, no v3 → tech-decisions.md
- [project] No purple/violet colors in UI → project-conventions.md
## Feedback
- [feedback] User likes concise responses, no filler → feedback-history.md
- [feedback] User dislikes verbose explanations → feedback-history.md
- [feedback] User prefers tables over bullet lists → feedback-history.md
## Reference
- [reference] Squid proxy runs on port 3128 → infrastructure-notes.md
- [reference] Git workflow: feature branches → main → project-conventions.md
Topic File Format
Each topic file has frontmatter and structured content:
---
type: user | feedback | project | reference
created: 2026-04-01
updated: 2026-04-01
---
# User Preferences
## Development Environment
- OS: Windows 11
- Shell: PowerShell
- Editor: Cursor / Windsurf
- Package Manager: bun (NOT npm)
## Communication Style
- Prefers concise responses
- Likes tables for comparisons
- Dislikes verbose explanations
Memory Taxonomy
| Type | What to Store | Example |
|---|---|---|
| user | Role, preferences, tools, communication style | "Senior DevOps, prefers dark mode" |
| feedback | What user liked/disliked about agent output | "User said 'too verbose', prefers tables" |
| project | Coding standards, tech choices, conventions | "Use bun not npm, Tailwind v4" |
| reference | Non-sensitive infrastructure notes, public URLs, configs | "Prod API hostname and port" |
What NOT to Save
| Don't Save | Why |
|---|---|
| Secrets, credentials, tokens, passwords, private keys, or API keys | Memory is persistent and may be shared across sessions |
| Information derivable from code | Read package.json instead of memorizing deps |
| Temporary debug context | Clutters memory, not useful later |
| Exact code snippets | Code changes — memory becomes stale |
| File paths that may move | Use glob patterns or descriptions instead |
| Entire conversation transcripts | Memory is for distilled insights only |
Operations
Save (Trigger: user says "remember", "save", "don't forget")
- Identify the information type (user/feedback/project/reference)
- Check if relevant topic file exists
- If yes → append to existing topic file
- If no → create new topic file with frontmatter
- Update MEMORY.md index with one-line pointer
- Confirm to user: "Saved to memory: [summary]"
Recall (Trigger: session start, or "what do you remember about X")
- Read
.agents/memory/MEMORY.mdindex - Scan for relevant entries matching the current task
- If match found → read the referenced topic file
- Apply recalled context silently (don't recite memories unless asked)
Search (Trigger: "do I have any notes about X")
- Grep across
.agents/memory/*.mdfor the search term - Return matching entries with file references
- Offer to read full topic file if user wants details
Prune (Trigger: index exceeds 200 lines)
- Warn: "Memory index is getting large (X lines). Review recommended."
- Suggest merging related entries
- Suggest archiving old entries to
memory/archive/ - Never auto-delete — always ask user first
Session Start Protocol
At the start of every session:
1. Check: Does `.agents/memory/MEMORY.md` exist?
→ YES: Read index. Apply relevant context silently.
→ NO: Continue without memory. Create on first "remember" trigger.
2. Apply memory WITHOUT reciting it.
❌ WRONG: "I remember you prefer dark mode and use bun..."
✅ RIGHT: (silently apply preferences, use bun in commands)
3. Exception: If user asks "what do you remember?" → recite relevant memories.
Memory vs. Plan vs. Task
| Artifact | Purpose | Lifespan | Location |
|---|---|---|---|
| Memory | Cross-session knowledge | Permanent until pruned | .agents/memory/ |
| Plan | Task breakdown for current project | Until project complete | Project root |
| Task | Progress tracker for current session | Until session ends | Artifact directory |
Memory = what you KNOW. Plan = what you'll DO. Task = what you're DOING NOW.