How OpenClaw Remembers Everything
A technical exploration of the OpenClaw memory architecture that enables AI agents to maintain persistent context across sessions through hybrid search, intelligent compaction, and human-readable storage.
AI Agents Forget Everything
Every time you start a new conversation with an AI, it has no memory of your past interactions. Context is lost, decisions are forgotten, and you have to re-explain everything.
Session-Bound Context
Traditional LLMs lose all context when a session ends
Limited Context Windows
Even within sessions, there's a hard limit on how much can be remembered
OpenClaw's Solution
Persistent memory that survives sessions and context compaction
Traditional AI
OpenClaw
Each session builds on previous memories
The Big Picture
OpenClaw acts as a central hub, routing messages between channels and your AI agent while managing persistent memory.
Three Layers of Memory
OpenClaw uses a layered approach to memory storage, combining human-readable files with a searchable database.
Click each layer to see example code
1# ~/.openclaw/MEMORY.md2 3## Project Context4OpenClaw is a memory architecture for AI agents.5 6## Key Decisions7- SQLite for local storage8- Markdown for human readability9- Hybrid search for retrieval10 11## User Preferences12- Dark mode preferred13- TypeScript enthusiastExplore the Memory Files
OpenClaw stores memories in human-readable files. Click on any file to see its contents.
Select a file to preview its contents
MEMORY.md
The main memory file containing curated long-term knowledge, preferences, and key decisions.
Daily Logs
Automatic daily markdown files capturing conversations, insights, and TODOs from each day.
memory.sqlite
SQLite database with vector embeddings for semantic search across all stored memories.
Finding the Right Memory
OpenClaw combines vector similarity search with BM25 keyword matching to retrieve the most relevant memories.
Vector Search (Semantic)
Understands the meaning behind your words. When you ask "What did we decide about the API?", it finds memories about "REST endpoint design" even though the exact words don't match.
BM25 Search (Keyword)
Finds exact word matches with smart ranking. If you search for "PostgreSQL", it will find all mentions of that specific term, prioritizing documents where it appears frequently.
Why Combine Both?
Vector search alone might miss exact technical terms. Keyword search alone doesn't understand synonyms or context. By combining them with weighted scoring, OpenClaw gets the best of both worlds: semantic understanding plus precise term matching. This is especially important for technical content where both concepts and specific terminology matter.
Step 1: Query Input
The user's question is received and prepared for hybrid search
Convert query to embedding for semantic similarity matching
Tokenize query for keyword frequency matching
Search Approach Comparison
| Aspect | Vector Only | Keyword Only | Hybrid |
|---|---|---|---|
| Semantic Understanding | Excellent - understands meaning | Poor - literal matching only | Excellent with precision boost |
| Exact Matches | May miss exact terms | Excellent - finds exact words | Best of both approaches |
| Typo Tolerance | Good - similar embeddings | None - exact match required | Good with fallback |
| Speed | Slower (ANN index) | Fast (inverted index) | Moderate (parallel search) |
Save Before You Forget
When context windows fill up, OpenClaw ensures important memories are saved before the LLM compresses or forgets them.
The Problem: Context Window Limits
LLMs have finite context windows. When they fill up, older information gets compressed or dropped entirely. Without intervention, valuable context about decisions, preferences, and ongoing work can be permanently lost.
Normal Operation
Agent is operating normally with plenty of context space available.
Implementation: Flush Trigger
1// Pre-compaction flush trigger2async function checkContextUsage(agent: Agent) {3 const usage = agent.getContextUsage();4 const threshold = 0.9; // 90%5 6 if (usage >= threshold) {7 console.log('Context threshold reached, initiating flush...');8 9 // Extract important memories from current context10 const memories = await agent.extractImportantMemories();11 12 // Write to daily log before compaction13 await writeToDailyLog(memories);14 15 // Signal that compaction can proceed safely16 return { canCompact: true, memoriesSaved: memories.length };17 }18 19 return { canCompact: false };20}21 22// Runs before each context compaction23agent.onBeforeCompaction(checkContextUsage);How It Works
Automatic Detection
Monitors context usage and triggers at 90% threshold
Memory Extraction
Identifies and extracts important information from context
Daily Log Storage
Writes memories to dated markdown files for persistence
Safe Compaction
Only allows compaction after memories are safely stored
Key Takeaways
OpenClaw's memory architecture solves the fundamental problem of AI amnesia with a practical, transparent approach.
Understanding AI Memory Systems
This technical deep dive demonstrates the key concepts behind OpenClaw's persistent AI memory: layered storage, hybrid retrieval, and intelligent context management. These patterns enable AI systems to maintain continuity across conversations and provide more contextual, personalized assistance.