ChromaDB Memory
Long-term semantic memory backed by ChromaDB and local Ollama embeddings. Zero cloud dependencies.
What It Does
- Auto-recall: Before every agent turn, queries ChromaDB with the user's message and injects relevant context automatically
chromadb_search
tool: Manual semantic search over your ChromaDB collection- 100% local: Ollama (nomic-embed-text) for embeddings, ChromaDB for vector storage
Prerequisites
-
ChromaDB running (Docker recommended):
docker run -d --name chromadb -p 8100:8000 chromadb/chroma:latest
-
Ollama with an embedding model:
ollama pull nomic-embed-text
-
Indexed documents in ChromaDB. Use any ChromaDB-compatible indexer to populate your collection.
Install
# 1. Copy the plugin extension
mkdir -p ~/.openclaw/extensions/chromadb-memory
cp {baseDir}/scripts/index.ts ~/.openclaw/extensions/chromadb-memory/
cp {baseDir}/scripts/openclaw.plugin.json ~/.openclaw/extensions/chromadb-memory/
2. Add to your OpenClaw config (~/.openclaw/openclaw.json):
{
"plugins": {
"entries": {
"chromadb-memory": {
"enabled": true,
"config": {
"chromaUrl": "http://localhost:8100",
"collectionName": "longterm_memory",
"ollamaUrl": "http://localhost:11434",
"embeddingModel": "nomic-embed-text",
"autoRecall": true,
"autoRecallResults": 3,
"minScore": 0.5
}
}
}
}
}
# 4. Restart the gateway
openclaw gateway restart
Config Options
| Option | Default | Description |
|---|
chromaUrl
| http://localhost:8100
| ChromaDB server URL |
collectionName
| longterm_memory
| Collection name (auto-resolves UUID, survives reindexing) |
collectionId
| — | Collection UUID (optional fallback) |
ollamaUrl
| http://localhost:11434
| Ollama API URL |
embeddingModel
| nomic-embed-text
| Ollama embedding model |
autoRecall
| true
| Auto-inject relevant memories each turn |
autoRecallResults
| 3
| Max auto-recall results per turn |
minScore
| 0.5
| Minimum similarity score (0-1) |
How It Works
- You send a message
- Plugin embeds your message via Ollama (nomic-embed-text, 768 dimensions)
- Queries ChromaDB for nearest neighbors
- Results above
minScore
are injected into the agent's context as <chromadb-memories>
- Agent responds with relevant long-term context available
Token Cost
Auto-recall adds ~275 tokens per turn worst case (3 results × ~300 chars + wrapper). Against a 200K+ context window, this is negligible.
Tuning
- Too noisy? Raise
minScore
to 0.6 or 0.7
- Missing context? Lower
minScore
to 0.4, increase autoRecallResults
to 5
- Want manual only? Set
autoRecall: false
, use chromadb_search
tool
Architecture
User Message → Ollama (embed) → ChromaDB (query) → Context Injection
↓
Agent Response
No OpenAI. No cloud. Your memories stay on your hardware.
