Prerequisites
- Docker installed and running
- OpenAI API key
Setup Steps
1
Set Your API Key
2
Create Environment File
3
Start the Server
4
Verify the Server
Persist Data
By default, the container removes its local data when it stops. Use a bind mount or named Docker volume if you want memory to survive restarts.cognee_data with either:
- A named Docker volume, such as
cognee_data:/app/data - A local directory path, such as
./cognee_data:/app/data
Kuzu/Ladybug JSON Extension
The default Ladybug (Kuzu) graph backend needs its JSON extension for graph queries that rely on JSON — includingrecall and temporal search. The cognee/cognee-mcp image pre-installs this extension at build time, so it is baked into the image even when the container has no network access at runtime. Pulling the latest image (or rebuilding it) ensures the extension is present.
If you run the MCP server in a network-restricted container that does not already contain the extension, the adapter attempts a one-time runtime INSTALL JSON; LOAD JSON; on startup. When it cannot install or load the extension, it logs a warning explaining that JSON-dependent queries (such as recall and temporal search) will otherwise fail with Extension: json ... has not been installed. To resolve it, give the process network access at startup, use an image that already bundles the extension, or run INSTALL json; LOAD json; once against the database.
API Mode (Shared Knowledge Graph)
To connect multiple clients to a shared knowledge graph, run MCP in API mode pointing to a centralized Cognee backend:1
Start Cognee Backend
First, start a Cognee backend instance:
2
Start MCP in API Mode
Start the MCP server and point it to the backend:The container rewrites
localhost / 127.0.0.1 in API_URL to a host-reachable address so the MCP container can reach a backend running on your host machine. The entrypoint auto-detects the address using the following fallback order: host.docker.internal (Docker Desktop), then host.lima.internal (Colima / Lima), then the container’s default gateway IP (plain Linux Docker, typically 172.17.0.1). If none resolve it keeps host.docker.internal and prints guidance. This means Docker Desktop, Colima, and plain Linux Docker generally work without manual configuration. The MCP server now acts as an interface to the shared backend.3
Connect Additional Clients (Optional)
If you need to support multiple clients, start additional MCP instances on different ports:Each client connects to its own MCP instance, but all share the same knowledge graph through the backend.
- The API mode requires SSE or HTTP transport
- If
API_URLuseslocalhost/127.0.0.1, the container rewrites it to the first host address it can resolve:host.docker.internal(Docker Desktop), thenhost.lima.internal(Colima / Lima), then the default gateway IP (plain Linux Docker, typically172.17.0.1) - If auto-detection still fails, use
--network host(Linux) or setAPI_URLto a bridge address such ashttp://172.17.0.1:8000directly; on Colima, start the VM withcolima start --network-address - Add
-e API_TOKEN=your_tokenif your backend requires authentication - For backend authentication setup and how to obtain a Bearer token, see Deploy REST API Server
Docker Compose (Production Setup)
For production deployments, use Docker Compose to run the Cognee backend and MCP server together. This avoidslocalhost mapping issues and uses Docker’s internal DNS for service discovery.
docker-compose.yml
Networking notes:
- Use the service name (
cognee-backend) as the hostname inAPI_URL— Docker resolves it automatically within the same network. - Use the internal port (
8000) inAPI_URL, not the host-mapped port (8080). - If you place a reverse proxy (Nginx, Caddy) in front, you do not need to set a
Host: localhostheader — the backend accepts requests on any host. - Add
-e API_TOKEN=your_tokento the MCP service if your backend requires authentication.
Troubleshooting
Graph queries fail with 'Extension: json ... has not been installed'
Graph queries fail with 'Extension: json ... has not been installed'
The default Ladybug graph store (Kuzu) downloads a JSON extension at startup, which some graph queries (such as recall and temporal search) rely on. In a network-restricted container, that download can fail and queries surface a cryptic
Extension: json ... has not been installed Binder error.The published cognee/cognee-mcp image now bakes this extension in at build time, so pulling and running the latest image is enough. If you build the MCP image yourself, rebuild it after updating to pick up this change.When the extension still cannot be installed (for example, an offline container built without network access), the server now logs a clear warning at startup and attempts to install and load the extension directly on its database connection. To remediate, either give the process network access at startup, pre-install the extension in your image, or run INSTALL json; LOAD json; once against the database.Client gets repeated 404s on /sse (or /mcp)
Client gets repeated 404s on /sse (or /mcp)
The The
TRANSPORT_MODE environment variable sets which endpoint the container exposes, and it must match the URL your MCP client connects to. A 404 on /sse almost always means the client is pointed at the SSE endpoint while the server was started with TRANSPORT_MODE=http (or vice versa).stdio is the default when TRANSPORT_MODE is unset, so a network client (http/sse) needs the variable set explicitly, as in the Quickstart. To fix the 404, either change your client’s URL to match the running mode, or restart the container with the TRANSPORT_MODE your client expects:/health check answers on any of the network modes, so a healthy /health but a 404 on /sse or /mcp is a transport mismatch, not a server that failed to start. See Local Setup — Transport Modes for the full list of transports and their client configuration.Why is the image so large and why does it install NVIDIA/CUDA packages?
Why is the image so large and why does it install NVIDIA/CUDA packages?
The
cognee/cognee-mcp image is several GB because it bundles Cognee’s document-processing stack. The MCP package installs cognee[postgres-binary,docs,neo4j], and the docs extra pulls unstructured[pdf] for parsing PDFs, Office files, and other documents. That chain brings in heavy ML libraries — torch, torchvision, timm, onnxruntime, and opencv-python — used by unstructured-inference for layout/OCR models.The nvidia-*-cu12 (CUDA) packages you see during the build come from the default PyPI torch wheel, which bundles the CUDA runtime as hard dependencies. They are installed regardless of whether a GPU is present, and account for most of the image size. No GPU or NVIDIA driver is required to run the server — these libraries simply ship with the standard torch wheel and fall back to CPU.There is currently no published slim / CPU-only image variant, but a CPU-only image is on the way. If you don’t need document parsing and want a smaller build today, remove the docs extra from cognee-mcp/pyproject.toml, regenerate cognee-mcp/uv.lock, and build a custom image from the source Dockerfile. The Dockerfile uses uv sync --frozen, so the lockfile must match the edited dependency set. Removing docs drops the unstructured, torch, and CUDA dependencies. See Local Setup for building from source.Connect to AI Clients
After starting the server, connect it to your AI development tool:Cursor
AI-powered code editor with native MCP support
Claude Code
Command-line AI assistant from Anthropic
Codex
OpenAI coding agent with built-in MCP support
Cline
VS Code extension for AI-assisted development
Continue
Open-source AI coding assistant
Python Agent
Build your own MCP client
Next Steps
Tools Reference
See all available MCP tools and operations
Local Setup
Run from source for customization and development