DataLink semantic service¶

DataLink is an optional semantic graph service for DataFoundry. It connects schemas and profiles to business concepts, entities, join paths, and confidence-scored relationships. The implementation is included under services/datalink, but it runs as a separate Python service.

Runtime topology¶

Process	Default endpoint	Purpose
DataLink MCP	`http://127.0.0.1:8080/mcp`	Exposes `datalink_explore` for agent grounding
DataLink REST	`http://127.0.0.1:8081`	Graph management and visualization API

DataFoundry's Web and API processes remain unchanged. DataLink is not started by deploy.sh or npm run start; start it separately when semantic grounding is needed.

Install and start¶

From the service directory, install Python 3.10+ and uv:

cd services/datalink
uv pip install -e .
cp datalink_config.example.json datalink_config.json

Set the LLM and embedding provider in datalink_config.json, then start both processes in separate terminals:

uv run datalink serve --port 8080 --transport streamable-http
uv run datalink api --port 8081

The service README contains provider examples and CLI commands for building and exploring a graph.

Connect it in DataFoundry¶

In the Web workbench, open MCP settings and add an external server with:

Field	Example
`serverUrl`	`http://127.0.0.1:8080/mcp`
`apiUrl`	`http://127.0.0.1:8081`
`transport`	`streamable-http`
`toolManifest`	`[{ "name": "datalink_explore" }]`

Use a name or id containing datalink so the DataLink panel recognizes the server.

Verify¶

curl http://127.0.0.1:8081/healthz

If the panel reports the service as unavailable, check both processes, ports 8080 and 8081, the configured graph path, and the MCP transport. Keep API keys in environment variables or a secret manager; do not commit them to datalink_config.json.