Other MCP clients

Any MCP client can reach the Datamesh MCP server through one of two general patterns. The exact configuration keys differ between clients — check your client’s documentation — but the Oceanum-specific values below never change.

Hosted server (remote)

Add a remote (streamable-HTTP) MCP server pointing at:

https://mcp.oceanum.io/datamesh

and send your Datamesh token as a custom HTTP header:

X-DATAMESH-TOKEN: <your-datamesh-token>

Most clients express this as a server entry with a url (sometimes serverUrl) and a headers object. The hosted server is read-only and multi-tenant — each request runs as your user. query_data results come back inline (capped ~50 MB), so large results aren’t returned in the conversation; for those, call export_query, which on the hosted server returns a time-limited download link to the full result (fetch it out-of-band — no credential, so treat it as a secret). The local server below writes export_query output to a file instead.

Local server (stdio)

The local server writes export_query output to a file on your machine (rather than returning a download link) and gives full read/write access. Add a stdio MCP server that runs:

uvx oceanum-mcp datamesh

with your token supplied through the DATAMESH_TOKEN environment variable. This requires uv on your PATH, and gives full read/write including export_query to local files. If your client cannot set environment variables per server, export DATAMESH_TOKEN=... in the shell that launches the client.

A note on OAuth

The hosted server also offers an OAuth “sign in with Oceanum.io” flow, but it currently allowlists only Anthropic’s Claude clients’ callback URLs. A client that lets you set custom headers can still connect with the X-DATAMESH-TOKEN header (or send the Datamesh token as a bearer credential), and any client that runs local stdio servers can use the local server — but OAuth for other vendors is not yet enabled. Note that some tools support neither: ChatGPT, for example, is remote-only and has no custom-header field. If you need OAuth enabled for a specific client, contact Oceanum to have its callback URL registered.

Keep your token safe

Your Datamesh token grants access to all of your organisation’s permissioned datasources — including the ability to modify or delete them. Treat it as a secret, and prefer the hosted read-only server for exploratory use.