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 --python 3.13 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. The --python 3.13 argument has uv run the server on Python 3.13 (downloading it if needed), as some of the server’s dependencies don’t yet install on Python 3.14. 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 works for Anthropic’s Claude clients only: other clients can’t register with the sign-in service, so their sign-in fails. 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. Note that some tools support neither: ChatGPT on the web, for example, is remote-only and has no custom-header or token field. If you need sign-in for a specific client, contact Oceanum.

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.