Model Context Protocol

GSEIN MCP connector

Connect Claude, or any compatible MCP client, to the public GSEIN Verify service. Give it a complete GSEIN and it returns the legal name of the entity that holds it, exactly as GSEIN Verify on gsein.org does.

Server URLhttps://mcp.gsein.org/mcp

TransportStreamable HTTP

AuthenticationNone (public data)

AccessRead-only, one tool

Connect

Claude: add a custom connector and enter https://mcp.gsein.org/mcp as its URL. No account or sign-in is needed.
Other MCP clients: add a remote MCP server that uses the Streamable HTTP transport, with the same URL.

Tool: `verify_gsein`

Verifies one exact GSEIN and returns the public GSEIN Verify result. It is read-only and never changes anything.

Input: gsein, one complete GSEIN in the form GSEIN-XXXX-XXXX-XXXX-XXXX.

What it does not do: it does not search by company name, does not accept partial numbers or lists, and returns no registration numbers, addresses, contacts, sources or any other entity details. It cannot request, issue, activate or pay for a GSEIN.

Outcome	Structured result (the GSEIN Verify response)	Notes
Verified	`{"ok":true,"verified":true,"result":{"gsein_id":"GSEIN-…","name":"…"}}`	Includes a link to the public record on gsein.org.
Not found	`{"ok":true,"verified":false,"gsein":"GSEIN-…"}`	The GSEIN is well formed but identifies no entity in GSEIN Verify.
Invalid	`{"ok":false,"error":"INVALID_GSEIN"}`	Wrong format or check digits; nothing is looked up.
Unavailable	`{"ok":false,"error":"VERIFY_UNAVAILABLE"}`	Returned as a tool error; try again later.

Example prompts

Verify GSEIN-XXXX-XXXX-XXXX-XXXX.
Which entity does this GSEIN identify: GSEIN-XXXX-XXXX-XXXX-XXXX?
Check whether GSEIN-XXXX-XXXX-XXXX-XXXX is a valid GSEIN identifier.

Replace XXXX-XXXX-XXXX-XXXX with the 16 digits of a real GSEIN.

Limits and availability

One GSEIN per call. Requests are rate limited per client and in total; a client over the limit receives HTTP 429 and can retry after a minute.
Service status: /health.

Privacy

The connector receives only the GSEIN in each tool call. It does not receive or store your prompts, your conversation or any other context from your AI assistant, and it does not store the GSEINs you look up. See the connector privacy notice and the GSEIN Legal & Governance Policy.

Support

Questions or problems: hello@gsein.org.