> ## Documentation Index > Fetch the complete documentation index at: https://docs.baselayer.com/llms.txt > Use this file to discover all available pages before exploring further. # MCP Overview > Connect Baselayer to Claude, ChatGPT or another AI assistant so it can run business verification for you. Know how sign-in, environments and billing work. The Baselayer MCP server exposes Baselayer's business verification products as tools that an AI assistant can call on your behalf. Connect it once and your assistant can run business searches in the US and abroad, screen names against watchlists, verify TINs, pull lien and litigation records, and analyze a business's online presence, all inside a normal conversation. The server implements the [Model Context Protocol](https://modelcontextprotocol.io) (MCP), an open standard supported by Claude, ChatGPT, Cursor, and most other AI clients. Baselayer hosts it as a remote server, so there is nothing to install or run yourself. | Page | What it covers | | - | - | | [MCP Tools](https://docs.baselayer.com/docs/mcp-tools.md) | Tools, parameters, and return values. | | [Claude](https://docs.baselayer.com/docs/claude.md) | Connect from Claude web, Desktop, or Code. | | [ChatGPT](https://docs.baselayer.com/docs/chatgpt.md) | Connect from ChatGPT web or desktop. | | [How to Use Baselayer with LLMs](https://docs.baselayer.com/docs/how-to-use-baselayer-with-llms.md) | Use an AI assistant to build your integration. | | [API Reference](https://docs.baselayer.com/api-reference) | Matching REST requests and responses. | ## Server details | Setting | Value | | - | - | | **Server URL** | `https://api.baselayer.com/mcp` | | **Transport** | Streamable HTTP | | **Authentication** | OAuth 2.1 or an API key via `X-API-Key` | | **Tools** | 19 (see [MCP Tools](https://docs.baselayer.com/docs/mcp-tools.md)) | ## How authentication works Connect with your Baselayer login through OAuth, or use an existing customer API key if your MCP client supports custom HTTP headers. Both methods use the same server URL and expose the same tools. ### OAuth: sign in with Baselayer When you add the server to an OAuth-capable client, the client discovers Baselayer's login page automatically. Sign in with your Baselayer credentials and approve the consent screen: "Search and verify businesses with Baselayer on your behalf". The client receives an OAuth token; no API key is required. Every OAuth tool call runs as you, scoped by the same organization membership and role permissions that govern your access in the [Baselayer Console](https://console.baselayer.com). If you do not have a Baselayer account yet, the login page links to [self-serve sign-up](https://console.baselayer.com/signup). ### API key: connect with custom headers Use an existing Baselayer customer API key with the same access you use for the REST API. No separate MCP key, grant, role, or opt-in is needed. Configure your client's remote MCP connection with: * Server URL: `https://api.baselayer.com/mcp` * Transport: Streamable HTTP * Custom header: `X-API-Key: ` Send that header on every request. API keys must go in `X-API-Key`, rather than a bearer token field. Configure the connection to use the key without OAuth: requests containing both `X-API-Key` and any `Authorization` header are rejected, as are duplicate `X-API-Key` headers. Tool calls use the key's permissions, grants, and organization/application scope, just as they do on the REST API. Organization keys with explicit grants must include `api`; exports-only and operator keys cannot use MCP. Keys without explicit organization grants retain their existing API access. An invalid or revoked key returns a `401` error; an exports-only or operator key returns `403`. Key authentication errors do not trigger an OAuth login challenge. Revocation and permission changes take effect on the next request or tool call; work already running is not cancelled. ## Organizations and applications ### With OAuth By default, tool calls run in your default organization and its production application. This is the right choice for most users. If you belong to several organizations, or want to work against a sandbox application, use a client that supports custom request headers: | Header | Effect | | - | - | | `X-Organization-ID` | Select an organization you are a member of. | | `X-Application-ID` | Select an application within that organization. | | `X-Federation-ID` | Select a federation you belong to. | See [Claude](https://docs.baselayer.com/docs/claude.md#add-baselayer-as-a-connector) for connection instructions. ### With an API key Organization keys are bound to their organization and application, including its sandbox or production environment. Request headers cannot switch an organization key to a different organization or application. To change the environment, use a key for the intended application. Federation keys retain their federation grants. To target an application, send `X-External-ID` with the target application's external ID, or send both `X-Organization-ID` and `X-Application-ID`. The target must belong to the key's federation, and the key must allow the target's sandbox or production environment. See [Sandbox vs. production environments](https://docs.baselayer.com/docs/sandbox-vs-production-environments.md) for how the two environments differ. ## Billing Tools that start a search or verification order the same paid work as the matching REST endpoint, at the same price, and appear in your usage the same way. Read tools (`get_*`) are free. `search_watchlists` writes one billable order per watchlist requested, so ask for only the watchlists you need. `search_international_business` bills each add-on in `options` separately, and `analyze_online_presence` adds an international surcharge for a business outside the US. Both charges apply when the request is submitted, whether or not it finds a match. ## Support Questions or issues connecting? Email [support@baselayer.com](mailto:support@baselayer.com) or check [status.baselayer.com](https://status.baselayer.com). This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.