SignalHire runs its own remote MCP server at https://mcp.signalhire.services/mcp, included on every paid plan. In Claude you add it as a custom connector and sign in with your SignalHire login (OAuth), so no key is typed, and ChatGPT connects through SignalHire's listing in its app directory. Claude Code, Cursor, VS Code, Windsurf, Codex and n8n connect with your SignalHire API key as a bearer token. Either way the account needs an API key generated first, or every call is refused. It exposes eleven tools: search profiles with Boolean filters, read full profiles without contacts, reveal emails and phone numbers, look up companies and headcount, and check your credits. Searches and profile reads cost no contact credits. A contact reveal costs 1 contact credit per match and a company lookup 1 company credit, and the assistant asks your permission before spending either.