MCP server

NexaCloser runs a Model Context Protocol server. Connect an AI client to it and the client can look up contacts, move deals, book meetings, send WhatsApp messages, run automations and manage ad campaigns in your workspace, with your permissions.

Endpoint	https://api.nexacloser.com/mcp
Transport	Streamable HTTP (JSON-RPC 2.0 over POST)
Protocol version	2025-06-18
Sign-in	OAuth 2.1 (automatic in most clients), an MCP server token, or an API key
Tools	See the tool reference

How it works

1. You create an MCP server in NexaCloser: a named, revocable identity for one AI client, for example Claude Desktop or Cursor.
2. You add https://api.nexacloser.com/mcp to the client. Clients that support OAuth open a NexaCloser sign-in page where you pick which MCP server to authorize.
3. The client lists the tools and calls them as you ask. Every call acts in your workspace.

Step by step: Connect an AI client.

What a client can see

Tools act in one workspace: the one the MCP server or key belongs to.

• Contacts and deals follow the same rules as the Contacts page in the app: deleted records are never shown, and a team member set to Only see assigned records sees only the contacts and deals assigned to them or created by them. Owners, admins and managers see the whole team.
• Automations, calendars, bookings, ad accounts and campaigns are read across the workspace, teammates’ included, and never across workspaces.
• Messages and ad changes go out through the workspace’s own connections (WhatsApp, SMS, Google, Meta, TikTok). A tool that needs a connection you have not set up answers with an error that says so.

Read and write tools

Every tool is either read (only looks at data) or write (changes data, sends a message or changes an ad account). The server marks read tools with readOnlyHint: true in tools/list, so clients can run them without asking you each time. A read-only MCP server (scope mcp:read) can call only read tools.

Write tools that change ad accounts accept dry_run: true where shown in the tool reference, so the client can preview a change before making it.

Errors

A tool that fails still answers with HTTP 200 and a JSON-RPC result whose isError is true; the text says why (for example a missing connection, a tool the MCP server is not allowed to use, or a scope that is missing). A bad or missing credential answers HTTP 401 with JSON-RPC error -32001 Unauthorized.