Lead Accounting Plus MCP server (official ModelContextProtocol C# SDK)
MCP endpoint: /mcp (Streamable HTTP, JSON-RPC 2.0)
Modules: accounting (Lead API), CRM (crm_* tools) and HRMS (hr_* tools).
  Limit a connection with ?modules=lead,crm,hrms (any subset), e.g. /mcp?modules=crm

Auth (preferred): OAuth 2.1 — connect from an MCP client and you will be
  taken to a Lead sign-in page. Discovery: /.well-known/oauth-protected-resource

Auth (alternatives): X-Lead-* headers, ?comid=..&comkey=..&userid=..&password=..
  on the URL, or LEAD_* environment variables (single-tenant).