Invoice Simple MCP Server and API by Cotlet for ChatGPT

dev.cotlet/invoice-simple

Invoice Simple small business invoicing MCP server: create invoice, send invoice, create estimate.

client:ChatGPT transport:streamable-http

Install Invoice Simple MCP Server and API by Cotlet in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://cotlet.dev/mcp/v1/invoice-simple/connect

Custom connectors are a paid-plan feature and take a remote URL only. ChatGPT cannot run a packaged server locally. ChatGPT docs