Dutyfinch for ChatGPT

dev.workers.cybermax-tools.cybermax/dutyfinch

US tariff API + MCP: HTS duty rates, Section 301 lists. Keys $19/mo; 50 free calls a day.

client:ChatGPT transport:streamable-http tools:4

Install Dutyfinch in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://dutyfinch.cybermaxtools.com/mcp?via=mcp-registry

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