Omnicost for ChatGPT

com.omnicost/catalog

Construction unit prices with source and date for Spain, the US and the EU. OAuth or API key.

client:ChatGPT transport:streamable-http tools:4

Install Omnicost in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://omnicost.com/api/mcp

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