can i combine tools like web_search with my own tools + mcp server (FastMCP), since that I’ve heard that with other providers you can’t do that.
You can offer the tools to the AI, including the internal hosted web search tool on the Responses API:
And then if your tool is more relevant than searching and is the only one logical to be used, it can be called:
However, you won’t like the results in general: When web search tool is called, OpenAI injects their own system message after the results, telling the model what to write and what to cite from web search return. This instruction not only takes over your application and makes solely a “search results” page, it is essentially impossible for the AI to disobey and then call your own tools after.