OpenAI Responses API + MCP in Practice: From Function Calling to Agent Workflows

If you’ve already used function calling but keep writing glue code for every non-trivial task, you’re likely at the point where Responses API + MCP makes more sense. This guide is practical: how to move from single tool calls to a scalable agent workflow where retrieval, execution, validation, and write-back follow a consistent structure. ...

February 11, 2026 · 3 min · mengboy