GPT-6.1 Tool Calling Moves to Responses: 3 Models, 5 Changes to Complete the Migration
Author’s note: if your agent still uses client.chat.completions.create with tools, switching to GPT-6.1 will land you at a very specific fork. Plain text still works, but tool calls need a different endpoint. Why Tool Calling Gets Blocked at the Endpoint After Upgrading to GPT-6.1 Here’s the short version: GPT-6 Astra, GPT-6.1 Sol, and GPT-6.1 Terra…