gpt-6.1-sol

Publication date: 2026-09-30 Fix GPT-6.1 Sol tool calls: migrate a complete loop to Responses

If an application switches its model name to gpt-6.1-sol and its tools stop working, check the endpoint before changing the prompt. GPT‑6.1 Sol supports tool calling through the Responses API; its Chat Completions support excludes tool calling. It also rejects the none and minimal reasoning levels. A model-name-only migration can therefore leave a valid old request incompatible with the new model.

This tutorial migrates a small read-only inventory tool through the full request–tool–result cycle. It includes a downloadable Python implementation and offline tests. Those tests validate our application logic with synthetic responses; they are not a paid API test or a model-performance benchmark. Facts were checked on September 30, 2026 against the model documentation , migration guide , and function-calling guide .

Read from the provider's text; the quote is the provider's exact lines.

To use GPT‑6.1 Sol in Codex, select it in an eligible client’s model control or launch the CLI with codex --model gpt-6.1-sol.

Read from the provider's text; the quote is the provider's exact lines.