GPT-6.1 Sol Flex
Use it free in free-pi
slower, half price · ~0.05x usage
npx free-pi-cli
/model gpt-6.1-sol-flexAbout GPT-6.1 Sol Flex
GPT-6.1 Sol Flex is the same model as GPT-6.1 Sol, OpenAI's agentic coding model, served on OpenAI's flex tier, which is slower and cheaper. The model is unchanged: the same context window of about 1,050,000 tokens, the same text, image, and file input, and the same reasoning, tool calling, and structured output support. The agent can still read and edit files, run commands, and use free-pi's web search and documentation tools.
The difference is speed and allowance. Responses are slower on the flex tier, and the model uses less of your daily allowance. In free-pi it counts as about 0.05x usage, compared with about 0.02x for the regular version, so your allowance lasts a bit more than twice as long. It is still free with no API key and no card.
When to pick it
For GPT-6.1 Sol's quality on work that is not urgent, such as a large refactor or a long investigation, pick GPT-6.1 Sol Flex. It suits work where saving allowance matters more than fast replies.
For faster responses, pick the regular GPT-6.1 Sol. For everyday work that uses far less allowance, pick the default DeepSeek V4 Flash.