GPT-5.1-Codex

Test planned changes, test execution, dependency updates, review quality, and any image or screenshot inputs in a controlled repository.

Use representative tasks and compare quality, latency, token use, and relevant tool behavior with your current model. Start with a scoped coding task, version control, and explicit acceptance tests before expanding to more autonomous workflows.

gpt-5.1-codex supports prompt caching, which can significantly reduce costs for repeated prompts with shared prefixes. The cache read price is substantially lower than the standard input price. Check the current pricing page for the exact cache hit discount ratio for gpt-5.1-codex.

Set task boundaries, review requirements, failure handling, and monitoring that match the consequences of the workload. Do not rely on an unevaluated model response for irreversible actions.

gpt-5.1-codex supports up to 128000 output tokens per request. Plan your prompts to stay within this limit, and use the max_tokens or max_completion_tokens parameter to control output length.

GPT-5.1-Codex uses a single published rate for input, regardless of request length; see the pricing table for the applicable amount.

GPT-5.1-Codex is billed per use and the record publishes no free-tier allowance. The current published rates are input $1.2500 per 1M tokens and output $10.0000 per 1M tokens. Trial credit or promotional quota is tied to your account rather than to the model, so check the console before planning around a free tier.