GPT-5.5 with the Responses API: Reasoning Effort, Tools, and Long Tasks May 8, 2026 Use a fixed GPT-5.5 snapshot in a controlled Responses API tool loop with reasoning policy, validation, idempotent execution, and recoverable checkpoints.
A First Look at GPT-5.5: Evaluating Capability for Real Work Apr 27, 2026 Evaluate GPT-5.5 on frozen tasks, hidden acceptance, tool traces, blinded review, and total task cost after its April 2026 API availability.