GPT-5.1 for developers

OpenAI's GPT-5.1 line focuses on deeper tool use, longer context, and steadier behavior for production apps.

What changed

• Tool calling stability: better argument shaping and lower invalid-call rates.
• Longer context: improved recall and compression for multi-turn sessions.
• Steadier outputs: reduced style drift between calls and fewer formatting regressions.

Migration tips

• Re-evaluate temperature or top-p; 5.1 may need slightly lower sampling to stay concise.
• Refresh evals that cover function calling, JSON formatting, and safety refusals.
• Update safety filters and red-team prompts; new capabilities can surface new risks.

Where it shines

• Research agents that search, cite, and synthesize across many sources.
• Workflow copilots that call multiple tools such as tickets, docs, and dashboards in one session.
• Voice or real-time agents that need consistent latency and structured replies.

Next steps: run A or B tests against your current model, watch tool-call correctness and latency, then cut over when KPIs hold.