GPT-5.5 Pro

At a glance

What GPT-5.5 Pro does

Vision, Tool use, Streaming, Structured output, Extended reasoning, Deep thinking, Function calling, Prompt caching

Best for

Hardest reasoning problems, math olympiad, research-grade analysis, mission-critical coding tasks where cost is no object

Works well with

Conflicts & caveats

• Trae's built-in model menu may not include GPT-5.5 Pro — Trae primarily ships with Claude/GPT/Gemini/DeepSeek.
• Kiro's spec mode is tuned for Claude models — GPT-5.5 Pro may work but spec-driven flows are best with Claude.
• Gemini CLI is locked to Google Gemini models — your LLM is GPT-5.5 Pro.
• Claude Code only works with Claude models — your LLM is GPT-5.5 Pro.
• Devin uses Cognition's proprietary model internally — your selected GPT-5.5 Pro will be ignored.
• OpenAI Codex (Cloud) runs GPT-5.1 Codex internally — your selected GPT-5.5 Pro will be ignored.
• Jules runs Gemini models internally — your selected GPT-5.5 Pro will be ignored.
• The Claude Code SDK is tuned for Claude models — GPT-5.5 Pro may work via the model adapter but loses Claude-specific features (thinking, prompt caching, sub-agents).
• Lovable uses a fixed internal model — your selected GPT-5.5 Pro will be ignored.
• Replit Agent 3 uses its own model selection internally — your selected GPT-5.5 Pro will be ignored.