OpenAIPopular

GPT-5.5

OpenAI's flagship for coding, agents and research-grade reasoning.

GPT-5.5 is OpenAI's top general-purpose model and the engine behind modern Codex: state-of-the-art coding, computer use and multi-step reasoning with a ~1M-token window. The default pick when you want one model that handles everything.

Best for

Complex codingResearch & analysisAgents

Strengths

  • Frontier reasoning
  • Agentic tool use
  • 1M-token context

Use GPT-5.5 via AnyModel

One OpenAI-compatible endpoint — just set the model id:

curl https://anymodel.org/v1/chat/completions \
  -H "Authorization: Bearer $ANYMODEL_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.5",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'