GPT 5.5

openai/gpt-5.5

A chat model with a 1M-token context window, at $5.25 per million input tokens and $31.50 per million output tokens.

Details

Maker: openai
Kind: Chat
Context window: 1,000,000 tokens
Max output: 128,000 tokens
Input: $5.25 per million tokens
Cached input: $0.525 per million tokens, 90% off
Cache write: Same as input
Output: $31.50 per million tokens
Capabilities: Reasoning, tool use, vision, file input, web search, fast
Takes: Text, image, pdf
Returns: Text
Zero data retention: Not on every provider
No training on requests: Yes, on every provider
Released: 2026-04-24
Newer model: openai/gpt-6.1-solReleased later by the same maker, costs no more, and lists the same capabilities. Compare the two

Description

GPT‑5.5 understands what you’re trying to do faster and can carry more of the work itself. It excels at writing and debugging code, researching online, analyzing data, creating documents and spreadsheets, operating software, and moving across tools until a task is finished. Instead of carefully managing every step, you can give GPT‑5.5 a messy, multi-part task and trust it to plan, use tools, check its work, navigate through ambiguity, and keep going.

Call it

curl

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

Set PHANTOM_KEY to your key. Any OpenAI client works with the base URL https://phantom.codes/v1.

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