About GPT 5.5
GPT 5.5 succeeds GPT 5.4 with improved reasoning, instruction following, and tool use. It carries forward the 1,050,000-token context window and configurable reasoning effort levels (none, low, medium, high, xhigh), with broad tool support including web search, file search, image generation, code interpreter, hosted shell, computer use, and MCP.
Note: Prompts exceeding 272K input tokens incur 2x input and 1.5x output pricing for the full session.
| Metric | Value |
|---|---|
| Context Length | 1,050,000 tokens |
| Max Output Tokens | 128,000 tokens |
| Multilingual | Yes |
Ready to build with GPT 5.5?
Try GPT 5.5 in the Workbench to prompt it, compare outputs, and iterate on prompts without writing any code. When you're ready to ship, call the same model from our API and build your own apps on top of it.
curl -sSf -X POST https://hub.oxen.ai/api/ai/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $OXEN_API_KEY" \
-d '{
"model": "gpt-5-5-2026-04-23",
"messages": [
{
"role": "user",
"content": "Try sending a message."
}
]
}'API endpoint
See the API reference for request and response formats.
POST
https://hub.oxen.ai/api/ai/chat/completions