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OpenAI · Language model

o3

openai/o3
  • Language
Released Apr 16, 2025

o3 is a well-rounded and powerful model across domains. It sets a new standard for math, science, coding, and visual reasoning tasks. It also excels at technical writing and instruction-following....

Specifications

Context window
200,000 tokens
Max output
100,000 tokens
Input
image, text, file
Output
text
Reasoning
supported
Tokenizer
GPT
Knowledge cutoff
2024-06-30
Moderation
provider-moderated

Supported parameters

Accepted by the model and forwarded as-is by the gateway.

  • max_tokens
  • reasoning
  • response_format
  • seed
  • structured_outputs
  • tool_choice
  • tools

Use it

POST /api/v1/chat/completions · MCP chat · full reference

curl https://omnirail.org/api/v1/chat/completions \
  -H "Authorization: Bearer $OMNIRAIL_KEY" -H "Content-Type: application/json" \
  -d '{"model":"openai/o3","messages":[{"role":"user","content":"Hello"}],"max_tokens":300}'