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o3-pro

openaiopenai/o3-pro

API guide

Chat completion

Call openai/o3-pro through TheRouter's standard chat completions endpoint. The reasoning chain runs server-side and the model returns the final answer in a single message. Hard problems can take minutes β€” raise your client timeout to at least 600s.

cURL
curl https://api.therouter.ai/v1/chat/completions \
  -H "Authorization: Bearer $THEROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  --max-time 900 \
  -d '{
    "model": "openai/o3-pro",
    "messages": [
      {"role": "user", "content": "Prove that for every prime p > 2, p^2 - 1 is divisible by 24. Show every step."}
    ]
  }'

Reasoning effort

o3-pro accepts a reasoning parameter for explicit control. The model is tuned for high-effort by design β€” lower settings reduce compute used per request and may degrade quality on hard problems. Pass reasoning.effort='high' for the full o3-pro experience.

cURL
curl https://api.therouter.ai/v1/chat/completions \
  -H "Authorization: Bearer $THEROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  --max-time 900 \
  -d '{
    "model": "openai/o3-pro",
    "reasoning": { "effort": "high" },
    "messages": [
      {"role": "user", "content": "Diagnose why this Kubernetes pod is OOMKilled even though resources.limits.memory is set to 4Gi."}
    ]
  }'

Tool calling

o3-pro supports function calling and ChatGPT-style tools (web search, file analysis, Python). Use it for agent loops where each step is genuinely hard β€” e.g. multi-document research, complex code refactors, or financial / scientific analysis where wrong tool choices are costly.

cURL
curl https://api.therouter.ai/v1/chat/completions \
  -H "Authorization: Bearer $THEROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/o3-pro",
    "messages": [{"role": "user", "content": "Compare last quarter revenue growth for Apple, Microsoft and Nvidia and rank them."}],
    "tools": [{
      "type": "function",
      "function": {
        "name": "get_earnings",
        "description": "Fetch most recent reported revenue for a stock ticker",
        "parameters": {
          "type": "object",
          "properties": { "ticker": {"type": "string"} },
          "required": ["ticker"]
        }
      }
    }],
    "parallel_tool_calls": true
  }'

Vision

o3-pro accepts images alongside text. Useful for reading complex diagrams, dense charts, math/proof scans, or screenshots of legacy code where the structure is essential to understanding.

cURL
curl https://api.therouter.ai/v1/chat/completions \
  -H "Authorization: Bearer $THEROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/o3-pro",
    "messages": [{"role": "user", "content": [
      {"type": "text", "text": "Read this circuit schematic and explain how the feedback loop stabilises gain."},
      {"type": "image_url", "image_url": {"url": "https://therouter.ai/assets/vision-sample.png"}}
    ]}]
  }'
Fact ledger β€” every claim on this page traces here
sourceURLretrieved
Release datetechcrunch.com β†—2026-06-01verified
Knowledge cutoffllm-stats.com β†—2026-06-01verified
Reasoning modeplatform.openai.com β†—2026-06-01verified
Native API surfaceplatform.openai.com β†—2026-06-01verified
Tool supporttechcrunch.com β†—2026-06-01verified
Licenseβ€”β€”verified
AIME 2024r/singularity launch-day benchmarks thread β†—2026-06-01to verify
GPQA Diamondtechcrunch.com β†—2026-06-01to verify
4-for-4 reliability (AIME 2024)OpenAI launch chart summary β†—2026-06-01to verify
4-for-4 reliability (GPQA Diamond)OpenAI launch chart summary β†—2026-06-01to verify
GPT-5 Pro launched at OpenAI DevDay 2025openai.com β†—2026-06-01verified
o3-pro released, replacing o1-protechcrunch.com β†—2026-06-01verified
o3 and o4-mini launched, o3-pro preview announcedopenai.com β†—2026-06-01verified
How long do o3-pro responses take?platform.openai.com β†—2026-06-01to verify
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