Model overview
ProReasoningVisionToolsGPT-5.5 Pro is the highest-reasoning GPT-5.5 tier for the hardest tasks. It supports text and image input, text output, long context, tool use, streaming, structured outputs, and Responses API access.
Company: OpenAIProvider: OpenAI
Model capabilities
Input modalityT
Output modalityT
Model experience✓
Function calling✓
Structured output✓
Web search✓
Prefix completion-
Context cache×
Batch inference✓
Fine-tuning×
Model pricing
Input$30/1M tokens
Output$180/1M tokens
Input (Batch)$15/1M tokens
Output (Batch)$90/1M tokens
Input (over 200K context)$60/1M tokens
Output (over 200K context)$270/1M tokens
Tool call pricing
Web search Responses API$10/1K calls + model token charges
File search Responses APIUsage based
Rate limits and context
Maximum input length1M
Context length1M
Maximum output length128K
Knowledge cutoff2025-12-01
Supported endpointsResponses
API reference
EndpointPOST /v1/responses
SDKOpenAI-compatible
API code examples
from openai import OpenAI client = OpenAI( api_key="$WLROUTER_API_KEY", base_url="https://api.wlrouter.com/v1" ) response = client.responses.create( model="gpt-5.5-pro", input="Reply with one short sentence.", max_output_tokens=32 ) print(getattr(response, "output_text", response))