GPT-5.5 Pro API

GPT-5.5 Pro is a large language model by OpenAI, available on the Venice API as openai-gpt-55-pro. Requests are anonymized, so the provider never sees your identity.GPT-5.5 Pro is OpenAI’s most advanced model, building on GPT-5.5’s unified architecture with enhanced reasoning for complex, high-stakes tasks. It provides a 1M+ token context window (922K input, 128K output) and supports text and image inputs.

GPT-5.5 Pro API pricing

Model ID	Variant	Privacy	Price
`openai-gpt-55-pro`	Standard	Anonymized	$37.50 input /$ 225.00 output per 1M tokens

GPT-5.5 Pro specifications

Spec	Value
Provider	OpenAI
Released	Apr 24, 2026
Privacy	Anonymized
Context window	1M tokens
Max output	125K tokens
Reasoning effort	medium, high, xhigh

How to use the GPT-5.5 Pro API

Send requests to POST https://api.venice.ai/api/v1/responses with "model": "openai-gpt-55-pro" and your API key.

curl https://api.venice.ai/api/v1/responses \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai-gpt-55-pro",
    "input": "Explain TEE attestation in two sentences.",
    "reasoning": { "effort": "medium" }
  }'

GPT-5.5 Pro API FAQ

How much does the GPT-5.5 Pro API cost?

37.50 per 1M input tokens and

225 per 1M output tokens. Prices are in USD and can be paid in DIEM at parity.

What is the GPT-5.5 Pro model ID?

Use openai-gpt-55-pro as the model parameter.

Is the GPT-5.5 Pro API private?

GPT-5.5 Pro is anonymized: Venice forwards requests to the provider without your identity, but the provider may retain prompt data, so use a private model for sensitive work.

What is the context window of GPT-5.5 Pro?

1M tokens of context, with up to 125K output tokens per response.

What does GPT-5.5 Pro support?

GPT-5.5 Pro supports function calling, structured outputs, reasoning, image input and web search. Reasoning effort is adjustable with reasoning_effort: medium, high and xhigh (default medium).

Which endpoint does the GPT-5.5 Pro API use?

Call POST /responses. /chat/completions is also supported. Pro and Codex models are Responses-native upstream. Use /responses for typed reasoning, tool-call and message items; /chat/completions stays fully supported.

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