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OpenKey

GPT-5 Pro

OpenAIReleased Oct 6, 2025

GPT-5 Pro is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and...

Try in playground
Context window
400K tokens
Max output
128K tokens
Input
image, text, file
Output
text
Tokenizer
GPT
Knowledge cutoff
Sep 30, 2024
Released
Oct 6, 2025
Reasoning
always on

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$15.00$0.450$15.45
Output$120.00$3.60$123.60

Supported parameters

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

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model openai/gpt-5-pro.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5-pro",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="openai/gpt-5-pro",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "openai/gpt-5-pro",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does GPT-5 Pro cost via API?
Through OpenKey, GPT-5 Pro costs $15.45 per 1M input tokens and $123.60 per 1M output tokens. That is the provider price ($15.00 / $120.00) plus a flat 3% fee — nothing else.
What is GPT-5 Pro's context window?
GPT-5 Pro accepts up to 400K tokens of context and returns up to 128K tokens per request.
Is GPT-5 Pro OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "openai/gpt-5-pro" using any OpenAI SDK — only the base URL and API key change.
What inputs does GPT-5 Pro support?
GPT-5 Pro accepts image, text, file input and produces text output. Its knowledge cutoff is Sep 30, 2024.

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