GPT-5.5
Access GPT-5.5 through one API key. OpenAI's newest and most capable model.
OpenAI's newest flagship. A major step up in reasoning, agentic tool use, and coding over GPT-5.4, with a 1M token context window.
No credit card required. Takes 30 seconds.
2,400+
Developers
1.2M+
API calls served
100+
Endpoints
$0.01
Per call
Yep, that's it.
Try it live
Send a message and see GPT-5.5 respond in real time.
Maximum tokens in the response.
Real-time tokens
Context Window
1.1M tokens
Max Output
33K tokens
Input Price
$7.00 / 1M tokens
Output Price
$42.00 / 1M tokens
Strengths
GPT-5.5 is OpenAI's most recent flagship, a step up over GPT-5.4 in reasoning, agentic tool use, and coding.
Handles up to 1,050,000 tokens per request, enough to load entire codebases, large document sets, or long agent histories at once.
Tuned for multi-step reasoning and agentic workflows, making it well-suited to tool-using agents and complex planning.
Generates and refactors large amounts of code reliably, with up to 32,768 output tokens per response for substantial implementations.
Quick start
Copy this snippet and start making calls with GPT-5.5.
const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
method: 'POST',
headers: {
'x-api-key': 'YOUR_API_KEY',
'Content-Type': 'application/json',
},
body: JSON.stringify({
"model": "openai/gpt-5.5",
"messages": [
{
"role": "user",
"content": "Explain API gateways in 2 sentences."
}
],
"maxTokens": 256
}),
});
const { data } = await res.json();
console.log(data.message.content);Why use GPT-5.5 through YepAPI?
GPT-5.5 API — pricing, context window & access
GPT-5.5 is OpenAI's newest flagship model, a major step up over GPT-5.4 in reasoning, agentic tool use, and coding. It pairs a 1,050,000-token context window with up to 32,768 output tokens per response.
With YepAPI you reach GPT-5.5 through one OpenAI-compatible key — the same key that also covers the GPT-5.4 family, Claude, Gemini, and the SEO, SERP and scraping APIs.
What is GPT-5.5?
GPT-5.5 is OpenAI's newest flagship, succeeding GPT-5.4. It's a frontier general-purpose model built around three priorities: deeper reasoning, stronger agentic tool use, and best-in-class code generation. Its 1,050,000-token context window lets it hold entire codebases, large document collections, or long agent transcripts in a single request, while up to 32,768 output tokens per call support substantial generated artifacts. It's the model to reach for when you want OpenAI's current top-tier intelligence rather than a smaller, cheaper variant.
Build with GPT-5.5 via YepAPI
YepAPI serves GPT-5.5 on the OpenAI-compatible /v1/ai/chat endpoint. Point your base URL at YepAPI, add your key, and set the model string to gpt-5.5 — the chat-completions format you already use carries straight over. Dropping to GPT-5.4 or GPT-5.4 Mini for cheaper work, or switching to Claude or Gemini, is one string. The same key also reaches search and scraping endpoints, so flagship agents and data pipelines share a single account.
GPT-5.5 API pricing — $7.00 / 1M input, $42.00 / 1M output
GPT-5.5 costs $7.00 per 1M input tokens and $42.00 per 1M output tokens through YepAPI. As a frontier flagship its output rate is high, so it pays to reserve GPT-5.5 for tasks that need its reasoning and route routine work to cheaper models. The 1M-token window means large-context jobs can run up input volume, so size prompts deliberately. You pay only for tokens used, with no minimums.
GPT-5.5 for agents & complex reasoning
GPT-5.5 is built for agentic and reasoning-heavy work. Its tuning for tool use makes it a strong engine for agents that plan, call functions, and iterate over many steps, while the 1M-token window lets an agent keep a long working memory of files, tool outputs, and history. Combined with best-in-class code generation and 32K output tokens, it suits autonomous coding, large-scale refactors, and demanding analysis where frontier intelligence is worth the cost.
Try GPT-5.5 free
Every new YepAPI account includes $5 in free credit, no card required. That's enough to test GPT-5.5's reasoning and agentic behavior on your own prompts before committing to flagship spend. Create an account, copy your key, and start calling GPT-5.5 right away.
Start generating in 30 seconds
$5 free credit on signup. No credit card required. Pay per call.
What developers say
“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Frequently asked questions
OpenAI's newest flagship. A major step up in reasoning, agentic tool use, and coding over GPT-5.4, with a 1M token context window.
Input tokens cost $7.00 per 1M tokens and output tokens cost $42.00 per 1M tokens through YepAPI. No monthly minimums — you only pay for what you use.
Sign up for a free API key, then send requests to the /v1/ai/chat endpoint.
GPT-5.5 supports a 1.1M token context window with up to 33K output tokens per request.
Ready to use GPT-5.5?
$5 free credit on signup. No credit card required. Pay per call.
Explore more models
GPT-4o Mini
OpenAIAccess GPT-4o Mini through one API key. Fast, cheap, and OpenAI-compatible.
GPT-4o
OpenAIAccess GPT-4o through one API key. Flagship reasoning and multimodal capabilities.
GPT-5.5 Pro
OpenAIAccess GPT-5.5 Pro through one API key. OpenAI's most powerful reasoning model.