OpenAI Language New Popular

GPT-5.5

OpenAI's advanced reasoning model for agentic coding, knowledge work, scientific research, and complex multi-step task execution.

256K Context window

Text + Vision Modalities

General Specialty

Yes Streaming

Get API key — free View docs →

Model ID gpt-5-5-openai-resp /v1/chat/completions

Our pricing –72% vs official

Input tokens per 1M tok

$1.40

Output tokens per 1M tok

$8.40

Cached input per 1M tok

$0.140

Pay-as-you-go · No minimums · Cancel anytime

OpenAI-compatible ( api.belugapi.com/v1)

Start for free →

No credit card required to test

Capabilities

What GPT-5.5
can do for you.

Native API parity with the official provider — every feature surfaced one-to-one.

Streaming

Server-sent events out of the box

Vision

Analyze images, charts & documents

Function calling

Parallel & nested tool calls

Reasoning

Deep chain-of-thought for hard tasks

Long context

200K+ tokens of working memory

Integration

2-line migration.
Zero friction.

BelugAPI is 100 % compatible with the OpenAI SDK. Point base_url to our endpoint and you're done — no refactoring, no learning curve.

Same request & response schema

Python · Node.js · REST · Go · Ruby

Streaming, tool-calling, structured output

Automatic failover & load balancing

Python

from openai import OpenAI

client = OpenAI(
  api_key=bel-your-key,
  base_url=https://api.belugapi.com/v1
)

response = client.chat.completions.create(
  model=gpt-5-5-openai-resp,
  messages=[{"role": user, "content": Hello!}]
)
print(response.choices[0].message.content)

Node.js

import OpenAI from openai;

const client = new OpenAI({
  apiKey:  bel-your-key,
  baseURL: https://api.belugapi.com/v1,
});

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

cURL

curl https://api.belugapi.com/v1/v1/chat/completions \
  -H Authorization: Bearer bel-your-key \
  -H Content-Type: application/json \
  -d {"model":"gpt-5-5-openai-resp","messages":[{"role":"user","content":"Hello!"}]}

Highlights

Built for production.

Reasoning

Agentic coding

Knowledge work

Scientific research

Multi-step tasks

Streaming

Function_calling

Web_access

Complete guide

Everything about
GPT-5.5.

Specifications, pricing, capabilities, and integration tips — kept up to date with every OpenAI release.

By OpenAI 2 min read Updated May 2026

OpenAI's advanced reasoning model for agentic coding, knowledge work, scientific research, and complex multi-step task execution.

Overview

GPT-5.5 is a cutting-edge large language model (llm) developed by OpenAI, designed to push the boundaries of artificial intelligence-powered content generation.

This model excels in reasoning, agentic coding, knowledge work, making it a top choice for professionals seeking high-quality, scalable AI solutions. Whether you're building production applications, researching new AI capabilities, or creating stunning visual content, GPT-5.5 delivers industry-leading performance and reliability.

Key Specifications

Specification	Details
Model Name	GPT-5.5
Provider	OpenAI
Category	Large Language Model (LLM)
Model Type	Chat

Pricing

Input: $1.40/M tokens (280 credits)
Cached Input: $0.14/M tokens (28 credits)
Output: $8.40/M tokens (1680 credits)

Savings vs Official: ~72%

Key Features & Capabilities

Reasoning: Advanced capability for professional-grade output.
Agentic Coding: Advanced capability for professional-grade output.
Knowledge Work: Advanced capability for professional-grade output.
Scientific Research: Advanced capability for professional-grade output.
Multi Step Tasks: Advanced capability for professional-grade output.
Streaming: Advanced capability for professional-grade output.
Function_Calling: Advanced capability for professional-grade output.
Web_Access: Advanced capability for professional-grade output.

Use Cases & Applications

Customer support chatbots
Content creation and writing assistants
Knowledge base Q&A systems
Educational tutoring platforms

Frequently asked questions

What is GPT-5.5 best used for?

GPT-5.5 excels at reasoning, agentic coding, knowledge work, making it ideal for professional and enterprise applications.

Who developed GPT-5.5?

GPT-5.5 was developed by OpenAI, a leading AI research and development company.

How do I integrate GPT-5.5 into my application?

You can integrate GPT-5.5 via its official API endpoint using standard HTTP requests with your API key. SDKs are available for Python, JavaScript, and other languages.

What is the pricing model for GPT-5.5?

Pricing is based on input. Check the pricing section above for detailed rates.

Ready to ship? Start using GPT-5.5 in under 30 seconds.

Get free API key