GPT-5.4 API
gpt-5-4GPT-5.4 is OpenAI’s frontier model for complex professional work and agentic coding. Served via the Responses API (`/v1/responses`) with adjustable reasoning effort (low–xhigh), web search, function calling, and multimodal input. Drop-in for OpenAI Codex CLI with wire_api = "responses".
API Documentation
View complete API reference with all parameters and examples.
Advanced Features
Streaming
Enable real-time streaming responses with Server-Sent Events.
{
"model": "gpt-5-4",
"stream": true,
"messages": [...]
}Function Calling (Tools)
Enable the model to use tools and call functions.
{
"model": "gpt-5-4",
"tools": [{
"type": "function",
"function": {
"name": "get_weather",
"description": "Get current weather for a location",
"parameters": {
"type": "object",
"properties": {
"location": {"type": "string", "description": "City name"}
},
"required": ["location"]
}
}
}],
"messages": [{"role": "user", "content": "What's the weather in Tokyo?"}]
}JSON Mode
Get structured JSON responses from the model.
{
"model": "gpt-5-4",
"response_format": {"type": "json_object"},
"messages": [{"role": "user", "content": "Extract info as JSON: John is 30 years old"}]
}API Parameters Reference
| Parameter | Type | Required | Description |
|---|---|---|---|
| model | string | Yes | Model identifier (e.g., gpt-5-4) |
| messages | array | Yes | Array of message objects with role and content |
| max_tokens | integer | No | Maximum tokens in the response |
| stream | boolean | No | Enable streaming responses (SSE) |
| temperature | number | No | Sampling temperature (0.0 - 2.0) |
| top_p | number | No | Nucleus sampling threshold (0.0 - 1.0) |
| tools | array | No | Function calling tools definition |
| response_format | object | No | Output format (e.g., json_object) |
Full API Documentation
View complete API reference with streaming, thinking, and more.
Pricing
Billing: Cost = (input_tokens * input_price + output_tokens * output_price) / 1,000,000
Frontier Model
Latest GPT generation for complex professional work
Adjustable Effort
reasoning.effort = low / medium / high / xhigh (request body, not a suffix)
Tools & Web Search
Built-in web search or function calling (one per request)
Codex-Compatible
Drop-in via wire_api = "responses" + model = "gpt-5-4"
About GPT-5.4
GPT-5.4 is a Large Language Model API provided by OpenAI. GPT-5.4 is OpenAI’s frontier model for complex professional work and agentic coding. Served via the Responses API (`/v1/responses`) with adjustable reasoning effort (low–xhigh), web search, function calling, and multimodal input. Drop-in for OpenAI Codex CLI with wire_api = "responses". Through APIMODELS platform, you can access this model via a unified API with transparent pay-as-you-go pricing. Current pricing: Input: $1.8, Output: $10.8 per 1M tokens.
Key Features
- Frontier Model -- Latest GPT generation for complex professional work
- Adjustable Effort -- reasoning.effort = low / medium / high / xhigh (request body, not a suffix)
- Tools & Web Search -- Built-in web search or function calling (one per request)
- Codex-Compatible -- Drop-in via wire_api = "responses" + model = "gpt-5-4"
Use Cases
Chatbot & Customer Support
Build intelligent conversational systems to automatically answer user queries and improve service efficiency.
Content Generation
Automatically write articles, emails, ad copy, and other text content to boost productivity.
Code Assistant
Assist with code writing, debugging, and code review to accelerate software development.
Data Analysis
Understand and analyze unstructured data, extract key insights, and generate summary reports.
Why APIMODELS
- Unified API -- One API key to access all models, no need to register on multiple platforms
- Transparent Pricing -- Pay-as-you-go with per-call pricing published on every model page, ideal for indie developers and startups
- Instant Access -- Start using immediately after signup, supports Stripe and Alipay payments
- Full Documentation -- Detailed API docs with code examples in cURL, Python, and Node.js
Frequently Asked Questions
How much does GPT-5.4 cost?
GPT-5.4 is available through APIMODELS at: Input: $1.8, Output: $10.8 per 1M tokens. Billing is pay-as-you-go — you only pay for what you generate.
How to use GPT-5.4 API?
Sign up at APIMODELS, get your API key, and call our unified API endpoint. We provide detailed API documentation with code examples in cURL, Python, and Node.js.
What is the difference between APIMODELS and the official OpenAI API?
APIMODELS offers the same GPT-5.4 model through our aggregation platform. We provide a unified API interface so you do not need separate accounts for each provider - one API key to access all models.
What is GPT-5.4 best for?
GPT-5.4 is a cost-efficient frontier reasoning model on the OpenAI Responses API with adjustable reasoning effort — a strong default for agentic coding in OpenAI Codex CLI (wire_api = responses) when you want capable reasoning without GPT-5.5's top-tier output cost.
GPT-5.4 vs GPT-5.5?
Pick GPT-5.4 for more affordable, fast everyday coding and agents; step up to GPT-5.5 for the hardest problems. Same Responses API and Codex setup — one model-name change to switch.
How do I use GPT-5.4 with Codex CLI?
Set base_url to api.apimodels.app/v1, wire_api = "responses", model = "gpt-5-4", and control depth with model_reasoning_effort. Full config at /docs/codex.
How does GPT-5.4 compare to other Large Language Model models?
On APIMODELS, GPT-5.4 runs alongside 60+ models on one API key and one balance, so choosing is about fit, not lock-in. It supports Frontier, Adjustable Reasoning, Web Search, Multimodal, and you can weigh it on price and capability against other Large Language Model models, then switch by changing a single model-name string — no new account or integration. Browse every Large Language Model option with live pricing at apimodels.app/models.
What can GPT-5.4 do?
GPT-5.4 supports: Frontier, Adjustable Reasoning, Web Search, Multimodal. See the APIMODELS docs for full parameters and call examples.
Can I access the GPT-5.4 API from anywhere (incl. China)?
Yes. APIMODELS exposes GPT-5.4 through a single unified API and one key — no separate provider accounts, and no need to handle each provider's regional network access yourself.
What payment methods are supported?
We support Stripe (Visa, Mastercard, and other international cards) and Alipay. Credits are available instantly after payment.