GPT 5.4
GPT-5.4 Pro is a high-performance general-purpose large language model variant developed by OpenAI.
Use cases
GPT-5.4 prototyping · GPT-5.4 production workflows
Input
Text, image
Output
Text
Billing
Per token
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Sign up to get $0.5 in free credits — about 20 free images
Pricing details
Transparent usage-based pricing with no hidden fees.
Detailed Pricing
Tiered pricingUsage-based pricing breakdown
| Spec | Price | Official | Savings |
|---|---|---|---|
| Input/1M tokens | 2 Credits≈$2 | 2.5 Credits | -20% |
| Output/1M tokens | 12 Credits≈$12 | 15 Credits | -20% |
| Cache Read/1M tokens | 0.2 Credits≈$0.2 | 0.25 Credits | -20% |
| Spec | Price | Official | Savings |
|---|---|---|---|
| Input/1M tokens | 4 Credits≈$4 | 5 Credits | -20% |
| Output/1M tokens | 18 Credits≈$18 | 22.5 Credits | -20% |
| Cache Read/1M tokens | 0.4 Credits≈$0.4 | 0.5 Credits | -20% |
Billing Rules
- Output price varies by model, resolution, quality, duration, or token usage.
- Uploaded reference files may be charged separately when supported.
- Add-on capabilities such as web search or image search may be billed per request.
- Token-based models are billed by input and output tokens.
- If the primary route is unavailable, Velokey may automatically switch to a stable fallback route when possible.
- Usage is pay-as-you-go with transparent credit deduction.
* Final cost depends on the generated result.
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Affordable GPT-5.4 API
Access OpenAI's flagship reasoning model for the hardest problems on Velokey — a 1.05M-token context, deeper extended reasoning, and a rich agent tool surface, with a unified endpoint and below-list pricing for demanding analysis, research, and autonomous tasks.
Meet GPT-5.4 and its API access
GPT-5.4 is the flagship reasoning variant of OpenAI's GPT-5.4 series, built for the hardest problems, with a knowledge cutoff of August 2025. It ships with roughly a 1.05M-token context window and up to 128K tokens of output, using more compute to think harder and deliver more consistent answers on complex, multi-step, long-running reasoning tasks.\n\nGPT-5.4 supports image input (text + image), function calling, and streaming, plus a rich tool surface including web search, file search, image generation, computer use, and MCP. Since some requests can take several minutes, background mode is recommended to avoid timeouts. Velokey provides an affordable, easy-to-integrate GPT-5.4 API: a unified chat endpoint, a clear request flow, and below-list pricing.
1.05M-token long context
Defaults to roughly a 1.05M-token context window with 128K-token output, staying coherent across very long codebases, documents, and complex material. Pair it with prompt caching — static content first, dynamic content last — to cut input cost on long workflows.
View Documentation →
Deeper extended reasoning
Tune reasoning depth across medium (default), high, and xhigh via reasoning.effort. pro spends more compute to think longer and deeper, giving more consistent, reliable answers on the hardest math, research, engineering, and analysis problems.
View Documentation →
Rich agent tools and computer use
Connects to web search, file search, image generation, apply patch, computer use, MCP, and tool search — fit for long-running autonomous tasks where you give a clear goal and the model plans and calls tools on its own.
View Documentation →
Multimodal vision input
Accepts text and image input (text output), reading charts, design mockups, screenshots, and scans — fit for professional workflows that reason and analyze with visual detail.
View Documentation →
How to deploy the GPT-5.4 API on Velokey
Get started with just a few steps.
Sign up and get an API Key
Sign in to the Velokey console to generate an API Key that authenticates every request sent to GPT-5.4.
Configure request parameters
Set model to gpt-5-4-pro and submit messages. Set reasoning.effort by task difficulty (medium by default; high or xhigh for the hardest tasks). Since deep reasoning requests can take minutes, enable background mode for long tasks to avoid timeouts.
Integrate and start calling
Send requests to Velokey's unified endpoint to power research assistants, analysis pipelines, and autonomous agents, with usage managed in one console.
Real-world use cases for GPT-5.4
For demanding professional scenarios that need deep reasoning.
Complex reasoning & hard problems
For the hardest math, logic, and research problems — reasoning deeply with more compute for more consistent, reliable conclusions.
Long-context deep analysis
With roughly 1.05M-token context, fit for retrieval, synthesis, and deep analysis across large volumes of long documents and reports.
Autonomous agents & computer use
Combining a rich tool surface with computer use — fit for long-running, multi-step autonomous tasks that plan and execute on their own.
Hard coding tasks
Fit for complex coding that needs deep planning and multi-step execution, staying stable over long runs in large codebases.
Finance & research modeling
Fit for financial modeling, data analysis, and scientific computation — high-reliability, reasoning-heavy professional data work.
Legal & compliance analysis
Long context and deep reasoning make it fit for retrieval and rigorous analysis across large contracts, regulations, and compliance documents.
Why choose Velokey for GPT-5.4
Discount on list price
Call GPT-5.4 at a lower price on Velokey — pay-as-you-go with no forced subscription, reducing the cost of a premium reasoning model.
Unified API interface
One API Key accesses GPT-5.4 and other models — no juggling multiple accounts and keys, simplifying integration.
Complete docs and migration guidance
Endpoint references, parameter details, and migration examples help you set reasoning.effort and background mode correctly to get the most from deep reasoning.
Stable and highly available
Automatic failover and stable fallback routes maintain availability when the primary route is down, keeping long reasoning tasks reliable.
API Reference
Complete API call examples and parameter descriptions
Endpoint
https://api.velokey.ai/v1/chat/completionsAuthentication
Bearer YOUR_API_KEYRequest Example
curl https://api.velokey.ai/v1/chat/completions \
-X POST \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.4",
"messages": [{"role": "user", "content": "Hello!"}],
"temperature": 0.7
}'Response Example
{
"id": "req_abc123",
"model": "gpt-5.4",
"created": 1234567890,
"data": { ... }
}GPT-5.4 API FAQ
What is the GPT-5.4 API?
GPT-5.4 is available through Velokey as a chat model. Set model to gpt-5-4-pro and use the family-specific endpoint.
Which parameters does GPT-5.4 use?
The playground shows the main fields for GPT-5.4, including the model id and the most important generation parameters.
How is GPT-5.4 billed?
Pricing is shown on this page when available, and credits are managed from one Velokey account.
Who should use GPT-5.4?
It fits teams that want to test, compare, and ship AI capabilities through a unified API.
Start building with GPT 5.4 today
Use one API key to access low-cost, stable AI models through Velokey.