Is GPT-5.4 Mini available on FastMetal?

Not at the moment. GPT-5.6 Sol, from the same lab, is available on the FastMetal API today.

What is the context window of GPT-5.4 Mini?

400,000 tokens, shared between the prompt and the response.

openai/gpt-5-4-mini

Not Available

GPT-5.4 Mini

GPT-5.4 mini brings the core capabilities of GPT-5.4 to a faster, more efficient model optimized for high-throughput workloads. It supports text and image inputs with strong performance across reasoning, coding, and tool use, while reducing latency and cost for large-scale deployments. The model is designed for production environments that require a balance of capability and efficiency, making it well suited for chat applications, coding assistants, and agent workflows that operate at scale. GPT-5.4 mini delivers reliable instruction following, solid multi-step reasoning, and consistent performance across diverse tasks with improved cost efficiency.

3/17/2026

400,000 tokens

Specifications

Modalities

Input

file

image

text

Output

text

Supported Parameters

include_reasoning

max_tokens

reasoning

response_format

seed

structured_outputs

tool_choice

tools

Max Output Tokens

128,000

Reasoning Configuration

Default: Thinking off
Selectable effort levels: xhigh
high
medium
low
none
Turning thinking off: Possible (reasoning.enabled: false)

How to control thinking, and what it costs

Frequently asked questions

Is GPT-5.4 Mini available on FastMetal?: Not at the moment. GPT-5.6 Sol, from the same lab, is available on the FastMetal API today.
What is the context window of GPT-5.4 Mini?: 400,000 tokens, shared between the prompt and the response.

Models you can use on FastMetal