Is gpt-5.4 suitable for software engineering tasks?

Yes. gpt-5.4 is described as a strong choice for coding, tool use, production-quality code generation, and complex software engineering workflows. Evaluate it against your repository, tests, and review standards before changing production routing.

Does gpt-5.4 charge more for long inputs?

Yes — gpt-5.4 uses tiered pricing for long-context requests. Inputs exceeding a token threshold are billed at a higher per-token rate. Check the model page for the exact threshold and long-context pricing tier applicable to gpt-5.4.

What model ID should you use for gpt-5.4?

Use the exact model ID gpt-5.4 . Start with your existing compatible client and validate the same request and evaluation path used by your current integration.

When should you consider gpt-5.4-pro instead of gpt-5.4?

Consider gpt-5.4-pro for the subset of tasks that need enhanced reasoning and higher confidence for complex, high-stakes, or long-context work. Compare both models on your own evaluation set before choosing a routing policy.

How does gpt-5.4 compare with other models, and what should you compare?

Compare gpt-5.4 against models of similar capability and pricing on your actual workload. Evaluate latency, output quality, instruction following, and cost per task. Run side-by-side tests with your own prompts — the best model depends on your specific use case, not just benchmark scores.

Can you call gpt-5.4 with the SDK you already use?

Yes. gpt-5.4 is compatible with the standard SDK. Set the model parameter to gpt-5.4 and use your MixRoute API key. If your current code already calls the compatible API, changing the base URL and model ID is typically all that is needed.

Model detail

GPT-5.4

Provided by OpenAI

Pay-as-you-go Dynamic pricing 2 tiers

GPT-5.4 is OpenAI’s latest frontier model, unifying the Codex and GPT lines into a single system. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs, enabling high-context reasoning, coding, and multimodal analysis within the same workflow. The model delivers improved performance in coding, document understanding, tool use, and instruction following. It is designed as a strong default for both general-purpose tasks and software engineering, capable of generating production-quality code, synthesizing information across multiple sources, and executing complex multi-step workflows with fewer iterations and greater token efficiency.

Model specs

Model ID: gpt-5.4

Context length: 1.05M
Max output: 128K
I/O modalities
Released: 2026-03

API endpoints

One MixRoute gateway, OpenAI-compatible

OpenAI-compatible /v1/chat/completions POST

Tiered pricing

Unit: /1M Tokens

Tier	Input /1M Tokens	Output /1M Tokens	Cache read /1M Tokens
standard Length ≤ 272K	$2.5000	$15.0000	$0.2500
long_context Length > 272K	$5.0000	$22.5000	$0.5000

Selection summary

Quickly judge whether it fits your workload

What is this model good for?

Flagship model for complex reasoning and agentic workflows

GPT-5.4: GPT-5.4 is a flagship model for complex professional work. Learn more in our GPT-5.4 model guidance. Reasoning.effort supports: none (default), low, medium, high and xhigh.. 1,050,000-token context.

What should you check before using it?

1,050,000 context, 128,000 output

OpenAI model. Supports tool calling, structured outputs, function calling. Knowledge cutoff: 2025-08-31.

Why use it through MixRoute?

Drop-in via OpenAI-compatible endpoint on MixRoute

Set the model parameter to "gpt-5.4" and use your MixRoute API key.

Capabilities & compatibility

Unconfirmed capabilities stay "Unknown," no guesses

Tool calling

GPT-5.4 supports function and tool calls.

EX Send a tools definition; the response returns tool_calls to execute and feed results back.

Structured output

GPT-5.4 can produce JSON-formatted output on demand.

EX response_format: { type: "json_schema" } forces valid JSON output.

Streaming

GPT-5.4 supports streamed responses.

EX stream: true streams tokens incrementally, so chat UIs render as they arrive.

Prompt caching

GPT-5.4 supports prompt caching under supported routing conditions.

EX Keep the system prompt and tool definitions at the start of the request; repeated prefixes are automatically billed at the cache-read rate.

Vision input

GPT-5.4 can process image inputs alongside text.

EX Pass a base64-encoded image in a image_url content part alongside text messages.

OpenAI SDK

Call GPT-5.4 through MixRoute's OpenAI-compatible endpoint.

EX Change base_url to https://api.mixroute.ai/v1; everything else follows the OpenAI style.

Token cost estimator

Live estimate from this page's pricing, not an actual bill

Input tokens Max per request 1.05M

Output tokens Max per request 128K

Requests / month

Cache hit rate 0%

Share of the same prefix read repeatedly, up to 100%

FAQ

gpt-5.4 rate limits vary by your MixRoute subscription plan. Check your plan details in the console for requests per minute (RPM) and tokens per minute (TPM) limits. Run a small load test before production to confirm your effective quota.

Get started

01

Create an API key

Generate a key in the Console; one key calls every model.
02

Set the base URL

Fully OpenAI SDK-compatible; just swap the URL to connect.

https://api.mixroute.ai/v1
03

Specify the model ID

In the request's model field, enter:

gpt-5.4

Create an API key

New users get $5 in free credits

Test this model and alternate routes with the same request format

Start from a real workload, then let quality, total cost, and failure conditions decide whether to send production traffic.

Create an API key View integration docs