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AI conversation model
OpenAI
GPT Codex

GPT-5.4 Codex

GPT-5.4 Codex has documented text, reasoning, and search capabilities, but this site cannot yet calculate a reliable maximum cost before a request. Its details remain available while generation stays disabled.

Online use is currently unavailable

This page is for reviewing the model's capabilities, use cases, and public references. The model does not appear in the home workbench, and you cannot submit generation tasks with it.

Current status
Generation unavailable
Series position
GPT-5.4 Codex
Access status
No request, no charge
30-second overview
  • Not Coming Soon; its preauthorization requirements are incomplete.
  • It does not appear in the chat selector, create requests, or charge credits.
  • Four reasoning levels and optional web search are confirmed.

Popular searches: Can I use GPT-5.4 Codex now? · How much does GPT-5.4 Codex cost? · What reasoning capabilities does GPT-5.4 Codex have?

Examples

Accessible Museum Tour: Opening day coordination

Plan a 90-minute Wednesday opening for Accessible Museum Tour at the museum lobby. We have 48 guide cards and groups of 12.
Use 4 groups with one coordinator per group. 00:00–00:10: welcome and explain the activity. 00:10–00:20: distribute 12 guide cards to each group. 00:20–01:05: run the main activity. 01:05–01:20: collect feedback and reusable equipment. 01:20–01:30: clean the museum lobby and check the inventory.
What should the coordinator check first?
Count the 48 guide cards before visitors arrive. Confirm a clear entrance and an accessible work area at the museum lobby, then give each of the 4 group leads the same timing sheet.

Accessible Museum Tour: Supply budget calculation

Accessible Museum Tour needs 48 guide cards at $4.00 each. Add a 10% reserve. Show the arithmetic.
Supplies: 48 × $4.00 = $192.00. Reserve: $192.00 × 0.10 = $19.20. Planned total: $211.20. This is a planning calculation using the supplied prices.
What if we reduce the quantity by one group?
Remove 12 units, leaving 36. Supplies become $144.00; a 10% reserve adds $14.40, for a total of $158.40.

Accessible Museum Tour: Visitor announcement

Write a warm announcement for Accessible Museum Tour, meeting on Wednesday at the museum lobby. Mention limited guide cards, without promising availability.
Join Accessible Museum Tour this Wednesday at the museum lobby. Meet neighbors, learn together, and take part at your own pace. We will share the available guide cards across small groups. Supplies are limited, so please check with the welcome desk when you arrive.
Shorten it to an event sign.
Accessible Museum Tour Wednesday · museum lobby Welcome! Ask the desk about available guide cards and today’s small-group activities.

Accessible Museum Tour: Inventory CSV validation

Write Python to validate Accessible Museum Tour inventory CSV with columns item,quantity. Quantity must be a nonnegative integer.
```python import csv def read_inventory(path): rows = [] with open(path, newline="", encoding="utf-8") as handle: reader = csv.DictReader(handle) if reader.fieldnames != ["item", "quantity"]: raise ValueError("Expected item,quantity columns") for line, row in enumerate(reader, 2): name = row["item"].strip() quantity = row["quantity"].strip() if not name or not quantity.isascii() or not quantity.isdecimal(): raise ValueError(f"Invalid inventory row {line}") rows.append((name, int(quantity))) return rows # Example row: guide cards,48 ```
What are two useful validation cases?
The row `guide cards,48` should pass. The row `guide cards,-1` should raise a ValueError because a negative quantity is outside the stated inventory contract. An empty item should also fail.

Accessible Museum Tour: Coordinator handover note

Create a concise handover note for Accessible Museum Tour: 48 guide cards, 4 groups, meeting Wednesday at museum lobby.
Handover — Accessible Museum Tour Location: museum lobby; day: Wednesday. Inventory: 48 guide cards, allocated as 4 groups × 12. Before opening: count supplies, set the welcome desk, and confirm group leads. During the event: record shortages and visitor questions. After closing: count returns and write one improvement for the next meeting.
Add a useful open question for the next lead.
Ask: “Were 12 guide cards per group enough for the activity, and which step created the longest wait?” Record the answer beside the returned inventory count.

Accessible Museum Tour: Participant question response

A visitor asks whether they can join Accessible Museum Tour halfway through the Wednesday session at museum lobby. Draft a welcoming but practical reply.
You are welcome to check in at the desk when you arrive. A coordinator can explain the current activity and see whether a group has space and spare guide cards. If the activity is already full, we can help you observe or find the next joining point.
What should we avoid saying?
Avoid guaranteeing a place or a set of guide cards before checking the group capacity. Keep the reply specific to the museum lobby session and offer a clear next step: speak with the welcome desk.

At a glance

Is this model right for you?

Generation unavailable: A provable maximum output-usage boundary is not yet available, so no request is created and no credits are charged.

What it does best
A lower-rate GPT-5.4 Codex candidate intended for frequent text tasks.
Who it is for
People tracking newer GPT capabilities for everyday Q&A, lightweight analysis, and search-assisted work who want to prepare repeatable tests in advance.
Why use it on Kyeo AI
Kyeo AI publishes verified facts and usable alternatives while keeping an incomplete billing contract out of the generation path.

Key facts

Quickly evaluate whether this model fits your business use case.

Vendor
OpenAI
Model family
GPT-5.4 Codex
Confirmed input
Structured text conversations
Confirmed reasoning levels
low, medium, high, xhigh
Current gap
Maximum output-usage bound

Other names

The same model may have different names in official documentation, community discussions, and API integrations. This section brings them together for you.

OpenAI GPT-5.4 Codex

Common questions

These practical questions focus on the task, input conditions, and result requirements you should confirm before choosing.

Can I use GPT-5.4 Codex now?
How much does GPT-5.4 Codex cost?
What reasoning capabilities does GPT-5.4 Codex have?
What are the best GPT-5.4 Codex alternatives?

Decision guide

Still deciding? Start with these key decision points.

1
If you need to finish a task now

Choose an available model such as Claude Sonnet 5; this model cannot currently accept messages.

2
If you want to prepare future tests

Save one non-sensitive sample each for everyday Q&A, summarization, and retrieval.

3
How to tell when access can open

Access can be reconsidered when a reliable maximum output limit is available.

Popular comparisons

Compare common alternatives on the same task to clarify differences in inputs, controls, and cost.

Should I choose GPT-5.4 Codex or Claude Sonnet 5?
Why is GPT-5.4 Codex generation unavailable?

Real-world experience

Practical guidance based on public sources, current on-site limits, and representative tasks.

Lower rates still need a hard bound

Even when the per-token rate is low, preauthorization cannot be guaranteed without a worst-case output limit.

Search access is not factual accuracy

An available search tool does not make every answer accurate; claims still need source verification.

Capabilities

Multi-turn text

Structured message input is confirmed. If access opens, the site's per-message character limit and history window will still apply.

Reasoning effort

The contract lists low, medium, high, and xhigh levels.

Web search

The optional search tool and function tools cannot be used in the same request.

Use cases

Frequent Q&A

Designed for everyday information organization and short-form collaboration.

Search-assisted summaries

A candidate for summaries that need leads from recent information.

Lightweight reasoning

Tiered reasoning can balance response speed and depth.

Prompt tips

Define acceptance criteria first

Specify length, format, evidence requirements, and prohibited content.

Verify search results

Check dates, figures, and conclusions against trusted sources.

Keep repeatable samples

Once access opens, compare quality, latency, and actual credits with currently available models.

Why choose it

Its conversation and reasoning contract is confirmed.
Its rate position makes it relevant for frequent-task evaluation.
The page clearly separates discoverable information from runtime availability.

What to know first

Standard and streaming generation are currently unavailable.
A maximum output-usage bound cannot yet be proven.
The attachment contract does not meet this site's release requirements.

Currently unavailable

This page is for reviewing the model's capabilities, use cases, and public references. The model does not appear in the home workbench, and you cannot submit generation tasks with it. A lower-rate GPT-5.4 Codex candidate intended for frequent text tasks.

No additional settings are available for this model.

Frequently asked questions

Related models

Still deciding? Take a quick look at these similar alternatives.

Claude Opus 4.8

Claude Opus 4.8 is designed for high-complexity text analysis and consequential writing. Kyeo AI offers text-only chat with up to 20,000 characters per message and an explicit 4,096-token maximum output.

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Token-based pricing

Claude Sonnet 5

Claude Sonnet 5 is the more balanced Claude candidate in this batch for research, code explanation, and structured writing. Its maximum output on this site is 4,096 tokens.

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Token-based pricing

Claude Opus 5

Claude Opus 5 is a flagship candidate for high-complexity text work. Kyeo AI limits each message to 20,000 characters, includes the 40 most recent submitted messages, and caps output at 4,096 tokens.

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Sources

This page is based on vendor materials, model-family documentation, and Kyeo AI integration settings.

Source note

Official information for OpenAI's `gpt-5.4` cannot be inherited as proof of this alias's model identity or capabilities.

Last updated: 2026-08-26
OpenAI: GPT-5.4
Official
Open original source
OpenAI: Introducing GPT-5.4
Official
Open original source