OpenAI: GPT-5.1 Codex

Codex GPT for repository edits, code review, and practical software agents

Model lab: OpenAI
Model family: gpt-codex

Modalitiestext, image → text

Context window400,000

Maximum output128,000

InputUSD 1 / 1M tokens

OutputUSD 8 / 1M tokens

Try now View docs

Quickstart

Use your Moduck API Key, set the API base URL to https://api.moduck.ai/v1, and set the model parameter to openai/gpt-5.1-codex.

import os
import requests

base_url = "https://api.moduck.ai/v1"
api_key = os.environ["MODUCK_API_KEY"]
model_id = "openai/gpt-5.1-codex"

response = requests.post(
    f"{base_url}/chat/completions",
    headers={
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    },
    json={
        "model": model_id,
        "messages": [{"role": "user", "content": "Hello!"}],
        "stream": False,
    },
    timeout=60,
)
response.raise_for_status()
print(response.json())

Use the familiar OpenAI-style chat request format to make model integration easier.

GPT-5.1 Codex API Pricing

Type	Price information
Input	USD 1 / 1M tokens
Output	USD 8 / 1M tokens
Cached input	USD 0.1 / 1M tokens

Benchmarks

High

Intelligence Index · v4.323.7

Coding Index—

Agentic Index—

Performance

Output speed124.83 tokens/s

Time to first token6 s

Time to first answer token—

End-to-end response time—

Measurement variant	Output speed	Time to first token	Time to first answer token	End-to-end response time
High	124.83 tokens/s	6 s	—	—

Performance trends

Throughput124.83 tok/sCurrent

Time to first token6 sCurrent

End-to-end latency7.2 sCurrent

Throughput

Current124.83 tok/s

Window average128.6 tok/s

Time to first token

Current6 s

Window average6.0 s

End-to-end latency

Current7.2 s

Window average7.5 s

Tail latency (P99)

Current14.1 s

Window average16.8 s

Prompt cache hit rate

Current18.0%

Window average24.5%

Error rate

Current0.0%

Window average0.2%

Availability

Uptime100%At least one provider responded

Availability100%Requests actually served

Error rate0%Share of failed requests

Served requests, hour by hour

24 hours agoNow

GPT-5.1 Codex Compare models

Model	Input price	Output price	Context window	Capabilities
GPT-5.1 CodexThis page	USD 1 / 1M tokens	USD 8 / 1M tokens	400,000	Text output · Reasoning · Tool calling
GPT-5.2 Chat	USD 1.4 / 1M tokens	USD 11.2 / 1M tokens	128,000	Text output · Reasoning · Tool calling
GPT-5.1 Chat	USD 1 / 1M tokens	USD 8 / 1M tokens	128,000	Text output · Reasoning · Tool calling
GPT-5.1 Codex Max	USD 1 / 1M tokens	USD 8 / 1M tokens	400,000	Text output · Reasoning · Tool calling
GPT-5.1 Codex mini	USD 0.2 / 1M tokens	USD 1.6 / 1M tokens	400,000	Text output · Reasoning · Tool calling

Model specifications

Input: text, image
Output: text
Context window: 400,000
Maximum input: 272,000
Maximum output: 128,000
Release date: 2025-11-13
Attachments: Yes
Reasoning: Yes
Tool calling: Yes
Structured output: Yes
Temperature setting: No
Open weights: No

Frequently asked questions

What is GPT-5.1 Codex for?

Codex GPT for repository edits, code review, and practical software agents

What inputs and outputs does GPT-5.1 Codex support?

Recorded inputs: text, images; outputs: text.

How is GPT-5.1 Codex priced?

The pricing table shows the current recorded Moduck price. For example: Input USD 1 / 1M tokens; Output USD 8 / 1M tokens. See the pricing table for all units, variants, and conditions.

What specifications are recorded for GPT-5.1 Codex?

Current model records list Context window 400,000 tokens; Maximum output 128,000 tokens.

What model parameter does the Quickstart use?

The example uses openai/gpt-5.1-codex. This value comes from the page identifier and is not confirmed as a callable Moduck public ID.

Can I call this model through the Moduck API now?

This page has no verified Moduck API call for this model. A Quickstart example or reserved ID does not establish access; check the models available to your account.