GPT 5.1 Codex API Pricing & Quick Start

Name: GPT 5.1 Codex API
Brand: OpenAI

GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....

Intelligence#97 / 573

Artificial Analysis Intelligence Index

Speed#166 / 586

0.0

Output tokens per second (median)

Input Price#454 / 586

$1.25NT$ 40

USD / 1M tokens

Output Price#490 / 586

$10.00NT$ 324

USD / 1M tokens

First-token latency#1 / 586

0.00s

Time to first token (AA median)

Provider	OpenAI
Released	November 2025
Model ID	`openai/gpt-5.1-codex`

Technical specifications

Context window

400K tokens

Reasoning

Yes

Input

TextImage

Output

Text

Pricing comparison

BazaarLink retail price alongside AA's observed market standard.

BazaarLink price our site

Input$1.25NT$ 40

Output$10.00NT$ 324

Cache read$0.13NT$ 4

Cache write—

3:1 blended (est.)$3.44NT$ 111

All prices per 1M tokens. Supports TWD credit card / official invoice.

Market reference Artificial Analysis

Input$1.25

Output$10.00

Cache readAA not tracked

Cache writeAA not tracked

3:1 blended$3.44

✓ Matches market reference — BazaarLink does not mark up.
Source: artificialanalysis.ai

Independent benchmarks

Scores below come from Artificial Analysis, an independent third party. BazaarLink does not participate in the testing.

Intelligence 35

Coding

Math 96

MMLU 86

GPQA 86

This modelCategory leader

Overall intelligence

#97out of 573 models

Aggregated across academic benchmarks

Math reasoning

#7out of 269 models

AIME / MATH-500 / SciCode

Time to first token

🥇

#1out of 586 models

AA 全球 p50：0.00 秒

Intelligence

Top 17%

This model

Category leader

Median

Math

Top 3%

This model

Category leader

Median

MMLU Pro

86%

—

This model

86%

Category leader

90%

Median

75%

GPQA

86%

—

This model

86%

Category leader

94%

Median

69%

LiveCodeBench

85%

—

This model

85%

Category leader

42%

Median

42%

HLE

23%

—

This model

23%

Category leader

53%

Median

SciCode

40%

—

This model

40%

Category leader

60%

Median

33%

IFBench

70%

—

This model

70%

Category leader

83%

Median

44%

τ²-Bench Telecom

83%

—

This model

83%

Category leader

99%

Median

46%

AA-LCR

67%

—

This model

67%

Category leader

76%

Median

40%

Terminal-Bench Hard

35%

—

This model

35%

Category leader

66%

Median

14%

Top 5 — CodingCoding Index leaderboard

1GPT-5.6 Sol (xhigh)openai/gpt-5-6-sol-xhigh78$5 / $30

2Claude Opus 5 (Adaptive Reasoning, Max Effort)anthropic/claude-opus-578$5 / $25

3GPT-5.6 Sol (max)openai/gpt-5-6-sol77$5 / $30

4GPT-5.6 Sol (high)openai/gpt-5-6-sol-high77$5 / $30

5Claude Opus 5 (Adaptive Reasoning, Xhigh Effort)anthropic/claude-opus-5-xhigh77$5 / $25

AASource: Artificial Analysis · Independent third-party evaluation; not influenced by BazaarLinkView full evaluation on AA →

Quick Start

Use GPT 5.1 Codex via BazaarLink API — just change the base_url:

Python

from openai import OpenAI

client = OpenAI(
    base_url="https://bazaarlink.ai/api/v1",
    api_key="sk-bl-YOUR_API_KEY",
)

response = client.chat.completions.create(
    model="openai/gpt-5.1-codex",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(response.choices[0].message.content)

TypeScript

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://bazaarlink.ai/api/v1",
  apiKey: "sk-bl-YOUR_API_KEY",
});

const response = await client.chat.completions.create({
  model: "openai/gpt-5.1-codex",
  messages: [{ role: "user", content: "Hello!" }],
});
console.log(response.choices[0].message.content);

Why use GPT 5.1 Codex via BazaarLink?

✓USD billing (TWD-quoted) + unified invoices — no foreign credit card needed for Taiwan teams
✓OpenAI-compatible API — zero code changes required
✓Automatic failover — multi-provider redundancy for the same model
✓Chinese-language support — local team, instant help

Try Now ← All Models

Frequently Asked Questions

What is GPT 5.1 Codex?

How much does the GPT 5.1 Codex API cost?

GPT 5.1 Codex costs $1.2500 per 1M input tokens and $10.0000 per 1M output tokens when accessed through BazaarLink.

How do I use GPT 5.1 Codex with the OpenAI SDK?

Set base_url to "https://bazaarlink.ai/api/v1" and use model ID "openai/gpt-5.1-codex". All OpenAI SDK methods (chat.completions, embeddings, streaming) work without code changes.

What is the context window for GPT 5.1 Codex?

GPT 5.1 Codex supports a context window of 400,000 tokens.

Is GPT 5.1 Codex available for free?

GPT 5.1 Codex is a paid model. BazaarLink offers free trial credits on registration so you can test it without a credit card.

Relay integrity checks

Tested endpoints: 4 runs
Independent hosts: 1
Model-family fingerprint match: 100%
Anomalies detected: 4 runs
Data range: past 90 days

BazaarLink Probe verifies endpoints that claim to serve this model and flags behavior that differs from the reference baseline.

View the full integrity report →

GPT 5.1 Codex API Pricing & Quick Start

Technical specifications

Pricing comparison

BazaarLink price our site

Market reference Artificial Analysis

Independent benchmarks

Top 5 — CodingCoding Index leaderboard

Quick Start

Why use GPT 5.1 Codex via BazaarLink?

Frequently Asked Questions

Relay integrity checks

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