GPT-5 Codex API

openai/gpt-5-codex
GPT-5 Codex on AIMLAPI.
Context
400K tokens
Input
$1.625 / 1M
Output
$13 / 1M

How to use GPT-5 Codex API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to openai/gpt-5-codex.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "openai/gpt-5-codex",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "openai/gpt-5-codex",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"openai/gpt-5-codex","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

GPT-5 Codex API Pricing

TypePrice
Input
$1.625 / 1M
Output
$13 / 1M

GPT-5 Codex Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
SWE-bench Verified
74.5%
Resolving verified real GitHub issuesSourceJuly 12, 2026
Intelligence
24.9
Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026
Math
98.7
Composite score across standardised mathematics evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026

GPT-5 Codex vs other models

ModelInputOutputContextBest for
GPT-5 Codex
This page
$1.625 / 1M
$13 / 1M
400K tokens
Reasoning + agents
$6.5 / 1M tokens
$39 / 1M tokens
1.05M tokens
Reasoning + agents
$2.6 / 1M tokens
$13 / 1M tokens
1M tokens
Balanced coding + agents
$3.9 / 1M tokens
$19.5 / 1M tokens
1M tokens
Long-context, multimodal & agentic workflows
$0.65 / 1M tokens
$3.9 / 1M tokens
1.05M tokens
Reasoning + agents

Frequently asked questions

GPT-5 Codex has a 400,000 tokens context window and can return up to 128,000 tokens.

GPT-5 Codex takes image, text as input and returns text.

Use openai/gpt-5-codex as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

GPT-5 Codex is priced at input $1.625 / 1M, output $13 / 1M.

Yes, GPT-5 Codex can stream responses as they are generated.

Yes, GPT-5 Codex accepts image input alongside text.

GPT-5 Codex was built by OpenAI.

Yes. It supports function calling, parallel tool calls, and structured outputs.

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