OpenAIText generationReleased September 23, 2025Deprecated

GPT-5 Codex

Name: GPT-5 Codex
Brand: OpenAI
SKU: gpt-5-codex
Availability: InStock

GPT-5 Codex costs $1.25 per 1M input tokens and $10 per 1M output tokens on LLM API, with a 400K-token context window.

Pricing

Served by Azure, the only provider.

GPT-5 Codex prices on LLM API
Input	$1.25	per 1M tokens
Output	$10	per 1M tokens
Cache read	$0.125	per 1M tokens

Features

ToolsYes
Parallel tool callsNo
Image inputYes
ReasoningYes
Levels: low, medium, high
Prompt cachingYes
Structured outputsYes
JSON modeYes
StreamingYes
Web searchNo

Call GPT-5 Codex

POST /v1/responsesSet LLMAPI_KEY to your LLM API key.Responses docs

import os

from openai import OpenAI

client = OpenAI(
    base_url="https://api.llmapi.ai/v1",
    api_key=os.environ["LLMAPI_KEY"],
)

response = client.responses.create(
    model="gpt-5-codex",
    input="Hello",
)
print(response.output_text)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.llmapi.ai/v1",
  apiKey: process.env.LLMAPI_KEY,
});

const response = await client.responses.create({
  model: "gpt-5-codex",
  input: "Hello",
});
console.log(response.output_text);

curl https://api.llmapi.ai/v1/responses \
  -H "Authorization: Bearer $LLMAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-5-codex", "input": "Hello"}'

POST /v1/chat/completionsSet LLMAPI_KEY to your LLM API key.Chat Completions docs

import os

from openai import OpenAI

client = OpenAI(
    base_url="https://api.llmapi.ai/v1",
    api_key=os.environ["LLMAPI_KEY"],
)

response = client.chat.completions.create(
    model="gpt-5-codex",
    messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.llmapi.ai/v1",
  apiKey: process.env.LLMAPI_KEY,
});

const response = await client.chat.completions.create({
  model: "gpt-5-codex",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(response.choices[0].message.content);

curl https://api.llmapi.ai/v1/chat/completions \
  -H "Authorization: Bearer $LLMAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5-codex",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

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Prices synced November 3, 2026.