LLM Reference

Using GPT-5.2 Codex on Vercel AI Gateway

Implementation guide · GPT-5 · OpenAI

Serverless

Quick Start

  1. 1
    Create an account at Vercel AI Gateway and generate an API key.
  2. 2
    Use the Vercel AI Gateway SDK or REST API to call openai/gpt-5.2-codex — see the documentation for request format.
  3. 3
    You'll be billed $1.75/1M input, $14.00/1M output tokens. See full pricing.

Code Examples

Install
pip install openai
API key
AI_GATEWAY_API_KEY
Model ID
openai/gpt-5.2-codex

creator/model-name e.g. kwaipilot/kat-coder-pro-v2

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["AI_GATEWAY_API_KEY"],
    base_url="https://ai-gateway.vercel.sh/v1"
)
response = client.chat.completions.create(
    model="openai/gpt-5.2-codex",
    messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content)

About Vercel AI Gateway

Vercel AI Gateway is a unified AI proxy providing a single OpenAI-compatible API endpoint to 275+ models from 25+ providers including Anthropic, OpenAI, Google, Meta, Mistral, DeepSeek, xAI, Alibaba, Amazon, ByteDance, Cohere, MiniMax, MoonshotAI, KwaiPilot, Black Forest Labs, Recraft, Voyage AI, NVIDIA, and more. Pricing is pass-through at provider list rates with zero markup. Includes $5/month free tier; paid is pay-as-you-go. Features: automatic provider fallbacks, unified observability, streaming, tool use, vision, embeddings, image/video generation, BYOK mode. Integrates via @ai-sdk/gateway package or plain model ID strings in Vercel AI SDK. API details: API key via Authorization: Bearer <AI_GATEWAY_API_KEY>. Key from Vercel dashboard. Free $5/month credit; paid tier is provider list price with zero markup. BYOK (bring-your-own-key) also supported with no markup or fee. Model IDs use {provider-owner}/{model-name} — e.g., anthropic/claude-opus-4.6, openai/gpt-5.

Vercel AI Gateway is a unified AI proxy providing a single OpenAI-compatible API endpoint to 275+ models from 25+ providers including Anthropic, OpenAI, Google, Meta, Mistral, DeepSeek, xAI, Alibaba, Amazon, ByteDance, Cohere, MiniMax, MoonshotAI, KwaiPilot, Black Forest Labs, Recraft, Voyage AI, NVIDIA, and more. Pricing is pass-through at provider list rates with zero markup. Includes $5/month free tier; paid is pay-as-you-go. Features: automatic provider fallbacks, unified observability, streaming, tool use, vision, embeddings, image/video generation, BYOK mode. Integrates via @ai-sdk/gateway package or plain model ID strings in Vercel AI SDK.

Pricing on Vercel AI Gateway

TypePrice (per 1M)
Input tokens$1.75
Output tokens$14.00
Query$10.00

Capabilities

VisionMultimodalReasoningFunction CallingTool UseCode Execution

About GPT-5.2 Codex

GPT-5.2-Codex is OpenAI's agentic coding model built on GPT-5.2, released December 18, 2025. Optimized for long-horizon professional software engineering tasks including large refactors, multi-file changes, and codebase migrations. Features context compaction for handling tasks exceeding a single context window, enhanced vision for interpreting screenshots, diagrams, and UI, and strengthened safeguards for defensive cybersecurity workflows. Available to paid ChatGPT users and via the Responses API.

Model Specs

Released2025-12-18
ArchitectureDecoder Only
Knowledge cutoff2025-08

Provider

Vercel AI Gateway

Vercel