Last refreshed 2026-05-22. Next refresh: weekly.
Why use GPT-5.3-Codex on Vercel AI Gateway?
Vercel AI Gateway offers GPT-5.3-Codex with pay-as-you-go pricing at $1.75/1M input tokens. 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.
Compare GPT-5.3-Codex across 3 providers to find the best fit for your use caseSetup recipe
Python + curlpip install openaiexport AI_GATEWAY_API_KEY=...import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["AI_GATEWAY_API_KEY"],openai/gpt-5.3-codexRequest example
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-5.3-codex",
messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content)Gotchas
- Use provider model ID "openai/gpt-5.3-codex", not the LLMReference slug "gpt-5.3-codex".
- creator/model-name e.g. kwaipilot/kat-coder-pro-v2
- The examples expect AI_GATEWAY_API_KEY; rename it only if your application config maps the new variable.
Compare GPT-5.3-Codex Across Providers
| Provider | Input (per 1M) | Output (per 1M) |
|---|---|---|
| OpenRouter | $1.75 | $14.00 |
| OpenAI API | $1.75 | $14.00 |
| Vercel AI Gateway | $1.75 | $14.00 |
Pricing
| Type | Price (per 1M) |
|---|---|
| Input tokens | $1.75 |
| Output tokens | $14.00 |
| Query | $10.00 |
Capabilities
About GPT-5.3-Codex
Most capable agentic coding model from OpenAI. Optimized for long-horizon, agentic coding tasks in the Codex CLI and API. Note: GPT-5.3-Codex-Spark is a distinct ChatGPT Pro research preview (not API-accessible).
FAQ
What does GPT-5.3-Codex cost on Vercel AI Gateway?
On Vercel AI Gateway, GPT-5.3-Codex costs $1.75 per 1M input tokens and $14 per 1M output tokens.
What is the context window for GPT-5.3-Codex on Vercel AI Gateway?
GPT-5.3-Codex supports a 400,000 token context window on Vercel AI Gateway.
How does Vercel AI Gateway compare to other GPT-5.3-Codex providers?
GPT-5.3-Codex is available from 3 providers. The cheapest input pricing is $1.75/1M tokens from OpenRouter.
What API model ID do I use for GPT-5.3-Codex on Vercel AI Gateway?
Use the model ID openai/gpt-5.3-codex when calling Vercel AI Gateway's API.
Who created GPT-5.3-Codex?
GPT-5.3-Codex was created by OpenAI as part of the Codex model family.
Is GPT-5.3-Codex open source?
GPT-5.3-Codex is not open source; the seed data lists it as proprietary.