Openai: gpt-5.3-codex
gpt-5.3-codex
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GPT-5.3 Codex is a specialized model for coding and agentic software-engineering tasks. It is designed to understand code, handle complex multi-step development workflows, and carry out programming tasks with a high degree of autonomy.
Pricing
Current price per 1,000,000 tokens. Every request is billed automatically from its exact usage.
Included in plans
Statistics
Live performance and usage of this model, aggregated across all users.
Detailed statistics appear here as soon as this model starts receiving requests.
API
Call this model from any OpenAI-compatible client using your API token.
curl https://apiex.cloud/api/v1/chat/completions \
-H "Authorization: Bearer $NEW_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.3-codex",
"messages": [
{
"role": "user",
"content": "Explain quantum entanglement in one paragraph."
}
],
"temperature": 0.7
}'Authentication
Every request must include an Authorization: Bearer <TOKEN> header. Generate a token from your account's API Keys page — its access to models is set automatically from your active plans and redeemed codes, and you can set its rate limit and IP restrictions.
| Parameter | Type | Description |
|---|---|---|
model | string, required | This model's ID, exactly as shown above. |
messages | array, required | Conversation history as role/content objects (system, user, assistant). |
temperature | number, optional | Sampling randomness, typically 0–2. |
max_tokens | integer, optional | Upper limit on tokens generated in the reply. |
top_p | number, optional | Nucleus-sampling threshold, as an alternative to temperature. |
stream | boolean, ignored | Responses are always returned in full so the exact cost can be billed; streaming is not available. |
Replace YOUR_API_KEY with a token from your account, then see the full API reference for every parameter.
Frequently asked questions
What is gpt-5.3-codex?
GPT-5.3 Codex is a specialized model for coding and agentic software-engineering tasks. It is designed to understand code, handle complex multi-step development workflows, and carry out programming tasks with a high degree of autonomy.
How much does gpt-5.3-codex cost?
Input tokens are priced at $2,10 per 1,000,000 tokens and output tokens at $16,80 per 1,000,000 tokens. Pricing is billed automatically per request; no separate plan is required.
What is the context length of gpt-5.3-codex?
gpt-5.3-codex supports a context window of up to 400,000 tokens.
Does gpt-5.3-codex support image input?
Yes, gpt-5.3-codex accepts image input in addition to text.
Which provider is gpt-5.3-codex from?
gpt-5.3-codex is developed by Openai and made available on this gateway through our routing infrastructure.
When was gpt-5.3-codex added to this gateway?
gpt-5.3-codex has been available on this gateway since September 23, 2026.
Is gpt-5.3-codex currently available?
Yes, gpt-5.3-codex is active and can be used right now through this gateway.