GPT-5.3 Codex API: Pricing and Specs

GPT-5.3 Codex API

GPT-5.3 Codex is a large language model by OpenAI, available on the Venice API as openai-gpt-53-codex. Requests are anonymized, so the provider never sees your identity.GPT-5.3 Codex, the successor to GPT-5.2 Codex, is OpenAI’s specialized coding model, optimized for advanced software development, code generation, and technical problem-solving. It supports a longer context window and longer outputs than GPT-5.2 Codex.

GPT-5.3 Codex API pricing

Model ID	Variant	Privacy	Price
`openai-gpt-53-codex`	Standard	Anonymized	$1.75 / $14.00 per 1M

GPT-5.3 Codex specifications

Spec	Value
Provider	OpenAI
Released	Feb 24, 2026
Privacy	Anonymized
Status	Stable
Context window	400K tokens
Max output	128K tokens
Reasoning effort	none, low, medium, high, xhigh

How to use the GPT-5.3 Codex API

Send requests to POST https://api.venice.ai/api/v1/responses with "model": "openai-gpt-53-codex" and your API key.

curl https://api.venice.ai/api/v1/responses \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai-gpt-53-codex",
    "input": "Explain TEE attestation in two sentences.",
    "reasoning": { "effort": "high" }
  }'

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GPT-5.3 Codex API