> ## Documentation Index
> Fetch the complete documentation index at: https://veniceai-feat-models-redesign.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# GPT-5.3 Codex API

> GPT-5.3 Codex API on Venice: 400K context, $2.19 input and $17.50 output per 1M tokens. Anonymized access without your identity.

export const HubMount = ({view, children, ...props}) => {
  const [hub, setHub] = useState(null);
  const [failed, setFailed] = useState(false);
  useEffect(() => {
    let alive = true;
    const w = window;
    if (!w.__veniceModelHub) {
      const urls = w.location.hostname === 'localhost' ? ['http://localhost:3333/data/model-hub.bundle.json', '/data/model-hub.bundle.json'] : ['/data/model-hub.bundle.json'];
      const load = i => fetch(urls[i], {
        cache: 'no-cache'
      }).then(res => {
        if (!res.ok) throw new Error(`bundle ${res.status}`);
        return res.json();
      }).catch(err => i + 1 < urls.length ? load(i + 1) : Promise.reject(err));
      const Frag = <></>.type;
      const h = (type, props, ...kids) => {
        const T = type;
        const {key, ...rest} = props || ({});
        if (!kids.length) return <T key={key} {...rest} />;
        if (kids.length === 1) return <T key={key} {...rest}>{kids[0]}</T>;
        return <T key={key} {...rest}>{kids.map((kid, i) => <Frag key={i}>{kid}</Frag>)}</T>;
      };
      w.__veniceModelHub = load(0).then(bundle => new Function(`return (${bundle.code})`)()({
        h,
        Fragment: Frag,
        useState,
        useEffect,
        useRef,
        useMemo,
        useCallback
      }));
    }
    w.__veniceModelHub.then(instance => {
      if (alive) setHub(instance);
    }).catch(() => {
      w.__veniceModelHub = null;
      if (alive) setFailed(true);
    });
    return () => {
      alive = false;
    };
  }, []);
  const View = hub ? hub[view] : null;
  if (View) return <View {...props}>{children}</View>;
  if (failed) {
    return <div className="vx-mount is-failed">
        <p className="vx-mount-note">The interactive model catalog could not load. The full data is below.</p>
        {children}
      </div>;
  }
  return <div className="vx-mount" aria-busy="true">
      <div className="vx-mount-skeleton" aria-hidden="true"><span /><span /><span /></div>
      <div className="vx-mount-source">{children}</div>
    </div>;
};

<HubMount view="ModelPage" data={{"family":{"slug":"gpt-5-3-codex","name":"GPT-5.3 Codex","modality":"text","task":"chat","provider":"openai","description":"GPT-5.3 Codex is OpenAI specialized coding model built on GPT-5.3, optimized for advanced software development, code generation, and technical problem-solving.","primary":"openai-gpt-53-codex","variants":["openai-gpt-53-codex"],"created":1771891200,"updated":1771891200,"privacy":["anonymized"]},"models":[{"id":"openai-gpt-53-codex","name":"GPT-5.3 Codex","type":"text","modality":"text","task":"chat","variant":"standard","provider":"openai","created":1771891200,"description":"GPT-5.3 Codex is OpenAI specialized coding model built on GPT-5.3, optimized for advanced software development, code generation, and technical problem-solving.","source":"https://developers.openai.com/api/docs/models/gpt-5.3-codex","privacy":"anonymized","text":{"context":400000,"maxOutput":128000,"reasoning":{"supported":true,"effort":["none","low","medium","high","xhigh"],"defaultEffort":"high"},"caps":{"tools":true,"structured":true,"vision":true,"maxImages":10,"webSearch":true,"code":true}},"pricing":{"input":2.19,"output":17.5,"cacheRead":0.219,"blended":6.0175},"headline":{"value":6.0175,"unit":"per 1M tokens","basis":"blended"},"endpoints":[{"id":"chat","method":"POST","path":"/chat/completions","name":"Chat Completions","status":"stable"},{"id":"responses","method":"POST","path":"/responses","name":"Responses","status":"alpha","recommended":true,"recommendation":"Pro and Codex models are Responses-native upstream. Use /responses for typed reasoning, tool-call and message items; /chat/completions stays fully supported."}],"family":"gpt-5-3-codex"}],"related":{"similar":[{"slug":"gemini-3-1-pro-preview","name":"Gemini 3.1 Pro Preview","provider":"google","modality":"text","privacy":["anonymized"],"created":1771459200,"headline":{"value":5.625,"unit":"per 1M tokens","basis":"blended"},"variants":1},{"slug":"claude-sonnet-5","name":"Claude Sonnet 5","provider":"anthropic","modality":"text","privacy":["anonymized"],"created":1782691200,"headline":{"value":6,"unit":"per 1M tokens","basis":"blended"},"variants":1},{"slug":"claude-sonnet-4-6","name":"Claude Sonnet 4.6","provider":"anthropic","modality":"text","privacy":["anonymized"],"created":1771286400,"headline":{"value":7.2,"unit":"per 1M tokens","basis":"blended"},"variants":1},{"slug":"kimi-k3","name":"Kimi K3","provider":"moonshot","modality":"text","privacy":["private","e2ee"],"created":1784160000,"headline":{"value":7.5,"unit":"per 1M tokens","basis":"blended"},"variants":3}],"versions":[]},"providers":{"openai":{"slug":"openai","name":"OpenAI","logo":"/images/icons/models/openai.svg"},"google":{"slug":"google","name":"Google","logo":"/images/icons/models/google.svg"},"anthropic":{"slug":"anthropic","name":"Anthropic","logo":"/images/icons/models/opus.svg"},"moonshot":{"slug":"moonshot","name":"Moonshot AI","logo":"/images/icons/models/kimi.svg"}},"faq":[{"q":"How much does the GPT-5.3 Codex API cost?","a":"$2.19 per 1M input tokens and $17.50 per 1M output tokens, with cached input at $0.22 per 1M. Prices are in USD and can be paid in DIEM at parity."},{"q":"What is the GPT-5.3 Codex model ID?","a":"Use `openai-gpt-53-codex` as the `model` parameter."},{"q":"Is the GPT-5.3 Codex API private?","a":"GPT-5.3 Codex is anonymized: Venice forwards requests to the provider without your identity, but the provider may retain prompt data, so use a private model for sensitive work."},{"q":"What is the context window of GPT-5.3 Codex?","a":"400K tokens of context, with up to 125K output tokens per response."},{"q":"What does GPT-5.3 Codex support?","a":"GPT-5.3 Codex supports function calling, structured outputs, reasoning, image input, web search and prompt caching. Reasoning effort is adjustable with `reasoning_effort`: none, low, medium, high and xhigh (default high)."},{"q":"Which endpoint does the GPT-5.3 Codex API use?","a":"Call `POST /responses`. `/chat/completions` is also supported. Pro and Codex models are Responses-native upstream. Use /responses for typed reasoning, tool-call and message items; /chat/completions stays fully supported."}]}} />

<div className="vx-static">
  <Accordion title="Plain-text specification">
    # 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 is OpenAI specialized coding model built on GPT-5.3, optimized for advanced software development, code generation, and technical problem-solving.

    ## GPT-5.3 Codex API pricing

    | Model ID | Variant | Privacy | Price |
    | - | - | - | - |
    | `openai-gpt-53-codex` | Standard | Anonymized | $2.19 input / $17.50 output per 1M tokens |

    ## GPT-5.3 Codex specifications

    | Spec | Value |
    | - | - |
    | Provider | OpenAI |
    | Released | Feb 24, 2026 |
    | Privacy | Anonymized |
    | Context window | 400K tokens |
    | Max output | 125K 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.

    ```bash theme={null}
    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" }
      }'
    ```

    ## GPT-5.3 Codex API FAQ

    ### How much does the GPT-5.3 Codex API cost?

    $2.19 per 1M input tokens and $17.50 per 1M output tokens, with cached input at \$0.22 per 1M. Prices are in USD and can be paid in DIEM at parity.

    ### What is the GPT-5.3 Codex model ID?

    Use `openai-gpt-53-codex` as the `model` parameter.

    ### Is the GPT-5.3 Codex API private?

    GPT-5.3 Codex is anonymized: Venice forwards requests to the provider without your identity, but the provider may retain prompt data, so use a private model for sensitive work.

    ### What is the context window of GPT-5.3 Codex?

    400K tokens of context, with up to 125K output tokens per response.

    ### What does GPT-5.3 Codex support?

    GPT-5.3 Codex supports function calling, structured outputs, reasoning, image input, web search and prompt caching. Reasoning effort is adjustable with `reasoning_effort`: none, low, medium, high and xhigh (default high).

    ### Which endpoint does the GPT-5.3 Codex API use?

    Call `POST /responses`. `/chat/completions` is also supported. Pro and Codex models are Responses-native upstream. Use /responses for typed reasoning, tool-call and message items; /chat/completions stays fully supported.

    ## Related models

    * [Gemini 3.1 Pro Preview API](/models/gemini-3-1-pro-preview): $2.50 input / $15.00 output per 1M tokens
    * [Claude Sonnet 5 API](/models/claude-sonnet-5): $3.00 input / $15.00 output per 1M tokens
    * [Claude Sonnet 4.6 API](/models/claude-sonnet-4-6): $3.60 input / $18.00 output per 1M tokens
    * [Kimi K3 API](/models/kimi-k3): $3.75 input / $18.75 output per 1M tokens
  </Accordion>
</div>


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