GPT-5.3 Codex

Official list price in the directory snapshot: ¥11.7 input and ¥93.59 output per 1M tokens, in CNY. Relay prices below are what individual sites listed; they can be lower or higher, and they are not official prices.

24 sites in our public directory listed this model ID in the 2026-10-26 snapshot. Listed relay price range: ¥0.1–¥14.6 per 1M input tokens. A listing means the model appeared on the site's public model list; it is not proof that the site serves the genuine model.

1. Send a short request to the relay and read the model field in the response. It must match the ID you sent; a different ID is a mapping, not necessarily a substitution.
2. Run the same prompt against a known-good endpoint and compare prompt-token counts. A large, repeatable gap points at a different tokenizer or a different backend.
3. Run the seven checks. Billing, context retention, error shape, parameter compliance, tools, and streaming each produce evidence you can quote.

What is the context window of GPT-5.3 Codex?

The snapshot records 400,000 tokens.

How much does GPT-5.3 Codex cost?

Official list price: ¥11.7 input / ¥93.59 output per 1M tokens in CNY, per the directory snapshot. 24 relay sites listed it at ¥0.1–¥14.6 per 1M input tokens.

Is a relay really serving GPT-5.3 Codex?

A model ID in a response is not proof. The seven-check detection compares tokenizer ratios, billing, error shape, parameter compliance, tools, and streaming against the advertised family. Run it on a key you can afford to spend, and treat one run as a spot check, not 24/7 monitoring.