Which model ID should the request send?

Send gpt-5.3-codex. Do not put a different name in the model field.

What is the minimum top-up?

Prepaid credits, $5 minimum top-up, no subscription tier.

Use case

GPT-5.3 Codex chat completions

chat completions notes for gpt-5.3-codex: the rate card, a worked volume, and when to send this ID. A sample of 1 million input tokens plus 200 thousand output tokens is about $0.910 on corouter (input $0.350, output $0.560).

Chat completions shape

A familiar JSON shape carries model and messages. Set model to gpt-5.3-codex. Paths under https://api.corouter.co follow the client you already use.

GPT-5.3 Codex (gpt-5.3-codex) lists at $1.75 input and $14.00 output per million tokens. corouter bills $0.350 input and $2.80 output. Context is 272K.

Where this GPT ID sits

GPT-5.3 Codex is a coding ID with a 272K window. Its list rate matches GPT-5.2 Codex; the difference you bill is the ID itself, gpt-5.3-codex.

A sample of 1 million input tokens plus 200 thousand output tokens is about $0.910 on corouter (input $0.350, output $0.560).

Questions

Which model ID should the request send?: Send gpt-5.3-codex. Do not put a different name in the model field.
What is the minimum top-up?: Prepaid credits, $5 minimum top-up, no subscription tier.

Start with $5 credits