OpenAI: GPT-5 Codex (batch)

openai/gpt-5-codex:batch · OpenAIUnmeasurable

Declared family: GPT
Declared tokenizer tag: GPT
Entered catalogue: 23 September 2025
Measurement: Unavailable: the endpoint did not answer
Evidence confidence: Unknown

What we checked

Four different kinds of evidence, and what each one showed

We checked	What we found	Where it came from
How it counts tokens	Not measured yet	we measured it
How its API is set up	A combination of settings no other listing in the catalogue uses	api_d55f5d09
How much it can read and write	Reads up to 400,000 tokens at once, writes up to 128,000	its own listing
Whether it thinks before answering	Always reasons, and cannot be turned off	its own listing

Declared record

What the catalogue claims about this model

GPT-5-Codex is a specialized version of GPT-5 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....

Modalities: text+image->text
Declared tokenizer: GPT
Prompt price: $0.63 / M tokens
Completion price: $5.00 / M tokens

Supported parameters

include_reasoningmax_tokensreasoningresponse_formatseedstructured_outputstool_choicetools

defaults: {"temperature":null,"top_p":null,"frequency_penalty":null}

Catalogue entry

History

Every observation, kept as taken

23 September 2025Enters the OpenRouter catalogue declared as GPT.

* OpenAI: GPT-5 Codex (batch) no longer appears in the OpenRouter catalogue, first absent from the snapshot of 3 September 2026. The record stays because the measurements above were real when they were taken and this address has been published.