What is the context window of GPT-5 Codex by NanoGPT?

GPT-5 Codex by NanoGPT has a context window of 256K tokens. It supports up to 256K input tokens and can generate up to 33K output tokens.

What input and output types does GPT-5 Codex support?

GPT-5 Codex by NanoGPT accepts text as input and can generate text as output.

Is GPT-5 Codex by NanoGPT open source?

No, GPT-5 Codex by NanoGPT has closed weights. The model is only available through the NanoGPT API.

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GPT-5 Codex API

NanoGPT

About

Process massive datasets with GPT-5 Codex, featuring an expansive 256K context window for long-document analysis. This model delivers cost-effective pricing at $10.00/1M input and $19.99/1M output tokens. Access GPT-5 Codex via the NanoGPT API with up to 33K output tokens.

Capabilities

Input Modalities

text

Output Modalities

text

Reasoning

Structured Output

Tool Use

WeightsClosed

Temperature

Fixed

Attachment

Not Supported

Limits

Context Window

256K

Tokens

Input Limit

256K

Tokens

Max Output

33K

Tokens

Pricing

Standard (per 1M tokens)

Input

$10.00

Output

$19.99

Frequently Asked Questions

GPT-5 Codex by NanoGPT costs $10.00 per 1M input tokens and $19.99 per 1M output tokens.

Model Details

openai/gpt-5-codex

Provider

NanoGPT

Family

gpt-codex

Release Date

Sep 15, 2025

Knowledge Cutoff

N/A

API Integration

NPM Package

@ai-sdk/openai-compatible

Environment Variables

NANO_GPT_API_KEY

API Base URL

https://nano-gpt.com/api/v1

Documentation