gpt-5-1-codex-mini
GPT-5.1-Codex-Mini is a smaller, faster version of GPT-5.1-Codex for coding work where latency and cost matter.
Pricing: Input 50 credits / 1M tokens (≈ $0.25), Output 400 credits / 1M tokens (≈ $2.00).
Prices updated
How can I help you today?
This demo page does not include the full memory features of the client. For the complete experience, please use the client or the CLI.
More AI models from OpenAI
Latest and popular AI models
GPT-5.1-Codex-Mini API on ModelFold
GPT-5.1-Codex-Mini is a smaller, faster version of GPT-5.1-Codex for coding work where latency and cost matter. Try GPT-5.1-Codex-Mini in the ModelFold Playground, then call it from your own code through an OpenAI-compatible chat completions API.
What Is the GPT-5.1-Codex-Mini API
GPT-5.1-Codex-Mini at a glance
GPT-5.1-Codex-Mini is a chat model from OpenAI. It accepts text and images as input and returns text, with a context window of up to 400K tokens.
Use it without hosting anything
On ModelFold you call GPT-5.1-Codex-Mini with a single API key — no model weights to download and no inference servers to run. The same key also works for the other chat, image, video and audio models on ModelFold.
Core Capabilities of GPT-5.1-Codex-Mini
Up to 400K tokens of context
Keep long conversations, large documents and sizeable code in a single request, so the model can reason over the full material instead of fragments.
Understands images
Besides text, GPT-5.1-Codex-Mini accepts images as input, so a single request can combine instructions with visual or other media.
Function calling
GPT-5.1-Codex-Mini supports tool (function) calling: describe your functions in the request and the model returns structured calls your code can run — the basis for agents and integrations.
Adjustable reasoning effort
Choose a reasoning effort level (low, medium or high) per request to balance depth of thinking against speed and token usage.
Structured outputs
Ask for JSON that follows a schema (response_format), which makes extraction, classification and system integrations more reliable.
How to Use GPT-5.1-Codex-Mini on ModelFold
- 1
Step 1: Try it in the Playground
Open the Playground at the top of this page, type a prompt and see how GPT-5.1-Codex-Mini responds before writing any code.
- 2
Step 2: Create an API key
Sign in to ModelFold and create an API key in the console. Keep it secret and send it as a Bearer token.
- 3
Step 3: Send a request
Call POST https://modelfold.ai/v1/chat/completions with "model": "gpt-5-1-codex-mini" and your messages. Existing OpenAI-compatible SDKs work by changing the base URL and key.
- ✓
Step 4: Ship and monitor
Integrate the response into your product and check token usage and spend for every call in the console logs.
What You Can Build with GPT-5.1-Codex-Mini
AI coding assistants
Generate, explain, debug and refactor code, review pull requests and work through multi-file changes in developer tools and IDE plugins.
Low-latency experiences
Power chat interfaces, autocomplete and interactive tools where users expect fast responses.
High-volume pipelines
Run classification, extraction, rewriting and batch jobs at scale where cost per request matters.
Tool-calling backends
Route requests, call functions and chain API calls as the worker model inside larger agent systems.
Frequently Asked Questions
What is GPT-5.1-Codex-Mini?⌄
GPT-5.1-Codex-Mini is a smaller, faster version of GPT-5.1-Codex for coding work where latency and cost matter.
Which inputs does GPT-5.1-Codex-Mini support?⌄
GPT-5.1-Codex-Mini accepts text and images and returns text. Through ModelFold you can send text and images (OpenAI-style image_url content); in the Playground you can also attach documents, which are converted to text.
How long is the context window of GPT-5.1-Codex-Mini?⌄
Up to 400K tokens, shared between your input and the model’s output.
Does GPT-5.1-Codex-Mini support function calling?⌄
Yes. GPT-5.1-Codex-Mini supports tools / function calling through the standard tools parameter of the chat completions API.
How is GPT-5.1-Codex-Mini billed on ModelFold?⌄
Pay as you go by tokens: input and output tokens are charged at the per-million-token prices shown on this page. There is no monthly fee, and failed requests are not charged.
How do I call GPT-5.1-Codex-Mini through the API?⌄
Send a POST request to https://modelfold.ai/v1/chat/completions with "model": "gpt-5-1-codex-mini", using your ModelFold API key as the Bearer token.
| Input | 50 credits 1M tokens≈ $0.25 |
| Output | 400 credits 1M tokens≈ $2.00 |
Billed per token: input and output are priced separately, and thinking tokens count as output. The Playground charges exactly the same way.
Read API docs →AI Agents · Claude Code / Cursor / Trae →curl https://modelfold.ai/v1/chat/completions \
-H "Authorization: Bearer $MODELFOLD_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"gpt-5-1-codex-mini","messages":[{"role":"user","content":"Hello"}]}'