Cheaper, faster member of the GPT-5.1 Codex family for lighter coding tasks. Keeps the agentic-coding tuning and Responses API interface at roughly one fifth of the Codex price.
Test this model instantly in the Console Playground โ no code required
Copy usage instructions for Claude, ChatGPT, or other AI
| Token Type | Credits | USD Equivalent |
|---|---|---|
| Input Tokens | 464.5 | $0.31 |
| Output Tokens | 3,716 | $2.48 |
| Cached Tokens | 46.45 | $0.03 |
* 1,500 credits โ $1 (actual charges may vary based on usage)
curl -X POST "https://api.core.today/llm/openai/v1/responses" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer cdt_your_api_key" \
-d '{
"model": "gpt-5.1-codex-mini",
"input": "Add null checks to this function and explain the change in one sentence:\n\n<code snippet>",
"max_output_tokens": 1000
}'| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
model | string | Yes | gpt-5.1-codex-mini | Model identifier |
input | string | array | Yes | - | Responses API input: a plain string or an array of input items (messages, tool results) |
instructions | string | No | - | System-level instructions for the run |
max_output_tokens | integer | No | - | Maximum tokens in the response (Responses API field; not max_tokens) |
stream | boolean | No | false | Enable Server-Sent Events streaming |
Low-cost Responses API request for a small coding task
curl -X POST "https://api.core.today/llm/openai/v1/responses" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer cdt_your_api_key" \
-d '{
"model": "gpt-5.1-codex-mini",
"input": "Add null checks to this function and explain the change in one sentence:\n\n<code snippet>",
"max_output_tokens": 1000
}'POST /llm/openai/v1/responses