GPT-5.1 Codex Mini

openaiopenai/gpt-5.1-codex-mini

Smaller, more cost-effective version of GPT-5.1-Codex.

Context Length

400K

Max Output

128K

Input Price

$0.300/ 1M tokens

Output Price

$2.40/ 1M tokens

Modalities

textimage→text

Pricing Breakdown

Type	Rate
Input	$0.300 / 1M tokens
Output	$2.40 / 1M tokens

Supported Parameters

temperaturemax_tokenstop_ptoolstool_choiceresponse_formatreasoningstop

API Usage Examples

cURL

curl https://api.therouter.ai/v1/chat/completions   -H "Content-Type: application/json"   -H "Authorization: Bearer $THE_ROUTER_API_KEY"   -d '{
    "model": "openai/gpt-5.1-codex-mini",
    "messages": [
      {"role": "user", "content": "Summarize the key points from this input."}
    ]
  }'