gpt-5.1-chat· Released Nov 13, 2025

Name: gpt-5.1-chat
Brand: openai

openai/gpt-5.1-chat

GPT-5.1 Chat (AKA Instant is the fast, lightweight member of the 5.1 family, optimized for low-latency chat while retaining strong general intelligence. It uses adaptive reasoning to selectively “think” on...

Input

From$1.03125/M

Output

From$8.25/M

Context

Up to 128K

Max output

Up to 16K

Modalities

FileImageTextText

Input and output show the lowest price across upstreams, for reference. Your actual prices are listed per upstream below.

Upstreams & pricing

Upstream	Context	Max output	Input $/1M	Output $/1M	Cached input $/1M
Zenlayer AI Gateway-openai_compat (Global)From price	128K	16K	$1.03125	$8.25	$0.103125

Routed in real time — you pay the listed price of whichever upstream serves your call.

How to call

curlrequest.sh

curl https://api.tkex.ai/v1/chat/completions \
  -H "Authorization: Bearer $TX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.1-chat",
    "messages": [
      {"role": "user", "content": "Say hello in five words."}
    ]
  }'