Supported AI Models

Claude Opus 4.6 Most Powerful

Anthropic's flagship model. Best-in-class reasoning, analysis, and code generation. Handles complex multi-step tasks with high accuracy. Ideal for research, advanced coding, and detailed analysis where quality matters most.

Claude Sonnet 4.6 New

Near-Opus intelligence at a fraction of the cost. The sweet spot for most production workloads — fast enough for real-time applications, smart enough for complex tasks. Great for coding assistants, content generation, and data processing.

Claude Haiku 4.5

Ultra-fast and lightweight. Perfect for high-volume, low-latency tasks: classification, extraction, simple Q&A, and content moderation. Responses typically arrive in under a second.

Claude Extended Thinking

Enable extended thinking on any Claude model for complex reasoning tasks. The model "thinks out loud" before responding, producing more accurate results for math, logic, coding, and multi-step analysis.

GPT-5 Series Latest

The full GPT-5 family from OpenAI, including the Codex coding model. State-of-the-art language understanding, generation, and tool use. Native function calling and JSON mode supported.

OpenAI-Compatible API Format

KissAPI uses the standard OpenAI API format. If your code works with OpenAI, it works with KissAPI — just change the base URL.

curl https://api.kissapi.ai/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-6",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": true
  }'

Works with Cursor IDE, Claude Code, Cherry Studio, OpenAI Python SDK, and any OpenAI-compatible client.