Anthropic/v1/ai/anthropic/claude-opus-4.6-fast

Claude Opus 4.6 Fast

Access Claude Opus 4.6 Fast through one API key. Fastest Opus with 128K output.

Anthropic's fastest Opus variant. Same intelligence as Opus 4.6 with faster output and 128K output tokens.

Full Docs Get API Key

Context Window

1M tokens

Max Output

128K tokens

Input Price

$30.00 / 1M tokens

Output Price

$150.00 / 1M tokens

Try it live

Send a message and see Claude Opus 4.6 Fast respond in real time.

POST /v1/ai/anthropic/claude-opus-4.6-fastLive testing

API Key

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time token streaming

Hit "Run" to see the response

Strengths

✓Opus-level intelligence

✓Faster output

✓128K output tokens

✓1M context

Quick start

Copy this snippet and start making calls with Claude Opus 4.6 Fast.

const res = await fetch('https://api.yepapi.com/v1/ai/anthropic/claude-opus-4.6-fast', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const data = await res.json();
console.log(data);

Why use Claude Opus 4.6 Fast through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

Frequently asked questions

Anthropic's fastest Opus variant. Same intelligence as Opus 4.6 with faster output and 128K output tokens.

Input tokens cost $30.00 per 1M tokens and output tokens cost $150.00 per 1M tokens through YepAPI. No monthly minimums — you only pay for what you use.

Sign up for a free API key, then send requests to the /v1/ai/anthropic/claude-opus-4.6-fast endpoint. YepAPI is OpenAI SDK compatible, so you can use it with any tool that supports OpenAI — just change the base URL.

Claude Opus 4.6 Fast supports a 1M token context window with up to 128K output tokens per request.