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Claude Opus 4.6

AnthropicReleased Feb 4, 2026

Opus 4.6 is Anthropic’s strongest model for coding and long-running professional tasks. It is built for agents that operate across entire workflows rather than single prompts, making it especially effective...

Try in playground
Context window
1M tokens
Max output
128K tokens
Input
text, image, file
Output
text
Tokenizer
Claude
Released
Feb 4, 2026
Reasoning
optional

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$5.00$0.150$5.15
Output$25.00$0.750$25.75
Cache read$0.500$0.015$0.515
Cache write$6.25$0.188$6.44

Benchmarks

Design Arena

CategoryEloWin rateRank
androidnativeagents121668.8%#11
Full-stackagents128868.6%#4
Mobile appsagents126160.5%#3
Web appsagents126660.9%#4
3Dmodels135165.2%#4
ASCII artmodels130763.5%#6
Codemodels134263.9%#3
Data vizmodels132261.7%#5
Game devmodels134463.2%#4
SVGmodels128862.7%#4
UI componentsmodels135064.5%#3
Websitesmodels133863.3%#3

Head-to-head preference voting. How we filter and rank

Supported parameters

  • include_reasoning
  • max_completion_tokens
  • max_tokens
  • reasoning
  • response_format
  • stop
  • structured_outputs
  • temperature
  • tool_choice
  • tools
  • top_k
  • top_p
  • verbosity

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model anthropic/claude-opus-4.6.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-opus-4.6",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="anthropic/claude-opus-4.6",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "anthropic/claude-opus-4.6",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does Claude Opus 4.6 cost via API?
Through OpenKey, Claude Opus 4.6 costs $5.15 per 1M input tokens and $25.75 per 1M output tokens. That is the provider price ($5.00 / $25.00) plus a flat 3% fee — nothing else.
What is Claude Opus 4.6's context window?
Claude Opus 4.6 accepts up to 1M tokens of context and returns up to 128K tokens per request.
Is Claude Opus 4.6 OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "anthropic/claude-opus-4.6" using any OpenAI SDK — only the base URL and API key change.
What inputs does Claude Opus 4.6 support?
Claude Opus 4.6 accepts text, image, file input and produces text output.

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