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Claude · AnthropicBalanced tier

Claude Sonnet 4.5

claude-sonnet-4.5

Previous-generation Sonnet, kept available so pinned workloads stay reproducible.

Get an API key Use it in Claude Code

Specs & rates

Context window
131K
131,072 tokens
Input
$1.30
per 1M tokens
Output
$6.00
per 1M tokens
Cached input
$1.30
per 1M tokens
Cache write · 5m
$1.30
per 1M tokens
Cache write · 1h
$1.30
per 1M tokens

Use Claude Sonnet 4.5

Native endpoint: /v1/messages. Also available on /v1/chat/completions for OpenAI-compatible clients.

export ANTHROPIC_BASE_URL="https://api.evolved.to"
export ANTHROPIC_AUTH_TOKEN="$EVOLVED_API_KEY"
export ANTHROPIC_MODEL="claude-sonnet-4.5"

claude
curl https://api.evolved.to/v1/messages \
  -H "x-api-key: $EVOLVED_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-sonnet-4.5",
    "max_tokens": 16000,
    "messages": [{"role": "user", "content": "Hello, Claude"}]
  }'
import os
import anthropic

client = anthropic.Anthropic(
    base_url="https://api.evolved.to",
    api_key=os.environ["EVOLVED_API_KEY"],
)

message = client.messages.create(
    model="claude-sonnet-4.5",
    max_tokens=16000,
    messages=[{"role": "user", "content": "Hello, Claude"}],
)

for block in message.content:
    if block.type == "text":
        print(block.text)
import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic({
  baseURL: "https://api.evolved.to",
  apiKey: process.env.EVOLVED_API_KEY,
});

const message = await client.messages.create({
  model: "claude-sonnet-4.5",
  max_tokens: 16000,
  messages: [{ role: "user", content: "Hello, Claude" }],
});

for (const block of message.content) {
  if (block.type === "text") console.log(block.text);
}