Name: Claude 4.5 Sonnet Thinking API
Brand: Anthropic

Overview

What is Claude 4.5 Sonnet API?

Claude 4.5 Sonnet offers a balance of intelligence and speed for diverse enterprise and coding tasks.

Technical Specifications
- Supported inputs: Text
- Output: Text
- Context window: 200,000 tokens / Max output: 64,000 tokens
- Endpoint: /chat/completions

Performance Benchmarks
[embed]

Claude 4.5 Sonnet API Pricing
- Input: $3.9 / 1M tokens
- Output: $19.5 / 1M tokens

Where to Use Claude 4.5 Sonnet

Coding and code review
Generate, debug, and review code across languages, reading whole files or repos in a single prompt.

Long-document analysis
Summarize and extract from contracts, papers, and reports without aggressive chunking.

Code Sample
[embed]

Uptime and performance

Uptime (24h): 100%
Uptime (7d): 99.0%
Availability (24h): 100%
Error rate (24h): 0%
End-to-end latency (24h median): 4.7s
Throughput (24h median): 20.6 tok/s

Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.

Use cases

Programming assistance: code generation, debugging, review
Autonomous agent management for software tools and workflows
Financial and cybersecurity data analysis and automation
Research data synthesis and multi-agent coordination
Editing and generating documents, spreadsheets, presentations within conversations

How to use Claude 4.5 Sonnet Thinking API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to anthropic/claude-sonnet-4.5.

import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "anthropic/claude-sonnet-4.5",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())

const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "anthropic/claude-sonnet-4.5",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());

curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"anthropic/claude-sonnet-4.5","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.