AnthropicPaidOperational
Claude Sonnet 4.5
API model name: claude-sonnet-4.5
Claude Sonnet 4.5 is Anthropic's chat model, served on the Api.Airforce unified API. It has a 200K-token context window. Beyond text, it accepts image, document as input. Capabilities include Vision, Tool calling, Reasoning, Documents, Prompt caching. It is priced at $0.40 per million input tokens and $2.00 per million output tokens. That is below the provider's $3.00 official input rate. Knowledge cutoff: 2025-08. Access it through the OpenAI-compatible API with one key, alongside 100+ other models on Api.Airforce.
Pricing
Api.Airforce price vs. the provider's official rate.
Specifications
- Provider
- Anthropic
- Type
- chat model
- Context window
- 200K tokens
- Max output
- 64K tokens
- Knowledge cutoff
- 2025-08
- Input
- text, image, document
- Output
- text
- Prompt caching
- Supported
Capabilities
VisionTool callingReasoningDocumentsPrompt cachingStreaming
What is Claude Sonnet 4.5 used for?
- Chatbots & assistants — conversational AI, drafting, summarizing and Q&A.
- Image understanding — analyze photos, screenshots, charts and scanned documents.
- Agents & automation — function calling and tool use for multi-step workflows.
- Complex reasoning — math, coding and step-by-step problem solving.
- Document analysis — summarize and answer questions across long files.
- Long-context tasks — process entire documents or codebases in a single prompt.
- Real-time experiences — stream tokens for responsive chat and apps.
Claude Sonnet 4.5 vs. similar models
| Model | Intelligence | Context | Input / 1M | Output / 1M |
|---|---|---|---|---|
| Claude Sonnet 4.5 | — | 200K | $0.40 | $2.00 |
| Claude Fable 5 | 64.9 | — | $7.00 | $35.00 |
| Claude Haiku 4.5 | — | 200K | $0.30 | $1.80 |
| Claude Opus 4 | — | — | $2.25 | $11.25 |
Prices are Api.Airforce pay-as-you-go rates per 1M tokens. Context is the maximum input length.
Related models
Claude Fable 5Anthropic · $7.00 / 1MClaude Haiku 4.5Anthropic · $0.30 / 1MClaude Opus 4Anthropic · $2.25 / 1MClaude Opus 4.1Anthropic · $2.25 / 1MClaude Opus 4.5Anthropic · $0.80 / 1MClaude Opus 4.5 RpAnthropic · $3.00 / 1MClaude Opus 4.6Anthropic · $2.50 / 1MClaude Opus 4.6 RpAnthropic · $2.50 / 1MClaude Opus 4.7Anthropic · $0.80 / 1MClaude Opus 4.8Anthropic · $4.00 / 1MClaude Sonnet 4Anthropic · $0.45 / 1MClaude Sonnet 4.5 RpAnthropic · $1.00 / 1M
Claude Sonnet 4.5 — frequently asked questions
- How much does Claude Sonnet 4.5 cost?
- Claude Sonnet 4.5 is billed pay-as-you-go at $0.40 per 1M input tokens and $2.00 per 1M output tokens. There is no subscription — you only pay for what you use.
- What is the context window of Claude Sonnet 4.5?
- Claude Sonnet 4.5 supports a context window of up to 200K tokens. It can return up to 64K tokens in a single response.
- What can Claude Sonnet 4.5 do?
- Claude Sonnet 4.5 supports Vision, Tool calling, Reasoning, Documents, Prompt caching.
- Is Claude Sonnet 4.5 free to use?
- Claude Sonnet 4.5 is a paid, pay-as-you-go model — no subscription, you are only charged for usage.
- How do I use Claude Sonnet 4.5 via the API?
- Claude Sonnet 4.5 is OpenAI-compatible. Point any OpenAI SDK at https://api.airforce/v1 and pass the model ID claude-sonnet-4.5 with your Api.Airforce API key.
- Who makes Claude Sonnet 4.5?
- Claude Sonnet 4.5 is Anthropic's chat model, served through the unified Api.Airforce gateway alongside 100+ other models.
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Use Claude Sonnet 4.5 via the API
OpenAI-compatible — point any OpenAI SDK at https://api.airforce/v1 and pass claude-sonnet-4.5 as the model.
cURL
curl https://api.airforce/v1/chat/completions \
-H "Authorization: Bearer $AIRFORCE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-sonnet-4.5",
"messages": [{ "role": "user", "content": "Hello!" }]
}'Python
from openai import OpenAI
client = OpenAI(base_url="https://api.airforce/v1", api_key="$AIRFORCE_API_KEY")
r = client.chat.completions.create(
model="claude-sonnet-4.5",
messages=[{"role": "user", "content": "Hello!"}],
)
print(r.choices[0].message.content)JavaScript
import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://api.airforce/v1", apiKey: process.env.AIRFORCE_API_KEY });
const r = await client.chat.completions.create({
model: "claude-sonnet-4.5",
messages: [{ role: "user", content: "Hello!" }],
});
console.log(r.choices[0].message.content);