About
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows.
Pricing
| Input | $4.20 | per 1M prompt tokens |
|---|---|---|
| Output | $21.00 | per 1M generated tokens, reasoning included |
| Cached input | $0.42 | per 1M tokens read back from the prompt cache |
| Cache write | $5.25 | per 1M tokens written to the prompt cache |
| Input over 200K | $8.40 | the whole prompt is billed at this rate once it passes the threshold |
| Output over 200K | $31.50 | applies to replies to those prompts |
| Web search | $0.014 | per request that uses the provider’s built-in search |
What a request costs
| Typical request | Each | Per 1,000 |
|---|---|---|
| Short chat reply1,500 in · 400 out | $0.015 | $14.70 |
| Question over a long document40,000 in · 800 out | $0.185 | $184.80 |
| Agent tool step20,000 in · 1,200 out | $0.109 | $109.20 |
| Very long prompt (over 200K)250,000 in · 1,500 out | $2.15 | $2,147 |
At the developer-API rate, before any provider promotion or prompt-cache saving. In the app, the model picker shows what a message costs on your plan before you send it.
Benchmarks
Head-to-head rankings
- #22ASCII artModel arenaElo 120756% wins
- #31Mobile appsAgent arenaElo 113453% wins
- #35Full stackAgent arenaElo 105044% wins
- #37Web appsAgent arenaElo 105343% wins
- #56SVGModel arenaElo 111352% wins
- #62CodeModel arenaElo 118452% wins
- #653DModel arenaElo 115851% wins
- #65Game devModel arenaElo 116951% wins
- #66UI componentsModel arenaElo 117250% wins
- #66WebsitesModel arenaElo 119152% wins
Scores from Artificial Analysis; bars are scaled to the best model on our list. Rankings from Design Arena head-to-head votes. Published by OpenRouter alongside its catalogue.
Call it from code
OpenAI-compatible: point any OpenAI SDK at https://api.privateer.pro/v1 and set
model. Keys are created in the app under Settings.
cURL
curl https://api.privateer.pro/v1/chat/completions \
-H "Authorization: Bearer $PRIVATEER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "anthropic/claude-sonnet-4.5",
"messages": [{ "role": "user", "content": "Hello" }]
}'Python
import os
from openai import OpenAI
client = OpenAI(
base_url="https://api.privateer.pro/v1",
api_key=os.environ["PRIVATEER_API_KEY"],
)
reply = client.chat.completions.create(
model="anthropic/claude-sonnet-4.5",
messages=[{"role": "user", "content": "Hello"}],
)
print(reply.choices[0].message.content)JavaScript
import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://api.privateer.pro/v1",
apiKey: process.env.PRIVATEER_API_KEY,
});
const reply = await client.chat.completions.create({
model: "anthropic/claude-sonnet-4.5",
messages: [{ role: "user", content: "Hello" }],
});
console.log(reply.choices[0].message.content);Parameters this model accepts
include_reasoningmax_completion_tokensmax_tokensreasoningresponse_formatstopstructured_outputstemperaturetool_choicetoolstop_ktop_p