OpenLuxClaude Sonnet 4.5 API
Claude Sonnet 4.5 is the workhorse of the Claude line: coding, long-context analysis and tool use at $0.2647 per million tokens — 91% below list pricing — behind the same OpenAI-compatible endpoint as every OpenLux model.
Pay-as-you-go rate
$0.2647 / 1M tokens
-91% vs official list pricing. Billed in USD, metered per request with real-time cost in the console.
Access
One OpenLux key and the OpenAI-compatible endpoint: set base_url to https://openlux.lol/v1 and pass claude-sonnet-4-5-20250929 as the model.
Get started
Create a key in the console, then follow the five-minute docs for streaming, tools and error codes.
What Claude Sonnet 4.5 delivers
Sonnet sits at the balanced point of the Claude family: close to flagship quality on many coding and analysis tasks at a fraction of the rate. It handles long documents, multi-file code review and tool-driven agent loops reliably.
On OpenLux the durable model name is claude-sonnet-4-5-20250929 — the dated snapshot — so integrations stay reproducible while new Anthropic releases appear in the catalogue as they become available upstream.
At $0.2647 per 1M tokens, most teams run Sonnet as the default coding assistant and escalate to Claude Opus 5 ($0.4412) only for the hardest reasoning, with both models on one key and one bill.
Call Claude Sonnet 4.5 in minutes
Every OpenLux model speaks the OpenAI protocol. Reuse your existing SDKs and replace two values: the base URL and the API key.
cURL
curl https://openlux.lol/v1/chat/completions \
-H "Authorization: Bearer $OPENLUX_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-sonnet-4-5-20250929",
"messages": [{"role": "user", "content": "Review this Python function for edge cases and propose a corrected version."}]
}'Python (OpenAI SDK)
from openai import OpenAI
client = OpenAI(
api_key="sk-openlux-...",
base_url="https://openlux.lol/v1",
)
resp = client.chat.completions.create(
model="claude-sonnet-4-5-20250929",
messages=[{"role": "user", "content": "Review this Python function for edge cases and propose a corrected version."}],
)
print(resp.choices[0].message.content)Node.js (OpenAI SDK)
import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.OPENLUX_API_KEY,
baseURL: "https://openlux.lol/v1",
});
const resp = await client.chat.completions.create({
model: "claude-sonnet-4-5-20250929",
messages: [{ role: "user", content: "Review this Python function for edge cases and propose a corrected version." }],
});
console.log(resp.choices[0].message.content);Where Claude Sonnet 4.5 fits
Coding quality
Strong across languages, multi-file changes and review — a default for engineering workflows.
Long context
Analyses large documents and repositories without losing the thread of the argument.
Tool use and agents
Function calling robust enough for multi-step agent architectures.
Vision input
Reads diagrams, screenshots and design references alongside code.
Code review and refactoring
Review pull requests, propose refactors and catch edge cases before human review.
Agentic workflows
Tool-driven agents that need dependable instruction following over long tasks.
Long-document analysis
Contracts, specifications and research that exceed comfortable context sizes.
How claude-sonnet-4-5-20250929 is priced on OpenLux
Claude Sonnet 4.5 is metered pay as you go at $0.2647 / 1M tokens (-91% vs official rates). There is no subscription requirement for API access: top up a balance, call the model, and see the cost of every request in the console.
| Model | Provider | Rate | Discount |
|---|---|---|---|
| claude-sonnet-4-5-20250929 (this model) | Anthropic | $0.2647 / 1M tokens | -91% |
| claude-opus-5 | Anthropic | $0.4412 / 1M tokens | -91% |
| claude-fable-5-1 | Anthropic | $1.765 / 1M tokens | -82% |
| gpt-6-astra | OpenAI | $0.3677 / 1M tokens | -96% |
Rates follow official provider pricing and are shown in USD. See the full model catalogue and pricing plans for credit allowances.
Claude Sonnet 4.5 questions
How much does Claude Sonnet 4.5 cost on OpenLux?
$0.2647 per 1 million tokens, 91% below official list pricing, metered pay as you go with real-time cost in the console.
How do I call Claude through OpenLux?
Use the OpenAI protocol: base_url https://openlux.lol/v1, your OpenLux key and "model": "claude-sonnet-4-5-20250929". No separate Anthropic account is required, though the Anthropic SDK also works against the endpoint.
Sonnet or Opus — which Claude should I use?
Sonnet at $0.2647 covers most coding and production work; Opus 5 at $0.4412 is worth it for the hardest reasoning, nuanced editing and critical decisions. Both are called with the same key, so you can escalate per request.
Why does the model name include a date?
claude-sonnet-4-5-20250929 is a dated snapshot name that pins the exact model version for reproducible output. Newer Claude releases appear in the catalogue under their own names as they become available.
Start calling Claude Sonnet 4.5 today
Create an OpenLux key and send your first request in minutes. Compare Claude Sonnet 4.5 with the rest of the catalogue on the same endpoint and the same bill.