Claude Sonnet 4.5
$3/Mtok inFrontier-quality text and reasoning through one OpenAI-compatible endpoint.
Playground
Try it in the browser
Facts
At a glance
Availability
Live
Pricing
$3 / M input · $15 / M output
Endpoint
Chat Completions
/v1/chat/completions
Context window
200k tokens
API
Call it from code
import OpenAI from "openai"
const client = new OpenAI({
baseURL: "https://api.companyfabric.com/v1",
apiKey: process.env.COMPANYFABRIC_API_KEY,
})
const res = await client.chat.completions.create({
model: "anthropic/claude-sonnet-4-5",
max_tokens: 1024,
temperature: 0.7,
messages: [{ role: "user", content: "Say hello from the fabric." }],
})
console.log(res.choices[0].message.content)Prompt library
Example runs
Summarize the three biggest risks in this launch plan, then rewrite the executive summary in half the words.
This exact run cost $0.014
Review this pull request for correctness bugs. Explain each finding with the failing input.
This exact run cost $0.019
Turn these 12 support tickets into a prioritized product backlog with effort estimates.
This exact run cost $0.012
FAQ
Frequently asked questions
How much does Claude Sonnet 4.5 cost?
$3 / M input · $15 / M output. The exact cost of each call is shown before you run it and metered to your prepaid balance — no subscription required.
Why use Claude Sonnet 4.5 on CompanyFabric instead of going direct?
One key and one balance across every model in the library, at pricing at parity with or below the direct API. Switching models is a one-line change.
Is Claude Sonnet 4.5 available through the OpenAI SDK?
Yes — point any OpenAI SDK at api.companyfabric.com/v1 and set model to "anthropic/claude-sonnet-4-5".
Variants
Same family
Explore
Related model APIs
One key. Every model. Exact prices.
Run Claude Sonnet 4.5 with free starter credits. Free starter credits included — no subscription required.