Claude Sonnet 4.5

Sonnet 4.5 dated snapshot

Model ID: claude-sonnet-4-5-20250929 · Type: chat · Provider: Anthropic

Endpoints: /v1/messages · /v1/chat/completions

Pricing

Capabilities

• vision
• thinking
• function_calling
• cache

from openai import OpenAI

client = OpenAI(api_key="sk-...", base_url="https://api.router.ai/v1")
resp = client.chat.completions.create(
    model="claude-sonnet-4-5-20250929",
    messages=[{"role": "user", "content": "Hello"}],
)
print(resp.choices[0].message.content)

FAQ

How much does Claude Sonnet 4.5 cost on OpenCrow?

Claude Sonnet 4.5 (`claude-sonnet-4-5-20250929`) is billed per usage at $2.7/1M in · $13.5/1M out, in USD. Current pricing is always listed at https://opencrow.ai/models/claude-sonnet-4-5-20250929.

How do I call Claude Sonnet 4.5 through OpenCrow?

Send a request to https://api.router.ai/v1/v1/messages with the header `Authorization: Bearer <your API key>` and `"model": "claude-sonnet-4-5-20250929"`. The API is OpenAI-compatible, so any OpenAI SDK works by changing base_url to https://api.router.ai/v1 — no other code change.

Which endpoints does Claude Sonnet 4.5 support?

Claude Sonnet 4.5 can be called on: /v1/messages; /v1/chat/completions.

What is Claude Sonnet 4.5's context window?

Claude Sonnet 4.5 accepts up to 200,000 input tokens and can return up to 64,000 output tokens. Requests exceeding the input limit are rejected before reaching the model.

What can Claude Sonnet 4.5 do?

Claude Sonnet 4.5 supports: vision, function_calling, prompt_caching, thinking, cache.

Who makes Claude Sonnet 4.5?

Claude Sonnet 4.5 is a chat model from Anthropic, available through the OpenCrow gateway with the same API key as every other model.

Call it through the OpenCrow OpenAI-compatible endpoint (API base: https://api.router.ai/v1). AI agents can discover and call every model on this gateway through MCP (https://mcp.router.ai/mcp) with no manual integration.

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