Claude Sonnet 4.5 API
Claude Sonnet 4.5 is a language model from anthropic, available on Routeriva under the model ID claude-sonnet-4-5. You call it with the same sk- key you use for every other model — no separate anthropic account is needed.
On Routeriva it costs $0.45 per 1M input tokens and $2.25 per 1M output tokens, compared with the official list price of $3.00 / $15.00 — about 85% less. Prices shown are the lowest across the routes that serve this model; your key is charged at its own route's price.
Because Routeriva speaks the native Anthropic /v1/messages format, Claude Sonnet 4.5 works directly in Claude Code, Cline and the Anthropic SDK, with extended thinking and prompt caching passed through unchanged. It also works through the OpenAI-compatible /v1/chat/completions endpoint.
Key facts
- Model ID:
claude-sonnet-4-5 - Provider: anthropic
- Type: text
- Input: $0.45 / 1M (list $3.00)
- Output: $2.25 / 1M (list $15.00)
- Endpoints: /v1/chat/completions, /v1/responses, /v1/messages
Good for
- Coding agents (Claude Code, Cline, Cursor)
- Long-document analysis and writing
- Multi-step tool use and reasoning
Prices by route
| Route | Input / 1M | Output / 1M |
|---|---|---|
| Claude KIRO ENTERPRISE | $0.45 | $2.25 |
Code sample
from openai import OpenAI
client = OpenAI(base_url="https://api.routeriva.com/v1", api_key="sk-your-key")
r = client.chat.completions.create(model="claude-sonnet-4-5", messages=[{"role": "user", "content": "Hello"}])
print(r.choices[0].message.content)Claude Code: export ANTHROPIC_BASE_URL=https://api.routeriva.com and export ANTHROPIC_AUTH_TOKEN=sk-your-key, then pick claude-sonnet-4-5.
FAQ
How much does the Claude Sonnet 4.5 API cost on Routeriva?
From $0.45 per 1M input tokens and $2.25 per 1M output tokens (official list $3.00 / $15.00, about 85% less). Live prices are on routeriva.com/models/claude-sonnet-4-5.
What model ID do I use for Claude Sonnet 4.5?
Use "claude-sonnet-4-5" as the model value with base URL https://api.routeriva.com/v1 and your sk- key.
Which endpoints support Claude Sonnet 4.5?
/v1/chat/completions, /v1/responses, /v1/messages on https://api.routeriva.com.