Use the Claude Haiku 4.5 API with one key and pay-as-you-go pricing

What is Claude Haiku 4.5?

Claude Haiku 4.5 is a Claude Haiku model from Anthropic for chat, reasoning, coding and agent workflows. It was released on 2025-11-01. On Crazyrouter it runs behind the same API key and billing account as 300+ other models, so you can benchmark it against alternatives and route traffic without new credentials.

Claude Haiku 4.5 API quickstart

Point your OpenAI SDK at https://crazyrouter.com/v1 and set the model to claude-haiku-4-5. If your client speaks Anthropic Messages natively, use the second example instead.

curl https://crazyrouter.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $CRAZYROUTER_API_KEY" \
  -d '{
    "model": "claude-haiku-4-5",
    "messages": [{"role": "user", "content": "Explain the tradeoffs of this architecture decision."}],
    "stream": true
  }'

curl https://crazyrouter.com/v1/messages \
  -H "Content-Type: application/json" \
  -H "x-api-key: $CRAZYROUTER_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-haiku-4-5",
    "max_tokens": 2048,
    "messages": [{"role": "user", "content": "Explain the tradeoffs of this architecture decision."}],
    "stream": true
  }'

Best use cases

Works with developer tools

Claude Haiku 4.5 FAQ