Handle API errors

try:
    response = client.messages.create(...)
except anthropic.BadRequestError as e:
    print("Bad request:", e.message)
except anthropic.AuthenticationError:
    print("Invalid API key")
except anthropic.RateLimitError as e:
    print("Retry after", e.response.headers.get("retry-after"))
except anthropic.APIStatusError as e:
    print("API error", e.status_code)
except anthropic.APIConnectionError:
    print("Network error")