APIConnectionTimeoutError thrown after ~10-60min on long tool calls; requests fail silently if non-streaming with large max_tokens; retries attempted but may fail.[@anthropic-ai/sdk npm](https://www.npmjs.com/package/@anthropic-ai/sdk)

Default 10min timeout (dynamic up to 60min for large max_tokens non-streaming) too short for long-running tool use requests; networks drop idle connections; SDK proactively terminates expected long (>10min) non-streaming requests before completion.[@anthropic-ai/sdk npm](https://www.npmjs.com/package/@anthropic-ai/sdk)