Batch processing

The Message Batches API is Anthropic's system for submitting large numbers of independent Claude API requests as a single grouped job for asynchronous processing. Instead of sending requests one at a time and waiting for each response, you package up to 100,000 requests into a batch, submit it once, and retrieve all results when processing completes — typically within an hour, with a 24-hour maximum window. The primary benefit is cost: all batch requests are charged at 50% of standard API prices. This discount can be combined with prompt caching discounts, so heavily cached batches can cost significantly less than real-time equivalents. Throughput is also higher than sequential real-time calls, because Anthropic's infrastructure processes batches during available capacity. Batch processing is designed for workloads that don't need immediate responses — things like overnight data enrichment, bulk content generation, large-scale evaluations, or any job where a one-hour turnaround is acceptable. It supports all standard Messages API features including vision, tool use, extended thinking, and prompt caching. Results are stored for 29 days after batch creation.