Anthropic Files API Is Now Generally Available: Upload Once, Reuse Across Calls

Anthropic's Files API is now generally available — no beta header required. Upload PDFs, images, and other documents once, then pass a file_id to any Messages call instead of re-uploading each time.

The GA release adds an expires_at field on file objects (so you can manage expiry proactively), pagination on the list endpoint (page/next_page + ids[] filter), and removes the files-api-2025-04-14 beta header requirement.

Storage is 1 TB per organization at 500 requests per minute. Files do expire, so long-lived agents need to detect and re-upload when expires_at passes — it's not zero-maintenance. The API stores raw bytes; it doesn't embed or index content, so it isn't a retrieval layer on its own.

Why it matters: Multi-turn document agents — code review over a spec, analysis across a knowledge base — no longer pay re-upload latency and input-token overhead on every turn.

Sources: Files API — Anthropic Docs · Claude API release notes — Anthropic