Exa Snapshot 上线：4000 亿历史网页快照可按时间检索
Exa 推出 Snapshot（研究预览）：逾 4000 亿网页历史快照，Search/Contents 可用 snapshotAsOf 检索某一时刻网页；面向 RL 防泄漏、回测与探索 AI 前网络。
We built a time machine for the web. Introducing Exa Snapshot: an index of 400 billion historical snapshots of webpages that lets you search as if it's the past. Snapshot is already being used for backtesting prediction models, RL at labs, exploring the pre-AI web, and more. Research notes: - Blog: https://exa.ai/blog/exa-snapshot (2026-09-18) - Capability: given a date, return results from the web as it was then; powered by 400B+ webpage snapshots spanning ~2 decades - API: set snapshotAsOf / snapshot_as_of on /search and /contents (research preview) - Use cases: prevent web leakage in RL evals, finance/quant backtests on point-in-time web, explore pre-AI web; diffs across time (Will Bryk) - Official @ExaAILabs; posted 2026-09-17