Upstream

Upstream is an email client that treats your AI agents as first-class participants in the inbox. Instead of fighting between human reading and bot delivery, agents sort messages by priority, draft replies in your voice, and queue follow-ups while you stay the final yes or no on what actually sends.

The product separates noisy notifications from real conversation and surfaces only what needs your attention. Drafts inherit your tone from past sent mail, and agents handle the repetitive parts: confirmations, scheduling back-and-forth, and routine status updates.

Backed by Y Combinator, Upstream is free to use at launch, with paid tiers planned for power users and teams.