Top accelerator startups

14,448 startups · 29 programs

Upstream

Active · The inbox that handles itself

9signal of 100 · rising 3
  • team of 7Team size · YC's directory+4.7
  • went through YCProgram · this site+4

A sum of public facts, not a judgement and not investment advice.

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Also from S23 in AI

All of S23

About Upstream

Your inbox, handled for you. Upstream's agents sort the noise, draft replies in your exact voice, follow up at the right time, and do what you ask - like finding receipts or scheduling meetings - so you can fly through your inbox and have fun doing it.

YC batch
S23 · Summer 2023
Status, per YC
Active
Category
AI
Team size
7
Location
Paris, Île-de-France, France
Checked
7h ago

Changes seen

One-linerOct 5, 2026

Rewrote its one-liner; it read "The first inbox designed for humans and agents"

Upstream in S23: 220 companies, 78% AI

Upstream: questions

Which YC batch was Upstream in?

Upstream was in Y Combinator's Summer 2023 batch (S23).

Is Upstream still active?

Y Combinator lists Upstream as active.

Where is Upstream based?

Upstream lists Paris, Île-de-France, France as its location on YC's directory.