Upstream

The inbox that handles itself

2.6Score#494 of 999 agents#1 of 4 in Executive assistant

Why it ranks #494

Upstream, an AI executive assistant from YC S23, ranks #494 of 999 AI agents and #1 of 4 in Executive assistant, with a score of 2.6 of 10. Data as of 3 Oct 2026.

The score adds four parts, each 0 to 10, by weight. Every point comes from public evidence. How scoring works ·

Proof 0 × 30% 0.0
Scale 3 × 30% 0.9
Momentum 3 × 25% 0.8
Autonomy 6 × 15% 0.9
= 2.6

Proof
Do customers use it? 30% of the score
0
No public claims of customers or revenue yet.
Not found: revenue or growth (+4), named customers (+3), a customer result (+2), a customer count (+2), work done at scale (+2)
Scale
Is there a real company behind it? 30% of the score
3
7 people.
- +3
  7 people on its YC page5 to 9 people
Not found: funding round in its news (+3)
Momentum
Is it shipping and growing now? 25% of the score
3
Shows a recent launch.
- +3
  Launched in the last 6 monthsUpstream - The first inbox designed for humans and agentsLaunch YC post · 22 Jun 2026
Not found: open roles on YC (+2), new traction claim in the last 6 months (+2), funding news in the last year (+2), a batch in the last year (it is YC Summer 2023) (+1)
Autonomy
How much of the job does it do on its own? 15% of the score
6
Supervised agent: takes actions in other systems; a person approves key steps.
- +6
  Level 2 of 4: Supervised agentTakes actions in other systems; a person approves key steps.
What the model read
- Acts in other systems: 81% likely
- Finishes whole tasks: 18% likely
- Calls itself an agent: 94% likely
Level 2: Takes actions in other systems; a person approves key steps.

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.