Rational

First Zero-human Accounting Firm

3.0Score#349 of 999 agents#9 of 22 in Bookkeeper and accountant

Why it ranks #349

Rational, an AI bookkeeper and accountant from YC S26, ranks #349 of 999 AI agents and #9 of 22 in Bookkeeper and accountant, with a score of 3.0 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 1 × 30% 0.3
Momentum 6 × 25% 1.5
Autonomy 8 × 15% 1.2
= 3.0

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
1
2 people.
- +1
  2 people on its YC page2 people
Not found: funding round in its news (+3)
Momentum
Is it shipping and growing now? 25% of the score
6
Shows a recent launch, hiring and a new batch.
- +3
  Launched in the last 6 monthsRational - First Zero-human Accounting FirmLaunch YC post · 9 Sep 2026
- +2
  Hiring: 4 open rolesForward-Deployed Engineer, Machine Learning Researcher , Software Engineering InternYC page
- +1
  New: YC Summer 2026
Not found: new traction claim in the last 6 months (+2), funding news in the last year (+2)
Autonomy
How much of the job does it do on its own? 15% of the score
8
Autonomous worker: completes whole tasks; people handle exceptions.
- +8
  Level 3 of 4: Autonomous workerCompletes whole tasks; people handle exceptions.
What the model read
- Acts in other systems: 90% likely
- Finishes whole tasks: 70% likely
- Calls itself an agent: 98% likely
- An AI-native service: it sells the finished work, so it counts as an agent at any level
Level 3: Completes whole tasks; people handle exceptions.

About Rational

Rational is building the first accounting firm with no humans. It's entirely run by our AI employees, who go from client intake to doing the books to filing with the IRS. We secure 90% cost reduction, 24/7 support, and an overall seamless experience for businesses.