Letterbook

Customer Support & Help Desk Software

Overview

Letterbook is an AI-native customer support platform that helps teams deliver faster, smarter support.

Funding and backers

Backers
1
Y Combinator
Momentum
0/100
no fresh signals
Last sign of life
1 mo ago
a posting or a news item
The story so fareach stage dated by its source: the company's releases, the press, registers, filings
Mar 2026 Website went live first capture in the Wayback Machine Jun 2023 Went through Y Combinator
Tractionpublic signals, read monthly
Web presence
top 7%
of 133.2M domains by links, Common Crawl
Backed byfrom the funds' portfolios and accelerator catalogs
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Connections

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Found in company registers, site code, DNS and hiring. Each connection shows how sure we are and the evidence, with its source and date.
Shared investors1
Y CombinatorVia a fund
6310 portfolio companies

Offices

Where the company hires and what each office is for
Cities
1
Hiring now
0
Countries
1
San Francisco United States
HQ