Resend, Inc. is a Delaware-incorporated transactional and marketing email API company founded in 2022 by Zeno Rocha and Bu Kinoshita. The product is a developer-first email platform with a clean REST API, native React Email integration (an OSS framework Resend authors), broadcast scheduling, audience management, deliverability monitoring, and webhook events for opens, clicks, bounces, and complaints.
Resend is positioned as a modern alternative to Mailgun, Postmark, and SendGrid, with explicit focus on developer experience and React/Next.js workflows. Operational headquarters are remote-first with team distribution across the Americas and Europe.
Resend graduated from Y Combinator in the W23 batch and has raised a 3 million US dollar seed round followed by an 18 million US dollar Series A led by Andreessen Horowitz in 2024, bringing total funding above 21 million US dollars. Customers include Vercel, Cal.com, Linear, Documenso, and a long tail of dev-tools and SaaS startups.
The legal entity is Resend, Inc., a Delaware C-Corporation with its registered agent at the Corporation Trust Center in Wilmington.
Resend is the YC-backed dev-tools template at its purest: SAFEs from YC and follow-on angels, priced Series A from a top-tier lead, open-source side project (React Email) as both adoption funnel and recruiting magnet, and a Delaware C-Corp with all the standard preferred-stock plumbing.
The capital stack: YC standard post-money SAFE at the W23 batch, additional post-money SAFEs from angels and seed funds in 2022-2023, then the priced 18 million US dollar Series A led by a16z in 2024.
The Series A converted all outstanding SAFEs into Series A Preferred Stock at the better of the cap or discount, with 1x non-participating liquidation preference, weighted-average anti-dilution, pro rata rights, and standard NVCA documentation.
The option pool was sized at 10-15 percent at the Series A, top-up paid pre-money by existing common holders - relatively standard for a Series A dev-tools company. The 409A valuation was refreshed at the Series A and is updated annually thereafter, with common stock priced at a 20-30 percent discount to the latest preferred (typical for an early-stage company with an active hiring market).
Resend does not have super-voting founder shares - far too early.
The open-source side - React Email under MIT - serves multiple purposes: it builds developer mindshare, it gives the company technical credibility, and it provides a recruiting funnel for engineers who care about email deliverability. The Resend platform itself (the API, the multi-tenant infrastructure, the deliverability stack) is closed source.
The Contributor License Agreement covers React Email contributions; CIIAA covers all employee work. Trademarks are USPTO-registered to Resend, Inc. Delaware is required by a16z and assumed by every NVCA document.
YC standardizes on its post-money SAFE for the YC check itself (currently 500k US dollars on a 5 million US dollar post-money cap as of 2026, though terms shift) and for most follow-on angel and pre-seed checks. SAFEs are fast (days) and cheap (under 1k US dollars in legal cost), and they convert at the priced Series A at the better of cap or discount.
Resend followed this exact path: YC SAFE, additional SAFEs from angels and seed funds, priced Series A led by a16z. The risk is SAFE stacking - too many caps converting at once can produce surprising Series A dilution.
YC explicitly prefers Delaware because the YC SAFE template is drafted assuming Delaware default rules, every Series A lead requires Delaware, the Chancery court has the deepest preferred-stock case law, and QSBS Section 1202 treatment requires a domestic C-Corporation. Wyoming's LLC privacy is irrelevant after the YC investment because YC publishes its portfolio.
A redomicile to Delaware before the Series A costs legal fees, resets the QSBS five-year holding clock, and adds friction with no offsetting benefit.
Release the OSS side project (React Email at Resend) under MIT or Apache 2.0 to maximize adoption among developers - this becomes a marketing funnel and recruiting magnet. Keep the commercial platform (the API, the deliverability stack, the multi-tenant infrastructure) closed source. A Contributor License Agreement governs OSS contributions and grants the Delaware C-Corp broad relicensing rights.
Trademarks for both the OSS project and the commercial platform are USPTO-registered to the C-Corp. CIIAA at hire covers all employee work.
Four-year vesting with a one-year cliff is universal at any priced round, including the Series A. The YC standard is also four-year vesting from incorporation, even though the YC check itself is a SAFE. Double-trigger acceleration on change of control is the a16z and Sequoia standard at Series A. 83(b) elections within 30 days of restricted stock issuance are mandatory.
Repurchase rights at fair market value remain in force through and beyond the Series A for any unvested shares of departing founders or employees.
