Series Sane: The Goldilocks Financing for Seed-Stage Startups

Originally published April 3, 2026. Updated October 8, 2026 for the October release, which rebuilt the documents on the current NVCA model documents. The section "What changed in October 2026" below describes the release.

If you've raised a seed round recently, you've probably confronted an uncomfortable choice: use a SAFE and defer all the decisions that matter, or negotiate a full NVCA equity round and spend a month and $50K+ in legal fees while you're still confirming product-market fit.

For a lot of companies, neither is the right answer.

The SAFE is a brilliant instrument for what it was designed to do: fast, lightweight pre-seed checks where pricing is premature. And the NVCA suite is the gold standard for Series A and beyond, where the stakes justify the overhead. But there's a large population of seed-stage companies caught in the middle: ready for real equity, a clean cap table, and a functional board, but not ready to negotiate registration rights and IPO demand thresholds.

That's who the Series Seed was built for. And after years of languishing without updates, we think it deserves a revival.

Series Sane is that revival: the Series Seed documents, rebuilt on the current NVCA model documents. It's open source, free to use, and designed for companies in the middle.

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A brief history

The Series Seed documents were originally developed by Ted Wang at Fenwick & West as a lightweight alternative to the full NVCA suite for seed-stage financings. They were elegant: a term sheet, an investment agreement, and a certificate of incorporation. Three documents instead of five. Real preferred stock, a real board, real investor rights, without the hundred-page overhead.

But the documents hadn't been materially updated since v3.2, and the market has moved. The NVCA released significant model document revisions in October 2025. National security compliance requirements have changed. QSBS rules have evolved. Drafting conventions have modernized. The original Series Seed needed a refresh to remain viable, so we built one.

Why not just use a SAFE?

SAFEs work. For early pre-seed checks where pricing is genuinely premature, they're still the right tool. But we regularly see companies raising $1M, $2M, even $3M+ on stacked SAFEs when a priced seed round would serve everyone better.

If you've raised on SAFEs, especially multiple SAFEs at different valuation caps, you know the friction that accumulates. Series Sane is for you.

Why founders should care

Cap table certainty. While SAFEs are outstanding, nobody, including you, knows exactly who owns what. Dilution modeling becomes guesswork. Pro rata rights are theoretical. The post-money SAFE was supposed to fix this, but it introduced its own complications. With priced equity, the cap table is clean and final at closing. You know your number.

A functional board. SAFEs defer governance entirely. That might sound like freedom, but it also means no formal board, no designated seats, and no structured accountability. For companies past the napkin-sketch stage, an engaged board with founder and investor seats creates strategic value, not just oversight. You get advisors who are contractually in the room, not just on a text thread.

No conversion surprises. SAFE stacking at different valuation caps creates a web of contingent economics that only resolves at the next priced round. Founders routinely get surprised by how much dilution materializes when the SAFEs convert, not because the terms were bad, but because the interaction effects were invisible. A priced seed round converts the SAFEs now, on their own terms, and then the surprises stop. What you negotiate is what you get.

One page of blanks. Every deal-specific term lives in a Deal Terms table at the front of the Investment Agreement, on the schedule of purchasers, or in the charter blanks. The body of the agreement is never edited, which is most of why the round can close in days.

Series A readiness. Clean preferred stock on documents that follow the NVCA model means your Series A starts from solid footing. Your next-round counsel can redline the Series Sane charter against the NVCA model charter and see the delta in an afternoon. No archaeology, no unwinding a non-standard structure.

Why investors should care

Better tax treatment. SAFE holders arguably don't start the clock on qualified small business stock (QSBS) treatment until conversion, a point the IRS hasn't definitively resolved, and one that matters a lot for investors planning to hold through a significant exit. Preferred stock purchased in a priced round starts the QSBS holding period at closing, and the company represents its eligibility and covenants to maintain it. For investors targeting the Section 1202 exclusion, that timing can be worth a great deal.

Cap table certainty cuts both ways. Investors with SAFEs outstanding can't cleanly calculate their ownership percentage, their liquidation waterfall position, or their effective pro rata. With priced equity, every investor knows exactly what they own and exactly where they stand.

Real governance rights. A SAFE gives investors no governance rights on its own. No board seat, no protective provisions, no consent rights over actions that could harm their investment. Series Sane provides all of these: designated board seats, consent rights over a sale of the company, charter amendments, senior stock, dividends and redemptions, and board size, and, for major purchasers, information and inspection rights, a pro rata participation right in future rounds, and a right of first refusal on founder transfers.

Anti-dilution and next-round protection. The charter includes broad-based weighted average anti-dilution in the NVCA form. And the next-financing clause is written so that nobody has to argue about it later: whatever rights the next round grants to all of its investors flow to the Series Seed holders, major-investor rights are available to Series Seed holders who meet the threshold (counting their Series Seed investment), and the new series' economic terms and anything negotiated by name or by side letter do not carry over.

What's in the box

SANE stands for Simple Agreement for Now Equity, a deliberate nod to the instrument it's designed to complement.

The entire suite is three core documents:

1. Term Sheet. A two-page non-binding summary of the deal.
2. Investment Agreement. One agreement, in NVCA order, covering the purchase, representations, investor rights, transfer restrictions, voting and drag-along. It does the work the NVCA spreads across four separate agreements, with a one-page Deal Terms table holding every variable.
3. Certificate of Incorporation. An amended and restated Delaware charter that follows the NVCA model charter article for article, with an optional sub-series for SAFEs and notes that convert below the round price.

A one-page Variable Reference Map shows which numbers have to match across the three documents. Board and stockholder consents and an investor questionnaire are on the way.

Three documents. A closing timeline measured in days. Legal costs closer to a SAFE round than a Series A.

Built as an NVCA on-ramp

One of the core design goals was making the transition to a full NVCA suite at Series A as frictionless as possible.

The Certificate of Incorporation follows the NVCA model charter section for section, with the same section numbers. The Investment Agreement follows the order of the NVCA Stock Purchase Agreement, Investors' Rights Agreement, Right of First Refusal and Co-Sale Agreement, and Voting Agreement, so a lawyer who works with those documents can map each provision to its counterpart on sight. Section 5.5 of the Investment Agreement provides for the transition and says exactly which seed rights carry into the next round's documents. Your Series A lawyers aren't unwinding a non-standard structure; they're upgrading a familiar one.

What changed in October 2026

The April release was a fork of Series Seed v3.2 with targeted updates. The October release is a rebuild on the current NVCA model documents (the October 2025 charter, stock purchase agreement and investors' rights agreement, and the 2026 voting and right of first refusal agreements). The seed-stage philosophy is unchanged; the architecture is now the NVCA's.

In the charter: the NVCA model's article and section order; broad-based weighted average anti-dilution; an optional Series Seed-1 sub-series so that SAFEs and notes converting below the round price get the liquidation preference they actually paid for; the NVCA mechanics for an asset sale and for escrow and earn-out allocation; officer exculpation and an exclusive forum provision.

In the agreement: a conventional structure with a Deal Terms table and Articles 2 through 8 in NVCA order; Delaware law and courts; a rewritten next-financing clause; a right of first refusal on founder transfers stated in the agreement itself; complete board, drag-along and proxy mechanics; a spousal consent.

Intentionally left out: co-sale rights, registration rights, redemption rights, pay-to-play, tranched closings, closing conditions and legal opinions, the Investor Director approval list, the governance policy suite, and the CFIUS, outbound-investment and data-security representations. Each is a Series A matter, and the next-financing clause brings it in if the Series A investors receive it.

The documents still include the seed-stage essentials from the April release: sanctions and Rule 506(d) bad actor representations, a QSBS representation and covenant, the conversion mechanics for SAFEs and notes, and drafting that follows Adams, A Manual of Style for Contract Drafting (4th ed.).

When to use Series Sane

This isn't a SAFE replacement. SAFEs remain the right tool when pricing is genuinely premature, the check is small, and governance can wait.

Series Sane is the right fit for a Delaware corporation in the middle, and a lot of companies are:

• You're raising a priced seed round, typically $1M or more, and your investors expect governance rights
• You want cap table certainty, not conversion math you'll reconcile later
• You want a board that functions as a board
• QSBS timing matters to your investors
• You've already done a SAFE round and you're ready for something more substantial
• You want Series A readiness without Series A overhead

Open source, free to use

The entire document suite is available at seriessane.com and on GitHub. Download the Word documents, browse the Markdown source, and use the Variable Reference Map to check the numbers that have to match. Each document carries drafting notes written for the people using it. Fork it, use it, submit a PR if you find something to improve.

If you want help putting it to work, or you're deciding whether a SAFE, Series Sane, or full NVCA round is the right structure for your raise, book a call. That's what we're here for.

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The Series Seed documents were originally developed by Ted Wang at Fenwick & West. Series Sane is a fork of Series Seed v3.2, with select provisions adapted from the Cooley LLP fork, rebuilt on the NVCA model legal documents and maintained by Rubicon Law and Flux. These are forms, not legal advice; have a lawyer review them for your deal.