Overview
Y Combinator has created and open-sourced a comprehensive set of legal documents designed specifically for early-stage startups. These documents are tailored to make fundraising simpler, faster, and more founder-friendly.Y Combinator’s documents are specifically designed for YC-funded startups raising capital from angels and early-stage investors, typically in the 2M range.
Document Collections
SAFE Agreements
Simple Agreement for Future Equity - the most popular early-stage investment instrument
Series AA Documents
Complete equity financing package for seed rounds with angels
Why Use Y Combinator Documents?
Y Combinator’s legal templates offer several advantages for early-stage startups:Simplicity & Speed
Simplicity & Speed
These documents are designed to be straightforward and quick to execute. Unlike complex VC documents, YC templates focus on essential terms that matter most at the seed stage.
Founder-Friendly Terms
Founder-Friendly Terms
The documents are generally balanced but lean toward being founder-friendly, reflecting Y Combinator’s philosophy of backing entrepreneurs and giving them maximum flexibility to build their companies.
Industry Standard
Industry Standard
Since Y Combinator introduced these documents, they have become widely adopted across the startup ecosystem. Most investors and attorneys are familiar with them, reducing negotiation friction.
Well-Tested & Refined
Well-Tested & Refined
These documents have been used by thousands of YC companies and refined over many years based on real-world usage and feedback from both founders and investors.
Key Document Types
SAFE (Simple Agreement for Future Equity)
The SAFE is Y Combinator’s most influential contribution to startup financing. Introduced in 2013 and updated in 2018 to the “post-money” version, SAFEs have largely replaced convertible notes for early-stage investments. Key Features:- Not debt - no interest, no maturity date
- Converts to equity in future priced rounds
- Four variants to match different deal structures
- Typically 5-10 pages vs. 30+ for traditional documents
Series AA Documents
When you’re ready for a priced equity round, Y Combinator’s Series AA documents provide a complete package for angel financing rounds. Includes:- Term Sheet
- Stock Purchase Agreement
- Certificate of Incorporation
- Investors’ Rights Agreement
- Board Consent
- Stockholder Consent
Document Philosophy
Y Combinator’s document philosophy emphasizes:- Minimal Complexity - Only include terms that truly matter at early stages
- Trust & Partnership - Assume good faith between founders and investors
- Future Flexibility - Don’t over-optimize for edge cases
- Fair Economics - Balanced terms that work for both sides
Getting Started
Understand Your Needs
Determine whether you need a SAFE (most common for pre-seed/seed) or a full equity round (Series AA).
Choose the Right Variant
For SAFEs, select the appropriate variant based on your deal terms (cap, discount, or MFN).
Review Official Resources
Visit Y Combinator’s official documents page for the latest versions and guidance.
Additional Resources
Y Combinator Official Docs
Official source for all YC legal documents
SAFE User Guide
Comprehensive guide to understanding and using SAFEs
Series AA Guide
Official Series AA documents page
OpenLaw Templates
Automated versions of YC documents
Version History
- 2018 - Post-money SAFE introduced, replacing pre-money version
- 2013 - Original SAFE introduced
- Earlier - Series AA documents created for YC portfolio companies
Always use the most recent version of Y Combinator documents. The post-money SAFE (2018) is significantly different from the original pre-money version.
Community & Support
For questions about Y Combinator documents:- Review the official SAFE primer
- Consult with startup-focused legal counsel
- Connect with other founders in the YC community
- Review case studies and founder experiences on the YC blog