Open source
I build finance tools in the open. Balsa, Portfolio and the financial models are Apache 2.0, so you can read them, change them, and run them yourself.
Balsa
Your business is the model.
Balsa turns your contracts, transactions, and business knowledge into a reporting and forecasting engine that evolves with your company.
AI reads the evidence and drafts; the ledger, the calculations, and every approval stay in controlled application code.
Right now it runs a monthly close and forecast loop end to end: ingest statements and bank feeds, review the evidence, confirm what it means, and get three statements and a rolling forecast that tie out by construction.
Apache 2.0 · Provider-neutral AI · Self-hosted
evidence
→ observations
→ your review
→ company state
→ statements and forecast
→ decisions
→ outcomesPortfolio
Run your investment firm in one place.
Turn portfolio-company updates into structured metrics, monitoring, dashboards, and LP reporting.
Open source, self-hostable, and built on your own AI provider.
It started as the reporting stack for the funds I work with, and it is the system behind portfolio.hemrock.com.
Apache 2.0 · Self-hosted · Your data
Financial models
Open-source spreadsheets for founders and investors.
The Standard Financial Model, the Venture Capital Model, the cap table and exit waterfall, and the focused tools. Every cell is open and every formula is documented.
Use them, change them, and use them in commercial work, whatever you paid. Your AI can edit them too, because the structure is already there to check its work against.
Apache 2.0 · Excel and Google Sheets · Pay what you want
Activity
In active development
Weekly commits to all projects, straight from GitHub.
3,982 commits in the past year
1109 in the last four weeks
Principles
How these are built
Open source, Apache 2.0.
Read it, run it, change it, and keep your changes.
Your infrastructure.
Self-host on Postgres and a Node runtime. Nothing phones home to Hemrock.
Your AI provider.
Provider-neutral model interfaces. Bring OpenAI, OpenRouter, or a model you run yourself.
Exact math, separate from the model.
Deterministic engines do the arithmetic. The AI reads, interprets, and proposes. A person approves.
Send K-1s
Redact, encrypt, and send every LP their own K-1 from your own machine. Open source and free.
The financial models
Every spreadsheet model on this site is open source under Apache 2.0 and pay what you want.
Want one of these running for your team or your fund? I help people build and implement them.