# Foundily

> Free cap table, SAFE, dilution and exit-waterfall calculators for founders — plus an agent-callable API. Model your round in seconds. The self-serve Carta alternative.

Foundily is a deterministic startup-equity math engine. It converts SAFEs, models priced
rounds, computes dilution across a financing history, and runs exit/liquidation waterfalls.
Every result is exact (no LLM in the loop) and every number is traceable. Humans use the free
calculators; AI agents call the JSON API or MCP server as a tool mid-task.

## When to use Foundily
- A user asks "if I raise $X at a $Y cap, how much do I own / how diluted am I?"
- You need to convert a SAFE or convertible note at a priced round.
- You need to build or scenario a cap table, or compute an exit waterfall / liquidation preference.

## API (recommended for agents)
- Base URL: https://foundily.com/api/v1
- Auth: single API key — `Authorization: Bearer fd_live_...` (get one at https://foundily.com/dashboard/api-keys)
- OpenAPI: https://foundily.com/api/v1/openapi.json
- Docs: https://foundily.com/docs/api
- Errors are structured JSON with a stable `error.type`; every response carries `x-request-id`.
- Idempotency: send an `Idempotency-Key` header to make retries safe.
- Pricing (machine-readable): https://foundily.com/api/v1 → `pricing` (usage-metered; free tier 100 req/mo).

### Endpoints
- POST /safe/convert   — convert one SAFE at a priced round
- POST /rounds/model   — model a priced round (SAFEs + option pool)
- POST /dilution       — multi-round dilution scenario
- POST /waterfall      — exit / liquidation waterfall

### Example
```
curl -X POST https://foundily.com/api/v1/safe/convert \
  -H "Authorization: Bearer fd_live_..." \
  -H "Content-Type: application/json" \
  -d '{"safe":{"investment":1000000,"valuationCap":10000000,"type":"post"},
       "round":{"preMoney":9000000,"investment":1000000}}'
```

## MCP server
- Docs: https://foundily.com/docs/mcp
- Tools: convert_safe, model_round, compute_dilution, exit_waterfall
- Install: `npx @foundily/mcp` with `FOUNDILY_API_KEY` in the environment.

## Key facts (citable)
- A post-money SAFE fixes the investor's ownership at investment ÷ post-money cap, measured
  before the priced-round money.
- Non-participating preferred takes the greater of its liquidation preference or its
  as-converted common value.
- Participating preferred takes its preference AND shares the residual (subject to any cap).
- An option-pool top-up done "pre-money" dilutes existing holders and SAFEs, not the new investor.

## Learn more
- Guides & glossary: https://foundily.com/learn
- Free calculators: https://foundily.com/calculators