Developers

Raziel Calculators API and MCP server

Q: How do I report a bug or ask for a calculator?

Use the contact form . Include the calculator name and the input you sent.

Give your app or AI assistant exact finance math and answers it can cite. 25 free calculators for IRR, MOIC, SAFE conversion, dilution, TVPI, QSBS, burn multiple and more, plus Raziel guides, a glossary and prompts. No API key.

Connect your AI assistant OpenAPI spec

MCP server

https://raziel.co/mcp

REST API

https://raziel.co/api/v1/calculators

No key
Streamable HTTP
OpenAPI 3.1

What you get

The calculators from raziel.co, as an API

Every calculator on our free tools page is also available to your code and your AI assistant, with the same tested math.

Free, no API key

Call it from anywhere. There is nothing to sign up for.
28 tools

25 calculators and founder metrics with the same tested math as raziel.co/tools, plus guide search, a glossary and platform comparisons.
Built for AI agents

A remote MCP server with clear tool descriptions, plus a plain JSON REST API.
No customer data

Pure math on the inputs you send. Nothing is stored and nothing touches Raziel accounts.

MCP server

Connect your AI assistant

Add one URL and your assistant can call every calculator as a tool. The server is stateless, read only and needs no sign-in.

Claude Code

Run once in your terminal.

claude mcp add --transport http raziel https://raziel.co/mcp

Claude (web and desktop)

Settings, Connectors, Add custom connector, then paste the URL.

https://raziel.co/mcp

Cursor

Add to ~/.cursor/mcp.json.

{
  "mcpServers": {
    "raziel": {
      "url": "https://raziel.co/mcp"
    }
  }
}

VS Code

Add to .vscode/mcp.json.

{
  "servers": {
    "raziel": {
      "type": "http",
      "url": "https://raziel.co/mcp"
    }
  }
}

ChatGPT and other clients

Any client that supports remote MCP servers over Streamable HTTP. No sign-in needed.

https://raziel.co/mcp

REST API

Quick start in one request

POST a JSON body to a calculator and get JSON back. GET the same URL for its input schema and a working example.

GET/api/v1/calculatorsList every calculator
GET/api/v1/calculators/{name}Input schema and example
POST/api/v1/calculators/{name}Run it
GET/api/v1/guides?q=Search Raziel guides
GET/api/v1/glossary?term=Define a term
GET/api/v1/compare?competitor=Compare platforms
GET/api/openapi.jsonOpenAPI 3.1 spec

Request

curl -X POST https://raziel.co/api/v1/calculators/moic \
  -H "Content-Type: application/json" \
  -d '{"invested_usd":1000000,"value_returned_usd":2500000,"years":5}'

Response

{
  "ok": true,
  "calculator": "moic",
  "result": {
    "moic": 2.5,
    "total_return_pct": 150,
    "annualized_return_pct": 20.11,
    "net_profit_usd": 1500000,
    "calculator_url": "https://raziel.co/tools/moic-calculator"
  }
}

Reference

Every tool

The tool name is the MCP tool name and the last part of the REST URL.

Calculators

Run with POST /api/v1/calculators/{name}, or as an MCP tool.

Tool name	What it does	Page on raziel.co
`irr`	IRR calculatorInternal rate of return for evenly spaced yearly cash flows after an initial investment. Use xirr instead when cash flows have specific dates or irregular timing.	Try it
`xirr`	XIRR calculatorAnnualized return (XIRR) for cash flows on specific dates, like Excel XIRR. Use this for real investments with irregular timing (capital calls, distributions, follow-ons); use irr only for evenly spaced yearly flows.	Try it
`moic`	MOIC calculatorMultiple on invested capital: total value returned (distributions plus current value) divided by the amount invested, with the implied annualized return when a holding period is given. Use tvpi_dpi for fund-level LP multiples.	Try it
`cagr`	CAGR calculatorCompound annual growth rate between a start value and an end value over a number of years. Use for growth of a single value (revenue, an asset price); use irr or xirr when there are multiple cash flows.	Try it
`tvpi_dpi`	TVPI and DPI calculatorFund performance multiples for an LP or a fund: TVPI (total value to paid-in), DPI (distributions to paid-in, realized) and RVPI (NAV to paid-in, unrealized). Use moic for a single deal and xirr for time-weighted returns.	Try it
`carried_interest`	Carried interest calculatorEuropean (whole-fund) distribution waterfall: management fees, return of capital, preferred return (hurdle), GP catch-up and carried interest split, with LP net multiple and the gross-to-net drag.	Try it
`safe_conversion`	SAFE conversion calculatorHow a YC-style SAFE (post-money or pre-money) converts in a priced equity round: conversion price, whether the cap or discount applies, shares issued and ownership after the round, including an option pool top-up. Use convertible_note for notes that accrue interest.	Try it
`convertible_note`	Convertible note calculatorHow a convertible note converts in a priced round: accrued interest, conversion price (cap vs discount), shares received and effective discount. Use safe_conversion for SAFEs, which have no interest.	Try it
`startup_valuation`	Startup valuation calculatorPre-money to post-money for a single priced round: post-money valuation, price per share, new shares issued, investor ownership (investment / post-money) and founder dilution. Use dilution for several rounds and option_pool for pool math.	Try it
`dilution`	Startup dilution calculatorFounder and investor ownership across several future funding rounds, including option pool top-ups before each round. Use option_pool for a single round when the question is how a pre-money pool shifts value, and startup_valuation for one simple round.	Try it
`option_pool`	Option pool calculatorThe "option pool shuffle" for one round: how much the pool must grow to hit a post-money target, the effective pre-money valuation, and how much founder ownership the pre-money pool costs versus adding it after the round.	Try it
`pro_rata`	Pro rata calculatorFor an existing investor in a new round: the check needed to keep the same ownership (pro rata), ownership after the round if they skip or write a planned check, and the value of the stake at the new post-money.	Try it
`liquidation_preference`	Liquidation preference calculatorExit waterfall: how sale proceeds split between preferred series and common, with preference multiples, non-participating, participating or capped participation, and stacked or pari passu seniority. Each series converts to common when that pays more.	Try it
`secondary_sale`	Secondary sale calculatorProceeds from selling private company shares on the secondary market: sale price after a discount (or premium) to the last round price or a valuation, fees, net proceeds, gain over cost basis and the implied company valuation.	Try it
`qsbs`	QSBS (Section 1202) calculatorEstimates the US federal capital gains exclusion for qualified small business stock under IRC Section 1202, including the July 2025 changes (tiered 3, 4 and 5 year exclusions and the $15M cap for stock acquired after July 4, 2025). Assumes the stock otherwise qualifies.	Try it
`tax_deadlines`	83(b) and QSBS date calculatorKey US equity tax dates. stock_grant_date: the 83(b) election deadline, 30 days after restricted stock is transferred (rolled to the next business day when the 30th day is a weekend or legal holiday). qsbs_acquired_date: the Section 1202 holding-period milestones (50%, 75% and 100% exclusion at 3, 4 and 5 years for stock acquired after July 4, 2025; 5 years before). Give either or both. Use qsbs for the dollar exclusion on a sale.	Try it
`runway`	Startup runway calculatorMonths of cash runway for a startup, either from a monthly net burn ("burn" mode) or from monthly revenue and expenses with growth rates ("pl" mode), including the break-even month and whether the company is default alive within 10 years.	Try it
`cap_rate`	Cap rate calculatorCapitalization rate of an income property (net operating income / property value), plus gross rent multiplier and price per unit. Give noi_usd directly or gross income and operating expenses. Use cash_on_cash when financing matters.	Try it
`cash_on_cash`	Cash on cash return calculatorLeveraged rental property returns: mortgage payment, NOI, annual cash flow, cash on cash return, DSCR and break-even occupancy. Use cap_rate for an unlevered view of the same property.	Try it
`portfolio_allocation`	Portfolio allocation analyzerAllocation of a portfolio across asset classes (stocks, bonds, real estate, crypto, venture capital, private equity, cash, other), with a simple diversification score and a concentration read. Holdings in the same class are summed.	Try it

Founder metrics

Startup efficiency and SaaS metrics for investor updates and board decks. Same endpoints as the calculators.

Tool name	What it does	Page on raziel.co
`burn_multiple`	Burn multipleCapital efficiency: net burn divided by net new ARR over the same period (a quarter or a year). Lower is better. Returns the multiple and a rough band (under 1 amazing, 1 to 1.5 great, 1.5 to 2 good, 2 to 3 suspect, over 3 bad, a rule of thumb popularized by David Sacks). Use rule_of_40 for growth versus profitability instead.	Read
`rule_of_40`	Rule of 40Adds revenue growth rate and profit margin (usually EBITDA or free cash flow margin, both in percent). A score of 40 or more is the common rule of thumb for a healthy software company balancing growth and profitability. Use burn_multiple for capital efficiency instead.	Read
`ltv_cac`	LTV to CACCustomer lifetime value (monthly revenue per account x gross margin / monthly churn) compared with customer acquisition cost. Returns LTV, the LTV:CAC ratio and CAC payback months. Around 3:1 or better is a commonly cited target. Use cac_payback when you only need the payback period.	Read
`cac_payback`	CAC payback periodMonths of gross profit needed to earn back the cost of acquiring a customer: CAC / (monthly revenue per account x gross margin). Give cac_usd directly, or sales_marketing_spend_usd and new_customers for the same period. Many SaaS investors look for roughly 12 to 18 months or less, shorter for SMB. Use ltv_cac to also see lifetime value.	Read
`net_revenue_retention`	Net and gross revenue retentionNet revenue retention (NRR) and gross revenue retention (GRR) for a cohort of existing customers over a period, usually 12 months: (starting revenue + expansion - contraction - churn) / starting revenue. Above 100% NRR means existing customers grow on their own. Exclude revenue from new customers.	Read

Research and reference

Search 549 Raziel guides, define private-market terms and compare platforms. REST endpoints are GET with query parameters.

Tool name	What it does	Page on raziel.co
`search_guides`	Search Raziel guidesSearches Raziel's 549 Learn articles on private investing, startups, funds and founder topics (SAFEs, cap tables, K-1s, capital calls, QSBS, investor updates and more). Returns titles, URLs, summaries and matching section headings to cite. Use define_term for a one-line definition instead.`GET /api/v1/guides?q={query}&limit={limit}`	Browse
`define_term`	Define a private-market termPlain-English definition of a private-market, venture or fund term (pro rata, MFN, liquidation preference, valuation cap, DPI, TVPI, carried interest, hurdle, capital call, NAV, K-1, QSBS, 83(b), 409A, drag-along, ROFR and about 33 more), with a link to the Raziel guide or calculator. Pass "list" to get every term. Use search_guides for longer explanations.`GET /api/v1/glossary?term={term}`	Browse
`compare_platforms`	Compare Raziel with another platformResearched, sourced comparison of Raziel with another investing or startup platform (Addepar, Allocations, AngelList, Cake Equity, Carta, Empower, Eqvista, Foundersuite, getquin, Juniper Square, Kubera, Ledgy, Masttro, Pulley, Seraf, Sharesight, spreadsheets, Sydecar, Visible, Vyzer): pricing, feature coverage, key differences, where the other platform is stronger, and sources. Pass "list" to see every platform. Facts are as of the research date in the result.`GET /api/v1/compare?competitor={competitor}`	Browse

Prompts

MCP prompts your assistant can offer as one-click templates, built from Raziel guides.

investor_update
Draft a monthly investor update

For founders: drafts a concise monthly investor update in the structure Raziel recommends (summary, metrics, wins, challenges, financials, team, asks).

Arguments: company, month, metrics (optional), highlights (optional), lowlights (optional), asks (optional)
due_diligence_checklist
Startup due diligence checklist

For investors: builds a due diligence checklist for a specific startup and stage, with the questions to ask and documents to request.

Arguments: company, stage (optional), check_size (optional)
data_room_checklist
Fundraising data room checklist

For founders: lists what to put in a fundraising data room for your stage, split into a first-look folder and full diligence folders.

Arguments: stage

Limits and terms

Free to use, fair to share

Free to use in apps, agents, spreadsheets and research. A link to raziel.co is appreciated.
Rate limit: 60 requests per minute per IP address for calculations, MCP calls and searches. Reading the list and schemas is not limited.
Money is in US dollars (fields ending in _usd), percentages are percent numbers (20 means 20%), and dates are YYYY-MM-DD.
Calculator results include calculator_url (or guide_url for founder metrics), a page where people can adjust the inputs or read more.
For education only. Not tax, legal or investment advice.

Developer questions

The API, the MCP server and how they relate to the Raziel app.

Do I need an account or an API key?

No. The API and the MCP server are open to everyone. Requests are rate limited per IP address to keep the service fast for all.

What is MCP?

The Model Context Protocol is an open standard that lets AI assistants like Claude and ChatGPT call outside tools. Adding the Raziel server gives your assistant exact calculators, so it stops estimating IRR or SAFE conversions in its head, plus Raziel guides it can cite and ready-made prompts.

What are the prompts?

Templates your AI assistant can offer in one click: draft a monthly investor update, build a due diligence checklist for a startup, or list what goes in a fundraising data room. In clients that support MCP prompts they appear in the prompt or slash command menu.

Does this connect to my Raziel account?

No. These calculators only do math on the numbers you send. To track a real portfolio, cap table or raise, use the Raziel app.

Where is the full API reference?

The OpenAPI 3.1 spec at /api/openapi.json lists every endpoint with its input schema and an example. Import it into Postman, Insomnia or any OpenAPI tool.

How do I report a bug or ask for a calculator?

Use the contact form. Include the calculator name and the input you sent.

Beyond the calculators

Track your real portfolio in Raziel

Startups, SAFEs, funds and SPVs in one dashboard, with MOIC and IRR calculated from your actual cash flows.

Get started Book a demo

Raziel Calculators API and MCP server

The calculators from raziel.co, as an API

Free, no API key

28 tools

Built for AI agents

No customer data

Connect your AI assistant

Claude Code

Claude (web and desktop)

Cursor

VS Code

ChatGPT and other clients

Quick start in one request

Every tool

Calculators

Founder metrics

Research and reference

Prompts

Draft a monthly investor update

Startup due diligence checklist

Fundraising data room checklist

Free to use, fair to share

Developer questions

Do I need an account or an API key?

What is MCP?

What are the prompts?

Does this connect to my Raziel account?

Where is the full API reference?

How do I report a bug or ask for a calculator?

Track your real portfolio in Raziel