MetricTree Public API

Free product-metric calculations as JSON. 22 metrics. No signup, no API key, CORS open. Built for developers.

✓ Free forever ✓ No API key ✓ No signup ✓ CORS open Edge-hosted (low latency) Open source MIT

Quickstart

Calculate LTV via GET:

curl "https://metricstree.vercel.app/api/calc?metric=ltv&aov=2500&freq=4&life=3"

Response:

{
  "metric": "ltv",
  "inputs": { "aov": 2500, "freq": 4, "life": 3 },
  "formula": "AOV × Frequency × Lifetime",
  "result": 30000,
  "unit": "$",
  "insight": "LTV target ≥ 3× CAC for healthy unit economics",
  "rating": "high",
  "calculator_url": "https://metricstree.vercel.app/ltv",
  "docs_url": "https://metricstree.vercel.app/api-docs"
}

Try it now

Edit URL and hit Calculate:

POST with JSON body

curl -X POST "https://metricstree.vercel.app/api/calc" \
  -H "Content-Type: application/json" \
  -d '{"metric":"nrr","inputs":{"start":1000000,"expansion":200000,"churn":50000,"contraction":10000}}'

Endpoints

Endpoint	Method	Description
`/api/calc`	GET, POST	Calculate any supported metric
`/api/lead`	POST	(Internal — used by MetricTree forms only)

Supported metrics (22)

metric	Required inputs	Returns (unit)
`ltv`	`aov, freq, life`	Lifetime Value ($)
`cac`	`spend, customers`	CAC ($)
`ltv_cac`	`ltv, cac`	LTV:CAC ratio (x)
`mrr`	`mrr`	MRR ($)
`arr`	`mrr`	ARR = MRR×12 ($)
`nrr`	`start, expansion, churn, contraction`	NRR (%)
`grr`	`start, churn, contraction`	GRR (%)
`churn`	`lost, total`	Churn Rate (%)
`runway`	`cash, burn`	Runway (months)
`burnMultiple`	`burn, newArr`	Burn Multiple (x)
`ruleOf40`	`growth, margin`	Rule of 40 (%)
`quickRatio`	`newMrr, expansionMrr, churnMrr, contractionMrr`	Quick Ratio (x)
`magicNumber`	`newArrQuarter, sm`	Magic Number (x)
`nps`	`promoters, detractors, total`	NPS (score)
`cacPayback`	`cac, mrrPerCustomer, grossMargin`	CAC Payback (months)
`roas`	`revenue, spend`	ROAS (x)
`stickiness`	`dau, mau`	Stickiness (%)
`salesVelocity`	`opps, acv, winRate, cycleDays`	$/day
`winRate`	`won, total`	Win Rate (%)
`pipelineCoverage`	`pipeline, quota`	Coverage (x)
`aov`	`revenue, orders`	AOV ($)
`mrrGrowthRate`	`startMrr, endMrr`	MoM growth (%)

JavaScript example

// Calculate LTV:CAC from browser
const r = await fetch('https://metricstree.vercel.app/api/calc?metric=ltv_cac<v=15000&cac=3000');
const data = await r.json();
console.log(data.result);   // 5
console.log(data.insight);  // "Excellent (or under-investing in growth)"
console.log(data.rating);   // "excellent"

Python example

import requests

r = requests.get('https://metricstree.vercel.app/api/calc', params={
    'metric': 'runway', 'cash': 5000000, 'burn': 300000
})
print(r.json())
# { "result": 16.67, "unit": "months", "rating": "healthy", ... }

Response format

Field	Type	Description
`metric`	string	Echo of the requested metric
`inputs`	object	Echo of provided inputs
`formula`	string	Plain-English formula
`result`	number \| "Infinity"	Calculated value (rounded to 2 decimals)
`unit`	string	"$" / "%" / "x" / "months" / etc
`insight`	string	Plain-English interpretation + benchmark
`rating`	string	Categorical: "healthy" / "critical" / "excellent" / etc
`calculator_url`	string	Link to interactive calculator on MetricTree

Errors

Status	Meaning
`400`	Missing required inputs / invalid JSON body
`404`	Unknown metric
`405`	Method not allowed (use GET, POST, or OPTIONS)
`422`	Inputs valid but calculation undefined (e.g., divide by zero)

Rate limiting

Soft limit ~60 requests/minute per IP (Edge runtime default). No hard limit, no API key required. Be reasonable.

If you need higher throughput or SLA guarantees — get in touch (rodion.121093@gmail.com). The future Pro tier will include higher limits + sub-50ms guaranteed latency.

CORS

Access-Control-Allow-Origin: * — open to all origins. Use directly from browser apps.

Caching

Cache-Control: public, max-age=300 — responses cacheable 5 minutes (calculations are deterministic by inputs).

Want a metric we don't support?

Open an issue on GitHub or email — we'll add it within 48 hours if it's a standard product metric.

License

MIT — use commercially, modify, redistribute. Attribution appreciated but not required.

Use cases

Internal dashboards — embed metric calculations in your team's Notion/Confluence
SaaS-blog automation — auto-update benchmark tables in posts
Slack/Discord bots — slash-command to compute metric (just like our Telegram bot)
Zapier/Make automations — feed metric calculations into your CRM / spreadsheet
Learning — verify your hand-calculation against canonical formula