firenum runs entirely in the browser. The tools below let you reuse it: embed a calculator, show that you are listed in the directory, or hand structured financial data to the Fire Planner and get back a shareable link. All endpoints are open, CORS-enabled, and unauthenticated.
Embed a calculator
Drop any of the 8 FIRE calculators into your page with an iframe. The embed resizes itself as readers change inputs and adapts to their currency. The snippet builder gives you the currency, theme, and auto-resize code ready to paste.
Partner badge
Listed in the advisor directory? Show the "Featured on firenum" badge on your site. Four layouts, dark and light, with copy-paste code.
REST API
POST /api/fire-plan takes a JSON object of financial data and returns a URL that
opens the Fire Planner with everything pre-loaded in sandbox mode. The reader reviews, adjusts,
and saves. A banner tells them the profile was generated from an external source.
Income is annual. Expenses and contributions are monthly. Amounts are in whole currency units. Every field is optional. Unknown fields are ignored.
Request
curl -X POST https://firenum.com/api/fire-plan \
-H "Content-Type: application/json" \
-d '{ "salary": 80000, "expenses": 4000, "retirement": 200000, "birth": 1990, "retire_age": 55 }'Response
{
"url": "https://firenum.com/fire-planner?salary=80000&expenses=4000&retirement=200000&birth=1990&retire_age=55&source=agent",
"params_applied": ["salary", "expenses", "retirement", "birth", "retire_age"]
}The full parameter list (assets, debts, per-category expenses, growth and inflation rates, currency, and the retirement timeline) lives in the OpenAPI spec: firenum.com/openapi.yaml.
Agent-to-agent API
The same capability is exposed as an A2A skill over JSON-RPC 2.0, so an agent can create a FIRE plan without scraping the site. The agent card is published at /.well-known/agent-card.json.
Send the financial data as a DataPart (kind: "data") inside a
message/send call. The result is a completed task whose artifact carries the
planner URL and the list of applied parameters.
Request
POST https://firenum.com/a2a
Content-Type: application/json
{
"jsonrpc": "2.0",
"id": 1,
"method": "message/send",
"params": {
"message": {
"parts": [
{ "kind": "data", "data": { "salary": 80000, "expenses": 4000, "retirement": 200000, "birth": 1990, "retire_age": 55 } }
]
}
}
}
Send message/send with no DataPart and the agent replies with an
input-required status describing the fields it expects. Same parameter names as the
REST API. Streaming and push notifications are not supported.
Fair use
No key, no cost, no rate tiers to sign up for. Requests are lightly rate-limited per IP to keep the service healthy. The APIs build a planner URL from the data you send. They do not store your data or return financial advice. See the terms for the details.