For developers & AI assistants
Verified Financial Models
Every model here has a public contract: what it takes, what it computes, what it assumes, what it ignores. A second, independent implementation must reproduce the engine exactly before anything ships, and every IRS and SSA constant is traced to its source with the date we checked it. When a model changes, the changelog says so. Always.
Use the models
MCP server (AI assistants): https://worthune.com/api/mcp/mcp — your agent lists the catalog, reads the contract, runs the model. Three tools, no auth, in the official MCP registry as com.worthune/models.
REST API: GET /api/v1/models lists the catalog; every model serves its contract, its full spec, and a POST endpoint that validates before it computes — out-of-range requests get an error, not a quietly adjusted answer. Responses carry their spec version, assumptions, and sourced constants.
Aggregate usage is public at /api/v1/telemetry — counters only, never personal data.
The catalog — 27 verified models
| Model | Spec | Try it | Contract |
|---|---|---|---|
| relocation | v1.0.0 | calculator | JSON |
| rent-vs-buy | v1.1.0 | calculator | JSON |
| fire | v1.0.1 | calculator | JSON |
| roth-vs-traditional | v1.0.1 | calculator | JSON |
| refinance | v1.0.0 | calculator | JSON |
| windfall | v1.0.1 | calculator | JSON |
| sabbatical | v1.0.0 | calculator | JSON |
| one-income | v1.0.0 | calculator | JSON |
| second-home | v1.1.0 | calculator | JSON |
| divorce | v1.1.0 | calculator | JSON |
| down-payment | v1.0.0 | calculator | JSON |
| rsu | v1.1.0 | calculator | JSON |
| debt-payoff | v1.0.0 | calculator | JSON |
| student-loan-payoff | v1.0.0 | calculator | JSON |
| emergency-fund | v1.0.0 | calculator | JSON |
| salary-jump | v1.0.1 | calculator | JSON |
| having-a-child | v1.0.0 | calculator | JSON |
| wedding | v1.0.0 | calculator | JSON |
| renovation | v1.0.0 | calculator | JSON |
| side-business | v1.0.1 | calculator | JSON |
| mega-backdoor-roth | v1.0.0 | calculator | JSON |
| 529-college-savings | v1.0.0 | calculator | JSON |
| private-school | v1.2.0 | calculator | JSON |
| social-security-timing | v1.0.0 | calculator | JSON |
| long-term-care | v1.0.0 | calculator | JSON |
| eldercare | v1.0.1 | calculator | JSON |
| estate-planning | v1.1.0 | calculator | JSON |
Model changes are never silent — the full version history is at /models/changelog, generated from the specs themselves. The verification bar: an independent implementation, written from the spec alone, must reproduce the engine bit-for-bit — 250 fuzzed cases per model, charts included, anchored to textbook values, on every code change. Models are illustrative planning tools, not financial advice.