---
title: "What If"
method: POST
path: "/api/simulator/what-if/{user_id}"
tags: ["Simulator"]
---

# What If

`POST /api/simulator/what-if/{user_id}`

## Request

- Base URL: `https://api.earmarkiq.app` (the document declares no server; this is the origin it was published from)
- URL: `https://api.earmarkiq.app/api/simulator/what-if/{user_id}`
- Auth: HTTP bearer

Run what-if scenario calculations using the user's latest analysis data.
Falls back to running a fresh analysis if none exists.

## Path parameters

- `user_id` string, uuid, required

## Request body

- WhatIfRequest
  - `scenarios` ScenarioInput[], required
    - `type` string, required
    - `change_amount` number, required
    - `category` string, nullable

## Response `200`

Successful Response

- WhatIfResponse
  - `scenarios` ScenarioResult[], required
    - `type` string, required
    - `description` string, required
    - `monthly_impact` number, required
    - `annual_impact` number, required
    - `five_year_impact` number, required
    - `projected_savings_balance` number, required
    - `comparison` object, required
  - `combined_impact` CombinedImpact, required
    - `monthly` number, required
    - `annual` number, required
    - `five_year` number, required

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/earmarkiq/apis/earmark-api.md) · [All operations](https://skmtc.dev/earmarkiq/apis/earmark-api/llms.txt) · [OpenAPI document](https://skmtc.dev/earmarkiq/apis/earmark-api/revisions/4a2c41907105?raw)