> For the complete documentation index, see [llms.txt](https://even-financial.gitbook.io/developer-center/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://even-financial.gitbook.io/developer-center/marketplace-integrations/web-embeds/banking-deposits-marketplace.md).

# Banking (Deposits) Marketplace

Banking (Deposits) Embed: Implementation, Syntax, Demo, Tags, Tracking, and Best Practices

{% hint style="success" icon="person-waving" %}
This page outlines what's needed to integrate Engine's **Banking Embed** into your website. In this guide, we will explore what Engine’s Embed syntax looks like and best practices for loading it on your site. This includes topics like proactively addressing layout shift for optimized performance.

This is a high-level guide, and specific implementation details should be discussed with your Engine team.
{% endhint %}

## Standard Embed Implementation

## Banking Specific Syntax

{% hint style="info" %}
Engine's banking embed **requires an additional tag** to be included at the end of the standard script to be able to mount correctly: `<moneylion-banking></moneylion-banking>`
{% endhint %}

Full sample embed script looks like the following:

```html
<script
  async
src="https://www.moneylion.com/network/{channel}/{zone}/web-component/banking/index.js"
></script><moneylion-banking
tags="tag.clientId=c1&tag.source=email&app.providedCreditRating=excellent&app.zipcode=93105\"
></moneylion-banking>
```

#### Component Names

* **`/web-component/banking/`:** A full application-style flow where consumers browse and compare banking deposit offers on your site, in a block that feels like part of your page instead of redirecting them elsewhere. It keeps the experience focused on exploring rates and products in context, so users stay in your environment while they shop for savings-related accounts.

## Banking Embed Demo

{% embed url="<https://fiona.com/explore/savings>" %}

## Client Tags for Attribution

#### **Banking Experience Data Pre-population**

Engine's Banking experience **does not use tags for the purpose of pre-populating consumer data** like other Engine marketplaces do. This is because Banking doesn't require the same degree of fidelity when it comes to user information.

The one piece of consumer information that can be changed is <mark style="color:$primary;">`zipcode`</mark>. Instead of pre-populating with tags, **Engine leverages programmatic geolocation-based information to pr-epopulate&#x20;**<mark style="color:$primary;">**`zipcode`**</mark> <mark style="color:$primary;">- t</mark>he precedence is as follows:

* An explicit ZIP filter (if defined)
* The visitor's geolocation-derived zipcode (this is the default behavior for Engine embeds)
* A fallback zipcode (<mark style="color:$primary;">`10001`</mark>), only if geolocation is unavailable)

#### Use Cases **for** Client Tags

* Prefilling customer data for certain non-PII fields
  * Decreases friction in the user experience and increases application submission rates
  * Useful when you already have that info on hand for that user, or want the front-end to default to particular values

#### **How to Implement Client Tags for Reporting & Customer Data Prefill**

To **add client tags** in an embed, use the following syntax in the `data-tags` attribute within the embed script:

```
tag.key_1=value_1&tag.key_2=value_2
```

#### <mark style="color:$primary;">Sample Implementation</mark>

{% code overflow="wrap" %}

```html
<script
  async
src="https://www.moneylion.com/network/{channel}/{zone}/web-component/banking/index.js"
></script><moneylion-banking
tags="tag.clientId=c1&tag.source=email\"
></moneylion-banking>
```

{% endcode %}

<mark style="color:$primary;">In the above example,</mark> <mark style="color:$primary;">`clientId`</mark> <mark style="color:$primary;">and</mark> <mark style="color:$primary;">`source`</mark> <mark style="color:$primary;">are available as tags for reporting purposes and the embed and the</mark> <mark style="color:$primary;">`zipcode`</mark> <mark style="color:$primary;">field will be prepopulated when the embed is rendered.</mark>

#### Supported Client Tag Keys

{% hint style="warning" %}
**Client tag keys are matched exactly, including case.** For example - `subid` and `subId` are stored as separate tags and will appear as separate keys in your reporting.

**Please send each key with consistent casing across all requests, and use the exact spelling shown above.**
{% endhint %}

Below are the client tag keys that are currently supported:

* agentId
* campaignId
* clickId
* clientId
* deviceId
* medium
* sourceId
* subId
* subId1
* subId2
* subId3
* target
* trafficsource
* userId

If a different key is needed, please reach out to your Partner Manager - we *may* be able to accommodate, but adding nonstandard keys will increase the time it takes Engine to report Client Tag values back to you and is therefore not recommended.

## Tracking Events Emitted by Embed

When you embed the Banking experience, event callbacks fire automatically.

#### How It Works

As a consumer navigates through the experience, the embed emits **partner messages**: JSON objects with a `name` (the event type) and a `payload` (event-specific data). The iframe posts them to your host page via `window.parent.postMessage(message, '*')`.

* **You do not register callbacks with Engine.** You listen on your host page; messages arrive whether or not you handle them.
* **Not every UI action sends a message.** Only the events listed below are part of the partner contract.
* **Messages are one-way.** There is no acknowledgement or response channel.

#### Implementation Path

Partners using Web Embed receive events by listening for browser `message` events on the host page:

```javascript
window.addEventListener('message', (event) => {
  const message = event.data
  if (!message || typeof message !== 'object' || typeof message.name !== 'string') return
  console.log(message.name, message.payload)
})
```

#### Message Envelope

```json
{
  "name": "eventName",
  "payload": {}
}
```

| Field     | Description                                                        |
| --------- | ------------------------------------------------------------------ |
| `name`    | The event name (e.g. `"onCreate"`, `"onRateTableRender"`)          |
| `payload` | Event-specific data; always includes `timestamp` (ISO-8601 string) |

#### Events & Data

#### `onCreate`: Emitted when a lead is created on the explore page.

```json
{
  "name": "onCreate",
  "payload": {
    "timestamp": "2026-06-03T14:22:10.123Z",
    "leadUuid": "00000000-0000-0000-0000-000000000000",
    "createPage": "explore",
    "editingPage": null
  }
}
```

Note: `onCreate` is suppressed if no `leadUuid` is available.

#### `onRateTableRender`: Emitted when offers are rendered on the explore page.

```json
{
  "name": "onRateTableRender",
  "payload": {
    "timestamp": "2026-06-03T14:22:10.123Z",
    "rateTableUuid": "123e4567-e89b-12d3-a456-426614174000",
    "bankingOffers": []
  }
}
```

**`bankingOffers[]` item**

| Field                      | Type             | Definition                                      |
| -------------------------- | ---------------- | ----------------------------------------------- |
| `offerUuid`                | string           | Offer UUID                                      |
| `financialInstitutionName` | string           | Partner name                                    |
| `financialInstitutionUuid` | string           | Partner UUID (empty string if unavailable)      |
| `productType`              | string           | Product type (e.g. `"savings"`)                 |
| `productSubType`           | string           | Product subtype (e.g. `"savings_account"`)      |
| `accountName`              | string           | Account name shown in the UI                    |
| `annualPercentYield`       | number \| string | APY, or `""` if unavailable                     |
| `minimumDeposit`           | number \| string | Minimum opening deposit, or `""` if unavailable |
| `monthlyFee`               | number \| string | Monthly maintenance fee, or `""` if unavailable |

Example:

```json
{
  "offerUuid": "offer-123",
  "financialInstitutionName": "Partner Bank",
  "financialInstitutionUuid": "fi-123",
  "productType": "savings",
  "productSubType": "savings_account",
  "accountName": "High-Yield Savings",
  "annualPercentYield": 4.75,
  "minimumDeposit": 0,
  "monthlyFee": 0
}
```

***

#### `onOfferClick`: Emitted when the user clicks an offer call-to-action. Suppressed if no `leadUuid` is available.

```json
{
  "name": "onOfferClick",
  "payload": {
    "timestamp": "2026-06-03T14:22:10.123Z",
    "leadUuid": "00000000-0000-0000-0000-000000000000",
    "offerUuid": "offer-123",
    "financialInstitutionName": "Partner Bank",
    "financialInstitutionUuid": "fi-123",
    "productType": "savings",
    "productSubType": "savings_account"
  }
}
```

**Payload fields**

| Field                      | Type   | Definition                              |
| -------------------------- | ------ | --------------------------------------- |
| `timestamp`                | string | ISO-8601 time when the click occurred   |
| `leadUuid`                 | string | Applicant lead UUID (required on click) |
| `offerUuid`                | string | Clicked offer UUID                      |
| `financialInstitutionName` | string | Partner name                            |
| `financialInstitutionUuid` | string | Partner UUID                            |
| `productType`              | string | Product type                            |
| `productSubType`           | string | Product subtype                         |

Note: `onOfferClick` does not include `accountName`, `annualPercentYield`, `minimumDeposit`, or `monthlyFee`. Use the `offerUuid` to correlate with the corresponding item from `onRateTableRender` if those fields are needed.

***

#### Common `productSubType` values

| Value                           | Product                                              |
| ------------------------------- | ---------------------------------------------------- |
| `savings_account`               | Savings account                                      |
| `checking`                      | Checking account (includes `high_interest_checking`) |
| `money_market_account`          | Money market account                                 |
| `cash_management_account`       | Cash management account                              |
| `certificate_of_deposit`        | Certificate of deposit                               |
| `individual_retirement_account` | Individual retirement account                        |

Treat this as a representative set, not a frozen enum — new subtypes may appear as products are added.

***

#### `onErrorPageView`: Emitted when the error page is shown.

```json
{
  "name": "onErrorPageView",
  "payload": {
    "timestamp": "2026-06-03T14:22:10.123Z",
    "leadUuid": "00000000-0000-0000-0000-000000000000",
    "fromPage": "explore",
    "editingPage": null
  }
}
```

#### `onErrorPageRetry`: Emitted when the user clicks retry from the error page.

```json
{
  "name": "onErrorPageRetry",
  "payload": {
    "timestamp": "2026-06-03T14:22:10.123Z",
    "leadUuid": "00000000-0000-0000-0000-000000000000",
    "toPage": "explore",
    "editingPage": null
  }
}
```

## Embed Best Practices & Troubleshooting

{% hint style="success" %}

#### Best practices

1. **Use the snippet Engine gives you.** Don't hardcode channel, zone, or component paths yourself.
2. **Keep `async` on the script tag.** This prevents the embed script from blocking the rest of your page.
3. **Give the embed a real container.** Set a width on the parent. Set a `min-height` when possible. This gives the iframe room to render and avoids large layout shifts.
4. **Allow Engine in your CSP.** Your Content Security Policy must allow the Engine script in `script-src` and `https://www.moneylion.com` (or your Engine environment host) in `frame-src`.
5. **Follow this page's tags and prefill guidance.** Attributes differ by product. Use this page's sample, or your Engine-provided snippet, rather than copying syntax from another embed.
   {% endhint %}

{% hint style="warning" %}

#### Troubleshooting

**The component doesn't show**

1. Check your install mode:
   * **Explicit custom element:** Confirm the `moneylion-*` element from your snippet is on the page.
2. Open the browser console. Check for script load failures or CSP blocks.

**The page feels slow**

1. Confirm the `async` attribute is on the `<script>` tag.
2. Avoid nesting the embed in a hidden container, such as `display: none`, at first load. This can delay useful height and layout work.

**Events aren't firing**

1. Confirm you listen for `message` events. Check for `{ name, payload }` objects. See the tracking section on this page for product-specific events.
2. In production, filter by Engine's origin. This ignores unrelated `postMessage` traffic from other page scripts.
   {% endhint %}


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