> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ripio.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Launch the widget

> Widget URLs for on-ramp and off-ramp, sandbox hosts, and every query parameter you can prefill.

Once you have a [session token](/ramps-api/widget/get-started/authentication), you launch the widget by sending the user from your platform to a Ripio URL with the token in the `_to` query parameter. There is nothing to install and no script to embed — the widget is a hosted page.

### Widget URLs

The on-ramp and the off-ramp are separate entry points.

| Environment | On-ramp                                                                  | Off-ramp                                                                              |
| ----------- | ------------------------------------------------------------------------ | ------------------------------------------------------------------------------------- |
| Production  | `https://b2b-widget-onramp.ripio.com?_to=<authentication_token>`         | `https://b2b-widget-onramp.ripio.com/offramp.html?_to=<authentication_token>`         |
| Sandbox     | `https://b2b-widget-onramp.sandbox.ripio.com?_to=<authentication_token>` | `https://b2b-widget-onramp.sandbox.ripio.com/offramp.html?_to=<authentication_token>` |

Example:

```bash theme={null}
https://b2b-widget-onramp.ripio.com?_to=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uIjoiMThhYjZkNmM4ZDk4NWE5Y2M4N2IwMTcyN2ExMWYwOTQ4YzJmNGUxYzQ0ODEzZTZhNDU0MzcxYTg1NzY3YjE5OSIsImV4cCI6MTcwODI5ODMzM30.4aRUEXLkUs3jf-DYMcH8claUuDKfc8qbTjW6JzpBTjI
```

Both entry points open on the same first screen: the user is asked for their email address, which is where sign-in begins. See [Sign-in and terms](/ramps-api/widget/flows/identity-and-terms).

### Query parameters

Every parameter below is optional. They prefill or constrain the flow so the user has less to type.

| Parameter           | Type                | Description                                                                                                                                                                                              |
| ------------------- | ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `_addr`             | *string* (Optional) | Wallet address to prefill for the on-ramp. When set, the field is not editable. Ex: `0x646eE511616A20a321A1cB72DADCB04C0485b97e`                                                                         |
| `_net`              | *string* (Optional) | Preselect the blockchain network. It must match the networks available to your account. Ex: `ETHEREUM`                                                                                                   |
| `_amount`           | *string* (Optional) | Prefill the fiat amount. Ex: `1000` or `4321.35`                                                                                                                                                         |
| `_crypto`           | *string* (Optional) | Preselect the cryptocurrency, which then is not editable. It must match the cryptos available to your account. Ex: `USDT`                                                                                |
| `_la`               | *string* (Optional) | Force the interface language, overriding the one derived from your account country. One of `es`, `es-rp`, `en`, `br`. See [Partner settings](/ramps-api/widget/configuration/partner-settings#language). |
| `_tracking_session` | *string* (Optional) | Custom identifier to track the user session on your end. It will be returned in the webhooks under `metadata.session`. Ex: `random-tracking-id-onramp`                                                   |

<Warning>
  `_addr` is a prefill for users who have no address on file, not an override. If the end user already has a wallet address stored with Ripio, that address wins and the field is read-only. Sending a different `_addr` for a returning user has no effect.
</Warning>

<img src="https://mintcdn.com/ripio-9dfd4837/08vkB56X36FZiua_/ramps-api/widget/assets/widget-onramp-address.png?fit=max&auto=format&n=08vkB56X36FZiua_&q=85&s=f476514de4f7006d2b8d2d874e3d86e7" alt="The destination screen with a prefilled, non-editable wallet address" width="640" height="1120" data-path="ramps-api/widget/assets/widget-onramp-address.png" />

<Note>
  Prefills are cached for the lifetime of the session token, so a user who reloads the page mid-flow keeps them. Passing the same token again with different values will not reset a flow already in progress.
</Note>

#### Tracking session parameter

The `_tracking_session` parameter can be used as follow:

```bash theme={null}
https://b2b-widget-onramp.sandbox.ripio.com/index.html?_to=<token>&_tracking_session=random-tracking-id-onramp
```

Then, you will receive the tracking session in the webhooks as follows:

```json theme={null}
{
  "eventType": "ON-RAMP.DEPOSIT.RECEIVED",
  "transactionObject": {
    ...
    "metadata": {
      "session": "random-tracking-id-onramp"
    }
  }
}
```

It is also echoed back to you on the redirect as `session_id` — see [Returning to your app](/ramps-api/widget/get-started/returning-to-your-app).

### Reserved parameters

You will see three more parameters in your logs. Ripio generates them, and you should not construct them yourself.

| Parameter              | Generated by                                             | Purpose                                                                                                                                                    |
| ---------------------- | -------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `order_status=pending` | Ripio, as the return URL handed to payment gateways      | Brings the user back into the widget on the order-confirmed screen after they pay at their bank or card provider.                                          |
| `kyc=pending`          | Ripio, as the return URL handed to the identity provider | Brings the user back into the widget on the verification-status screen. See [Identity verification](/ramps-api/widget/flows/kyc).                          |
| `_at`                  | Ripio, inside the payout-rejected email                  | Opens the widget directly in the recovery flow for a rejected off-ramp payout. See [Recovering a rejected payout](/ramps-api/widget/flows/order-recovery). |

<Warning>
  `_at` travels in the **URL fragment** (`#_at=…`), not the query string, so the token never reaches server logs or a `Referer` header. If your edge, WAF or analytics layer rewrites or strips URL fragments on links your users open, the recovery link will not work.
</Warning>

### Next steps

<CardGroup cols={2}>
  <Card title="Returning to your app" icon="arrow-right-from-bracket" href="/ramps-api/widget/get-started/returning-to-your-app">
    Which screens redirect back to you, and exactly which parameters they append.
  </Card>

  <Card title="User flows" icon="list-check" href="/ramps-api/widget/flows/on-ramp">
    What the user does inside the widget, country by country.
  </Card>
</CardGroup>