# Redeeming Stablecoins

ERC20 aTerra tokens (e.g. aUST) can be redeemed to ERC20 stablecoins using the below endpoints:

| Endpoint                                                      | Method | Description                                             |
| ------------------------------------------------------------- | ------ | ------------------------------------------------------- |
| [`init_redeem_stable`](#initiate-stablecoin-redemption)       | POST   | Initiates the redemption of ERC20 aTerra                |
| [`finish_redeem_stable`](#finish-stablecoin-redemption)       | POST   | Claims redeemed ERC20 stablecoins                       |
| [`redeem_stable_status`](#check-stablecoin-redemption-status) | GET    | Gets status of an ongoing stablecoin redemption request |

## Initiate stablecoin redemption

<mark style="color:green;">`POST`</mark> `https://eth-api.anchorprotocol.com/api/v1/init_redeem_stable`

`POST /api/v1/init_redeem_stable` allows you to fabricate an unsigned Ethereum Tx payload that initiates a stablecoin redemption request. The client can sign and broadcast the resulting Tx payload with their Ethereum account key, or use a custodian API that supports the signing of a raw Tx payload.\
\
Note that only **one** `init_redeem_stable` operation can take place at the same time; even if you successfully broadcast the resulting Tx to the network, the EthAnchor Account contract will block any subsequent operations until an ongoing stablecoin redemption is finished with `finish_redeem_stable`.

#### Headers

| Name           | Type   | Description        |
| -------------- | ------ | ------------------ |
| Authentication | string | Anchor client key. |

#### Request Body

| Name              | Type   | Description                                                                                                |
| ----------------- | ------ | ---------------------------------------------------------------------------------------------------------- |
| underlying\_denom | string | <p>Underlying stablecoin denomination of aTerra to redeem from Anchor.<br>Example: <code>"uusd"</code></p> |
| a\_terra\_amount  | string | (uint256) amount of aTerra to redeem from Anchor in 18 decimals. If empty, redeems all aTerra holdings.    |

{% tabs %}
{% tab title="200 init\_redeem\_stable unsigned Tx hash." %}

```
{
    "success": true,
    "tx_hash": "0x......",
    "action": "anchor/init_redeem_stable",
    "underlying_denom": "uusd", 
    "a_terra_amount": "500000000"
}
```

{% endtab %}

{% tab title="401 You are not authorized to call this endpoint; client not registered." %}

```
{
    "success": false,
    "error": "unauthorized; client not registered"
}
```

{% endtab %}
{% endtabs %}

## Finish stablecoin redemption

<mark style="color:green;">`POST`</mark> `https://eth-api.anchorprotocol.com/api/v1/finish_redeem_stable`

`POST /api/v1/finish_redeem_stable` allows you to finish a previously requested `redeem_stable` operation.\
\
This endpoint returns an unsigned Ethereum transaction payload. You can sign this transaction yourself and send to the network, or broadcast using any custodian API that supports signing a raw Tx payload.

#### Headers

| Name           | Type   | Description        |
| -------------- | ------ | ------------------ |
| Authentication | string | Anchor client key. |

{% tabs %}
{% tab title="200 finsish\_redeem\_stable unsigned Tx hash." %}

```
{
    "success": true,
    "tx_hash": "0x......",
    "action": "anchor/finish_redeem_stable"
}
```

{% endtab %}

{% tab title="401 You are not authorized to call this endpoint; client not registered." %}

```
{
    "success": false,
    "error": "unauthorized; client not registered"
}
```

{% endtab %}
{% endtabs %}

## Check stablecoin redemption status

<mark style="color:blue;">`GET`</mark> `https://eth-api.anchorprotocol.com/api/v1/redeem_stable_status`

`GET /api/v1/redeem_stable_status` allows you to check the status of an ongoing `redeem_stable` operation.\
\
You may want to periodically check the progress of your `redeem_stable` request, since an operation may take up to minutes to finish due to congestion on either side of the networks.\
\
Note that status being `"finished"` does **NOT** mean you have run a full cycle of `redeem_stable` operation; you still need to send another transaction from `POST /api/v1/finish_redeem_stable` to finalize your operation.This endpoint responds with HTTP 204 when there is no ongoing operation.

#### Headers

| Name           | Type   | Description               |
| -------------- | ------ | ------------------------- |
| Authentication | string | Anchor client access key. |

{% tabs %}
{% tab title="200 Current status of ongoing redeem\_stable operation." %}

```
{
    // Phase
    // 0 - (Ethereum) wrapper contract has received aTerra tokens (e.g. aUST) and 
    //     dispatched through Shuttle
    // 1 - (Terra) terra-side client account has received aTerra tokens
    //     triggering RedeemStable soon
    // 2 - (Terra) RedeemStable action is processed and stablecoins (e.g. UST) have
    //     been received
    // 3 - (Terra) stablecoins are sent to the ether-side wrapper contract
    //     through Shuttle
    // 4 - (Ethereum) contract has received stablecoins; operation finished
    "phase": 0,

    // LastUpdated
    // Unix timestamp at which the last update to this response has been made
    "last_updated": 1608662606,

    // Status
    // Operation status
    // pending   - operation in flight
    // failed    - operation failed; last known tx has been recorded
    // finished  - operation finished; you can call /finish_redeem_stable
    "status": "pending",

    // UnderlyingDenom
    // Underlying denomination of aTerra tokens to be redeemed
    "underlying_denom": "uusd", 

    // aTerraAmount
    // amount of aTerra tokens to be redeemed
    "a_terra_amount": :20000000:,

    // TxHash
    // List of known tx hashes and the corresponding network name
    "tx_hash": [
        {
            "network": "ethereum",
            "tx_hash": "0x...."
        },
        {
            "network": "terra",
            "tx_hash": "00ABCD..."
        },
        ...
    ]
}
```

{% endtab %}

{% tab title="204 No ongoing redeem\_stable operation." %}

```
{
    "status": "idle"
}
```

{% endtab %}
{% endtabs %}