# Runes

## POST /brc20swap/v2/create\_add\_liquid\_psbt2

> Build the PSBT for adding liquidity

```json
{"openapi":"3.0.1","info":{"title":"Backend API","version":"1.0.0"},"servers":[{"url":"https://api-testnet4.dotswap.app","description":"Swap test"},{"url":"https://api.dotswap.app","description":"Swap official"}],"security":[],"paths":{"/brc20swap/v2/create_add_liquid_psbt2":{"post":{"summary":"Build the PSBT for adding liquidity","deprecated":false,"description":"","tags":[],"parameters":[],"requestBody":{"content":{"application/json":{"schema":{"type":"object","properties":{"tick1":{"type":"string"},"tick2":{"type":"string"},"amount_1":{"type":"string"},"amount_2":{"type":"string"},"slipper":{"type":"string"},"payer_ord_addr":{"type":"string"},"fee_rate":{"type":"string"},"payer_btc_addr":{"type":"string"},"payer_pub_key":{"type":"string"},"coin_type_1":{"type":"string"},"coin_type_2":{"type":"string"},"token":{"type":"string"}},"required":["tick1","coin_type_1","amount_1","tick2","coin_type_2","amount_2","fee_rate","slipper","token","payer_ord_addr","payer_btc_addr","payer_pub_key"]}}}},"responses":{"200":{"description":"","content":{"application/json":{"schema":{"type":"object","properties":{"code":{"type":"integer"},"msg":{"type":"string"},"data":{"type":"object","properties":{"psbt":{"type":"string","title":"PSBT base64"},"ToSignInputs":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"type":{"type":"string"}},"required":["index","type"]}},"check_sum":{"type":"string"},"tx_size":{"type":"integer"},"usr_cnt":{"type":"integer"},"vins":{"type":"null"},"check_sign_only":{"type":"boolean"}},"required":["ToSignInputs","psbt","check_sum","tx_size","usr_cnt","vins","check_sign_only"]},"req_id":{"type":"string"}},"required":["code","msg","data","req_id"]}}},"headers":{}}}}}}}
```

## Important Notest

{% hint style="info" %}

1. Use the same address for both `payer_ord_addr` and `payer_btc_addr`.
   {% endhint %}

## POST /brc20swap/v2/add\_liquid\_by\_psbt

> Add liquidity

```json
{"openapi":"3.0.1","info":{"title":"Backend API","version":"1.0.0"},"servers":[{"url":"https://api-testnet4.dotswap.app","description":"Swap test"},{"url":"https://api.dotswap.app","description":"Swap official"}],"security":[],"paths":{"/brc20swap/v2/add_liquid_by_psbt":{"post":{"summary":"Add liquidity","deprecated":false,"description":"","tags":[],"parameters":[],"requestBody":{"content":{"application/json":{"schema":{"type":"object","properties":{"psbt":{"type":"string","title":"PSBT base64"},"tick1":{"type":"string"},"tick2":{"type":"string"},"amount_1":{"type":"string"},"amount_2":{"type":"string"},"slipper":{"type":"string"},"payer_ord_addr":{"type":"string"},"fee_rate":{"type":"string"},"payer_btc_addr":{"type":"string"},"payer_pub_key":{"type":"string"},"check_sum":{"type":"string"},"chl":{"type":"string"},"coin_type_1":{"type":"string"},"coin_type_2":{"type":"string"},"token":{"type":"string"}},"required":["tick1","coin_type_1","amount_1","tick2","coin_type_2","amount_2","fee_rate","slipper","token","payer_ord_addr","payer_btc_addr","payer_pub_key","psbt"]}}}},"responses":{"200":{"description":"","content":{"application/json":{"schema":{"type":"object","properties":{"code":{"type":"integer"},"msg":{"type":"string"},"data":{"type":"object","properties":{"order_id":{"type":"string","title":"Order number"}},"required":["order_id"]},"req_id":{"type":"string"}},"required":["code","msg","data","req_id"]}}},"headers":{}}}}}}}
```

Finally, send the signed PSBT. If the response indicates success, the liquidity has been added/created successfully.

{% hint style="info" %}
The request parameters of the previous interface are inherited, and an additional psbt is passed. export interface SendPoolPsbtBody extends PoolPsbtBody { psbt: string; }
{% endhint %}