> For the complete documentation index, see [llms.txt](https://docs.tinyman.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tinyman.org/v1-integration/transactions/swap.md).

# Swap

### Transaction Group

0\. Pay - pay fees in Algo from Swapper to Pool

* fees to cover Tx 1,2
* Signed by Swapper

```
{
  "txn": {
    "type": "pay",
    "rcv": "{POOL_ADDRESS}",
    "snd": "{SWAPPER_ADDRESS",
    "amt": 2000,
    "fee": 1000,
    ...
  },
  "sig": "{SWAPPER_SIG}",
}
```

1. App Call - NoOp call to Validator App with args \['swap', (fixed-input) or 'fo' (fixed-output)], with Swapper account
   * Signed by Pool LogicSig
   * Argument 1 'fi' specifies that the input (sell) is fixed but the output may vary with slippage
   * Argument 1 'fo' specifies that the output (buy) is fixed but the input may vary with slippage

```
{
  "txn": {
    "type": "appl",
    "snd": "{POOL_ADDRESS}",
    "apid": {VALIDATOR_APP_ID},
    "apan": 0, // OnComplete: NoOp
    "apaa": ['c3dhcA==', 'Zmk=' or 'Zm8='], // ['swap', 'fi' (fixed-input) or 'fo' (fixed-output)]
    "apas": [{ASSET1_ID}, {ASSET2_ID}, {LIQUIDITY_ASSET_ID}], // or just [{ASSET1_ID}, {LIQUIDITY_ASSET_ID}] if asset 2 is Algo
    "apat": [{SWAPPER_ADDRESS}],
    "fee": 1000,
    ...
  },
  "lsig": "{POOL_LOGICSIG}",
}
```

2\. (a) AssetTransfer - Transfer of sell asset from Swapper to Pool

* If sell asset is an ASA
* Signed by Swapper

```
{
  "txn": {
    "type": "axfer",
    "arcv": "{POOL_ADDRESS}",
    "snd": "{SWAPPER_ADDRESS}",
    "xaid": {SELL_ASSET_ID},
    "aamt": {SELL_ASSET_AMOUNT},
    "fee": 1000,
    ...
  },
  "sig": "{SWAPPER_SIG}",
}
```

2\. (b) Pay - Transfer of Algo from Swapper to Pool

* If sell asset is Algo
* Signed by Swapper

```
{
  "txn": {
    "type": "pay",
    "rcv": "{POOL_ADDRESS}",
    "snd": "{SWAPPER_ADDRESS}",
    "amt": {SELL_ASSET_AMOUNT},
    "fee": 1000,
    ...
  },
  "sig": "{SWAPPER_SIG}",
}
```

3\. (a) AssetTransfer - Transfer of buy asset from Pool to Swapper

* If buy asset is an ASA
* Signed by Pool LogicSig

```
{
  "txn": {
    "type": "axfer",
    "arcv": "{SWAPPER_ADDRESS}",
    "snd": "{POOL_ADDRESS}",
    "xaid": {BUY_ASSET_ID},
    "aamt": {BUY_ASSET_AMOUNT},
    "fee": 1000,
    ...
  },
  "lsig": "{POOL_LOGICSIG}",
}
```

3\. (b) Pay - Transfer of buy asset from Pool to Swapper

* If buy asset is Algo
* Signed by Pool LogicSig

```
{
  "txn": {
    "type": "pay",
    "rcv": "{SWAPPER_ADDRESS}",
    "snd": "{POOL_ADDRESS}",
    "amt": {BUY_ASSET_AMOUNT},
    "fee": 1000,
    ...
  },
  "lsig": "{POOL_LOGICSIG}",
}
```

#### Validator App State Changes

**Global State**

None

**Pool Account Local State**

* `o{ASSET1_ID}: {int}` // total outstanding unredeemed asset 1 amount
* `o{ASSET2_ID}: {int}` // total outstanding unredeemed asset 2 amount
* `p: {int}` // total unclaimed protocol fees amount

**Swapper Account Local State**

* `{POOL_ADDRESS}e{ASSET1_ID}: {int}` // excess asset 1 amount available for redemption
* `{POOL_ADDRESS}e{ASSET2_ID}: {int}` // excess asset 2 amount available for redemption