User Experience (assumptions)
Dotsama’s degens can get ready to buy the next dip, buy the spike faster, and (actually) take profits next time - OAK now supports cross-chain automation on supported Kusama parachains connected to Turing Network using a stream of data that you define.
While the naming and examples for these APIs imply a use case where the data stream is an asset price and the trigger is a swap, OAK APIs can be used by any multi-chain application to offer users the ability to perform any action at some point in the future.
Examples of “any action” include swaps (buys and sells), transfers (recurring and conditional payments), compounding yield (claim and supply / stake), and many more (any blockchain extrinsic or smart contract function). If “at some point in the future” for your user means a point or frequency in “time”, then you’re looking for the Time Trigger APIs. You’re in the right place if you want to use any off-chain data to trigger future transactions.
Let’s discuss what assets you would like to add and whitelisting you / your project to create and maintain a data stream. Once a data stream has been created, any user can define a transaction and condition when it will trigger (the direction and percentage of movement) and the Kusama parachain to communicate transaction instruction to. The APIs in this section are prefixed by automationPrice and can be used to:
addAsset- Define a new data streamassetPriceUpdate- Update an existing data streamscheduleTask- Schedule an action to occur based on an increase or decrease in data stream values.
| Environment | RPC Endpoint |
|---|---|
| Turing Staging (Rococo) | rpc.turing-staging.oak.tech |
| Turing (Kusama) | In Beta testing. Contact developers@oak.tech to get early access. |
| OAK (Polkadot) | Crowdloan launching soon! |
Parachain Requirements
The following requirements apply for any Kusama parachain that wishes to support cross-chain automation (including recurring payments, auto-compounding liquidity / staking rewards, automatic swaps, and more):
- Open bi-directional HRMP channels - HRMP Channels and You
-
Enable users to authorize future transactions powered by OAK using a proxy pallet and XCM origin converter.
2a. Proxy pallet implementation
2b. XCM converter implementation
2c. Get proxy accountId:
curl --location --request POST 'https://rpc.turing-staging.oak.tech' \
--header 'Content-Type: application/json' \
--data-raw '{
"id":1,
"jsonrpc":"2.0",
"method": "xcmpHandler_crossChainAccount",
"params": ["SS58_ACCOUNT_ID"]
}'
Replace SS58_ACCOUNT_ID with the account you want to lookup.
Application Requirements [Extrinsics]
Fees
Up front payment is collected from the user’s account to schedule future task(s), including fees for a defined number of future occurrences. Fees for indefinitely recurring transactions may be paid at each occurrence. An RPC endpoint to retrieve the following Turing Network Fees will be delivered in October:
- The Turing inclusion fee to store the future extrinsic(s).
- The Turing execution fee when the future extrinsic(s) are triggered.
- The XCM fee to communicate future extrinsic(s) to a foreign chain (if applicable).
Let’s discuss paying fees in another token and adding you to the whitelist to create a new data stream.
Define a new data stream (addAsset)
Creating a new data stream requires an initial value and the maximum amount of time that a tasks can remain open against this data stream. Examples include token values (fungible and non-fungible), network gas prices, or even account balance.
asset - a unique name for the data stream.
targetPrice - an integer representing the current value of the asset.
- The denominating currency and decimals are irrelevant as long as the same method is used for subsequent updates (i.e. multiply the value by factors of 10 until the asset’s significant value can be represented by an integer).
expirationPeriod - an integer representing the maximum amount of time (seconds) for a task to remain open.
- Minimum expiration period = 86,400 seconds (one day)
- Maximum expiration period = 2,592,000 seconds (30 days)
- Must be an even number of minutes (multiple of 60)
This example defines an asset with the name TUR:MGX with an initial value of 3:
Update an existing data stream (AssetPriceUpdate)
Only the account that created the data stream can update the stream with the (now-) current value:
asset - the unique name of the data stream to update (addAsset above).
value - an integer representing the (now-) current value of the asset.
- The denominating currency and decimals are irrelevant as long as the same method is used as previous updates (i.e. continue to multiply the value by the same factor of 10).
This example updates the asset named TUR:MGX with a new value of 2:
Schedule a task (scheduleTask)
Scheduling a future task enables your application and users to define trigger conditions that include a percentage change in a data stream’s value in either direction (up or down).
Any account on a connected parachain can authorize OAK to transact in the future. Proxy permissions can be included in the batch transaction to schedule the first task if it has not already been completed. (see Parachain Requirements above)
providedID - a unique identifier for this account’s task. A single account may schedule multiple tasks for a single data stream and single direction.
asset - the data stream’s name that can trigger the task’s execution.
direction - the direction (up or down) that will trigger the tasks’s execution.
triggerPercentage - the percent change in the defined direction which will transaction to be communicated via XCM.
- Let’s discuss what level of granularity is needed to optimize for application’s UX.
- Tasks cannot be scheduled to trigger immediately.
paraID - the parachain identifier for the transaction’s execution instructions (see Parachain Requirements above)
encodedExtrinsic - a proxied version of the batch call containing the extrinsic(s) to execute the transaction on the specified (in the future).
Schedule a Token Transfer
This API allows you to schedule transfering the provided token to another user.
Proxy permissions can be included in the batch transaction to schedule the first task if it has not already been completed. (see Parachain Requirements above)
providedID - a unique identifier for this account’s task. A single account may schedule multiple tasks for a single data stream and single direction.
asset - the data stream’s name that can trigger the task’s execution.
direction - the direction (up or down) that will trigger the tasks’s execution.
triggerPercentage - the percent change in the defined direction when the transaction will be triggered on Turing Network.
recipient - where TUR will be sent.
amount- the amount of TUR that will sent from your account to the recipient account when the above conditions have been met (in the future).
This example agrees to send 10 TUR to MATT-TEST when the value of TUR:MGX goes up by 10 percent:
Call
fn schedule_transfer_task(
/// The `account_id` of the caller. Automatically passed in when the transaction is signed.
origin: OriginFor<T>,
/// An id provided by the user. This id must be unique for the user.
provided_id: Vec<u8>,
/// The token you want to watch.
target_token: Token,
/// The comparison you want done. ex) greather than or equal to
comparison: Comparison,
/// The amount you want to compare to.
target_amount: u128,
/// The account you want to transfer tokens to.
receiver_account_id: AccountId,
/// The amount you want to transfer.
amount: u128,
/// The token you want to be transferred.
token: Token,
)
Cancel a Task
Only the account that created the task can cancel the task:
taskID - a unique identifier for this account’s task. A single account may schedule multiple tasks for a single data stream and single direction.
API Call
fn cancel_task(
/// The `account_id` of the caller. Automatically passed in when the transaction is signed.
origin: OriginFor<T>,
/// The id of the task.
task_id: Hash,
)
Errors
pub enum Error {
/// You are not the owner of the task.
NotTaskOwner,
/// The task does not exist.
TaskDoesNotExist,
}