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Sample t1-dApp Flow

Consider Yild, a cross-chain yield optimization dApp. The flow in Docker terms is:

  1. Yild's developer submits the Docker image with Yild's logic for t1 to pull and run, as a t1-dapp TEE-co-located with t1-core.
  2. The newly started Yild container proceeds to call initIdentity(callbackOnDeposit) on t1-core, where callbackOnDeposit is Yild's handler that will determine how to treat deposits (e.g. credit a user, supply to a new yield source, withdraw to a user).
  3. Furthermore, Yild will call registerCallbackOnTransaction(chainId, address, callback) for each chain where Yild users should be able to withdraw to, with the respective Yild ERC-20 share token contract address and a handler.
  4. Now, upon a new user deposit, t1-core will invoke the previously registered callbackOnDeposit handler and pass metadata such as chain ID, sender address, or deposited amount to the Yild t1-dapp container.
  5. Yild will then run its logic to determine the deposit type ("credit a user"), update its cross-chain global ledger, mint new Yild share tokens to the user, and determine which yield source to direct the new funds to.
  6. For example, Yild might proceed to call sendTx(chainId, payload, callback) with a payload constructed to mean opening a bridge intent from the deposit chain to the chain with the best yield source.
  7. Upon t1-core's subsequent invocation of the Yild-provided callback will the Yild t1-dapp decode the callback parameters to determine whether the transaction was sent correctly, and may decide to retry etc.
  8. Once a solver fills the intent on the target chain to Yild's initialized identity, will t1-core invoke callbackOnDeposit, as always—but this time, Yild will decode the callback parameters to interpret this deposit as a bridge (cross-chain optimization) transaction. It will therefore NOT credit these funds to a user, but instead call sendTx again, with a payload instructing t1-core to supply the newly arrived funds to a yield source on the new chain.
  9. If a user wishes to withdraw, they will burn their Yild share tokens. This will result in t1-core invoking the callback on t1-dapp from the previously registered watcher (via registerCallbackOnTransaction) on said share token address. Therefore, t1-dapp will be able to process the withdrawal request, update its ledger, and use sendTx calls to withdraw the calculated amount of funds from a yield source, bridge them if needed, and finally send them to the requesting user.