Alice (via dApp) called wraptokens inside the fio.oracle contract on FIO chain

fio.oracle contract actions:

• Parameter Validation ( ensuring amount, token codes, pubkey and fees are all properly set )

• Search oracle registration table (contains all registered oracles) and tally up the total number of registered oracles

• Collect Oracle fees, sort, and find the median.

• Send fee to all oracles.

• Emplace wrapping details inside the oracleldgrs table.

  

• Send the wrapped amount from Alice to fio.oracle contract.

• Collect BP fees

• Increase Alices RAM by 512.

• Send successful response to Alice

Oracle monitors wraptokens for transfers

Todd G What was the Go code doing to monitor the chain?

• Method 1: Web socket subscription via Hyperion (similar to

• Solidity contract subscription).

• • Note this method requires extra setup on the Hyperion node to do streaming.

• Method 2: Poll fio.oracle actions

• using V1 history node.

TBD: Both methods require a history node so we should reach out to BPs with the requirements . and ask which method they prefer

Oracle validates wraptokens transactionTodd G Need bullet list of validations

• Ensure finality

• . Don’t end up on a fork.

• • It is common to have

• • transactions go into a mempool, and then transaction ends up in an uncle

• • (orphan) block. If the transaction in the uncle block has not been validated elsewhere, then it should be returned to the mempool. But, there are situations where it can disappear from the mempool.

• How do transactions leave the memory pool?

• Why some transactions disappear from the mempool?

• Err on the side of waiting to make sure

• the block has reached finality.

• Only process one transaction at a time to reduce complexity.

If exceptions are found, Oracle takes action to unwind transaction

See Exception handling below

Todd G Need to flesh this out

Oracle executes wrap on Ethereum chain

wrap(ethaddress, FIO (SUF) amount, obtid);
ex. wrap(“0x00000000000”, 10000000, “0x123456789”);

fio.erc20 contract actions:

• ethereum wallet provider (usually truffle/hd-wallet-provider) set to use oracles ethereum private key

• wFIO recipient eth address, wFIO amount to mint (must match what was wrapped on FIO chain exactly), and the obtid of the FIO transaction are provided as parameters to wrap action

• Transaction is executed

  • address provided receives wrapped FIO assets

  • event emitted:
    wrapped(address ethaddress, uint256 amount, uint256 obtid);

Listen for unwrapped events

Oracle validates wrap transaction Todd G What type of validation is done on the Ethereum chain during a wrap?

• Oracles monitor all wrap transactions in process to ensure consensus has been reached.

• If a transaction is stuck in a pre-consensus state for some reason, a rollback should be triggered or a warning event should be thrown.

Once all Oracles have submitted wrap, the wFIO Tokens will be minted and transferred to designated Ethereum public address

Todd GTBD: Does the oracle do any kind of monitoring or validation of the overall transaction (post consensus?)

Alice (dApp) executes unwrap on Ethereum chain

unwrap(fio address, amount);
ex. unwrap(hard@edge, 100000000);

fio.erc20 contract actions:

• Alice provides amount to unwrap and the FIO Address for the oracle to send the FIO to as parameters to unwrap action

• Alice is paying gas fee for the unwrap

• Transaction executed:

  • wFIO amount is burned

  • event emitted:
    unwrapped(string fioaddress, uint256 amount);

Oracle monitors unwrap event for transfers

• Oracle subscribes to fio.erc20 events and reacts to the unwrap event

• No consensus is required for the unwrap transaction. Any oracle can initiate the FIO unwraptokens action.

  • TBD: How do we prevent multiple oracles from simultaneously initiating unwraptokens?

Oracle validates unwrap transaction

Validation includes:

• Has another Oracle already initiated the unwraptokens action on the FIO chain?

  • TBD: Other validations?

If exceptions are found, Oracle takes action to unwind transaction

See Exception handling below

Registered Oracles call upwraptokens inside the fio.oracle contract on FIO chain

fio.oracle contract Actions:

• Parameter Validation ( min/max amount, fio address check )

• Verify the actor is a registered oracle

• Find the fio.address inside the fionames table

• Search for previous votes of the same obt_id

  • If found

    • Search and verify actor has not voted prior

    • copy vector and push account name to list of voted oracles to the vector of votes

    • modify voters table with new vector

  • If not found

    • add actor to new vector

    • emplace new record with voters information

      

• Compare number of votes with number of registered oracles

  • if number of votes equal the number of registered oracles, transfer amount from fio.oracle contract to the fio.address provided.

• Send successful response to the oracle

Oracle validates unwraptokens transaction

• Oracles monitor all unwraptokens transactions in process to ensure consensus has been reached.

• If a transaction is stuck in a pre-consensus state for some reason, a rollback should be triggered or a warning event should be thrown.

Once all Oracles have submitted unwraptokens , the FIO Tokens will be transferred to designated Ethereum public address

TBD: Does the oracle do any kind of monitoring or validation of the overall transaction (post consensus?)