> For the complete documentation index, see [llms.txt](https://docs.babypiexyz.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.babypiexyz.io/babypies-architecture.md).

# Babypie's Architecture

<figure><img src="/files/qmanDP1cdvubn2fY26FL" alt=""><figcaption></figcaption></figure>

**1. Register Wallet:** User sends the following values to the Babypie Manager:

* User’s BTC address
* User’s EVM address
* Signature generated using the Bitcoin wallet by passing the EVM address as the message.

<figure><img src="/files/XDMypetoIQpsDypOsgVb" alt=""><figcaption></figcaption></figure>

**2. Babypie Manager Action:** The Babypie Manager calls the Chainlink Functions Consumer contract, passing the three values it received from the user.

* Babypie Manager: One of Babypie’s smart contracts.
* Functions Consumer: A smart contract that can send Functions requests to the Chainlink Oracle Network, where the oracle network returns the results of decentralized computation.

**3. Chainlink Functions Consumer Contract Action:** The Chainlink Functions Consumer contract sends a request to the Chainlink DON to run the script to verify the user's signature, using the EVM address as the message string.

* [DON - Decentralized Oracle Network](https://docs.chain.link/chainlink-functions/resources/architecture)

**4. Verification Result:** The DON returns the result of the verification to the Chainlink Functions Consumer contract by calling it with the result (this process takes around 30 seconds).<br>

**5. Update User Mapping:** The Chainlink Functions Consumer contract calls the Babypie Manager contract to update the user's BTC to EVM mapping if the signature is valid.

### Now, the user can transfer native BTC to Babypie’s MPC wallet (This step can even be done by user before mapping their BTC->EVM address)<br>

**6. BTC Transfer:** The user calls the Babypie Manager with the transaction hash of the BTC transfer to Babypie’s MPC wallet and the BTC address used for the transfer.

<figure><img src="/files/SbAFa1KpC0P1zX7dsxLj" alt=""><figcaption></figcaption></figure>

**7. Requests to initiate mBTC mint for BTC transfer:** User calls babypie manager to initiate verification of user's BTC transfer in txn and mint mBTC to user's mapped EVM address.

**8. Babypie Manager Action:** The Babypie Manager calls another Chainlink Functions Consumer contract with the transaction hash and the user’s BTC chain address.

**9. BTC Amount Retrieval:** The Chainlink Functions Consumer contract sends a request to the Chainlink DON to run a script that will get the amount of BTC transferred to the Babypie MPC wallet in the transaction.

**10. Amount Confirmation:** The Chainlink Functions Consumer contract receives the result (amount of BTC transferred) of the script from the Chainlink DON.

**11. Validation and Processing:** The Chainlink Functions Consumer contract checks if the amount is greater than 0. If yes, it calls the Babypie Manager with the result.

**12. Mark txn paid:** The Babypie Manager will mark the txn as paid and call the mint function of the mBTC contract with value equal to BTC transferred by user.

**13. mBTC mint:** mBTC token will be minted to the user.

<figure><img src="/files/3V60KQe21YMwRe6y0JNl" alt=""><figcaption></figcaption></figure>