# Token Bridging Model - Lock-Mint

SupraNova’s initial asset bridging uses the Lock-Mint model, a secure method that preserves the total supply of assets across chains while ensuring collateralization.

## What is the Lock-Mint Bridging Model?

**In a Lock-Mint model:**

* The asset on the source chain (Ethereum) is locked securely in a vault contract.
* A wrapped equivalent token is minted on the destination chain (Supra).

There is no destruction, burning, or movement of tokens between chains.

**Instead**:

* Original tokens remain locked.
* Wrapped tokens represent a claim on the locked original.
* The minting only occurs after proof verification by HyperNovaCore on Supra.

### How Lock-Mint Works in SupraNova

{% stepper %}
{% step %}
User initiates a bridge request locking ETH into HyperNovaCore (Ethereum)

{% endstep %}

{% step %}
Relayer submits proofs verifying the lock event

{% endstep %}

{% step %}
Supra’s HyperNovaCore verifier validates the proofs

{% endstep %}

{% step %}
The Token Bridge Service Contract mints equivalent wrapped asset, supETH on Supra to the recipient address

{% endstep %}
{% endstepper %}

**Example Flow**

* You bridge 5 ETH from Ethereum.
* SupraNova locks exactly 5 ETH in the Ethereum bridge vault.
* After proof validation, Supra mints the equivalent amount of supETH to your wallet, minus any applicable service fee.

{% hint style="warning" %}
**In the current testnet release, fee deductions may be waived or minimal.**
{% endhint %}

#### **Collateral Status:**

* ETH remains locked securely in Ethereum contracts.
* supETH is fully backed 1:1 by real ETH.

#### Security Guarantees

* **No Double Spending:** Because ETH remains immobile once locked.
* **Full Collateralization:** supETH minted on Supra cannot exceed ETH locked on Ethereum.
* **Proof-Driven Minting:** No minting happens without complete proof validation across transaction, receipt, and consensus.

### Why is Lock-Mint chosen?

SupraNova chose Lock-Mint because:

* It is simple and verifiable.
* It aligns perfectly with Supra’s trustless, proof-based validation model.
* It avoids complexities like token burns, which are harder to verify without replay attacks or external watchdogs.

### Supported Asset in Initial Release

| Source Token                | Destination Token           | Model     |
| --------------------------- | --------------------------- | --------- |
| ETH (Ethereum native asset) | supETH (Supra FA standard)  | Lock-Mint |
| USDC                        | supUSDC (Supra FA standard) | Lock-Mint |

{% hint style="danger" %}
**You cannot unlock ETH  or USDC back to Ethereum yet in this release.**

**Supra → Ethereum (burn-unlock model) will be added in a future HyperNova reverse bridge upgrade.**
{% endhint %}

### Future Transfer Models

SupraNova currently uses a Lock-Mint bridging model where original assets are locked on the source chain and mirrored on Supra through minting.

In future versions, the bridge will also support:

* **Burn-Release**: Users will burn wrapped tokens on Supra, which will trigger the release of locked assets back to the source chain.
* **Burn-Mint**: Burning wrapped assets on Supra to mint another representation on a different destination chain.

**These additional modes will allow Supra to offer both one-way and bi-directional bridging based on user needs and liquidity dynamics.**<br>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://supraoracles.gitbook.io/supra/supranova/token-bridging-model-lock-mint.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.