# Non-Prefunded AVAX Migration Runbook

**Date:** 2026-03-04  
**Scope:** Replace inventory-backed AVAX settlement behavior with a non-prefunded bridge path for future transfers.

## 1. Problem Statement

Current `138 -> AVAX` flow is inventory-backed:
- Source bridge on 138 escrows WETH.
- Destination bridge must already hold AVAX-side WETH to pay recipients.
- If destination inventory is zero, messages remain unprocessed.

This does not satisfy the requirement "move value to AVAX without pre-funding AVAX bridge inventory."

## 2. Target Architecture

Use a **lock/mint or burn/mint path** for the bridged asset, not release-from-inventory.

Recommended implementation in this repo:
1. Use dedicated receiver model from `CW_BRIDGE_APPROACH.md` (Option 2).
2. Bridge a mintable wrapped representation (for example `cW*` family), not canonical AVAX-side WETH.
3. Convert destination minted asset to required target assets through DEX routing.

Notes:
- Canonical WETH itself cannot be minted by your bridge contracts.
- If you require canonical WETH/AVAX output directly, you must use an external canonical bridge/protocol that supports that asset path.

## 3. Execution Order

### Phase A: Stop Further Loss Exposure
1. Freeze large `138 -> AVAX` sends on inventory-backed bridges.
2. Add preflight guard: block sends when destination delivery model is inventory-backed and inventory is below requested amount.
3. Keep BSC relay running only if still needed for legacy pending messages.

### Phase B: Recover Existing Stuck Message(s)
1. Enumerate pending message IDs (`processedTransfers == false`) on AVAX bridge.
2. For each pending message, either:
   - fund destination bridge inventory and relay once, or
   - implement explicit source-side refund path (if contract supports it; current WETH9 bridge does not expose one).
3. Verify each recovered message transitions to `processedTransfers == true`.

### Phase C: Deploy Non-Prefunded Path
1. Deploy/verify destination mintable token(s) and grant bridge roles:
   - `MINTER_ROLE` and `BURNER_ROLE` to dedicated receiver (`TwoWayTokenBridgeL2` or equivalent).
2. Deploy sender/receiver pair:
   - L1 sender/lock bridge on 138.
   - L2 receiver/mint bridge on AVAX.
3. Configure chain selector mapping and router support for AVAX selector `6433500567565415381`.
4. Wire fee token and fee approvals.
5. Register token mapping in routing/config files.

### Phase D: E2E Validation (Required Before Production)
1. Test amounts: `0.01`, `1`, `20` units.
2. Validate:
   - source escrow/burn,
   - destination mint,
   - no destination inventory dependency,
   - reverse path burn/send works if required.
3. Run consistency tests for quote/fee, message replay protection, and mapping correctness.

### Phase E: Cutover
1. Mark legacy AVAX inventory-backed route as deprecated.
2. Update all operator scripts/docs to new route.
3. Keep monitoring and alerting on:
   - message backlog,
   - mint/burn failures,
   - fee-token depletion.

## 4. Acceptance Criteria

Migration is complete only when all are true:
1. A `138 -> AVAX` transfer succeeds when destination bridge token inventory is `0`.
2. No relay payout from destination inventory is required.
3. End-to-end tests pass at small and medium sizes.
4. Runbooks/scripts no longer route AVAX through legacy inventory-backed path by default.

## 5. Immediate Operator Commands (Verification)

Check legacy destination dependency:
```bash
cast call 0x24293CA562aE1100E60a4640FF49bd656cFf93B4 "processedTransfers(bytes32)(bool)" <message_id> --rpc-url https://avalanche-c-chain.publicnode.com
cast call 0xa4B9DD039565AeD9641D45b57061f99d9cA6Df08 "balanceOf(address)(uint256)" 0x24293CA562aE1100E60a4640FF49bd656cFf93B4 --rpc-url https://avalanche-c-chain.publicnode.com
```

Check source escrow:
```bash
cast call 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 "balanceOf(address)(uint256)" 0x9cba0D04Ae5f6f16e3C599025aB97a05c4A593d5 --rpc-url https://rpc-http-pub.d-bis.org
```

## 6. Related Files

- `docs/07-ccip/CW_BRIDGE_APPROACH.md`
- `docs/11-references/CCIP_138_DESTINATION_RECEIVER_BY_CHAIN_AND_TOKEN.md`
- `smom-dbis-138/contracts/bridge/TwoWayTokenBridgeL1.sol`
- `smom-dbis-138/contracts/bridge/TwoWayTokenBridgeL2.sol`
- `smom-dbis-138/contracts/tokens/CompliantWrappedToken.sol`