**Purpose:** Single priority plan: (1) get liquidity on Ethereum Mainnet so 138→mainnet flows complete, then (2) wire fiat off-ramps and on-ramps so users can move value in and out.
**Status:** Operator-focused. Repo has scripts and contracts; execution depends on deployer mainnet balance and ramp API keys/partnerships.
---
## Priority 1 — Obtain liquid on Mainnet
Without mainnet liquidity, users cannot receive value when bridging from Chain 138 to Mainnet. Two destinations need funding.
### 1.1 Trustless LiquidityPoolETH (Mainnet)
**What it does:** Pays out ETH/WETH to users who lock on 138 and claim on Mainnet (trustless bridge).
**Prerequisite:** Deployer must have **ETH (and optionally WETH)** on Ethereum Mainnet.
| Step | Action |
|------|--------|
| 1 | Fund deployer on mainnet (exchange withdrawal, bridge from L2, or another wallet). See [FUNDING_AND_DEPLOYMENT_CHECKLIST](../03-deployment/FUNDING_AND_DEPLOYMENT_CHECKLIST.md) § Ethereum Mainnet. |
| 2 | Set in `.env`: `LIQUIDITY_POOL_ETH_MAINNET` (or `LIQUIDITY_POOL`), `ETHEREUM_MAINNET_RPC`, `PRIVATE_KEY`. |
**Current operator target:** see [FINAL_UNBLOCK_CHECKLIST_MAINNET_BSC](../03-deployment/FINAL_UNBLOCK_CHECKLIST_MAINNET_BSC.md) for exact current-to-target top-up deltas.
| **Providers** | MoonPay, Ramp Network, Onramper, Transak, Banxa, Coinbase, Stripe, Cybrid, Sardine, HoneyCoin | Require API keys; most support mainnet, not Chain 138. |
| **Chain support** | MetaMask ramp partners | Typically Ethereum, BNB, Polygon, etc. **Chain 138 not natively supported** by most ramp partners. |
**Refs:** [INTEGRATIONS_QUICK_REFERENCE](../../INTEGRATIONS_QUICK_REFERENCE.md), [MASTER_INDEX](../MASTER_INDEX.md) § Fiat On/Off Ramps, [METAMASK_BRIDGE_SWAP](../../smom-dbis-138/docs/operations/integrations/METAMASK_BRIDGE_SWAP.md).
### 2.2 On-ramp wiring (fiat → crypto)
| Step | Action |
|------|--------|
| 1 | **Mainnet path (works today):** User buys ETH/tokens on a supported chain (e.g. mainnet) via ramp → then bridges to Chain 138. Document this path in companion/dApp and [METAMASK_BRIDGE_SWAP](../../smom-dbis-138/docs/operations/integrations/METAMASK_BRIDGE_SWAP.md). |
| 2 | **Ramp API:** Ensure `metamask-integration` ramp server runs (`pnpm ramps:dev` or as part of app). Set API keys in .env: `MOONPAY_API_KEY`, `RAMP_NETWORK_API_KEY`, `ONRAMPER_API_KEY`, etc. See [MASTER_SECRETS_INVENTORY](../04-configuration/MASTER_SECRETS_INVENTORY.md), [API_KEYS_REQUIRED](../../reports/API_KEYS_REQUIRED.md). |
| 3 | **Companion/dApp:** Call `POST /ramps/on-ramp/session` with `chainId: 1` (or supported chain); show widget; instruct user to bridge to 138 if target is 138. |
| 4 | **Chain 138 native (future):** Partner with one or more ramp providers to add Chain 138. See [CONSENSYS_OUTREACH_PACKAGE](../../metamask-integration/docs/CONSENSYS_OUTREACH_PACKAGE.md), [ON_RAMP_INTEGRATION_GUIDE](../../metamask-integration/docs/ON_RAMP_INTEGRATION_GUIDE.md). |
### 2.3 Off-ramp wiring (crypto → fiat)
| Step | Action |
|------|--------|
| 1 | **Mainnet path (works once liquid):** User bridges 138→mainnet (trustless or CCIP), then sells on mainnet via off-ramp. Ensure mainnet liquidity (Priority 1) so bridge payouts succeed. |
| 2 | **Ramp API:**`POST /ramps/off-ramp/session` with `chainId: 1` (mainnet) and user’s mainnet address (or wallet that received bridged funds). |
| 3 | **Companion/dApp:** After bridge, show “Sell” / off-ramp option targeting mainnet; link to ramp provider or use embedded widget. |
| 4 | **Chain 138 native (future):** Same as on-ramp — partner with providers to support 138 for direct off-ramp from 138. |
### 2.4 Checklist — ramps
- [ ] Deployer/mainnet funded → Priority 1 done.
- [ ] Ramp API keys set in `metamask-integration/.env` (MoonPay, Ramp, etc.).
- [ ] Ramp server reachable from companion/dApp (`/ramps/on-ramp/session`, `/ramps/off-ramp/session`).
- [ ] Companion/dApp: on-ramp flow (buy on mainnet → bridge to 138) documented and linked → **[MAINNET_RAMP_USER_FLOWS.md](../04-configuration/MAINNET_RAMP_USER_FLOWS.md)**.
- [ ] Companion/dApp: off-ramp flow (138 → mainnet bridge → sell on mainnet) documented and linked → **[MAINNET_RAMP_USER_FLOWS.md](../04-configuration/MAINNET_RAMP_USER_FLOWS.md)**.
- [ ] (Optional) Outreach to ramp partners for Chain 138 support.
---
## Order of operations
1.**Obtain liquid on mainnet** — fund LiquidityPoolETH and (if used) Relay Bridge so 138→mainnet completes.
2.**Wire ramps to mainnet** — enable buy on mainnet (on-ramp) and sell on mainnet after bridge (off-ramp).
3.**Document user flows** — “Buy ETH on mainnet → bridge to 138” and “Bridge 138→mainnet → sell”.
4.**Later:** Ramp partner outreach for native Chain 138 on/off-ramp.
---
## Related
- [MAINNET_RAMP_USER_FLOWS](../04-configuration/MAINNET_RAMP_USER_FLOWS.md) — on-ramp and off-ramp user flows (buy on mainnet → bridge to 138; 138→mainnet → sell).
- [ALL_NEXT_STEPS_CURRENT](../../smom-dbis-138/docs/deployment/ALL_NEXT_STEPS_CURRENT.md) — runbook order (G4 fund mainnet LP is step 2).
- [FUNDING_AND_DEPLOYMENT_CHECKLIST](../03-deployment/FUNDING_AND_DEPLOYMENT_CHECKLIST.md) — where to get ETH/WETH per network.
- [LIQUIDITY_POOL_CONTROLS_RUNBOOK](../03-deployment/LIQUIDITY_POOL_CONTROLS_RUNBOOK.md) — LP controls and funding.
- [CHAIN138_ONLY_TO_CANONICAL_OTHER_NETWORKS](../../smom-dbis-138/docs/bridge/CHAIN138_ONLY_TO_CANONICAL_OTHER_NETWORKS.md) — who prefunds (operator).
