mvx-deploy-flow

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• SKILL.md

SKILL.md (first lines)

# MultiversX Smart Contract Deployment Flow

Guide through a safe, verified deployment workflow: build, verify artifacts, deploy, validate state, and verify source on the explorer.

## Pre-Flight Checks

### Step 1: Reproducible Build

Build the contract using the Docker-based reproducible build to ensure deterministic WASM output:

```bash
sc-meta all build --locked
```

Or with Docker for reproducible builds:
```bash
mxpy contract build --image=multiversx/sdk-rust-contract-builder:v11.0.0
```

**Verification**: The `code-hash` must match between local and Docker builds.

**Artifacts to preserve**: Store `.wasm`, `.abi.json`, and `.source.json` (from `output-docker/`) in a versioned registry or commit them to the repository.

### Step 2: Verify Build Artifacts

- Read the ABI file to understand the contract interface
- Extract from the ABI:
  - Constructor (`init`) parameters and their types
  - All endpoints (count mutable vs readonly)
  - Whether the contract is upgradeable, payable, payableBySmartContract
  - Build info if present (framework version, compiler)
- Verify the WASM file exists and note its size. WASM files larger than 400KB may hit deployment gas limits.

### Step 3: Wallet Balance Check

Ensure sufficient EGLD for deployment gas:
- Typical cost: 0.1-0.5 EGLD for most contracts, up to 1+ EGLD for large contracts
- On testnet/devnet, use the faucet if balance is low

**MCP shortcut**: If a MultiversX MCP server is available (multiversx-sc-mcp or multiversx-mcp-server), use `mvx_account` to check the deployer wallet balance.

### Step 4: Review Constructor Arguments

From the ABI, list every constructor parameter:

| Parameter | Type | Description |
|-----------|------|-------------|
| ... | ... | ... |

Validate types match expectations:
- Addresses should be valid bech32 (`erd1...`)
- Token identifiers should match the pattern `[A-Z]+-[a-f0-9]+`
- Numeric values should be within reasonable ranges
- BigUint values need proper denomination handling (e.g., 1 EGLD = 1000000000000000000)

### Step 5: Gas Estimation

Estimate deployment gas based on WASM size:
- < 100KB: ~60,000,000 gas
- 100-200KB: ~100,000,000 gas
- 200-400KB: ~150,000,000 gas
- > 400KB: ~200,000,000+ gas (warn about potential issues)

### Step 6: Security Checklist (Pre-Deploy)

Before deploying, verify:
- **Payable**: `#[payable("EGLD")]` is NOT set on endpoints unless strictly required
- **Upgradeable**: Is the contract meant to be immutable? If so, remove the upgrade code metadata flag
- **Owner**: Is the deployer a multi-sig or guardian wallet? For mainnet, consider having CI generate the tx payload and letting the multi-sig sign it
- **Code metadata**: Review flags -- upgradeable, payable, readable -- match the intended security posture

## Deployment

### Step 7: Deploy the Contract

**MAINNET SAFETY**: If deploying to mainnet, STOP and confirm before proceeding:
> You are about to deploy a new contract on MAINNET. This will use real funds for gas. Do you want to proceed?

**Using mxpy**:
```bash
mxpy contract deploy \
  --proxy https://gateway.multiversx.com --chain 1 \
  --recall-nonce --pem wallet.pem \
  --gas-limit 100000000 \
  --bytecode output/contract.wasm \
  --arguments [constructor_args] \
  --metadata-upgradeable --metadata-readable
```

**MCP shortcut**: If a MultiversX MCP server is available (multiversx-sc-mcp or multiversx-mcp-server), use `mvx_sc_deploy` with the wasmPath, network, constructor arguments, gas limit, and code metadata flags.

Record the deployment transaction hash.

### Step 8: Verify Deployment Transaction

After the deploy transaction completes, verify:
- Transaction status is "success"
- Smart contract result contains the new contract address
- No unexpected error messages
- Gas consumed vs gas limit (was it close to the limit?)

Extract the **new contract address** from the transaction results.

**MCP shortcut**: If a MultiversX MCP server is available (multiversx-sc-mcp or multiversx-mcp-server), use `mvx_tx_result` with the deployment transaction hash.

### Step 9: Confirm Contract Exists

Verify the deployed contract:
- The contract exists at the address
- The owner matches the deployer wallet
- The code hash is populated
- Properties match expectations (upgradeable, payable, etc.)

**MCP shortcut**: If a MultiversX MCP server is available (multiversx-sc-mcp or multiversx-mcp-server), use `mvx_account` with the new contract address.

## Post-Deployment Validation

### Step 10: ABI Verification

From multiversx/mx-ai-skills, MIT.

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