---
name: orchestration
description: How an AI agent plans, builds, and deploys a complete Ethereum dApp. The three-phase build system for Scaffold-ETH 2 projects. Use when building a full application on Ethereum — from contracts to frontend to production deployment on IPFS.
---

# dApp Orchestration

## What You Probably Got Wrong

**SE2 has specific patterns you must follow.** Generic "build a dApp" advice won't work. SE2 auto-generates `deployedContracts.ts` — DON'T edit it. Use Scaffold hooks, NOT raw wagmi. External contracts go in `externalContracts.ts` BEFORE building the frontend.

**There are three phases. Never skip or combine them.** Contracts → Frontend → Production. Each has validation gates.

## The Three-Phase Build System

| Phase | Environment | What Happens |
|-------|-------------|-------------|
| **Phase 1** | Local fork | Contracts + UI on localhost. Iterate fast. |
| **Phase 2** | Live network + local UI | Deploy contracts to mainnet/L2. Test with real state. Polish UI. |
| **Phase 3** | Production | Deploy frontend to IPFS/Vercel. Final QA. |

## Phase 1: Scaffold (Local)

### 1.1 Contracts

```bash
npx create-eth@latest my-dapp
cd my-dapp && yarn install
yarn fork --network base  # Terminal 1: fork of real chain (or mainnet, your target chain)
yarn deploy               # Terminal 2: deploy contracts
```

> **Always fork, never `yarn chain`.** `yarn fork` does everything `yarn chain` does AND gives you real protocol state — Uniswap, USDC, Aave, whale balances, everything already deployed (verified addresses: `addresses/SKILL.md`). `yarn chain` gives you an empty chain that tempts you into writing mock contracts you don't need. Don't mock what already exists onchain — just fork it.

**Critical steps:**
1. Write contracts in `packages/foundry/contracts/` (or `packages/hardhat/contracts/`)
2. Write deploy script
3. Add ALL external contracts to `packages/nextjs/contracts/externalContracts.ts` — BEFORE Phase 1.2
4. Write tests (≥90% coverage)
5. Audit contracts before moving to frontend — fetch [audit/SKILL.md](https://ethskills.com/audit/SKILL.md) and run through it

**Validate:** `yarn deploy` succeeds. `deployedContracts.ts` auto-generated. Tests pass.

### 1.2 Frontend

```bash
yarn fork --network base  # Terminal 1: fork of real chain (has Uniswap, USDC, etc.)
yarn deploy --watch       # Terminal 2: auto-redeploy on changes
yarn start                # Terminal 3: Next.js at localhost:3000
```

**USE SCAFFOLD HOOKS, NOT RAW WAGMI:**

```typescript
// Read
const { data } = useScaffoldReadContract({
  contractName: "YourContract",
  functionName: "balanceOf",
  args: [address],
  watch: true,
});

// Write
const { writeContractAsync, isMining } = useScaffoldWriteContract("YourContract");
await writeContractAsync({
  functionName: "swap",
  args: [tokenIn, tokenOut, amount],
  onBlockConfirmation: (receipt) => console.log("Done!", receipt),
});

// Events
const { data: events } = useScaffoldEventHistory({
  contractName: "YourContract",
  eventName: "SwapExecuted",
  fromBlock: 0n,
  watch: true,
});
```

### The Three-Button Flow (MANDATORY)

Any token interaction shows ONE button at a time:
1. **Switch Network** (if wrong chain)
2. **Approve Token** (if allowance insufficient)
3. **Execute Action** (only after 1 & 2 satisfied)

Never show Approve and Execute simultaneously.

### UX Rules

- **Human-readable amounts:** `formatEther()` / `formatUnits()` for display, `parseEther()` / `parseUnits()` for contracts
- **Loading states everywhere:** `isLoading`, `isMining` on all async operations
- **Disable buttons during pending txs** (blockchains take 5-12s)
- **Never use infinite approvals** — approve exact amount or 3-5x
- **Helpful errors:** Parse "insufficient funds," "user rejected," "execution reverted" into plain language

**Validate:** Full user journey works with real wallet on localhost. All edge cases handled.

## 🚨 NEVER COMMIT SECRETS TO GIT

**Before touching Phase 2, read this.** AI agents are the #1 source of leaked credentials on GitHub. Bots scrape repos in real-time and exploit leaked secrets within seconds.

**This means ALL secrets — not just wallet private keys:**
- **Wallet private keys** — funds drained in seconds
- **API keys** — Alchemy, Infura, Etherscan, WalletConnect project IDs
- **RPC URLs with embedded keys** — e.g. `https://base-mainnet.g.alchemy.com/v2/YOUR_KEY`
- **OAuth tokens, passwords, bearer tokens**

**⚠️ Common SE2 Trap: `scaffold.config.ts`**

`rpcOverrides` and `alchemyApiKey` in `scaffold.config.ts` are committed to Git. **NEVER paste API keys directly into this file.** Use environment variables:

```typescript
// ❌ WRONG — key committed to public repo
rpcOverrides: {
  [chains.base.id]: "https://base-mainnet.g.alchemy.com/v2/8GVG8WjDs-LEAKED",
},

// ✅ RIGHT — key stays in .env.local
rpcOverrides: {
  [chains.base.id]: process.env.NEXT_PUBLIC_BASE_RPC || "https://mainnet.base.org",
},
```

**Before every `git add` or `git commit`:**
```bash
# Check for leaked secrets
git diff --cached --name-only | grep -iE '\.env|key|secret|private'
grep -rn "0x[a-fA-F0-9]\{64\}" packages/ --include="*.ts" --include="*.js" --include="*.sol"
# Check for hardcoded API keys in config files
grep -rn "g.alchemy.com/v2/[A-Za-z0-9]" packages/ --include="*.ts" --include="*.js"
grep -rn "infura.io/v3/[A-Za-z0-9]" packages/ --include="*.ts" --include="*.js"
# If ANYTHING matches, STOP. Move the secret to .env and add .env to .gitignore.
```

**Your `.gitignore` MUST include:**
```
.env
.env.*
*.key
broadcast/
cache/
node_modules/
```

**SE2 handles deployer keys by default** — `yarn generate` creates a `.env` with the deployer key, and `.gitignore` excludes it. **Don't override this pattern.** Don't copy keys into scripts, config files, or deploy logs. This includes RPC keys, API keys, and any credential — not just wallet keys.

See `wallets/SKILL.md` for full key safety guide, what to do if you've already leaked a key, and safe patterns for deployment.

## Phase 2: Live Contracts + Local UI

1. Update `scaffold.config.ts`: `targetNetworks: [mainnet]` (or your L2)
2. Fund deployer: `yarn generate` → `yarn account` → send real ETH
3. Deploy: `yarn deploy --network mainnet`
4. Verify immediately after deploy: `yarn verify --network mainnet`
   - **No block explorer API key needed** — SE2 handles this for you
   - Run it right after deploy, not later. Don't skip it.
5. Test with real wallet, small amounts ($1-10)
6. Polish UI — remove SE2 branding, custom styling

**Design rule:** NO LLM SLOP. No generic purple gradients. Make it unique.

**Validate:** Contracts verified on block explorer. Full journey works with real contracts.

## Phase 3: Production Deploy

### Pre-deploy Checklist
- `burnerWalletMode: "localNetworksOnly"` in scaffold.config.ts (prevents burner wallet on prod)
- Update metadata (title, description, OG image 1200x630px)
- Restore any test values to production values
- Run a full frontend QA audit — fetch [qa/SKILL.md](https://ethskills.com/qa/SKILL.md) and give it to a separate agent before deploying

### Deploy

**IPFS** — use [BGIPFS](https://www.bgipfs.com/SKILL.md) for decentralized deploys (fetch that skill for full details). It's built into SE2 — no setup needed:
```bash
yarn ipfs
# → https://{CID}.ipfs.community.bgipfs.com/
```
Note: IPFS only works with static content — no server-side rendering, API endpoints, or functions.

**Vercel:**
```bash
yarn vercel
```

### Production QA
- [ ] App loads on public URL
- [ ] Wallet connects, network switching works
- [ ] Read + write contract operations work
- [ ] No console errors
- [ ] Burner wallet NOT showing
- [ ] OG image works in link previews
- [ ] Mobile responsive
- [ ] Tested with MetaMask, Rainbow, WalletConnect

## Phase Transition Rules

**Phase 3 bug → go back to Phase 2** (fix with local UI + prod contracts)
**Phase 2 contract bug → go back to Phase 1** (fix locally, write regression test, redeploy)
**Never hack around bugs in production.**

## Key SE2 Directories

```
packages/
├── foundry/contracts/          # Solidity contracts
├── foundry/script/             # Deploy scripts
├── foundry/test/               # Tests
└── nextjs/
    ├── app/                    # Pages
    ├── components/             # React components
    ├── contracts/
    │   ├── deployedContracts.ts   # AUTO-GENERATED (don't edit)
    │   └── externalContracts.ts   # YOUR external contracts (edit this)
    ├── hooks/scaffold-eth/     # USE THESE hooks
    └── scaffold.config.ts      # Main config
```

## Resources

- **SE2 Docs:** https://docs.scaffoldeth.io/
- **SE2 Skill:** https://docs.scaffoldeth.io/SKILL.md
- **UI Components:** https://ui.scaffoldeth.io/
- **SE2 AGENTS.md:** https://github.com/scaffold-eth/scaffold-eth-2/blob/main/AGENTS.md