MagicBlock Dev Skill

# MagicBlock Ephemeral Rollups Skill

## What this Skill is for
Use this Skill when the user asks for:
- MagicBlock Ephemeral Rollups integration
- Delegating/undelegating Solana accounts to ephemeral rollups
- High-performance, low-latency transaction flows
- Crank scheduling (recurring automated transactions)
- VRF (Verifiable Random Function) for provable randomness
- Dual-connection architecture (base layer + ephemeral rollup)
- Gaming and real-time app development on Solana

## Key Concepts

**Ephemeral Rollups** enable high-performance, low-latency transactions by temporarily delegating Solana account ownership to an ephemeral rollup. Ideal for gaming, real-time apps, and fast transaction throughput.

**Delegation** transfers account ownership from your program to the delegation program, allowing the ephemeral rollup to process transactions at ~10-50ms latency vs ~400ms on base layer.

**Architecture**:
```
┌─────────────────┐     delegate      ┌─────────────────────┐
│   Base Layer    │ ───────────────►  │  Ephemeral Rollup   │
│    (Solana)     │                   │    (MagicBlock)     │
│                 │  ◄───────────────  │                     │
└─────────────────┘    undelegate     └─────────────────────┘
     ~400ms                                  ~10-50ms
```

## Default stack decisions (opinionated)

1) **Programs: Anchor with ephemeral-rollups-sdk**
   - Use `ephemeral-rollups-sdk` with Anchor features
   - Apply `#[ephemeral]` macro before `#[program]`
   - Use `#[delegate]` and `#[commit]` macros for delegation contexts

2) **Dual Connections**
   - Base layer connection for initialization and delegation
   - Ephemeral rollup connection for operations on delegated accounts

3) **Transaction Routing**
   - Delegate transactions → Base Layer
   - Operations on delegated accounts → Ephemeral Rollup
   - Undelegate/commit transactions → Ephemeral Rollup

## Operating procedure (how to execute tasks)

### 1. Classify the operation type
- Account initialization (base layer)
- Delegation (base layer)
- Operations on delegated accounts (ephemeral rollup)
- Commit state (ephemeral rollup)
- Undelegation (ephemeral rollup)

### 2. Pick the right connection
- Base layer: `https://api.devnet.solana.com` (or mainnet)
- Ephemeral rollup: `https://devnet.magicblock.app/`

### 3. Implement with MagicBlock-specific correctness
Always be explicit about:
- Which connection to use for each transaction
- Delegation status checks before operations
- PDA seeds matching between delegate call and account definition
- Using `skipPreflight: true` for ER transactions
- Waiting for state propagation after delegate/undelegate

### 4. Add appropriate features
- Cranks for recurring automated transactions
- VRF for verifiable randomness in games/lotteries

### 5. Deliverables expectations
When you implement changes, provide:
- Exact files changed + diffs
- Commands to install/build/test
- Risk notes for anything touching delegation/signing/state commits

## Progressive disclosure (read when needed)
- Core delegation patterns: [delegation.md](delegation.md)
- TypeScript frontend setup: [typescript-setup.md](typescript-setup.md)
- Cranks (scheduled tasks): [cranks.md](cranks.md)
- VRF (randomness): [vrf.md](vrf.md)
- Reference links & versions: [resources.md](resources.md)