# Frequently Asked Questions

### General Questions

#### What is OPN Chain?

OPN Chain is a high-performance EVM blockchain optimized for Ethereum compatibility. Built on proven Cronos technology, it offers:

* \~1 second block times
* 7 Gwei minimum gas price
* Full EVM compatibility
* Support for latest Ethereum features (Pectra)

#### How is OPN Chain different from Ethereum?

| Feature       | OPN Chain      | Ethereum       |
| ------------- | -------------- | -------------- |
| Block Time    | \~1 second     | \~12 seconds   |
| Gas Price     | Fixed 7 Gwei   | Variable       |
| Consensus     | Tendermint BFT | Proof of Stake |
| Finality      | Instant        | Probabilistic  |
| Compatibility | 100% EVM       | Native         |

#### Is OPN Chain decentralized?

Yes! OPN Chain uses a decentralized network of validators running Tendermint consensus. Anyone can run a full node, and qualified participants can become validators.

#### What is the native token?

The native token is OPN, used for:

* Transaction fees (gas)
* Staking (validators)
* Governance voting
* Network security

### Getting Started

#### How do I connect to OPN Chain?

1. Install MetaMask
2. Add OPN network:
   * Network Name: OPN Testnet
   * RPC URL: <https://testnet-rpc.iopn.tech>
   * Chain ID: 984
   * Symbol: OPN

See our [detailed guide](https://iopn.gitbook.io/iopn/developer-docs/getting-started/connect-wallet).

#### What wallets are supported?

Any Ethereum-compatible wallet works:

* MetaMask (recommended)
* Trust Wallet
* Coinbase Wallet
* Rainbow
* Hardware wallets (Ledger, Trezor)
* WalletConnect compatible wallets

#### How do I bridge assets to OPN Chain?

Official bridge coming soon! For testnet:

1. Get test tokens from faucet
2. No bridging needed for testing
3. Mainnet bridge will support major assets

### Development Questions

#### Can I deploy my Ethereum contracts?

Yes! OPN Chain is 100% EVM compatible. Your existing contracts work without modification:

```javascript
// Just change the RPC URL
const web3 = new Web3('https://testnet-rpc.iopn.tech');
// Everything else stays the same!
```

#### What development tools work with OPN?

All Ethereum tools are supported:

* **Frameworks**: Hardhat, Foundry, Truffle, Remix
* **Libraries**: Web3.js, Ethers.js, Viem
* **Languages**: Solidity, Vyper
* **Testing**: Waffle, Chai, Jest

#### What version of Solidity should I use?

Latest stable version (0.8.19+) recommended. OPN supports:

* All Solidity versions
* Pectra EVM features
* Latest opcodes
* Gas optimizations

#### How do I verify contracts?

Contract verification options:

1. Manual verification on block explorer (coming soon)
2. Hardhat verification plugin (when explorer launches)
3. API verification endpoints

#### Are there any OPN-specific features?

While maintaining full EVM compatibility, OPN offers:

* Faster block times (adjust timing logic)
* Stable gas prices (simplifies estimation)
* Instant finality (no reorg concerns)

### Transaction Questions

#### What is the gas price?

Fixed minimum of 7 Gwei. Benefits:

* Predictable costs
* No gas wars
* Simple estimation
* Fair access

#### Why did my transaction fail?

Common reasons:

1. **Insufficient gas limit**: Increase gas limit
2. **Nonce issues**: Reset MetaMask account
3. **Contract revert**: Check revert reason
4. **Insufficient balance**: Get more test tokens

#### How long do transactions take?

* **Average**: 1-2 seconds
* **Finality**: Instant (no confirmations needed)
* **No pending**: Transactions process immediately

#### Can transactions be reversed?

No. Like all blockchains, transactions are immutable once confirmed. OPN's instant finality means no reorganizations.

#### What's the transaction format?

Standard Ethereum transactions:

* Type 0 (Legacy)
* Type 1 (EIP-2930)
* Type 2 (EIP-1559) All supported!

### Node Operation

#### What are the hardware requirements?

**Minimum:**

* 4 CPU cores
* 16GB RAM
* 500GB SSD
* 100 Mbps connection

**Recommended:**

* 8+ CPU cores
* 32GB RAM
* 2TB NVMe SSD
* 1 Gbps connection

#### How do I run a node?

Quick start:

```bash
# Download binary
wget https://github.com/

# Initialize
./opn-node init

# Start
./opn-node start
```

Full guide: [Running Nodes](https://iopn.gitbook.io/iopn/developer-docs/nodes/node-overview)

#### Can I become a validator?

Yes! Requirements:

* Run reliable infrastructure
* Stake OPN tokens
* Maintain high uptime (99%+)
* Participate in governance

#### What's the difference between node types?

* **Full Node**: Validates transactions, serves RPC
* **Archive Node**: Stores all historical data
* **Validator Node**: Participates in consensus
* **Light Client**: Minimal verification (planned)

#### How do I monitor my node?

Key metrics to watch:

```bash
# Check sync status
curl localhost:26657/status

# Monitor peers
curl localhost:26657/net_info

# View metrics
curl localhost:26657/metrics
```

### Smart Contract Questions

#### Is Pectra supported?

Yes! Full Pectra support including:

* EIP-7702 (EOA account code)
* Transient storage (TLOAD/TSTORE)
* Memory optimization (MCOPY)
* All latest opcodes

#### How do I optimize for OPN?

Key optimizations:

1. Account for 1-second blocks
2. Use stable gas price (7 Gwei)
3. Leverage instant finality
4. No reorg handling needed

#### Are there contract size limits?

Standard Ethereum limits apply:

* Max contract size: 24KB
* Max transaction size: 128KB
* Block gas limit: 30M

#### Can I use OpenZeppelin?

Yes! All standard libraries work:

```solidity
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
// Works perfectly on OPN Chain!
```

#### How do I handle errors?

Standard Ethereum error handling:

```solidity
require(condition, "Error message");
revert CustomError(param1, param2);
assert(invariant);
```

### Security Questions

#### Is OPN Chain secure?

Security measures:

* Byzantine fault tolerant consensus
* Slashing for misbehavior
* Regular security audits
* Bug bounty program
* Proven codebase (Cronos)

#### How do I secure my contracts?

Best practices:

1. Use audited libraries (OpenZeppelin)
2. Follow security patterns
3. Test thoroughly
4. Get audits for production
5. Monitor after deployment

#### What about private keys?

Standard Ethereum security:

* Never share private keys
* Use hardware wallets
* Secure key storage
* Multi-sig for large amounts

### Economic Questions

#### What's the token distribution?

Detailed tokenomics coming with mainnet. Testnet tokens have no value.

#### How are gas fees used?

Gas fees go to:

* Validators (block rewards)
* Network security
* Protocol development
* Community initiatives

#### Will there be staking?

Yes! Staking features:

* Validator staking (secure network)
* Delegation (earn rewards)
* Governance participation
* Slashing protection

#### What about inflation?

Inflation parameters:

* Controlled by governance
* Balanced for security
* Sustainable long-term
* Details at mainnet launch

### Technical Issues

#### "Cannot connect to network"

Solutions:

1. Check RPC URL: `https://testnet-rpc.iopn.tech`
2. Verify Chain ID: 984
3. Clear browser cache
4. Try different browser
5. Check firewall settings

#### "Insufficient funds for gas"

Solutions:

1. Get tokens from faucet
2. Check gas price (minimum 7 Gwei)
3. Ensure enough for gas + value
4. Try smaller test amount

#### "Transaction underpriced"

Set gas price to at least 7 Gwei:

```javascript
{
  gasPrice: '7000000000' // 7 Gwei in wei
}
```

#### "Nonce too high"

Reset account in MetaMask:

1. Settings → Advanced
2. Reset Account
3. Retry transaction

#### "Contract deployment failed"

Check:

1. Contract compiles successfully
2. Constructor parameters correct
3. Sufficient gas limit
4. Account has funds

### Integration Questions

#### How do I integrate OPN in my DApp?

Simple integration:

```javascript
// Just update your network config
const networks = {
  opn: {
    chainId: 984,
    rpcUrl: 'https://testnet-rpc.iopn.tech'
  }
};
```

#### Does Chainlink work on OPN?

Oracle integrations coming soon:

* Chainlink (planned)
* Band Protocol (evaluating)
* Native oracle solution
* API3 (considering)

#### Can I use Graph Protocol?

Indexing solutions:

* Graph Protocol (planned)
* Native indexer (in development)
* Custom indexing supported

#### What about IPFS integration?

Decentralized storage works normally:

* IPFS links in contracts
* Arweave integration
* Filecoin compatibility
* Standard patterns apply

### Mainnet Questions

#### When is mainnet launching?

Mainnet timeline:

* Q3 2025: Final testnet phase
* Late Q4 2025: Mainnet launch
* Follow announcements in Discord!

#### Will testnet tokens transfer?

No. Testnet tokens are for testing only and have no value. Mainnet will have separate distribution.

#### How do I prepare for mainnet?

Preparation checklist:

1. Test your contracts thoroughly
2. Audit critical code
3. Plan migration strategy
4. Join validator program
5. Stay updated in Discord

#### What happens to testnet?

Testnet continues running:

* Permanent testing environment
* New feature testing
* Developer playground
* Free tokens always available

### Community & Support

#### How do I get help?

Support channels:

1. [Discord](https://discord.gg/iopn) - Real-time help
2. Email: <info@iopn.io>

#### Can I contribute?

Yes! Contribution areas:

* Code contributions
* Documentation
* Community support
* Bug reports
* Feature suggestions

#### Are there grants available?

Grant program launching soon:

* Development grants
* Ecosystem grants
* Research funding
* Bug bounties

### Advanced Questions

#### How does Tendermint consensus work?

Tendermint BFT provides:

* Instant finality
* Byzantine fault tolerance
* No forks or reorgs
* High performance

[Learn more](https://iopn.gitbook.io/iopn/developer-docs/core-concepts/network-architecture)

#### What's the state management model?

Ethereum-compatible state:

* Account model
* Patricia Merkle tries
* Storage slots
* State root calculation

#### Can I run MEV bots?

MEV on OPN Chain:

* Different dynamics due to fast blocks
* No mempool sniping
* Fair ordering
* Reduced MEV opportunities

#### Is there a grants DAO?

Governance structure:

* Community DAO (planned)
* Validator governance
* Grant distribution
* Protocol upgrades

***

**Still have questions?**

* Ask in [Discord](https://discord.gg/iopn)&#x20;
* Contact <info@iopn.io>
