Create a Sandbox
Learn how to create a sandbox on BuildBear for seamless DApp development and testing. Customize your environment, fork from supported blockchains, and access essential tools for debugging and verification.
Create Your BuildBear Sandbox
Click Create a Sandbox to start configuring your test blockchain.
Supported Chains
| Network | Mainnet | Testnet |
|---|---|---|
| Ethereum | ✅ | ✅ (Sepolia, Holesky) |
| Polygon | ✅ | ✅ (Amoy) |
| Arbitrum | ✅ | ✅ (Sepolia) |
| Optimism | ✅ | - |
| Avalanche | ✅ | - |
| Binance Smart Chain | ✅ | ✅ (BSC Testnet) |
| Polygon zkEVM | ✅ | - |
| Linea | ✅ | ✅ (Sepolia) |
| Gnosis | ✅ | - |
| Kava EVM Co-Chain | ✅ | - |
| Berachain Bartio | ✅ | - |
| Base | ✅ | ✅ (Sepolia) |
| Monad | - | ✅ |
Forking Options
This feature allows you to create a sandbox, forked from the state of any supported blockchain. from any block number with random chain id
You can also create a test blockchain without forking from an existing chain.
Advanced Options
When creating a Sandbox, you can configure additional options to customize your environment:
- Deploy Large Contracts: Enable contracts larger than the default 24KB limit.
- Unlocked Accounts: Access unlocked accounts for easier script execution.
- Mnemonic: Generate a unique mnemonic phrase for your testnet.
- Override Gas Estimation: Detect and override gas estimation failures.
- Impersonation Transactions: Allow transactions using any address for testing.
- Snapshots: Take snapshots of the blockchain state for easy rollbacks.
- Block Mining & Timestamp Manipulation: Manually mine blocks and adjust timestamps.
Configure these options based on your development needs to optimize testing and debugging.
Need A Custon Network ?
If you need a testnet forked from a public chain not listed above, reach out to us at [email protected].
Your RPC Is Ready for Use
After clicking Create, select Go to Dashboard to access your newly created sandbox.
On the Dashboard, you’ll find essential details and tools to efficiently manage your test environment.
Key Components
- Forked Network – Displays the blockchain your sandbox is forked from.
- Chain ID – Chain ID for your testnet.
- Contracts & Transactions – Track deployed contracts and executed transactions.
- Block Number – Displays the latest block height of your sandbox.
- RPC & Mnemonic
- Copy your RPC URL to connect dApps and wallets.
- View or copy your Mnemonic for account management.
- Metamask Integration – Easily add your sandbox network to MetaMask with one click.
Available Tools
- BuildBear Explorer – Analyze transactions within your sandbox.
- Faucet – Instantly mint Native and ERC20 tokens for testing.
- One-Click Deploy – Quickly deploy widely used smart contracts effortlessly.
- Time Advancement – Manipulate blockchain time for testing time-dependent contracts.
Additional Features
- Unlocked Accounts – Enable under Advanced Options when creating your sandbox for script-based interactions.
- Integration Snippets – Access pre-built code snippets for quick integration.
- Verify Contracts – Verify deployed contracts directly in BuildBear.
- Support & Quick Guides – Access documentation and reach out for help if needed.
Use the dashboard to monitor transactions, deploy contracts, and interact with plugins for an optimized development experience.