Quick Start

Start using Phalcon Fork

Click the Fork menu on the App Suite's main menu to access Phalcon Fork. Login and sign up for a BlockSec Account are required if you do not have one yet.

  • Fork Status: The fork status shows the usage statistics, including Forks created, transactions sent, etc.

  • Fork List: The list of created Forks in the current project.

Click on the card in the Fork list to show the details of each Fork.

Create a Fork

Click the Create Fork button to create a new Fork.

Input necessary information about the new Fork.

  • Fork Name: Required. The name of the created Fork.

  • Network: Required. The network where the Fork is on.

  • Height: Optional. The block height for which the Fork will be created. The default value is the latest safe head block.

  • Position: Optional. The position in the block Height where the forked chain starts.

  • Anti-Replay Protection: Is the anti-replay protection enabled for this Fork?

Height and Position

Height and Position: The Height and Position affect the current block number and the following block number in the Fork.

Suppose the Height is N.

  • Position : 0 means the Fork starts from the position 0 of block N.

    • Current block number: N - 1

    • Next block number: N

  • Position: m (m is a non-zero value) means the Fork starts from position m in block N.

    • Current block number: N

    • Next block number: N + 1

Anti Replay

When simulating a signed raw transaction inside a Fork, users may have concerns that the signed raw transactions can be replayed on the mainnet (instead of a Fork). To mitigate this threat, the Anti-Replay Protection can be enabled.

Specifically, when this option is enabled, the chain ID will be altered to a magic number. Users can input any number within the range of 1-9999, and the final Chain ID will be '999' followed by the input number. For instance, if users input value 1, the final chain ID used in this Fork will be 9991. This prevents signed raw transactions from being replayed on the mainnet.

Fork Details

Click on a tab in the Fork List to access the detailed information about a Fork.


The RPC of this Fork. This can invoke methods and simulate transactions to this Fork via API or MetaMask.

Do not make this RPC public. Anyone with this RPC can directly access your Fork.

Add to MetaMask

This button adds the Fork RPC into MetaMask. Then, users can interact with the Fork using MetaMask to simulate transactions.

Next Block

This shows the next block information, including Block number, time stamp, gas limit, etc.

The header information in the next block can be overridden by clicking the Override button.

Input the value for the next block header. Note that such a modification is only effective for the Next Block once. When a new block is minted, this setting will be cleared.


This shows the EVM-related information and settings.

  • Anti Replay: This shows the status of the anti-replay protection of this Fork. This protection is enabled/disabled when creating a new Fork.

  • Set Gas Limit to 200,000,000: Self-explainable

  • Set Code Size Limit to 48KB: Set the code size limit inside a block to 48 KB.

  • Set Gas Fee to 0: Self-explainable

  • Enforce Signature Verification: Whether the transactions simulated inside this Fork need to be signed. See Permission Settings.


Click the Settings button to access detailed information on a Fork and make configurations.

  • RPC: The RPC of this Fork.

  • RPC ID: The RPC ID of this Fork. It will be used in the API.

  • Fork ID: The ID of this Fork. It will be used in the API.

Do NOT make this information public. Anyone with this information can access your Fork.

EVM Settings

  • Raise the block gas limit to 200,000,000: Self-explainable

  • Raise the code size limit to 48 KB: Self-explainable

  • Change the base fee to zero: Self-explainable

Permission Settings

Require users to sign in before accessing the Fork Scan

Each Fork is coupled with a transaction browser called Fork Scan (similar to Etherscan). By enabling this option (the default option), only the Fork owner can access the Fork Scan of a specified Fork. However, in some cases, the Fork owner may want anyone to view the transactions inside the Fork. In this case, disable this option to make the Fork Scan public to everyone.

Enforce transaction signature verification and prohibit unsigned transactions.

By default, the transactions simulated inside a Fork do not need to be signed. Enable this option to enforce signature verification inside a Fork. The user can then simulate signed transactions inside the Fork (to ensure their results are aligned with expectations) and directly submit the signed transactions to the mainnet.

Only addresses in the allowlist can send transactions.

By default, anyone with the RPC URL can directly simulate transactions inside a Fork. However, in some cases, e.g., the public testing scenario where a Fork owner wants to involve certain users in the testing process (allow them to simulate transactions inside a Fork using MetaMask) by sharing the Fork RPC. But, they cannot control whether the shared RPC will be disclosed to other related users. In this case, an allow list can be configured by the Fork owner to ensure that only the addresses inside the allow list can simulate transactions inside the Fork.


Apps are the utilities inside a Fork.

Send Transaction

The GUI to send a transaction (simulate a transaction) inside a Fork.

Fill in the sender, receiver, call data (if have), value, gas limit, and gas price of a transaction. The ABI will be shown if the receiver is a verified smart contract, facilitating the calldata's construction.


Claim the native tokens (Ether) used in this Fork.


Show the typical configurations when integrating Fork into different development frameworks. See this link for more details.


The link to the Fork Scan, which provides similar functionalities to Etherscan. The Fork Scan shows the transactions, addresses, and contracts inside a Fork.

Add Snapshot

A snapshot records the Fork's blockchain status, including simulated transactions, contracts being deployed, etc. Our system allows users to create multiple snapshots in the Fork and quickly switch between different snapshots. See XXX for more details.


Transactions show the list of transactions sent (simulated) inside the Fork. Users can add a note to a transaction to better describe the transaction.


Contracts show the list of smart contracts deployed inside the Fork. For verified contracts, the contract name will be shown.


Snapshots show the list of snapshots created inside this Fork. See this link for more details.

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