How to use function IDs for advanced smart contract labeling

Function ID labeling is a powerful way to categorize smart contract transactions with precision. Because function names are not retrieved automatically, working with Function IDs can require investigation before you can confidently build label rules.

The Smart Contract Function (SCF) Module and Self-Serve Contract Labeling feature in Cryptio bring these tools together, making it easier to explore Function IDs, understand their purpose, and create advanced labeling rules.

What Are Contract Addresses and Function IDs?

• Contract Address: the specific smart contract involved in the transaction.

• Function ID: the identifier of the smart contract function that was executed (sometimes referred to as a Method ID on Etherscan).

By combining these two elements, you can create rules that automatically categorize transactions based on the exact contract behavior, far beyond standard transaction types.

Locating Function IDs

In Cryptio:

1. Go to the Transactions page.

2. Click on a transaction to open the transaction drawer.

3. Scroll to the Transaction Hash section.

4. Find the Function ID and note it for later.

On blockchain:

1. From the Cryptio transaction drawer, click View on the blockchain.

2. On the blockchain page, expand the More details section.

3. In the Input data section, locate the Method ID (equivalent to the Function ID in Cryptio).

Locating Contract Addresses

In Cryptio:

1. Open the transaction drawer.

2. Scroll down to find the Contract Address.

3. Note this address for labeling rule setup.

On blockchain:

1. From the Cryptio transaction drawer, click View on Etherscan.

2. On the blockchain transaction page, check the To field.

3. Copy the smart contract address (starts with 0x...).

Exploring Function IDs with the SCF Module

The SCF Module is designed to streamline Function ID investigation.

To access the SCF Module:

1. Navigate to Business > Smart Contract Function in the side navigation bar.

Within the SCF Module, you can:

• View a table of Function IDs, sorted by transaction count.

• Click the transaction count to see the underlying transactions.

• Copy Function IDs and contract addresses for reference.

• Use explorer examples to better understand function purpose.

Creating a Label Rule

You can create label rules either from the Labels page or directly in the SCF Module.

From the Labels page:

1. Navigate to Business > Labels.

2. Select + Label.

3. Enter a label name and choose a color.

4. From the dropdown, select Function ID.

5. Input or paste the Function ID.

6. Add one or more Contract Addresses (optional for refinement).

7. Click Create to save.

From the SCF Module:

1. Click the Build Label Rule icon next to a Function ID.

2. The Label Creation drawer will open with the Function ID pre-filled.

3. Complete the setup as described above.

Updating or Deleting a Label Rule

• To update: Open the Label Edition drawer, select the rule, make changes, and click Update label.

• To delete: Open the Label Edition drawer, scroll down, and click Delete.

Why Use Advanced Labeling?

Advanced smart contract labeling helps you:

• Automate transaction categorization.

• Capture precise behaviors of DeFi pools, staking, and other contract-based activity.

• Improve reporting accuracy.

• Save time by reducing repetitive manual labeling.

Summary

The combination of Function ID labeling, the SCF Module, and Self-Serve Contract Labeling provides a streamlined way to investigate, understand, and apply smart contract labels. With these tools, you can confidently categorize complex transactions and automate workflows.