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Customizing with EIF and event configuration

This topic provides a detailed explanation of the EIF configuration in chromia.yml, which defines chain-specific parameters for tracking events and contracts. Before diving into the configurations below, we strongly recommend reviewing the EVM Event Receiver Configuration section to become more familiar with the topic.

Chain configuration​

The chains section specifies blockchain-related parameters, including network IDs, contract addresses, and event tracking.

Binance Smart Chain (BSC) Testnet configuration​

blockchains:
  <event_receiver_name>:
    module: <module_name>
    config:
      eif:
        chains:
          bsc:
            network_id: 97
            contracts:
              - "0x753218363422002DF74F3D0D8d67f6CB38bE32D0" # Testnet BSC TwoWeeksNotice contract (staking)
              - "0x8A2279d4A90B6fe1C4B30fa660cC9f926797bAA2" # Testnet BSC CHR token contract (tCHR)
            skip_to_height: 26282055
            events: !include ./config/events.yaml
  • network_id: Identifies the Binance Smart Chain (BSC) Testnet (ID: 97).
  • contracts:
    • 0x753218363422002DF74F3D0D8d67f6CB38bE32D0: Represents the TwoWeeksNotice staking contract on the BSC Testnet.
    • 0x8A2279d4A90B6fe1C4B30fa660cC9f926797bAA2: Represents the Testnet CHR token (tCHR).
  • skip_to_height: Specifies the block height from which to start tracking events.
  • events: References an external configuration file (events.yaml) that defines event tracking rules.

Events configuration for Chromia EVM governance dapp​

This section provides an overview of the EVM events configured in the events.yaml file. These events are monitored and processed within the Chromia EVM governance dapp.

Events overview​

The events.yaml file defines EVM events that are crucial for tracking governance-related activities. Each event includes attributes such as indexed parameters, types, and event names. The current configuration supports the following events:

Transfer event​

The Transfer event is a standard event in EVM-based blockchains, commonly used to track token transfers. It captures details about token movements from one address to another.

Event definition​

Transfer:
  parameters:
    - name: from
      type: address
      indexed: true
    - name: to
      type: address
      indexed: true
    - name: value
      type: uint256

Parameters​

  • from (address, indexed): The sender's address.
  • to (address, indexed): The recipient's address.
  • value (uint256): The amount transferred.

Processing in governance dapp​

  • This event is monitored to track token transfers relevant to governance transactions.
  • It helps identify governance token movements, ensuring correct allocation and participation tracking.

StakeUpdate event​

The StakeUpdate event is used to track changes in staking balances, which are essential for governance participation and voting power.

Event definition​

StakeUpdate:
  parameters:
    - name: from
      type: address
      indexed: true
    - name: balance
      type: uint64

Parameters​

  • from (address, indexed): The address whose stake is updated.
  • balance (uint64): The new stake balance.

Processing in governance dapp​

  • This event is monitored to update governance staking records.
  • Changes in stake balance influence voting power and governance participation.

Integration with Chromia EVM governance dapp​

  • The dapp listens for these events using an event listener integrated with the EVM-compatible smart contract.
  • When an event is emitted, the dapp processes the data and updates governance-related records accordingly.
  • The Transfer event helps track token ownership, while StakeUpdate ensures accurate staking records for voting mechanisms.

Configuration elements​

This section outlines the configuration elements from the YAML-like structure provided in the repository:

EIF test configuration (&eif_test):

  • chains:
    • bsc: Configuration for the Binance Smart Chain (BSC):
      • network_id: BSC Testnet network ID.
  • contracts: Addresses of two Testnet contracts for staking and CHR tokens.
    • skip_to_height: Block height to start processing from.
    • events: External event configuration from ./config/events.yaml.

Common arguments (&common_args):

  • lib.ft4.core.accounts: Configuration for account rate limits.
  • lib.ft4.core.admin: Admin public key.
  • lib.governance:
    • admin_pubkey, admin_evm_wallet
    • economy_chain_bridge
    • required_total_evm_chr_staked_balance_for_registration, required_total_evm_chr_balance_for_registration
    • lib.governance.citizens: Configurations related to citizen cooldowns, proposal rejections, and vetoes:
      • Settings such as citizen_cooldown_days_on_draft_proposal and citizen_cooldown_days_on_proposal_rejection are defined with specific cooldown periods.
    • lib.governance.proposals: Configuration for proposals:
      • proposal_configs:
        • option_item_limit: 10
        • max_duration: 2592000000000
        • min_duration: 3600000
        • title_min_length: 3
        • title_max_length: 100
        • category_min_length: 3
        • category_max_length: 30
        • option_min_length: 3
        • option_max_length: 30
        • description_max_length: 10000
    • lib.governance.extensions.eif: Sync transfers within the dapp:
      • sync_transfers_inside_dapp: true (This is true by default; there's no need to define it here. However, if set to false, stake and balance handling will be disabled.)
    • lib.governance.votes: Configuration for veto periods:
      • veto_config:
        • veto_period: 43200000 (Set to 72 hours in milliseconds)
    • lib.governance.auth: Optional configuration for authorization public key for governance, if using a centralized auth server.

Compile version:

  • rellVersion: Compilation version (0.14.9).

Activate EIF extension​

To activate the EIF extension, import the eif extension into your dapp's module, similar to how you would import ft4 library modules:

import lib.governance.extensions.eif;

EIF libraries overview​

The libraries used in the governance project form part of the Ethereum Interoperability Framework (EIF) and serve distinct purposes for enabling cross-chain communication between EVM and Postchain nodes.

For detailed information about EIF libraries, refer to the EIF documentation.

Libraries

eif

  • Registry: GitLab Repository
  • Path: postchain-eif-rell/rell/src/eif
  • Version: 0.9.0
  • Resource ID (RID): x"D9FAA2AA88DEE0D1EAAFDFE8E28C1BAD89284CE4B6E75C1DBA9272DD8C3D944E"
  • Insecure: false
  • Description: The core EIF library that manages the main framework for interoperability.

eif_event_receiver

  • Registry: GitLab Repository
  • Path: postchain-eif-rell/rell/src/eif_event_receiver
  • Version: 0.9.0
  • Resource ID (RID): x"BDEB142851437327590715FF0912258D5435D294A59857B545BF69D27A0ADBB0"
  • Insecure: false
  • Description: A sub-library for receiving and processing events emitted by EVM nodes or other components.

eif_event_connector

  • Registry: GitLab Repository
  • Path: postchain-eif-rell/rell/src/eif_event_connector
  • Version: 0.9.0
  • Resource ID (RID): x"4A669C5F98AEE970FECD5B77116E737196C7D3C7C6217DFD7EAC2F9317FC9461"
  • Insecure: false
  • Description: Handles the integration and connection of event data into the EIF workflow, enabling seamless data transfer between systems.

These libraries work together to form the backbone of the EIF framework:

  • The eif library manages the core interoperability features.
  • The eif_event_receiver library ensures efficient event listening and processing.
  • The eif_event_connector library integrates event data into the framework.

Dynamic configuration operations in EIF​

We introduce three dynamic configuration operations that enhance adaptability by allowing real-time updates to event and contract tracking capabilities:

Operations​

add_new_eif_events​

  • Purpose: Enables administrators to dynamically add new events to be tracked by the framework.
  • Input: A list of event configurations (eif_dynamic_config.event_config).
  • Benefit: Provides flexibility for monitoring evolving blockchain activity.

add_new_eif_contracts​

  • Purpose: Allows administrators to register new contracts within EIF.
  • Input: A list of contract configurations (eif_dynamic_config.contract_config).
  • Benefit: Facilitates seamless integration of additional contract systems.

add_new_evm_erc20_and_eif_contract​

  • Purpose: This function simplifies the process of adding new ERC20 tokens and their corresponding contracts to the EIF.
  • Input parameters:
    • Network ID
    • Token Address
    • Token Name
    • Token Symbol
    • Decimals
  • Functionality: It automatically registers the token on the specified EVM chain and links it as a contract in the EIF.

Key advantages​

These operations significantly enhance the modularity of the EIF by:

  • Allowing dynamic onboarding of tokens, contracts, and event tracking.
  • Minimizing the need for manual intervention.
  • Improving scalability in multi-chain environments.
note

Additionally, you can update the configuration in the chromia.yml file and redeploy the dapp to add new events or contracts.