cosmos-sdk/x/consensus

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x/consensus

The consensus module provides functionality to modify CometBFT's ABCI consensus parameters on-chain through governance proposals.

Overview

This module allows authorized entities (typically governance) to update critical consensus parameters that affect blockchain performance and security without requiring a hard fork.

Key Features

• Parameter Updates: Modify consensus parameters through governance proposals
• Authority Control: Only authorized addresses can update parameters
• Validation: Comprehensive parameter validation before updates
• ABCI Integration: Direct integration with CometBFT consensus engine

Consensus Parameters

The module manages the following CometBFT consensus parameters:

Block Parameters

• MaxBytes: Maximum block size in bytes
• MaxGas: Maximum gas per block

Evidence Parameters

• MaxAgeNumBlocks: Maximum age of evidence in blocks
• MaxAgeDuration: Maximum age of evidence in time
• MaxBytes: Maximum evidence size in bytes

Validator Parameters

• PubKeyTypes: Supported public key types for validators

ABCI Parameters

• VoteExtensionsEnableHeight: Height at which vote extensions are enabled

Usage

Governance Proposal

To update consensus parameters, submit a governance proposal with MsgUpdateParams:

import (
    "time"
    govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
    authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
)

msg := &types.MsgUpdateParams{
    Authority: authtypes.NewModuleAddress(govtypes.ModuleName).String(), // governance authority
    Block: &types.BlockParams{
        MaxBytes: 22020096,
        MaxGas:   10000000,
    },
    Evidence: &types.EvidenceParams{
        MaxAgeNumBlocks: 100000,
        MaxAgeDuration:  48 * time.Hour,
        MaxBytes:        1048576,
    },
    Validator: &types.ValidatorParams{
        PubKeyTypes: []string{"ed25519"},
    },
}

Query Parameters

Retrieve current consensus parameters:

<appd> q consensus params

Architecture

• Keeper: Manages parameter storage and validation
• Types: Defines message types and parameter structures
• Module: Integrates with the Cosmos SDK application lifecycle

Security

• Only the designated authority can update parameters
• All parameter changes are validated before application
• Updates are subject to governance approval process