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Module iota::protocol_config

This module provides access to protocol configuration feature flags. Feature flags control the availability of various protocol features and are enabled/disabled at specific protocol versions during epoch changes.

Module Functions​

pub(pkg) get_attr​

Returns the value of a protocol config parameter.

Aborts if the parameter is not defined in the current protocol version, if T does not match the parameter's actual type, or if param_name is not valid UTF-8 — all three are programming errors.

Restricted to internal use within the iota-framework package.

Arguments​

  • param_name - The name of the config parameter as bytes (e.g., b"max_arguments")

Type parameter​

  • T - Must be one of u16, u32, u64, or bool — the concrete type of the parameter.

Example (framework use only)​

let max_args: u32 = protocol_config::get_attr<u32>(b"max_arguments");
public(package) fun get_attr<T: copy, drop, store>(param_name: vector<u8>): T
Implementation
public(package) native fun get_attr<T: copy + drop + store>(param_name: vector<u8>): T;

pub(pkg) is_feature_enabled​

Checks if a specific protocol feature flag is enabled.

Restricted to internal use within the iota-framework package only. If we need to use it in iota-system, we can add friend declarations. We should never need to expose this to user packages.

Arguments​

  • feature_flag_name - The name of the feature flag as bytes (e.g., b"enable_vdf")
  • It is expected to be a valid UTF-8 string
  • The flag should exist in the protocol config

Returns​

  • true if the feature is enabled in the current protocol version
  • false if the feature is disabled

Example (for framework use only)​

use iota::protocol_config;

if (protocol_config::is_feature_enabled(b"enable_accumulators")) {
// Accumulators are available
};
public(package) fun is_feature_enabled(feature_flag_name: vector<u8>): bool
Implementation
public(package) native fun is_feature_enabled(feature_flag_name: vector<u8>): bool;