BeaconConfig

Storage Plain v216 → current

The Drand beacon configuration used for verifying randomness pulses.

Queried by: validatorsdevelopers

The Big Picture

This is the 'trust anchor' for on-chain randomness. It contains the Drand network's public key and parameters. When a pulse is submitted, the chain verifies its BLS signature against this configuration. If BeaconConfig is wrong, no valid pulses can be verified.

Why This Matters

All randomness verification depends on this configuration being correct. If you're building on Drand randomness or running infrastructure, you need to ensure your offchain worker fetches from a beacon matching this configuration.

Example Scenario

Query BeaconConfig() returns {public_key: '...', genesis_time: 1692803367, period: 30, ...}. This tells you the chain expects pulses from a Drand beacon with 30-second periods starting at that genesis time. Fetch from a matching beacon (e.g., api.drand.sh).

Common Questions

What if my offchain worker uses a different beacon?: Pulse verification will fail - signatures won't match. Ensure your worker fetches from a beacon matching BeaconConfig exactly.
How often does this change?: Rarely. Only when Drand itself migrates or the chain switches beacon networks. Most chains run years on the same configuration.

Use Cases

Configure offchain workers to fetch from correct Drand beacon
Verify current randomness source parameters
Debug pulse verification failures
Audit randomness infrastructure configuration

From Chain Metadata

the drand beacon configuration

Purpose & Usage

Purpose

Stores public keys, genesis time, period, and other parameters needed to verify Drand signatures.

Common Query Patterns

Query to understand current randomness source
Verify beacon parameters before submitting pulses
Check configuration for offchain worker setup

Notes

Contains BLS public key, genesis time, period, and chain hash
Must match the external Drand beacon exactly
Changed via set_beacon_config (root only)

Part of: Distributed Randomness

Stored Value

BeaconConfiguration

value (BeaconConfiguration)

Relationships

Modified By

set_beacon_config

Related Events

BeaconConfigChanged

Code Examples

import { ApiPromise, WsProvider } from "@polkadot/api";
import { stringCamelCase } from "@polkadot/util";

const provider = new WsProvider("wss://entrypoint-finney.opentensor.ai:443");
const api = await ApiPromise.create({ provider });

// Query BeaconConfig storage (no keys - plain value)
const result = await api.query
  [stringCamelCase("Drand")]
  [stringCamelCase("BeaconConfig")]();
console.log("BeaconConfig:", result.toHuman());

Runtime Info

View Source

Pallet: Drand
Storage Kind: Plain
First Version: v216
Current Version: v393

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