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TutorialsIndex Takeovers & Reigns

Index takeovers and reigns

Build a minimal indexer that:

  • tracks Crown ownership over time (reigns)
  • tracks takeovers (price paid, king payout routing, Barons allocation)

What you will use

  • deployments/<network>.json (addresses + start blocks)
  • abis/<network>/MineCore.abi.json (event decoding)
  • src/lib/Events.sol (canonical event signatures)

Data flow (high level)

Steps

1) Load addresses and start block from the manifest

  • Pick a network key used by the repo:
    • base_mainnet
    • base_sepolia
    • local

Example (TypeScript-ish pseudocode):

import fs from "node:fs";
 
type Deployment = {
  chainId: number;
  startBlock: number;
  contracts: Record<string, { address: string }>;
};
 
const manifest: Deployment = JSON.parse(
  fs.readFileSync(`deployments/base_mainnet.json`, "utf8")
);
 
const startBlock = manifest.startBlock;
const mineCore = manifest.contracts["MineCore"].address;

2) Stream logs starting at startBlock

  • Always start at the manifest startBlock (do not guess).
  • Store your cursor (last processed block) so re-indexing is idempotent.

3) Decode the canonical MineCore events

Minimum useful set:

  • Takeover
  • ReignFinalized
  • TakeoversPausedChanged

Implementation rules:

  • Prefer the ABI JSON shipped in abis/.
  • If you implement your own decoder, verify your signature list against src/lib/Events.sol.

4) Write two core tables

takeovers (1 row per takeover tx)

  • blockNumber, txHash, logIndex
  • reignId
  • newKing, prevKing
  • pricePaid (ETH)
  • kingPayout (ETH) and whether it was pushed or credited (if emitted)
  • baronsAllocation (ETH)

reigns (1 row per reign)

  • reignId
  • king
  • startTs, endTs
  • pricePaidToEnter (ETH)
  • minedClaimAmount (if emitted or derivable)

If your tables come from multiple events:

  • use (txHash, logIndex) as the stable event id
  • derive reign boundaries from ReignFinalized

5) Add 2 integrity checks

  • Chain continuity:
    • no gaps in processed blocks
  • Determinism:
    • replaying the same range produces the same rows

What success looks like

  • You can render a reign history page from your DB only.
  • You can compute “who is King now” by taking the latest takeover/reign state.
  • You can compute total ETH routed to Barons by summing baronsAllocation.

Next reads

OverviewCrown Price Widget + Takeover