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SUBMIT A PRSUBMIT AN ISSUElast edit: Jun 17, 2026

Crowdloan Precompile

The Crowdloan precompile lets EVM contracts create and manage crowdloans entirely on-chain. A campaign creator sets a funding cap and deadline, contributors deposit TAO, and when the cap is reached, the crowdloan can be finalized to execute either the stored call or a transfer to a target address.

See Crowdloans for the full concept and Substrate-side workflow.

Functions​

FunctionMutabilityDescription
create(uint64 deposit, uint64 minContribution, uint64 cap, uint32 end, address targetAddress)payableCreate a new campaign. end is the block number at which contributions close.
contribute(uint32 crowdloanId, uint64 amount)payableContribute to an active campaign.
withdraw(uint32 crowdloanId)payableWithdraw your contribution before finalization.
finalize(uint32 crowdloanId)payableFinalize a successful campaign and transfer funds to targetAddress.
refund(uint32 crowdloanId)payableRefund contributors of a failed campaign. Call repeatedly for large contributor sets.
dissolve(uint32 crowdloanId)payableClean up storage after full refund.
updateMinContribution(uint32 crowdloanId, uint64 newMinContribution)payableUpdate minimum contribution (creator only).
updateEnd(uint32 crowdloanId, uint32 newEnd)payableUpdate end block (creator only).
updateCap(uint32 crowdloanId, uint64 newCap)payableUpdate funding cap (creator only).
getCrowdloan(uint32 crowdloanId)viewReturns CrowdloanInfo struct.
getContribution(uint32 crowdloanId, bytes32 coldkey)viewReturns contributor's total deposit in RAO.

Usage examples​

ABI​

The canonical ABI is exported from contract-tests/src/contracts/crowdloan.ts. You can import the ABI and contract address if you have a local copy of the source files as shown:

import { ICrowdloanABI, ICROWDLOAN_ADDRESS } from "./contracts/crowdloan";

Creating a campaign​

Use create to launch a crowdloan campaign on-chain. The function takes the initial deposit amount, minimum contribution per contributor, funding cap, end block, and a target EVM address to receive the raised funds upon finalization.

The target address is a H160 address type, not bytes32. You must pass it as a plain EVM address:

import { ethers } from "ethers";
import { ICrowdloanABI, ICROWDLOAN_ADDRESS } from "./contracts/crowdloan";

// PROTECT YOUR PRIVATE KEYS WELL, NEVER COMMIT THEM TO GITHUB OR SHARE WITH ANYONE
const { ethPrivateKey, rpcUrl } = require("./config.js");

const provider = new ethers.JsonRpcProvider(rpcUrl);
const signer = new ethers.Wallet(ethPrivateKey, provider);
const contract = new ethers.Contract(ICROWDLOAN_ADDRESS, ICrowdloanABI, signer);

const DEPOSIT = 10_000_000_000n; // 10 TAO in RAO
const MIN_CONTRIBUTION = 1_000_000_000n; // 1 TAO in RAO
const CAP = 50_000_000_000n; // 50 TAO in RAO
const END_BLOCK = 8540500;

const tx = await contract.create(
  DEPOSIT,
  MIN_CONTRIBUTION,
  CAP,
  END_BLOCK,
  "0xYourTargetAddress",
  { gasLimit: 100_000n },
);
await tx.wait();

console.log(`Crowdloan created`);

Checking campaign progress​

Use getCrowdloan to crowdloan by ID.

import { ethers } from "ethers";
import { ICrowdloanABI, ICROWDLOAN_ADDRESS } from "./contracts/crowdloan";
const { rpcUrl } = require("./config.js");

const provider = new ethers.JsonRpcProvider(rpcUrl);
const contract = new ethers.Contract(
  ICROWDLOAN_ADDRESS,
  ICrowdloanABI,
  provider,
);

const info = await contract.getCrowdloan(0);
console.log(`Raised: ${info.raised} RAO of ${info.cap} RAO cap`);
console.log(`Finalized: ${info.finalized}`);
console.log(`Cap: ${info.cap}`);
console.log(`End: ${info.end}`);

Contribute to a crowdloan campaign​

Use contribute to add TAO to an active crowdloan campaign. The function takes the crowdloanId and the amount in RAO. The amount must be at least the campaign's min_contribution.

import { ethers } from "ethers";
import { ICrowdloanABI, ICROWDLOAN_ADDRESS } from "./contracts/crowdloan";

// PROTECT YOUR PRIVATE KEYS WELL, NEVER COMMIT THEM TO GITHUB OR SHARE WITH ANYONE
const { ethPrivateKey, rpcUrl } = require("./config.js");

const provider = new ethers.JsonRpcProvider(rpcUrl);
const signer = new ethers.Wallet(ethPrivateKey, provider);
const contract = new ethers.Contract(ICROWDLOAN_ADDRESS, ICrowdloanABI, signer);

const CROWDLOAN_ID = 0;
const AMOUNT = 1_000_000_000n; // 1 TAO in RAO

const tx = await contract.contribute(CROWDLOAN_ID, AMOUNT, {
  gasLimit: 2_000_000n,
});

console.log(`Contributed ${AMOUNT} RAO to crowdloan ${CROWDLOAN_ID}`);

Finalize a crowdloan campaign​

Use finalize to close a successfully funded campaign and transfer the raised TAO to the target address set at creation. The campaign must have reached its cap before the finalize function can be called.

import { ethers } from "ethers";
import { ICrowdloanABI, ICROWDLOAN_ADDRESS } from "./contracts/crowdloan";

// PROTECT YOUR PRIVATE KEYS WELL, NEVER COMMIT THEM TO GITHUB OR SHARE WITH ANYONE
const { ethPrivateKey, rpcUrl } = require("./config.js");

const provider = new ethers.JsonRpcProvider(rpcUrl);
const signer = new ethers.Wallet(ethPrivateKey, provider);
const contract = new ethers.Contract(ICROWDLOAN_ADDRESS, ICrowdloanABI, signer);

const CROWDLOAN_ID = 0;

const tx = await contract.finalize(CROWDLOAN_ID, { gasLimit: 2_000_000n });
const receipt = await tx.wait();
console.log(`Crowdloan ${CROWDLOAN_ID} finalized`);

Dissolve a crowdloan campaign​

Use dissolve to permanently remove a crowdloan from storage.

import { ethers } from "ethers";
import { ICrowdloanABI, ICROWDLOAN_ADDRESS } from "./contracts/crowdloan";

// PROTECT YOUR PRIVATE KEYS WELL, NEVER COMMIT THEM TO GITHUB OR SHARE WITH ANYONE
const { ethPrivateKey, rpcUrl } = require("./config.js");

const provider = new ethers.JsonRpcProvider(rpcUrl);
const signer = new ethers.Wallet(ethPrivateKey, provider);
const contract = new ethers.Contract(ICROWDLOAN_ADDRESS, ICrowdloanABI, signer);

const CROWDLOAN_ID = 0;

const tx = await contract.dissolve(CROWDLOAN_ID, { gasLimit: 2_000_000n });
const receipt = await tx.wait();
console.log(`Crowdloan ${CROWDLOAN_ID} dissolved`);
console.log(`  Block:   ${receipt.blockNumber}`);
console.log(`  Tx hash: ${receipt.hash}`);