Stake Pool Operations

Stake pool operators use registerPool to register a new pool on-chain and retirePool to announce retirement. Both operations require the pool operator's key to sign the transaction.

Pool Registration

import {
  Coin,
  KeyHash,
  PoolKeyHash,
  PoolMetadata,
  PoolParams,
  RewardAccount,
  SingleHostAddr,
  UnitInterval,
  Url,
  VrfKeyHash,
  Bytes32,
  IPv4,
  preprod,
  Client,
} from "@evolution-sdk/evolution"

const client = Client.make(preprod)
  .withBlockfrost({
    baseUrl: "https://cardano-preprod.blockfrost.io/api/v0",
    projectId: process.env.BLOCKFROST_API_KEY!
  })
  .withSeed({ mnemonic: process.env.WALLET_MNEMONIC!, accountIndex: 0 })

declare const operatorKeyHash: PoolKeyHash.PoolKeyHash // 28-byte pool operator key hash
declare const vrfKeyHash: VrfKeyHash.VrfKeyHash // 32-byte VRF verification key hash
declare const ownerKeyHash: KeyHash.KeyHash // 28-byte pool owner key hash
declare const rewardAccount: RewardAccount.RewardAccount // pool's reward account for collecting fees

const poolParams = new PoolParams.PoolParams({
  operator: operatorKeyHash,
  vrfKeyhash: vrfKeyHash,
  pledge: 500_000_000n , // 500 ADA pledge
  cost: 340_000_000n ,   // 340 ADA fixed cost per epoch
  margin: new UnitInterval.UnitInterval({ numerator: 1n, denominator: 100n }), // 1% margin
  rewardAccount,
  poolOwners: [ownerKeyHash],
  relays: [],       // see Relay Configuration below
  poolMetadata: null // see Pool Metadata below
})

const tx = await client
  .newTx()
  .registerPool({ poolParams })
  .build()

const signed = await tx.sign()
await signed.submit()

Pool Parameters Reference

Parameter	Type	Description
`operator`	`PoolKeyHash`	Pool operator's key hash (28 bytes)
`vrfKeyhash`	`VrfKeyHash`	VRF verification key hash (32 bytes)
`pledge`	`Coin`	Operator's pledge in lovelace
`cost`	`Coin`	Fixed cost per epoch in lovelace (min 340 ADA on mainnet)
`margin`	`UnitInterval`	Pool margin as a fraction (numerator/denominator)
`rewardAccount`	`RewardAccount`	Where pool fees are collected
`poolOwners`	`KeyHash[]`	Key hashes of all pool owners
`relays`	`Relay[]`	Network relay endpoints (see below)
`poolMetadata`	`PoolMetadata?`	Optional metadata URL + hash

Relay Configuration

Relays tell the network how to reach your pool. Use SingleHostAddr for IP-based relays:

import { IPv4, SingleHostAddr } from "@evolution-sdk/evolution"

// IP + port relay
const relay = new SingleHostAddr.SingleHostAddr({
  port: 3001n,
  ipv4: new IPv4.IPv4({ inner: new Uint8Array([192, 168, 1, 100]) }),
  ipv6: undefined,
})

Pass relays in the relays array of PoolParams.

Pool Metadata

Link to off-chain metadata (pool name, description, ticker) hosted at a URL:

import { Bytes32, PoolMetadata, Url } from "@evolution-sdk/evolution"

declare const metadataHash: Bytes32.Bytes32 // SHA-256 hash of metadata JSON file

const metadata = new PoolMetadata.PoolMetadata({
  url: new Url.Url({ url: "https://my-pool.com/metadata.json" }),
  hash: metadataHash,
})

The metadata JSON file must follow the CIP-6 standard with fields like name, description, ticker, and homepage.

Pool Retirement

Announce retirement effective at a future epoch:

import { PoolKeyHash, preprod, Client } from "@evolution-sdk/evolution"
import type { EpochNo } from "@evolution-sdk/evolution"

const client = Client.make(preprod)
  .withBlockfrost({
    baseUrl: "https://cardano-preprod.blockfrost.io/api/v0",
    projectId: process.env.BLOCKFROST_API_KEY!
  })
  .withSeed({ mnemonic: process.env.WALLET_MNEMONIC!, accountIndex: 0 })

declare const poolKeyHash: PoolKeyHash.PoolKeyHash // the pool to retire
declare const retirementEpoch: EpochNo.EpochNo // epoch when retirement takes effect

const tx = await client
  .newTx()
  .retirePool({
    poolKeyHash,
    epoch: retirementEpoch,
  })
  .build()

const signed = await tx.sign()
await signed.submit()

Retirement takes effect at the specified epoch. The pool deposit (500 ADA on mainnet) is refunded to the pool's reward account after retirement.

To update an existing pool's parameters (cost, margin, relays, metadata), submit a new registerPool with the updated PoolParams. The chain treats this as an update if the operator key hash matches an existing pool.

Next Steps

Stake Registration — Register stake credentials before delegating
Delegation — Delegate stake to a pool
Governance — Participate in on-chain governance

Stake Pool Operations

Stake Pool Operations

Pool Registration

Pool Parameters Reference

Relay Configuration

Pool Metadata

Pool Retirement

Update Pool Parameters

Next Steps

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