Run a Validator

This guide walks you through becoming an UltraDAG validator — from generating keys to staking UDAG and earning rewards.

Overview

Validators produce DAG vertices, participate in BFT finality, and earn block rewards proportional to their effective stake. UltraDAG supports up to 100 active validators at any time, selected by effective stake (own stake + delegations).

Requirements:

• Minimum stake: 2,000 UDAG
• Stable internet connection
• Low-latency network path to other validators
• Hardware: any machine capable of running the < 2 MB binary (1 CPU core, 128 MB RAM minimum)

Step 1: Generate a Keypair

Generate a fresh Ed25519 keypair:

curl http://localhost:10333/keygen

{
  "address": "e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8",
  "secret_key": "9f8e7d6c5b4a39281706f5e4d3c2b1a09f8e7d6c5b4a39281706f5e4d3c2b1a0"
}

Save the private key to a file:

echo "9f8e7d6c5b4a..." > validator.key
chmod 600 validator.key

Step 2: Get Testnet UDAG

On the testnet, use the faucet to get initial funds:

curl -X POST http://localhost:10333/faucet -H "Content-Type: application/json" -d '{"address":"e7f8a9b0c1d2...","amount":10000000000}'

{
  "tx_hash": "abc123...",
  "amount": 10000000000,
  "message": "Sent 100 UDAG to e7f8a9b0c1d2..."
}

You need at least 10,000 UDAG to stake. Request the faucet multiple times if needed (there may be rate limits).

Verify your balance:

curl http://localhost:10333/balance/e7f8a9b0c1d2...

Step 3: Run the Validator Node

Start the node with your private key and auto-staking enabled:

cargo run --release -p ultradag-node -- \
  --port 9333 \
  --validate \
  --pkey 9f8e7d6c5b4a... \
  --auto-stake 10000 \
  --testnet

Flags explained:

Step 4: Verify Validator Status

Check Your Stake

curl http://localhost:10333/stake/e7f8a9b0c1d2...

{
  "address": "e7f8a9b0c1d2...",
  "staked_amount": 1000000000000,
  "commission_percent": 10,
  "effective_stake": 1000000000000,
  "delegator_count": 0,
  "is_active_validator": true
}

View the Active Validator Set

curl http://localhost:10333/validators

{
  "validators": [
    {
      "address": "e7f8a9b0c1d2...",
      "effective_stake": 1000000000000,
      "commission_percent": 10,
      "is_active_validator": true
    }
  ],
  "total_staked": 1000000000000,
  "active_count": 1,
  "max_validators": 21
}

Step 5: Manual Staking (Without Auto-Stake)

If you prefer to stake manually rather than using --auto-stake:

Stake UDAG

curl -X POST http://localhost:10333/stake \
  -H "Content-Type: application/json" \
  -d '{
    "secret_key": "9f8e7d6c5b4a...",
    "amount": 1000000000000
  }'

{
  "tx_hash": "stake_abc123...",
  "status": "accepted",
  "message": "Staked 10000 UDAG"
}

Unstake UDAG

curl -X POST http://localhost:10333/unstake \
  -H "Content-Type: application/json" \
  -d '{
    "secret_key": "9f8e7d6c5b4a..."
  }'

Staking Economics

Minimum Stake

The minimum stake to become a validator is 2,000 UDAG (200,000,000,000 sats).

Active Validator Set

Only the top 100 validators by effective stake are active in each epoch. The validator set is recalculated every 210,000 rounds (one epoch, approximately 12 days at 5-second rounds).

Effective Stake

Your effective stake includes both your own stake and any delegations from other users:

$$ \text{effective_stake} = \text{own_stake} + \sum \text{delegations} $$

Reward Distribution

Active validators earn rewards proportional to their effective stake:

$$ \text{reward}_i = \text{round_reward} \times \frac{\text{effective_stake}_i}{\sum \text{effective_stakes}} $$

For delegation rewards, the validator takes their commission percentage, and the remainder is distributed to delegators.

Fee Exemptions

Staking operations are fee-exempt — you pay zero transaction fees for:

• Stake
• Unstake
• Delegate
• Undelegate
• SetCommission

Epoch System

UltraDAG operates on an epoch system:

At each epoch boundary:

1. Active validator set is recalculated based on effective stake rankings
2. Validators ranked 1-100 become active for the next epoch
3. Validators ranked 101+ continue earning passive staking rewards (50% rate)

Commission for Delegations

As a validator, you earn commission on delegated stake:

curl -X POST http://localhost:10333/set-commission \
  -H "Content-Type: application/json" \
  -d '{
    "secret_key": "9f8e7d6c5b4a...",
    "commission_percent": 15
  }'

• Default commission: 10%
• Range: 0-100%
• Commission applies to the delegator portion of rewards

Example: If a round produces 0.5 UDAG in rewards for your validator slot, and 40% of your effective stake comes from delegations:

• Validator base share (60%): 0.30 UDAG
• Delegation pool (40%): 0.20 UDAG
• Your commission (15% of 0.20): 0.03 UDAG
• Delegators receive: 0.17 UDAG (split proportionally)
• Your total: 0.33 UDAG

Slashing Risks

Validators can be slashed for equivocation (producing conflicting vertices in the same round):

• Penalty: 50% of staked amount (burned, reducing total supply)
• Governable range: 10-100% via Council proposal
• Cascading: Delegators also lose proportionally

See Security Model for full details on slashing mechanics.

Troubleshooting

”Insufficient stake” error

Ensure you have at least 2,000 UDAG (200,000,000,000 sats) available for staking. Check your balance:

curl http://localhost:10333/balance/YOUR_ADDRESS

Not in active validator set

If there are already 100 validators with more effective stake, you will not be active. You still earn passive staking rewards (50% rate). Increase your stake or attract delegations to enter the active set.

Node not producing vertices

1. Verify --validate flag is set
2. Check that your key is loaded: curl /status should show your address
3. Ensure you are connected to peers: curl /peers
4. Check finality is progressing: curl /status — finalized_round should be advancing

Next Steps

• Validator Handbook — detailed operational guide
• Staking & Delegation — full tokenomics details
• Monitoring — set up metrics and alerts
• Governance — participate in protocol governance