Running a slasher

Running slasher is completely optional and yet can help protect the chain and earn you extra ETH.

⏩ Quick steps guide

The following steps align with our mainnet guide. You may need to adjust file names and directory locations where appropriate. The core concepts remain the same.

🗡️ What is a Slasher?

• Validators might commit slashable transactions such as

  • Double Voting: signs more than one block in same epoch

  • Surround Votes: signs two contradictory attestations

• A slasher will submit proof of the above offenses into a block proposal.

• Running a slashing helps protect and keeps the network healthy.

• If your slasher successfully detects an offense and is lucky enough to include proof of the offense into your scheduled block proposal, your validator earns extra ETH.

Slashers tend to be resource intensive and is currently recommended for advanced users only.

🤖 Minimum Slasher System Requirements

• Quad-core or more CPU

• 16+ GB RAM

• 256GB+ SSD HD

🚧 How to Configure the Slasher

Slasher functionality is currently available in Lighthouse or Prysm.

Lighthouse

# Edit your beacon-chain unit file
sudo nano /etc/systemd/system/beacon-chain.service

# Append the following slasher flag to ExecStart
--slasher --debug-level debug

# Example of what your ExecStart could look like.
# lighthouse bn --staking --metrics --network mainnet --slasher --debug-level debug

# Reload the new unit file
sudo systemctl daemon-reload

# Restart your beacon-chain
sudo systemctl restart beacon-chain

Prysm

# Revamped Prysm slasher implementation.
# The slasher functionality is no longer a standalone binary.
# Note: Running the slasher has considerably increased resource requirements.
# Be sure to review the latest documentation before enabling this feature.

# Edit your beacon-chain unit file
sudo nano /etc/systemd/system/beacon-chain.service

# Append the following slasher flag to ExecStart
--slasher

# Example of what your ExecStart could look like.
# prysm.sh beacon-chain --slasher

# Reload the new unit file
sudo systemctl daemon-reload

# Restart your beacon-chain
sudo systemctl restart beacon-chain

Nice work. You're running a slasher now. 🗡️ 🤖 🔪

Be sure to familiarize yourself with the reference material for detailed official slasher documentation.

🤖 Start staking by building a validator

Congrats on completing the guide. ✨

🧩 Reference Material

Running a slasher | Prysm

Running a Slasher - Lighthouse Book