Docs

Configuration

Flowra Validator Client flags and the Programmable Block Policy file.

The Flowra Validator Client is configured through startup flags on agave-validator (the same pattern as any Agave-lineage client) plus a Programmable Block Policy file referenced by environment variable.

Flag Required Description
--block-engine-url Yes Your regional Block Engine endpoint. See Endpoints.
--relayer-url Yes Your regional Relayer endpoint. The validator fetches the relayer's TPU sockets and advertises them in gossip.
--tip-payment-program-pubkey Yes On-chain tip payment program address Mainnet address TBD
--tip-distribution-program-pubkey Yes On-chain tip distribution program address Mainnet address TBD
--merkle-root-upload-authority Yes Authority for tip distribution merkle root uploads
--commission-bps Yes Your MEV commission in basis points (0 to 10000), applied to tips before staker distribution
--bundle-cu-reserve-pct No Share of block compute units reserved for bundles. Default 15
--bundle-reserve-release-pct No Share of that reservation released back to regular flow when no bundles are pending. Default 70
--disable-block-engine-autoconfig Recommended Use the configured Block Engine URL as-is instead of RTT-probing for the closest region
--trust-block-engine-packets Optional Skip redundant signature verification for packets arriving from the Block Engine

Both regional endpoints must point at the same region.

The PBP policy file

Set the policy file path through the environment:

export FLOWRA_PBP_CONFIG=/etc/flowra/flowra-pbp.toml

The validator is the policy authority: it pushes this file to the Block Engine on connect and re-pushes automatically whenever the file changes. Full field reference and a complete example: Programmable Block Policy.

# flowra-pbp.toml (minimal example)
[policy]
allow_aggressive_mev = false

[address_blacklist]
addresses = []

If FLOWRA_PBP_CONFIG is unset, the default policy applies: open access, standard inclusion, no filters.

Policy semantics

  • Authority-push. Your file is the source of truth. The engine enforces whatever you last pushed.
  • Hot reload. Save the file and the client re-pushes it within seconds. No restart required.
  • Logged. Policy pushes and bundle rejections appear in client and engine logs.

Commission and distribution

Auction tips are lamport transfers to per-validator tip accounts, claimed through the on-chain tip distribution mechanism. After the 5% protocol fee, your --commission-bps determines the validator/staker split.

tip (100%) -> protocol fee (5%)
          \-> validator commission (your bps)
          \-> stakers (remainder)

Operational notes

  • Logs. Bundle and Block Engine activity is logged by the BundleStage and BlockEngineStage modules; run with your usual Agave log configuration.
  • Ledger replay. On restart the validator replays the ledger before going live, and the Block Engine connection is established only after replay completes. Budget for this in maintenance windows.
  • Upgrades. Client releases track upstream Agave/Jito-Solana versions; registered validators are notified through the operator channel.