Block Engine
Validator & infra
The Jito block engine is the service that receives bundles and transactions from searchers, simulates them, runs auctions for block space, and passes the winning bundles to the current leader’s Jito-Solana validator. It sits between the people who send transactions and the validators that include them. The tip paid with a bundle is what its auctions rank on.
Detailed explanation
A searcher does not send a bundle to the leader directly. It sends it to a block engine. The engine checks the bundle, simulates it, and holds it in an auction against other bundles that want the same block space.
The auctions run in parallel, at 50 millisecond ticks. At each tick the engine takes the highest-paying combination of bundles that fits, up to a compute limit, and submits it to the validator. Ranking is by tip, which is why the tip is the main lever a sender controls.
Only validators that run Jito-Solana take part. The documentation is explicit that tips do not prioritise transactions for a leader that is not running it. That means the engine matters for the slots a Jito-Solana validator leads, and not for the others.
The block engine is Jito’s infrastructure. A searcher connects to one of its endpoints, and the endpoints are run in several regions. Everything before it, the data a searcher reads and the code that decides what to send, is the searcher’s own.
When you'll see this
You see the block engine as the URL a searcher or bot sends bundles to, in status calls that report whether a bundle landed, and in documentation about tips and auctions.
How NoLimitNodes uses this
We do not run a block engine and we do not claim to. We run the feeds in front of it: Shredstream and Yellowstone gRPC. The MEV bots we build read those feeds and submit to a block engine of your choice.
Related terms
- Jito Bundle · Up to five transactions a Jito block engine executes in order and atomically, with a tip that sets how it ranks.
- Jito Tip · A SOL transfer to a Jito tip account that pays the block engine to include and order your transaction bundle.
- Solana Shred · An erasure-coded packet that carries part of a Solana leader block or recovery data through the Turbine tree.
- Yellowstone gRPC · The Triton-built Geyser plugin that exposes a gRPC stream of accounts, transactions, and slots over the wire.
- Processed, Confirmed, Finalized · The three Solana commitment levels, ordered from "this validator saw it" to "supermajority will not roll it back."