Flashblocks Architecture
The Flashblocks pipeline layers four new components — rollup-boost, op-rbuilder, websocket-proxy, and base — onto Base’s existing high-availability sequencer.
Before Flashblocks
Section titled “Before Flashblocks”Base operates a high-availability sequencer with five sequencer instances:
| Component | Role |
|---|---|
| op-node | Standard OP Stack consensus layer (CL). |
| op-geth | Standard OP Stack execution layer (EL). |
| op-conductor | High availability controller using Raft consensus for leader election. |
One sequencer instance is the leader and produces blocks, propagating them over P2P. The other four follow and sync the chain. Leadership transfers when the current leader stops producing blocks.
With Flashblocks
Section titled “With Flashblocks”Flashblocks add several new infrastructure components:
| Component | Purpose | What it unlocks |
|---|---|---|
| rollup-boost | CL↔EL Engine API proxy. | Streams Flashblocks to the EL without modifying the CL. Provides a stable seam for future block-building changes such as multi-builder. |
| op-rbuilder | Out-of-protocol builder running at 200ms cadence. | Produces sub-second Flashblocks decoupled from the EL and enables pluggable builder mechanisms. |
| websocket-proxy | Fan-out for the Flashblocks stream. | Lets many consumers read the stream without overwhelming the builder. |
| base | RPC surface that exposes preconfirmations. | Turns streamed Flashblocks into familiar RPC methods so apps and wallets can consume preconfirmed state. |
Flashbots builds and maintains rollup-boost and op-rbuilder; Base maintains the websocket-proxy and the base component.
Further reading
Section titled “Further reading”- Flashblocks Overview — key concepts and transaction lifecycle.
- Enable Flashblocks — run your own Flashblocks-aware RPC node.
- API Reference — RPC methods, WebSocket subscriptions, and infrastructure stream schema.
- Flashblocks deep dive — engineering blog post with implementation details.