> ## Documentation Index
> Fetch the complete documentation index at: https://optimism-373f39ad-soyboy-docs-op-supernode-guide.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# OP Conductor
> Understand how op-conductor keeps an OP Stack sequencer highly available, the guarantees it provides, and how its Raft-based design works.
This page explains what the `op-conductor` service is and how it works at a
high level. To add it to an existing network, follow the
[setup guide](/chain-operators/tools/op-conductor/setup). For the full flag and
RPC catalogue, see the
[configuration and RPC reference](/chain-operators/tools/op-conductor/reference).
## Enhancing sequencer reliability and availability
The [op-conductor](https://github.com/ethereum-optimism/optimism/tree/develop/op-conductor)
is an auxiliary service designed to enhance the reliability and availability of
a sequencer within high-availability setups. By minimizing the risks
associated with a single point of failure, the op-conductor ensures that the
sequencer remains operational and responsive.
### Assumptions
It is important to note that the `op-conductor` does not incorporate Byzantine
fault tolerance (BFT). This means the system operates under the assumption that
all participating nodes are honest and act correctly.
### Summary of guarantees
The design of the `op-conductor` provides the following guarantees:
* **No Unsafe Reorgs**
* **No Unsafe Head Stall During Network Partition**
* **100% Uptime with No More Than 1 Node Failure**
## Design
**On a high level, `op-conductor` serves the following functions:**
### Raft consensus layer participation
* **Leader determination:** Participates in the Raft consensus algorithm to
determine the leader among sequencers.
* **State management:** Stores the latest unsafe block ensuring consistency
across the system.
### RPC request handling
* **Admin RPC:** Provides administrative RPCs for manual recovery scenarios,
including, but not limited to: stopping the leadership vote and removing itself
from the cluster.
* **Health RPC:** Offers health RPCs for the `op-node` to determine whether it
should allow the publishing of transactions and unsafe blocks.
### Sequencer health monitoring
* Continuously monitors the health of the sequencer (op-node) to ensure
optimal performance and reliability.
### Control loop management
* Implements a control loop to manage the status of the sequencer (op-node),
including starting and stopping operations based on different scenarios and
health checks.
## Conductor state transition
The following is a state machine diagram of how the op-conductor manages the
sequencers Raft consensus.
**Helpful tips:** To better understand the graph, focus on one node at a time,
understand what can be transitioned to this current state and how it can
transition to other states. This way you could understand how we handle the
state transitions.
## Next steps
* Follow the [setup guide](/chain-operators/tools/op-conductor/setup) to add
op-conductor to an existing multi-sequencer network without downtime.
* Look up flags and admin RPCs in the
[configuration and RPC reference](/chain-operators/tools/op-conductor/reference).
* Checkout [op-conductor-mon](https://github.com/ethereum-optimism/infra):
which monitors multiple op-conductor instances and provides a unified interface
for reporting metrics.
* Get familiar with [op-conductor-ops](https://github.com/ethereum-optimism/infra/tree/main/op-conductor-ops) to interact with op-conductor.