> ## Documentation Index
> Fetch the complete documentation index at: https://docs.base.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Reliability and Liveness

> Where to find Base network status and incident history, third-party audits, bug bounties, censorship-resistance guarantees, and the open-source sequencer components.

## Network Status and Incident History

[status.base.org](https://status.base.org) reports the live status of Base Mainnet and Base Sepolia components, including block production, batch submission, Flashblocks, the transaction pool, deposits, withdrawals, and the public RPC API.

* **Incident history:** [status.base.org/history](https://status.base.org/history) lists past incidents with their timelines and resolutions.
* **Notifications:** subscribe on [status.base.org](https://status.base.org) to receive incident updates.
* **Postmortems:** Base publishes detailed postmortems for major incidents on the [Base Engineering Blog](https://blog.base.dev/), for example the [June 25th block production outage postmortem](https://blog.base.dev/postmortem-june-25th-block-production-outage).

## Audits

Third-party audit reports for the Base Stack are published in the open-source repositories they cover. Each report lists its scope, the reviewed commit, the findings, and how each finding was resolved.

* **Smart contracts:** [base/contracts audits](https://github.com/base/contracts/tree/main/audits), including the multiproof, proof, Cobalt, and dynamic upgrade contract reviews.
* **Node and precompiles:** [base/base audits](https://github.com/base/base/tree/main/audits), including the B20 precompile and dynamic upgrade node reviews.
* **Audit competitions:** [Immunefi reports](https://reports.immunefi.com/base), including the Azul hardfork competition.

Audits of the OP Stack components that Base used through OP Stack Upgrade 18, including the bridge and `OptimismPortal` contracts, are in [Optimism's security reviews](https://github.com/ethereum-optimism/optimism/tree/develop/docs/security-reviews).

## Bug Bounties and Audit Competitions

Base runs bug bounty programs on HackerOne (offchain components and infrastructure) and Cantina (deployed smart contracts), and ran a public Immunefi audit competition for the Azul upgrade. See [Report a Vulnerability](/specifications/security/report-a-vulnerability) for award limits, scope, and how to submit a report.

## Censorship Resistance and Sequencer Liveness

Base currently operates a single active sequencer. The sequencer runs as a high-availability cluster in which leadership transfers to a follower if the current leader stops producing blocks. See the [Flashblocks architecture](/specifications/flashblocks#architecture) for the components involved.

If the sequencer censors your transactions or stops producing blocks, you can still get a transaction onto Base by sending it as a [deposit](/specifications/base-protocol/bridging/deposits) through the `OptimismPortal` contract on Ethereum:

* **Deposits must be included.** Each L1 block defines the deposits that must be included in the first L2 block of its [sequencing epoch](/specifications/reference/glossary#sequencing-epoch). A block that omits them is invalid under the [derivation rules](/specifications/base-protocol/consensus/derivation).
* **Maximum delay.** If the sequencer does not post batches to Ethereum, nodes wait one [sequencing window](/specifications/reference/glossary#sequencing-window) and then derive the missing L2 blocks themselves, including the pending deposits. On Base the sequencing window is 3,600 L1 blocks, about 12 hours at a 12-second L1 block time (see [Configuration](/specifications/reference/configuration#consensus-parameters)).

Halts and degraded transaction inclusion are reported on [status.base.org](https://status.base.org). If the sequencer has to stop publishing Flashblocks, preconfirmations are disabled and confirmations fall back to standard 2-second blocks (see [Flashblocks](/specifications/flashblocks#block-building)).

## Open-Source Sequencer Components

The software that orders and sequences Base transactions is open source:

| Component | Role | Source |
| - | - | - |
| base-consensus | Consensus layer client, run by the sequencer and by node operators | [base/base](https://github.com/base/base/tree/main/crates/consensus) |
| base-reth-node | Execution layer client, including the transaction pool | [base/base](https://github.com/base/base/tree/main/crates/execution) |
| base-builder | Block builder that orders transactions into Flashblocks | [base/base](https://github.com/base/base/tree/main/crates/builder) |
| websocket-proxy | Fan-out for the Flashblocks stream | [base/base](https://github.com/base/base/tree/main/bin/websocket-proxy) |
| rollup-boost | Engine API proxy between the consensus and execution layers, maintained by Flashbots | [flashbots/rollup-boost](https://github.com/flashbots/rollup-boost) |
| op-conductor | High-availability controller that elects the sequencer leader | [ethereum-optimism/optimism](https://github.com/ethereum-optimism/optimism/tree/develop/op-conductor) |

The ordering rules these components implement are described in [Transaction Ordering](/specifications/transactions/transaction-ordering). Node operators independently derive and verify the canonical chain from batches and deposit data published on Ethereum.

## Planned Upgrades

Planned network upgrades and their target activation months are listed on the [Upgrades](/upgrades/overview) page.