> For a complete page index, fetch https://docs.conduit.xyz/llms.txt

# OP Stack

> OP Stack is the premiere open-source rollup implementation

> Conduit allows you to launch a rollup in a fraction of the time with the OP Stack.

OP Stack is the premiere open-source rollup implementation. You get:

* **10-100x cheaper fees** than Ethereum Mainnet
* **Interoperability** with Mainnet through trustless bridging
* **Ethereum Equivalence**, so you can use the same workflows and tooling
* Improved node performance, so you can get **thousands of transactions per second**

Below is a great primer on how the OP Stack works to bring you more performance while maintaining security:
[(Almost) Everything you need to know about Optimistic Rollup](https://www.paradigm.xyz/2021/01/almost-everything-you-need-to-know-about-optimistic-rollup)

## Supported JSON RPC Methods

`op-reth` implements the standard Ethereum JSON-RPC methods. The supported JSON-RPC methods can be found [here](https://reth.rs/jsonrpc/intro/).

## FAQ

### How do I withdraw/bridge tokens?

Please see our guide of using the Conduit SDK alongside the Optimism SDK [here](https://github.com/conduitxyz/optimism-tutorial/tree/main/cross-dom-bridge-eth).

### Can I use a Custom Gas Token (CGT)?

Yes. The OP Stack supports a **Custom Gas Token (CGT) self-serve** from the [deploy dashboard](https://app.conduit.xyz). A CGT replaces ETH as your chain's native asset for paying gas. It's treated as the chain's native token and it must use 18 decimals.

> **Warning**
>
> A Custom Gas Token can only be set **when your chain is deployed**. It cannot be added, removed, or changed after your chain is live, so decide before deploying.

### Are there any public audits?

Optimism audits can be found [here](https://github.com/ethereum-optimism/optimism/tree/develop/docs/security-reviews). Optimism has a [security model](https://docs.optimism.io/stack/security/faq-sec-model) to support the continuous development they do time by time.

For Celestia based op rollups, you can find the audit [here](https://docs.celestia.org/audits/Celestia_OP_Stack_Audit.pdf).

### Will my rollup come with any pre-deployed contracts or preinstalls?

Yes, when launching a rollup on the OP Stack, several core contracts come preinstalled, allowing you to move to production faster. These pre-deployed contracts include `Safe`, `SafeL2`, `Multicall3`, `MultiSend`, `MultiSendCallOnly`, `create2` Proxy, `create2deployer`, Safe Singleton Factory, `permit2`, ERC-4337 Entrypoint `v0.6.0`. For more details, visit the official [Optimism documentation](https://docs.optimism.io/builders/chain-operators/features/preinstalls).

To deploy your own Safe (multisig) wallet using the preinstalled factory, see our [guide to deploying a Safe](/chains/guides/deploy-a-safe).