# End of Support for op-geth and transition to op-reth

> Notice Date: April 16, 2026

## Overview

GIWA Chain's execution client is transitioning from op-geth to **op-reth**. This transition follows the broader OP Stack ecosystem's shift in execution client support, with official support for op-geth ending on <mark style="background-color:$danger;">**May 31, 2026**</mark>.

## Background

The OP Stack ecosystem is transitioning its execution client from op-geth (Go-based) to **op-reth** (Rust-based). After May 31, 2026, security patches and bug fixes for op-geth will be discontinued, and new feature development, including the upcoming **Karst** hardfork, will only be available on op-reth.

Additionally, the Fault Proof program is transitioning from op-program to **kona-client** (cannon-kona).

{% hint style="warning" %}
op-geth will not support the L1 Glamsterdam hardfork. Once Glamsterdam activates, nodes running op-geth will no longer be able to follow the canonical chain.
{% endhint %}

## Key Changes

| Component           | Before     | After           | Note                         |
| ------------------- | ---------- | --------------- | ---------------------------- |
| Execution Client    | op-geth    | **op-reth**     | End of support: May 31, 2026 |
| Fault Proof Program | op-program | **kona-client** | Transition at Karst hardfork |

## For Node Operators

If you are running your own GIWA Chain node, you will need to **migrate to op-reth before May 31, 2026**.

1. Start syncing an op-reth node in parallel with your existing op-geth node.
2. Verify sync accuracy by comparing block hashes, state roots, and RPC outputs.
3. Once verified, migrate production traffic to op-reth.

For op-reth node setup, refer to the [giwa-io/node](https://github.com/giwa-io/node) repository. You can easily run an op-reth node using the `CLIENT=reth` option.

{% hint style="info" %}
You can use [snapshots](https://docs.giwa.io/node-operators/snapshots) to quickly set up an op-reth node without syncing from scratch.
{% endhint %}

## For Developers

There is no impact on general DApp development. However, if you are connecting directly to a node RPC and using execution client-specific APIs, please verify compatibility with op-reth.

## Learn More

Want to learn more about the execution client transition? Check out the [OP Stack official notice](https://docs.optimism.io/notices/op-geth-deprecation).


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.giwa.io/notices/en/giwa-chain/op-geth-sunset.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.