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

# op-challenger Releases

> Release history for op-challenger. Dispute game challenger.

**op-challenger** is a modular dispute game agent that monitors and challenges invalid fault proof games on-chain. See the [fault proof specs](https://specs.optimism.io/experimental/fault-proof/index.html).

<Update label="May 26, 2026" description="v1.9.3" tags={["Latest", "Stable"]}>
  ## Overview

  This is release of op-challenger is required for [Upgrade 19](https://docs.optimism.io/notices/upgrade-19). It contains bug fixes, new features, and the removal of deprecated functionality.

  Note: ZK dispute games and super dispute games (interop) are not yet live in production. Changes to those code paths in this release are preparation for future functionality and do not affect operators today.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.9.3)
</Update>

<Update label="April 15, 2026" description="v1.9.1" tags={["Stable"]}>
  ## Overview

  This is a patch release of op-challenger that includes important security fixes for chains running permissionless fault proofs, along with other bug fixes. It is a required upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.9.1)
</Update>

<Update label="January 21, 2026" description="v1.9.0" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes important bug fixes. It is a required upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.9.0)
</Update>

<Update label="January 9, 2026" description="v1.8.0" tags={["Stable"]}>
  ## Overview

  This release of op-challenger includes support for Upgrade 18, plus minor bug fixes and improvements. It is a required upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.8.0)
</Update>

<Update label="November 6, 2025" description="v1.7.0" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger, it's an optional upgrade preparing for for [an upcoming refactor of the dispute game contracts to be reusable across chains](https://github.com/ethereum-optimism/optimism/issues/12421)

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.7.0)
</Update>

<Update label="October 7, 2025" description="v1.6.0" tags={["Stable"]}>
  ## Overview

  This release of `op-challenger` adds support for the [Ethereum Fusaka upgrade](https://forkcast.org/upgrade/fusaka/). It's a required upgrade.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.6.0)
</Update>

<Update label="June 12, 2025" description="v1.5.1" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes important bug fixes. It is a required upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.5.1)
</Update>

<Update label="June 4, 2025" description="v1.5.0" tags={["Stable"]}>
  ## Overview

  This release of `op-challenger` adds support for a new version of Cannon that is compatible with Go 1.23. It is a **required** upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.5.0)
</Update>

<Update label="April 15, 2025" description="v1.4.0" tags={["Stable"]}>
  ## Overview

  This release of `op-challenger` fixes a medium severity bug related to EIP-4844 blob data handling. It is a **required** upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.4.0)
</Update>

<Update label="March 20, 2025" description="v1.3.3" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes a fix to improve stability.  It is an optional upgrade.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.3.3)
</Update>

<Update label="March 3, 2025" description="v1.3.2" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes important bug fixes. It is a required upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.3.2)
</Update>

<Update label="February 12, 2025" description="v1.3.1" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger includes support for the Pectra hard fork on L1. It is a **required** upgrade for all users prior to Pectra activating on the L1 chain.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.3.1)
</Update>

<Update label="December 9, 2024" description="v1.3.0" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes minor new features and bug fixes. It is an optional upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.3.0)
</Update>

<Update label="November 5, 2024" description="v1.2.0" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes minor new features and bug fixes. It is an optional upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.2.0)
</Update>

<Update label="September 26, 2024" description="v1.1.2" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger with minor new features.  It is an optional upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.1.2)
</Update>

<Update label="September 11, 2024" description="v1.1.0" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes support for the Granite hard fork changes and bug fixes. It is a required upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.1.0)
</Update>

<Update label="June 15, 2024" description="v1.0.1" tags={["Stable"]}>
  ## Overview

  This is a minor release of op-challenger that includes minor new features. It is an optional upgrade for all users.

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.0.1)
</Update>

<Update label="June 10, 2024" description="v1.0.0" tags={["Stable"]}>
  ## Overview

  This is the 1.0 release of op-challenger, an implementation of the honest actor algorithm for fault dispute games. To learn more about dispute games, visit the [fault proof specs](https://specs.optimism.io/fault-proof/index.html).

  **🚢 Docker Image:**

  * [https://us-docker.pkg.dev/oplabs-tools-artifacts/images/op-challenger:v1.0.0](https://us-docker.pkg.dev/oplabs-tools-artifacts/images/op-challenger:v1.0.0)

  [View full release on GitHub →](https://github.com/ethereum-optimism/optimism/releases/tag/op-challenger/v1.0.0)
</Update>