Defender

Open in Claude

New sign-ups were disabled on June 30, 2025. Until the final shutdown on July 1, 2026, Defender will remain fully operational while we focus on the open source versions of tools like Relayers and Monitor. Detailed migration guides are coming soon to help you transition seamlessly to open source.

OpenZeppelin Defender is a mission-critical developer security platform to code, audit, deploy, monitor, and operate blockchain applications with confidence.

Integrating directly into the developer workflow, Defender makes it easy and fast for developers and operators to prevent and fix security issues pre and post-deployment.

Subscriptions

Defender offers flexible subscriptions to match your team’s needs and support your project at any scale.

Builder (Free) - Suitable for individuals and small projects that are getting started on testnets and need access to all basic features with limited quotas.
Professional - For mature projects running on mainnets that need access to premium features, higher quotas and metered billing, as well as access to OpenZeppelin support and SLA.
Enterprise - For large projects with higher volumes that need a custom plan to meet their project needs, with higher quotas, access to all premium and security features, and a dedicated support channel.

Modules

Defender modules work seamlessly together, providing users powerful features and a superior, integrated experience. Learn more about each module by clicking on its card.

Code Inspector

Automatic code analysis powered by AI models and tools developed by our security experts.

Audit

Manage the smart contract audit process and track issues and resolutions.

Deploy

Manage deployments and upgrades to ensure secure releases.

Relayers

Send transactions to the blockchain via Defender automatically.

Monitor

Detect smart contract activity and anomalies through trigger actions and alerts.

Transaction Proposals

Create transactions to be executed on-chain.

Actions

Create automated actions to perform on-chain and off-chain operations.

Address Book

Create a shared repository of user-friendly names for your accounts or contracts.

Access Control

Manage smart contract accounts, roles, and permissions easily.

Available networks

Defender works with most mainnet and testnet networks, as well as local mainnet forks.

Arbitrum One, Arbitrum Nova,window=_blank, Arbitrum Sepolia.
Aurora,window=_blank and Aurora Testnet.
Avalanche C,window=_blank and FUJI C-Chain.
Base Mainnet,window=_blank and Base Sepolia.
Binance Smart Chain,window=_blank and BSC testnet.
Celo,window=_blank and Alfajores.
Ethereum Mainnet, window=_blank, Sepolia testnet and Holesky testnet.
Fantom,window=_blank and Fantom Testnet.
Fuse,window=_blank.
Gnosis Chain,window=_blank
Hedera,window=_blank and Hedera Testnet.
Japan Open Chain,window=_blank and Japan Open Chain Testnet.
Linea Mainnet,window=_blank and Linea Sepolia.
Scroll Mainnet, window=_blank and Scroll Sepolia.
Mantle Mainnet, window=_blank and Mantle Sepolia.
Meld Mainnet, window=_blank and Meld Testnet.
Moonbeam,window=_blank, Moonriver, and Moonbase Alpha (Testnet).
OP Mainnet,window=_blank, OP Sepolia.
Polygon (POL),window=_blank, Amoy, zkEVM, window=_blank and Polygon Cardona zkEVM testnet
Scroll Mainnet, window=_blank and Scroll Sepolia.
Unichain, window=_blank and Unichain Sepolia.
zkSync Era Mainnet,window=_blank and zkSync Era Sepolia.
Geist Mainnet, window=_blank and Polter Testnet.
Abstract Mainnet,window=_blank and Abstract Sepolia.
Peaq Mainnet, window=_blank and Peaq Agung.
Sei, window=_blank and Sei Testnet (Atlantic-2).

If there is any other network or layer-2 solution you would like to use from Defender, please reach out to us via the form on Defender!

Status

You can check the status of Defender and the supported networks on our status page, window=_blank, where you can also subscribe to receive notifications. If a supported network experiences issues, some features in Defender for that network may not work properly.