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Morpho Bundlers

What are they?​

Morpho Bundlers allow externally owned accounts (EOAs) to bundle multiple operations into a single transaction. This reduces both the time needed between steps and overall gas costs. A bundler exposes a multicall function where each call can trigger different on-chain actions in one go.

Bundler3​

Bundler3 is the newest release, designed for complex DeFi use cases. It supports:

  • Atomic checks, approvals, and callbacks in a single transaction.
  • Adapter-based integrations (e.g. token swaps, bridging, slippage checks).
bundlers3 plot

A core innovation in Bundler3 is the introduction of adapters, specialized “wrappers” that manage DeFi interactions like transfers, slippage checks, or token approvals in a safe, atomic manner. Out of the box, Bundler3 comes with:

  • GeneralAdapter1 — Covers common operations (e.g. ERC20 transfers, wrap/unwrap, ERC4626 vault interactions, Morpho actions).
  • EthereumGeneralAdapter1 — Extends the general adapter with Ethereum-specific features (e.g. staking ETH, wstETH).
  • ParaswapAdapter — Integrates with ParaSwap to enable swapping tokens (buy/sell flows) within a Bundler3 transaction.
bundlers3 plot

All of these adapters inherit from a CoreAdapter contract that ensures only Bundler3 can call them, preserving user approvals and preventing malicious usage. If an adapter needs to perform additional steps—like a flash-loan scenario—it can call back into Bundler3 via the reenter function, all within the same atomic transaction.

Earlier versions like MorphoBundler, PermitBundler, and more specialized ones (e.g. WstEthBundler, ERC4626Bundler) remain available for simpler use cases. However, Bundler3 is recommended for its flexibility and robust security model.

Security​

Morpho employs a rigorous security approach, including:

  • Formal verification, continuous testing, and peer reviews.
  • Regular professional audits by leading firms (see security reviews).
  • Bug bounties and post-deployment monitoring.

Bundler3 follows these same high standards, and its code is publicly available for transparency and community inspection.

Bundler2​

Prior to Bundler3, Morpho offered several bundlers tailored to specific needs, such as:

  • MorphoBundler (for core Morpho interactions)
  • TransferBundler (transferring ETH or ERC20 tokens)
  • Permit(2)Bundler (token approvals using EIP-2612 or Permit2)
  • WstEthBundler (Lido-related staking and wrapping)
  • ERC4626Bundler (interactions with ERC4626 vaults)
  • UrdBundler (claiming rewards via a UniversalRewardsDistributor)
  • WNativeBundler (wrapping/unwrapping the chain’s native token)
blue-bundlers plot

These can still be used as standalone or in conjunction with each other. For newer projects or advanced functionality, Bundler3 is the recommended upgrade.