Overview

The Ethereum Vault Connector (EVC) is the account and coordination layer for modular lending in Euler V2. Acting as the primary entry point for advanced interactions, the EVC lets integrators build, automate, and orchestrate multi-step workflows across multiple vaults. For offchain TypeScript integrations, the Euler SDK abstracts most of these workflows; the pages in this section cover the contract level.

What the EVC coordinates

In Euler V2, the EVC mediates cross-vault operations:

Batching: Group multiple actions (deposits, borrows, swaps, repayments, etc.) into a single atomic transaction.
Sub-accounts: Create up to 256 separated positions per wallet, enabling strategy separation and clearer account-level risk tracking.
Operators: Delegate control of sub-accounts to reviewed contracts or automation bots for advanced use cases, such as stop-loss or intent-based trading.
Signed delegation: Authorize delegated execution with signed messages through the EVC permit function.
Deferred checks: Defer required account and vault status checks until the end of a call or batch. Only constraints represented by those required checks are deferred.
Unified Authentication: The EVC handles authentication, so vaults can focus on authorization and business logic.

Core concepts

Batching

The EVC's batching system allows integrators to bundle multiple operations, across different vaults and even external contracts, into a single transaction. All operations succeed or fail together, which reduces partial-execution risk within that batch.

Sub-accounts

Each user address is granted 256 virtual sub-accounts. These allow for position separation and management of multiple strategies under a single wallet. Risk is still determined by the vaults, controllers, collateral, and operators enabled for each sub-account.

Operators

Operators generalize the concept of token approvals. By assigning an operator to a sub-account, users can delegate control to automation contracts, keepers, or other parties. Operator permissions should be granted only after reviewing the delegated contract or account.

The EVC permit function lets an account owner sign an authorization offchain so another address can submit it onchain. Integrators can use this for delegated execution flows, while still treating the signed message as a sensitive permission that should be scoped and reviewed before signing.

Deferred checks and atomicity

Vaults request account and vault status checks, and the EVC can defer those checks until the end of a call or batch. Intermediate state may violate constraints represented by the deferred checks; the transaction succeeds only if all required final checks pass. A vault that fails to request the correct check is not protected by deferral. Integrators should model the full execution flow and failure cases.

Authentication and authorization

The EVC authenticates the originator of every action, while vaults retain control over authorization. This separation of concerns keeps account authentication and vault-level permissioning distinct.

Liquidations

Liquidations are orchestrated through the EVC so debt transfer or takeover, collateral seizure, and any liquidation incentive logic are executed atomically according to the controller vault's rules.

A key part of this process is the EVC's controlCollateral function. When a borrower's position becomes undercollateralized, the liability (controller) vault can invoke controlCollateral to seize collateral from the borrower's enabled collateral vaults. This function lets the controller vault transfer or withdraw collateral on behalf of the account in violation while the liquidator takes over the corresponding debt. From the collateral vault's perspective, this appears as a standard withdrawal or share transfer, but it is executed under the EVC's controller context and the liability vault's liquidation rules.

What integrators can do with the EVC

Build custom frontends and bots that leverage batching, sub-accounts, and operators
Create advanced automation, such as stop-loss, auto-rebalancing, or liquidation-response tooling
Integrate with other protocols using atomic cross-vault operations
Simulate complex transactions before execution
Design new market structures and risk management systems

For a full technical reference, see the EVC whitepaper, the EVC repository or the EVC dedicated website.