CCIP v2.0.0 SiloedLockReleaseTokenPool API Reference

SiloedLockReleaseTokenPool is a TokenPool implementation that uses separate lockboxes per remote chain for lock and release operations.

If you use this pool, tokens are locked into and released from chain-specific lockboxes rather than a single shared liquidity pool.

This approach preserves total token supply while isolating liquidity across chains.

Use this variant when you need per-chain liquidity isolation instead of a shared lockbox model.

This contract is not intended to be called directly by applications. It is used by CCIP infrastructure during token transfers.

Usage Boundary

You do not call this contract directly.

• The Router and OnRamp/OffRamp contracts invoke this pool during cross-chain token transfers.
• You choose this pool when configuring how a token is bridged across chains.
• Use this pool when you want to isolate liquidity per destination chain.
• You are responsible for configuring a lockbox for each supported chain.
• If a lockbox is not configured for a chain, transfers to that chain will revert.

Contract

pools/SiloedLockReleaseTokenPool.sol

Import

import {SiloedLockReleaseTokenPool} from "chainlink-ccip/pools/SiloedLockReleaseTokenPool.sol";

If you have not installed the package:

npm install @chainlink/contracts-ccip@2.0.0

Inheritance

• TokenPool
• ITypeAndVersion

Constructor

constructor(
  IERC20 token,
  uint8 localTokenDecimals,
  address advancedPoolHooks,
  address rmnProxy,
  address router
) TokenPool(
  token,
  localTokenDecimals,
  advancedPoolHooks,
  rmnProxy,
  router
)

External API

getAllLockBoxConfigs

function getAllLockBoxConfigs() external view returns (LockBoxConfig[] memory lockBoxConfigs)

Returns all configured lockbox mappings.

Returns:

configureLockBoxes

function configureLockBoxes(LockBoxConfig[] calldata lockBoxConfigs) public onlyOwner

Owner-only function to configure lockboxes for each remote chain. Incorrect configuration will cause transfers to fail.

getLockBox

function getLockBox(uint64 remoteChainSelector) public view returns (ILockBox)

Returns the lockbox configured for a specific remote chain.

Returns:

typeAndVersion

function typeAndVersion() external pure virtual override returns (string memory)

Returns:

Events

No new events declared.

For a cross-contract event index, see Events.

Errors

error LockBoxNotConfigured(uint64 remoteChainSelector);

Thrown when no lockbox is configured for the specified chain.

For a cross-contract error index, see Errors.

Internal Functions

_lockOrBurn

function _lockOrBurn(
  uint64 remoteChainSelector,
  uint256 amount
) internal override

Locks tokens into the lockbox configured for the destination chain.

• Tokens are transferred from the sender into the chain-specific lockbox.
• Reverts if no lockbox is configured.

_releaseOrMint

function _releaseOrMint(
  address receiver,
  uint256 amount,
  uint64 remoteChainSelector
) internal override

Releases tokens from the lockbox associated with the transfer for the destination chain.

• Tokens are transferred from the chain-specific lockbox to the receiver.
• Reverts if no lockbox is configured.

_preflightCheck

No-op override.

_postflightCheck

No-op override.

Security model

• Each chain uses a separate lockbox for custody.
• Correct token transfers require accurate lockbox configuration and sufficient per-chain liquidity.
• Only authorized CCIP components (OnRamp and OffRamp) can trigger token movements.
• Missing or incorrect lockbox configuration causes transfers to fail.

Notes

• This pool preserves total token supply using lock-and-release mechanics.
• Liquidity is isolated per chain rather than shared.
• Each chain maintains its own isolated liquidity pool, and transfers depend on the balance of the corresponding lockbox.
• Each lockbox must be pre-funded before transfers to that chain can succeed.
• Liquidity fragmentation can cause transfers to fail even if total system liquidity is sufficient.
• Compared to LockReleaseTokenPool, this model trades shared liquidity for per-chain isolation.
• Use LockReleaseTokenPool if you prefer a shared liquidity model.

Related Interfaces & Contracts

• TokenPool
• ILockBox
• ERC20LockBox
• LockReleaseTokenPool
• SiloedUSDCTokenPool