# Solidity Interfaces & Contracts Reference Documentation (EVM)
Source: https://docs.chain.link/ccip/api-reference/evm

> For the complete documentation index, see [llms.txt](/llms.txt).

## Available Versions

### Latest Release

- **[CCIP v1.6.1](/ccip/api-reference/evm/v1.6.1)** (Current Version)
  - Pool Library: `ReleaseOrMintInV1.amount` renamed to `sourceDenominatedAmount`
  - TokenPool events: `Locked`/`Burned` and `Released`/`Minted` replaced by unified `LockedOrBurned` and `ReleasedOrMinted`
  - Rate limiting: added `OutboundRateLimitConsumed` and `InboundRateLimitConsumed` events for monitoring consumption
  - LockReleaseTokenPool constructor: removed `acceptLiquidity` parameter; `canAcceptLiquidity` capability removed
  - LockReleaseTokenPool: removed `lockOrBurn` and `releaseOrMint` functions
  - LockReleaseTokenPool: added `RebalancerSet` event
  - Extensibility: standardized pool extension hooks via internal `_lockOrBurn` and `_releaseOrMint` in `TokenPool`

- **[CCIP v1.6.0](/ccip/api-reference/evm/v1.6.0)**
  - Added support for SVM (Solana Virtual Machine) chains

- **[CCIP v1.5.1](/ccip/api-reference/evm/v1.5.1)**
  - Added support for tokens with different decimals across chains
  - Enhanced token pool upgrades to support multiple active pools, ensuring in-flight messages remain deliverable during upgrades
  - Added decimal validation and overflow protection
  - Upgraded token pool access control from OwnerIsCreator to Ownable2StepMsgSender for better security
  - Introduced BurnMintERC20 contract for easy token deployment and cross-chain expansion
    - Configurable decimals and max supply
    - Built-in CCIP admin support
    - Role-based access control for minting and burning

### Previous Versions

- **[CCIP v1.5.0](/ccip/api-reference/evm/v1.5.0)** (Legacy Version)
  - Base implementation
  - Cross-chain:
    - Send arbitrary data
    - Transfer tokens
    - Programmable Token Transfers
  - [Cross-Chain Token (CCT) standard](/ccip/concepts/cross-chain-token/overview)
  - ⚠️ We recommend upgrading to v1.5.1 for latest features

## Documentation Structure

Each version includes detailed documentation for:

- Core Contracts (Router, Receiver)
- Token Pool Implementations
- Registry Components
- Interface Definitions
- Library Definitions
- Error Handling