# Chainlink CCIP Solidity Interfaces & Contracts Reference (EVM)
Source: https://docs.chain.link/ccip/evm/api-reference/v2.0.0/overview

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

This section is the Solidity API reference for CCIP on EVM chains. It covers the contracts, interfaces, libraries, events, and errors used when integrating CCIP onchain.

## Do I need to change anything for v2?

If you have an existing CCIP v1.x integration: in most cases, no. **If you don’t change your configuration, your integration continues to work as before.** You only need to engage with v2 features if you want additional control over behavior:

- You want faster-than-finality execution (lower latency by reducing confirmation requirements)
- You need **more control over fees** or how they are applied
- You are a **token issuer** configuring pool-level rules (fees, limits, finality)
- You are building **advanced integrations** involving custom verification or execution

If none of these apply, you can continue using CCIP as before.

## Start here

Most integrations start with:

- [Router](/ccip/evm/api-reference/v2.0.0/router) for sending messages and token transfers
- [IRouterClient](/ccip/evm/api-reference/v2.0.0/i-router-client) for the application-facing interface
- [CCIPReceiver](/ccip/evm/api-reference/v2.0.0/ccip-receiver) for receiving messages
- [FeeQuoter](/ccip/evm/api-reference/v2.0.0/fee-quoter) for fee estimation references

If your application transfers tokens, also review the token pool pages.

## How this reference is organized

- **Core Components** for sending and receiving messages
- **Token Pools** for token transfer mechanisms
- **Access & Administration** for ownership and token configuration
- **Fee & Pricing** for fee estimation (FeeQuoter)
- **Advanced** for execution and verification-related contracts
- **Libraries** for shared structs and utilities
- **Reference Tools** for the **Events** and **Errors** pages used in debugging and observability

## Token Pools

CCIP supports token transfer models based on:

- **Lock and release**
- **Burn and mint**

Use the token pool pages to determine which model fits your integration.

## Events and Errors

For cross-contract debugging and observability, see:

- [Events](/ccip/evm/api-reference/v2.0.0/events)
- [Errors](/ccip/evm/api-reference/v2.0.0/errors)