> ## Documentation Index
> Fetch the complete documentation index at: https://docs.polygon.technology/llms.txt
> Use this file to discover all available pages before exploring further.

# What is Polygon CDK?

> Enterprise-grade toolkit for building custom Ethereum L2 chains. Agglayer interoperability is built in by default.

The Polygon Chain Development Kit (CDK) is an enterprise-grade toolkit for building custom Ethereum Layer 2 (L2) chains. Every CDK chain connects to **Agglayer** by default — cross-chain interoperability, shared liquidity, and unified state are native features of the infrastructure, not optional add-ons.

## Execution clients

CDK supports two execution clients, both maintained as open source by implementation providers:

* **op-geth**: Geth-based client with OP Stack architecture. Familiar developer environment and broad tooling support.
* **op-reth**: Reth-based client optimized for high throughput and lower resource consumption.

Both clients are supported by **Conduit** and **Gateway**, who are building open source tooling for production CDK deployments.

## Performance

* 60 to 100+ million gas per second (Mgas/s)
* Over 4,700 peak TPS in standard configuration
* **20,000+ TPS** when optimized for payment workloads
* Finality in under 60 minutes in zkRollup and validium modes

## Rollup modes

Every CDK chain supports three operating modes:

| Mode          | Status         | Description                                                                                                                                               |
| ------------- | -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Sovereign** | Live           | Agglayer connectivity secured by pessimistic proofs. No prover required. Default configuration.                                                           |
| **Validium**  | Live           | ZK-secured execution with offchain data availability. Available today via OP Succinct AltDA; see [Privacy Configuration](/chain-development/cdk/privacy). |
| **zkRollup**  | In development | Fully onchain ZK rollup for maximum security and Ethereum-aligned trust.                                                                                  |

## Agglayer integration

All CDK chains connect to Agglayer by default. This provides unified liquidity, shared state, and cross-chain messaging as a native feature of every enterprise chain, without additional bridging infrastructure.

## Projects using CDK

* Ternoa
* Merlin Chain
* Magic Labs (Newton)
* Silicon Network
* Witness Chain
* WireX
* Lumia (formerly Orion)
* Okto Wallet
* Palm Network
* Prom
* OKX
* Moonveil

*...and more*

<CardGroup cols={2}>
  <Card title="Continue through CDK docs" icon="book" href="/chain-development/cdk/get-started/benefits">
    Compare execution clients, operating modes, and implementation options.
  </Card>

  <Card title="Request managed CDK deployment" icon="envelope" href="https://info.polygon.technology/get-early-access">
    Contact Polygon about a dedicated enterprise chain and managed deployment support.
  </Card>
</CardGroup>