# What is Newton? \[Newton Protocol is a decentralized policy engine for onchain transaction authorization, built as an EigenLayer AVS. Enforce spend limits, sanctions screening, fraud prevention, and compliance rules in smart contracts.]

Newton Protocol is a [policy engine](/developers/overview/core-concepts) that lets you encode, verify, and enforce rules — spend limits, sanctions screening, fraud prevention — directly within your smart contracts.

### The problem

<img src="/images/about-problem.png" alt="Problem: smart contracts lack offchain context" />

Smart contracts are **blind to offchain context**: whether a user is sanctioned, whether an AI agent is hallucinating, or whether a transaction violates a corporate spend policy. Traditional security relies on frontend filters or centralized API checks, leaving protocols vulnerable to unauthorized actions from third-party aggregators, autonomous agents, or direct contract calls.

### The solution

<img src="/images/about-solution.png" alt="Solution: Newton bridges offchain data to smart contracts" />

Newton bridges this gap with real-time offchain data — KYC status, market feeds, proof of reserves — evaluated by a [decentralized operator network](/developers/concepts/consensus-security) and enforced at the smart contract level. Your protocol stays protected regardless of where the transaction originates.

### Modular and chain-agnostic

Newton integrates with [most EVM-compatible networks](/developers/concepts/multichain) including Ethereum, Base, and Arbitrum. Non-EVM support is on the roadmap.

<Card title="Try the demo" icon="play" to="https://demo.newton.xyz/">
  See a live example of a Newton-powered sanctions-checked transfer app
</Card>

<Card title="Talk to an expert" icon="headphones" to="https://calendly.com/d/cxcy-vqp-9cm/meet-with-the-newton-team">
  Get in touch to discuss your integration or partnership opportunity
</Card>

## What it looks like

```ts twoslash
import { createWalletClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { sepolia } from 'viem/chains'
import { newtonWalletClientActions } from '@newton-xyz/sdk'
// ---cut---
async function simulate() {
  const client = createWalletClient({
    account: privateKeyToAccount('0x' + '1'.repeat(64) as `0x${string}`),
    chain: sepolia,
    transport: http(),
  }).extend(newtonWalletClientActions({ apiKey: 'test-api-key' }))

  const sender = '0x0000000000000000000000000000000000000000' as `0x${string}`
  const recipient = '0x0000000000000000000000000000000000000001' as `0x${string}`
  const calldata = '0x' as `0x${string}`
  const policyId = '0x' + '0'.repeat(64) as `0x${string}`
  const policyAddress = '0x1234567890123456789012345678901234567890' as `0x${string}`

  // Simulate a policy evaluation against a transaction intent
  const result = await client.simulateTask({
    intent: { from: sender, to: recipient, value: '0x0', data: calldata, chainId: 11155111, functionSignature: '0xa9059cbb' },
    policyTaskData: { policyId, policyAddress, policy: '0x', policyData: [] },
  })

  console.log(result.result?.allow) // true or false
}
```

<Card title="Quickstart" icon="rocket" to="/developers/overview/quickstart">
  Run this example end-to-end in 5 minutes
</Card>

## Walkthrough

<iframe className="w-full aspect-video rounded-xl" src="https://player.vimeo.com/video/1154806337" title="Newton Protocol walkthrough — how policy-based transaction authorization works" frameBorder="0" allow="autoplay; fullscreen; picture-in-picture" allowFullScreen />

## Why Newton

* **Verifiable Trust:** Every compliance decision is backed by a [BLS attestation](/developers/overview/core-concepts#attestation), not reputation.
* **Privacy-Preserving:** Only hashes and commitments are onchain — no PII or sensitive data exposure. See the [privacy layer](/developers/concepts/privacy-layer).
* **Composable:** Works with wallets, dApps, AI agents, and DeFi protocols through a [standard SDK interface](/developers/reference/sdk-reference).
* **Chain-Agnostic:** Newton proofs can be verified across [any supported EVM chain](/developers/concepts/multichain) via lightweight verifier contracts.
* **Extensible:** Supports both open-source policies and enterprise modules for regulated financial institutions.

## Next Steps

<Card title="Quickstart" icon="rocket" to="/developers/overview/quickstart">
  Simulate your first policy evaluation in 5 minutes
</Card>

<Card title="Core Concepts" icon="lightbulb" to="/developers/overview/core-concepts">
  Understand policies, intents, tasks, and attestations
</Card>