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

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.ton.org/feedback

```json
{
  "path": "/ecosystem/bridges",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# Bridges

export const Aside = ({type = "note", title = "", icon = "", iconType = "regular", children}) => {
  const asideVariants = ["note", "tip", "caution", "danger"];
  const asideComponents = {
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      calloutType: "tip",
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        </svg>
    },
    caution: {
      outerStyle: "border-amber-500/20 bg-amber-50/50 dark:border-amber-500/30 dark:bg-amber-500/10",
      innerStyle: "text-amber-900 dark:text-amber-200",
      calloutType: "warning",
      icon: <svg className="flex-none w-5 h-5 text-amber-400 dark:text-amber-300/80" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="2" aria-label="Warning">
          <path stroke-linecap="round" stroke-linejoin="round" d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z"></path>
        </svg>
    },
    danger: {
      outerStyle: "border-red-500/20 bg-red-50/50 dark:border-red-500/30 dark:bg-red-500/10",
      innerStyle: "text-red-900 dark:text-red-200",
      calloutType: "danger",
      icon: <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" fill="currentColor" className="text-red-600 dark:text-red-400/80 w-4 h-4" aria-label="Danger">
          <path d="M17.1 292c-12.9-22.3-12.9-49.7 0-72L105.4 67.1c12.9-22.3 36.6-36 62.4-36l176.6 0c25.7 0 49.5 13.7 62.4 36L494.9 220c12.9 22.3 12.9 49.7 0 72L406.6 444.9c-12.9 22.3-36.6 36-62.4 36l-176.6 0c-25.7 0-49.5-13.7-62.4-36L17.1 292zm41.6-48c-4.3 7.4-4.3 16.6 0 24l88.3 152.9c4.3 7.4 12.2 12 20.8 12l176.6 0c8.6 0 16.5-4.6 20.8-12L453.4 268c4.3-7.4 4.3-16.6 0-24L365.1 91.1c-4.3-7.4-12.2-12-20.8-12l-176.6 0c-8.6 0-16.5 4.6-20.8 12L58.6 244zM256 128c13.3 0 24 10.7 24 24l0 112c0 13.3-10.7 24-24 24s-24-10.7-24-24l0-112c0-13.3 10.7-24 24-24zM224 352a32 32 0 1 1 64 0 32 32 0 1 1 -64 0z"></path>
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    }
  };
  let variant = type;
  let gotInvalidVariant = false;
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    gotInvalidVariant = true;
    variant = "danger";
  }
  const iconVariants = ["regular", "solid", "light", "thin", "sharp-solid", "duotone", "brands"];
  if (!iconVariants.includes(iconType)) {
    iconType = "regular";
  }
  return <>
      <div className={`callout my-4 px-5 py-4 overflow-hidden rounded-2xl flex gap-3 border ${asideComponents[variant].outerStyle}`} data-callout-type={asideComponents[variant].calloutType}>
        <div className="mt-0.5 w-4" data-component-part="callout-icon">
          {}
          {icon === "" ? asideComponents[variant].icon : <Icon icon={icon} iconType={iconType} size={14} />}
        </div>
        <div className={`text-sm prose min-w-0 w-full ${asideComponents[variant].innerStyle}`} data-component-part="callout-content">
          {gotInvalidVariant ? <p>
              <span className="font-bold">
                Invalid <code>type</code> passed!
              </span>
              <br />
              <span className="font-bold">Received: </span>
              {type}
              <br />
              <span className="font-bold">Expected one of: </span>
              {asideVariants.join(", ")}
            </p> : <>
              {title && <p className="font-bold">{title}</p>}
              {children}
            </>}
        </div>
      </div>
    </>;
};

In the TON ecosystem, bridges allow users to transfer assets and data between TON and other major blockchains like Ethereum, BNB Chain, and Polygon.

In this article, we will explore cross-chain bridges on TON.

## What are Cross-Chain Bridges?

Cross-chain bridges are protocols that allow users to transfer cryptocurrencies, tokens, and sometimes arbitrary data from one blockchain to another. They act as connectors between otherwise isolated blockchain networks, enabling a multi-chain ecosystem where assets can move freely across different platforms.

Bridges typically work by locking assets on the source blockchain and minting equivalent wrapped tokens on the destination blockchain. When users want to move assets back, the wrapped tokens are burned on the destination chain, and the original assets are unlocked on the source chain.

### Types of Cross-Chain Bridges

#### 1. Trustless vs. Custodial Bridges

Trustless Bridges:

* Use smart contracts and cryptographic proofs for validation
* No single point of failure
* Decentralized verification mechanisms

Centralized Bridges:

* Rely on trusted entities or multi-signature wallets
* Single point of failure risk
* Generally, they are easier to implement

#### 2. Asset Transfer Methods

Lock-and-Mint Bridges:

* Lock original assets on the source chain
* Mint wrapped tokens on the destination chain
* Most common bridge type

Burn-and-Mint Bridges:

* Burn tokens on the source chain
* Mint new tokens on the destination chain
* Used for native multi-chain tokens

## Bridges on TON

The TON blockchain has a bridge ecosystem that connects it to major EVM-compatible networks. There are several kinds of bridge providers on TON.

### Legacy: Official TON Bridges

<Aside type="caution">
  During the early development of TON ecosystem (2021-2023) there were a few official TON bridges, supported at the protocol level. Now, they are considered legacy and not recommended for usage since they can be deprecated at any moment.
</Aside>

TON blockchain supports several official bridges configured at the protocol level:

#### Outbound Bridges (Config parameters 71-73)

These bridges wrap TON into other networks:

* **ETH-TON Bridge** ([Config Parameter 71](/foundations/config#param-71-73%3A-outbound-bridges))
* **BNB-TON Bridge** ([Config Parameter 72](/foundations/config#param-71-73%3A-outbound-bridges))
* **Polygon-TON Bridge** ([Config Parameter 73](/foundations/config#param-71-73%3A-outbound-bridges))

#### Inbound Bridges (Config parameters 79, 81-82)

These bridges wrap tokens from other networks into TON:

* **ETH-TON Bridge** ([Config Parameter 79](/foundations/config#param-79%2C-81-and-82%3A-inbound-bridges))
* **BNB-TON Bridge** ([Config Parameter 81](/foundations/config#param-79%2C-81-and-82%3A-inbound-bridges))
* **Polygon-TON Bridge** ([Config Parameter 82](/foundations/config#param-79%2C-81-and-82%3A-inbound-bridges))

You can read more about these bridge configuration parameters on the [TON Config page](/foundations/config).

### Third-Party Bridge Ecosystem

The TON ecosystem features multiple bridge providers offering different features and supported networks. You can read more about them in [TON Bridges page](https://ton.org/en/bridges).

You can see existing bridges statistics on [TON Foundation Bridge Dashboard](https://dune.com/ton_foundation/bridges).