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

# LayerZero Solana SDK

> Step-by-step guide to layerzero solana sdk using LayerZero V2. Build and deploy omnichain applications with crosschain messaging. Follow step-by-step develo...

### Package

Use the `@layerzerolabs/lz-solana-sdk-v2` package to interact with the LayerZero Endpoint program on Solana from TypeScript/JavaScript.

### Interacting with the Endpoint

Note that the SDK makes use of [`Umi`](https://developers.metaplex.com/umi) in place of `@solana/web3.js`

Create an `endpoint` instance:

```ts wrap theme={null}
import {TransactionBuilder, publicKey as umiPublicKey} from '@metaplex-foundation/umi';
import {EndpointProgram} from '@layerzerolabs/lz-solana-sdk-v2/umi';

const endpoint = new EndpointProgram.Endpoint(EndpointProgram.ENDPOINT_PROGRAM_ID);
```

Note: If the payload account is missing in some flows, call `endpoint.initVerify(umiWalletSigner, { srcEid, sender, receiver, nonce })` before `skip` or `clear`.

#### Skip a message

`endpoint.skip(umiWalletSigner, { sender, receiver, srcEid, nonce })`

* **When to use**: Bypass a stuck inbound message at a future nonce to unblock subsequent processing.
* **Preconditions**:
  * `nonce > inboundNonce`
  * `nonce <= inboundNonce + 256` (sliding window)
  * If the payload account is missing, call `initVerify` first
  * Caller is the authorized delegate

```ts wrap theme={null}
const skipIxn = endpoint.skip(umiWalletSigner, {
  sender: senderBytes32, // bytes32 normalized sender
  receiver: umiPublicKey('<RECEIVER_OAPP>'),
  srcEid: <SRC_EID>,
  nonce: BigInt(<NONCE>),
})
await new TransactionBuilder([skipIxn]).sendAndConfirm(umi)
```

Example usage: [https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/skip.ts](https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/skip.ts)

#### Nilify a nonce

`endpoint.oAppNilify(umiWalletSigner, { nonce, receiver, sender, srcEid, payloadHash })`

* **When to use**: Invalidate a verified payload by setting its payload hash to NIL without deleting the account.
* **Preconditions**:
  * Provide the exact `payloadHash` (must match onchain)
  * Typically after verification; does not create the payload account
  * Caller is the authorized delegate

```ts wrap theme={null}
const nilifyIxn = endpoint.oAppNilify(umiWalletSigner, {
  nonce: BigInt(<NONCE>),
  receiver: umiPublicKey('<RECEIVER_OAPP>'),
  sender: senderBytes32,
  srcEid: <SRC_EID>,
  payloadHash: payloadHashBytes32,
})
await new TransactionBuilder([nilifyIxn]).sendAndConfirm(umi)
```

Example usage: [https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/nilify.ts](https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/nilify.ts)

#### Burn a nonce

`endpoint.oAppBurnNonce(umiWalletSigner, { nonce, receiver, sender, srcEid, payloadHash })`

* **When to use**: Delete the payload hash account for an older nonce after inbound processing has advanced beyond it (state cleanup).
* **Preconditions**:
  * `nonce < inboundNonce`
  * Provide the exact `payloadHash` (must match onchain)
  * Caller is the authorized delegate

```ts wrap theme={null}
const burnIxn = endpoint.oAppBurnNonce(umiWalletSigner, {
  nonce: BigInt(<NONCE>),
  receiver: umiPublicKey('<RECEIVER_OAPP>'),
  sender: senderBytes32,
  srcEid: <SRC_EID>,
  payloadHash: payloadHashBytes32,
})
await new TransactionBuilder([burnIxn]).sendAndConfirm(umi)
```

Example usage: [https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/burn.ts](https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/burn.ts)

#### Clear a payload

Note that `clear` does not make use of the `endpoint` class, but instead requires usage of `EndpointProgram.instruction`.

`EndpointProgram.instructions.clear({ programs }, { accounts }, { args })`

* **When to use**: Finalize/ack a payload for a nonce that has already been verified; clean up state for a known payload.
* **Preconditions**:
  * `nonce <= inboundNonce`
  * Provide `payloadHash` OR `guid + message` (to derive the hash)
  * If payload account is missing, call `initVerify` first
  * Caller is the authorized delegate

```ts wrap theme={null}
// Derive PDAs
const [endpointPda] = endpoint.pda.setting()
const [noncePda] = endpoint.pda.nonce(umiPublicKey('<RECEIVER_OAPP>'), <SRC_EID>, senderBytes32)
const [oappRegistryPda] = endpoint.pda.oappRegistry(umiPublicKey('<RECEIVER_OAPP>'))
const [payloadHashPda] = endpoint.pda.payloadHash(umiPublicKey('<RECEIVER_OAPP>'), <SRC_EID>, senderBytes32, Number(<NONCE>))

const clearIxn = EndpointProgram.instructions.clear(
  { programs: endpoint.programRepo },
  {
    signer: umiWalletSigner,
    oappRegistry: oappRegistryPda,
    nonce: noncePda,
    payloadHash: payloadHashPda,
    endpoint: endpointPda,
    eventAuthority: endpoint.eventAuthority,
    program: endpoint.programId,
  },
  {
    receiver: umiPublicKey('<RECEIVER_OAPP>'),
    srcEid: <SRC_EID>,
    sender: senderBytes32,
    nonce: BigInt(<NONCE>),
    guid: guidBytes32,
    message: messageBytes,
  }
).items[0]
await new TransactionBuilder([clearIxn]).sendAndConfirm(umi)
```

Example usage: [https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/clear.ts](https://github.com/LayerZero-Labs/devtools/blob/main/examples/oft-solana/tasks/solana/endpoint/clear.ts)