# Methods References

The ZPass SDK provides a comprehensive set of methods for interacting with ZPass credentials on the Aleo blockchain.

## Core Operations

### Credential Management

* [signcredential](https://zpass.docs.aleo.org/zpass-sdk/overview/signcredential "mention") - Sign credential data with a private key
* [issuezpass](https://zpass.docs.aleo.org/zpass-sdk/overview/issuezpass "mention") - Issue a new ZPass credential on-chain
* [getzpassrecord](https://zpass.docs.aleo.org/zpass-sdk/overview/getzpassrecord "mention") - Retrieve and decrypt a ZPass record from the blockchain

### Proof Operations

* [proveonchain](https://zpass.docs.aleo.org/zpass-sdk/overview/proveonchain "mention") - Generate an on-chain proof for a ZPass credential
* [proveoffchain](https://zpass.docs.aleo.org/zpass-sdk/overview/proveoffchain "mention") - Generate an off-chain proof locally
* [verifyonchain](https://zpass.docs.aleo.org/zpass-sdk/overview/verifyonchain "mention") - Verify an on-chain ZPass proof
* [verifyoffchain](https://zpass.docs.aleo.org/zpass-sdk/overview/verifyoffchain "mention") - Verify an off-chain ZPass proof locally

### Merkle Tree Operations

* [getmerkleroot](https://zpass.docs.aleo.org/zpass-sdk/overview/getmerkleroot "mention") - Computes the Merkle root from an array of leaves
* [getmerkletree](https://zpass.docs.aleo.org/zpass-sdk/overview/getmerkletree "mention") **-** Constructs and serializes a Merkle tree from a list of leaves.
* [getmerkleproof](https://zpass.docs.aleo.org/zpass-sdk/overview/getmerkleproof "mention") **-** Generates a Merkle proof for a specified leaf index.
* [getleaveshashes](https://zpass.docs.aleo.org/zpass-sdk/overview/getleaveshashes "mention") **-** Hashes an array of raw values to produce leaf nodes.
* [signmerkleroot](https://zpass.docs.aleo.org/zpass-sdk/overview/signmerkleroot "mention") **-** Signs a Merkle root using the account’s private key.

## Worker Management

* [createaleoworker](https://zpass.docs.aleo.org/zpass-sdk/overview/createaleoworker "mention") - Create a Web Worker for Aleo computations
* [initthreadpool](https://zpass.docs.aleo.org/zpass-sdk/overview/initthreadpool "mention") - Initialize a thread pool for improved performance

## Getting Started

For a quick introduction to using the SDK, check out [quickstart](https://zpass.docs.aleo.org/zpass/quickstart "mention").