# 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](/zpass-sdk/overview/signcredential.md) - Sign credential data with a private key
* [issueZPass](/zpass-sdk/overview/issuezpass.md) - Issue a new ZPass credential on-chain
* [getZPassRecord](/zpass-sdk/overview/getzpassrecord.md) - Retrieve and decrypt a ZPass record from the blockchain

### Proof Operations

* [proveOnChain](/zpass-sdk/overview/proveonchain.md) - Generate an on-chain proof for a ZPass credential
* [proveOffChain](/zpass-sdk/overview/proveoffchain.md) - Generate an off-chain proof locally
* [verifyOnChain](/zpass-sdk/overview/verifyonchain.md) - Verify an on-chain ZPass proof
* [verifyOffChain](/zpass-sdk/overview/verifyoffchain.md) - Verify an off-chain ZPass proof locally

### Merkle Tree Operations

* [getMerkleRoot](/zpass-sdk/overview/getmerkleroot.md) - Computes the Merkle root from an array of leaves
* [getMerkleTree](/zpass-sdk/overview/getmerkletree.md) **-** Constructs and serializes a Merkle tree from a list of leaves.
* [getMerkleProof](/zpass-sdk/overview/getmerkleproof.md) **-** Generates a Merkle proof for a specified leaf index.
* [getLeavesHashes](/zpass-sdk/overview/getleaveshashes.md) **-** Hashes an array of raw values to produce leaf nodes.
* [signMerkleRoot](/zpass-sdk/overview/signmerkleroot.md) **-** Signs a Merkle root using the account’s private key.

## Worker Management

* [createAleoWorker](/zpass-sdk/overview/createaleoworker.md) - Create a Web Worker for Aleo computations
* [initThreadPool](/zpass-sdk/overview/initthreadpool.md) - Initialize a thread pool for improved performance

## Getting Started

For a quick introduction to using the SDK, check out [Quickstart](/zpass/quickstart.md).


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