# c32check

{% hint style="info" %}
For the c32check open-source repo: <https://github.com/stacks-network/c32check>
{% endhint %}

The Stacks blockchain uses c32-encoded public key hashes as addresses. Specifically, a **c32check address** is a c32check-encoded ripemd160 hash. This library is meant for generating and decoding addresses on the Stacks blockchain.

### How it works

Each c32check string encodes a 1-byte version and a 4-byte checksum. When decoded as a hex string, the wire format looks like this:

```
0      1                             n+1             n+5
|------|-----------------------------|---------------|
version     n-byte hex payload          4-byte hash
```

If `version` is the version byte (a 1-byte `number`) and `payload` is the raw bytes (e.g. as a `string`), then the `checksum` is calculated as follows:

```
checksum = sha256(sha256(version + payload)).substring(0,4)
```

In other words, the checksum is the first four bytes of the double-sha256 of the bytestring concatenation of the `version` and `payload`. This is similar to base58check encoding, for example.

### Examples

**Installation**

{% code title="terminal" %}

```shellscript
npm install c32check
```

{% endcode %}

```typescript
> c32 = require('c32check')
{ c32encode: [Function: c32encode],
  c32decode: [Function: c32decode],
  c32checkEncode: [Function: c32checkEncode],
  c32checkDecode: [Function: c32checkDecode],
  c32address: [Function: c32address],
  c32addressDecode: [Function: c32addressDecode],
  versions:
   { mainnet: { p2pkh: 22, p2sh: 20 },
     testnet: { p2pkh: 26, p2sh: 21 } },
  c32ToB58: [Function: c32ToB58],
  b58ToC32: [Function: b58ToC32] }
```

#### c32encode, c32decode

```typescript
> c32check.c32encode(Buffer.from('hello world').toString('hex'))
'38CNP6RVS0EXQQ4V34'
> c32check.c32decode('38CNP6RVS0EXQQ4V34')
'68656c6c6f20776f726c64'
> Buffer.from('68656c6c6f20776f726c64', 'hex').toString()
'hello world'
```

#### c32checkEncode, c32checkDecode

```typescript
> version = 12
> c32check.c32checkEncode(version, Buffer.from('hello world').toString('hex'))
'CD1JPRV3F41VPYWKCCGRMASC8'
> c32check.c32checkDecode('CD1JPRV3F41VPYWKCCGRMASC8')
[ 12, '68656c6c6f20776f726c64' ]
> Buffer.from('68656c6c6f20776f726c64', 'hex').toString()
'hello world'
```

#### c32address, c32addressDecode

> **Note**: These methods only work on ripemd160 hashes

```typescript
> hash160 = 'a46ff88886c2ef9762d970b4d2c63678835bd39d'
> version = c32check.versions.mainnet.p2pkh
22
> c32check.c32address(version, hash160)
'SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7'
> c32check.c32addressDecode('SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7')
[ 22, 'a46ff88886c2ef9762d970b4d2c63678835bd39d' ]
```

#### c32ToB58, b58ToC32

Convert a Stacks address to its corresponding Bitcoin address, or vice versa.

> **Note**: Common address versions are converted between c32check and base58check seamlessly, in order to accommodate Stacks addresses.

```typescript
> b58addr = '16EMaNw3pkn3v6f2BgnSSs53zAKH4Q8YJg'
> c32check.b58ToC32(b58addr)
'SPWNYDJ3STG7XH7ERWXMV6MQ7Q6EATWVY5Q1QMP8'
> c32check.c32ToB58('SPWNYDJ3STG7XH7ERWXMV6MQ7Q6EATWVY5Q1QMP8')
'16EMaNw3pkn3v6f2BgnSSs53zAKH4Q8YJg'
```

```typescript
> b58addr = '3D2oetdNuZUqQHPJmcMDDHYoqkyNVsFk9r'
> c32check.b58ToC32(b58addr)
'SM1Y6EXF21RZ9739DFTEQKB1H044BMM0XVCM4A4NY'
> c32check.c32ToB58('SM1Y6EXF21RZ9739DFTEQKB1H044BMM0XVCM4A4NY')
'3D2oetdNuZUqQHPJmcMDDHYoqkyNVsFk9r'
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.stacks.co/reference/stacks.js/c32check.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.