# @iota/checksum

> Add, remove and validate checksums

Latest version **1.0.0-beta.30** (published 2020-06-18) · MIT license · 0 weekly downloads

## Install

```sh
npm install @iota/checksum
pnpm add @iota/checksum
yarn add @iota/checksum
bun add @iota/checksum
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: has types; no vulnerabilities; high quality score.

Warnings: low downloads; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.0.0-beta.30 |
| Published | 2020-06-18 |
| First published | 2018-06-25 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Dependencies | 2 |
| Unpacked size | 92.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 948 |
| Maintainers | domschiener, laumair, lexerr, lucasfernog, martyniota, nothingismagick |
| Keywords | iota, tangle, address, checksum |

## Links

- npm: https://www.npmjs.com/package/@iota/checksum
- Repository: https://github.com/iotaledger/iota.js.git/tree/develop/packages/crypto
- Issues: https://github.com/iotaledger/iota.js/issues
- npm.io page: https://npm.io/package/@iota/checksum

## Dependencies (2)

- [@iota/kerl](https://npm.io/package/@iota/kerl.md) ^1.0.0-beta.30
- [@iota/converter](https://npm.io/package/@iota/converter.md) ^1.0.0-beta.30

## Recent versions

- 1.0.0-beta.30 (latest) — 2020-06-18
- 1.0.0-alpha.a09e7908 (canary) — 2019-02-20
- 1.0.0-beta.23 — 2019-11-27
- 1.0.0-beta.21 — 2019-08-05
- 1.0.0-beta.19 — 2019-07-19
- 1.0.0-beta.16 — 2019-06-20
- 1.0.0-beta.15 — 2019-06-14
- 1.0.0-beta.12 — 2019-04-09
- 1.0.0-beta.11 — 2019-02-22
- 1.0.0-beta.10 — 2019-02-21
- 1.0.0-beta.9 — 2019-02-21
- 1.0.0-alpha.66ccc99f — 2019-02-19
- 1.0.0-alpha.e5bd9497 — 2019-02-19
- 1.0.0-alpha.912642aa — 2019-02-18
- 1.0.0-alpha.899a376d — 2019-02-17
- … 25 more at https://npm.io/package/@iota/checksum/versions

## README

# @iota/checksum

Add, remove and validate checksums.

## Installation

Install using [npm](https://www.npmjs.org/):
```
npm install @iota/checksum
```

or using [yarn](https://yarnpkg.com/):

``` yarn
yarn add @iota/checksum
```

## API Reference

    
* [checksum](#module_checksum)

    * [.addChecksum(input, [checksumLength], [isAddress])](#module_checksum.addChecksum)

    * [.removeChecksum(input)](#module_checksum.removeChecksum)

    * [.isValidChecksum(addressWithChecksum)](#module_checksum.isValidChecksum)


<a name="module_checksum.addChecksum"></a>

### *checksum*.addChecksum(input, [checksumLength], [isAddress])
**Summary**: Generates a checksum and appends it to the given trytes.  
**Throws**:

- <code>errors.INVALID\_ADDRESS</code> : Make sure that the given address is 90 trytes long.
- <code>errors.INVALID\_TRYTES</code> : Make sure that the `input` argument contains only [trytes](https://docs.iota.org/docs/getting-started/0.1/introduction/ternary)
- <code>errors.INVALID\_CHECKSUM\_LENGTH</code> : Make sure that the `checksumLength` argument is a number greater than or equal to 3. If the `isAddress` argument is set to true, make sure that the `checksumLength` argument is 9.


| Param | Type | Default | Description |
| --- | --- | --- | --- |
| input | <code>string</code> |  | 81 trytes to which to append the checksum |
| [checksumLength] | <code>number</code> | <code>9</code> | Length of the checksum to generate |
| [isAddress] | <code>boolean</code> | <code>true</code> | Whether the input is an address |

This method takes 81 trytes, which could be an address or a seed, generates the [checksum](https://docs.iota.org/docs/getting-started/0.1/clients/checksums) and appends it to the trytes.

To generate a checksum that is less than 9 trytes long, make sure to set the `isAddress` argument to false.

## Related methods

To generate an address, use the [`getNewAddress()`](#module_core.getNewAddress) method.

**Returns**: <code>string</code> - The original trytes with an appended checksum.  
**Example**  
```js
let addressWithChecksum = Checksum.addChecksum('ADDRESS...');
```
<a name="module_checksum.removeChecksum"></a>

### *checksum*.removeChecksum(input)
**Summary**: Removes the checksum from the given address.  
**Throws**:

- <code>errors.INVALID\_ADDRESS</code> : Make sure that the given address is 90 trytes long.


| Param | Type | Description |
| --- | --- | --- |
| input | <code>string</code> | Address from which to remove the checksum |

This method takes an address of 90 trytes, and removes the last 9 trytes to return the address without a checksum.

## Related methods

To generate an address, use the [`getNewAddress()`](#module_core.getNewAddress) method.
To add a checksum to an address, use the [`addChecksum()`](#module_checksum.addChecksum) method.

**Returns**: <code>string</code> - The original address without the appended checksum.  
**Example**  
```js
let addressWithoutChecksum = Checksum.removeChecksum('ADDRESS...');
```
<a name="module_checksum.isValidChecksum"></a>

### *checksum*.isValidChecksum(addressWithChecksum)
**Summary**: Validates the checksum of an address.  
**Throws**:

- <code>errors.INVALID\_ADDRESS</code> : Make sure that the given address is 90 trytes long.


| Param | Type | Description |
| --- | --- | --- |
| addressWithChecksum | <code>string</code> | Address with a checksum |

This method takes an address of 90 trytes, and checks if the checksum is valid.

## Related methods

To generate an address, use the [`getNewAddress()`](#module_core.getNewAddress) method.
To add a checksum to an address, use the [`addChecksum()`](#module_checksum.addChecksum) method.

**Returns**: <code>boolean</code> - Whether the checksum is valid.  
**Example**  
```js
let valid = Checksum.isValidChecksum('ADDRESS...');
```

---
_Source: https://npm.io/package/@iota/checksum · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._