# ecpair

> Client-side Bitcoin JavaScript library ECPair

Latest version **3.0.2** (published 2026-08-28) · MIT license · 0 weekly downloads

## Install

```sh
npm install ecpair
pnpm add ecpair
yarn add ecpair
bun add ecpair
```

## Health

**Score 70/100 (B)** — status: active.

Positive: has types; esm support; no vulnerabilities; recently updated; high maintenance score; high quality score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 3.0.2 |
| Published | 2026-08-28 |
| First published | 2021-10-20 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Node | >=20.0.0 |
| Dependencies | 3 |
| Unpacked size | 44.6 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 29 |
| Maintainers | junderw, jl.landabaso |
| Keywords | bitcoinjs, bitcoin, browserify, javascript, bitcoinjs |

## Links

- npm: https://www.npmjs.com/package/ecpair
- Repository: https://github.com/bitcoinjs/ecpair
- Homepage: https://github.com/bitcoinjs/ecpair#readme
- Issues: https://github.com/bitcoinjs/ecpair/issues
- npm.io page: https://npm.io/package/ecpair

## Dependencies (3)

- [wif](https://npm.io/package/wif.md) ^5.0.0
- [valibot](https://npm.io/package/valibot.md) ^1.2.0
- [uint8array-tools](https://npm.io/package/uint8array-tools.md) ^0.0.8

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## Recent versions

- 3.0.2 (latest) — 2026-08-28
- 3.0.1 — 2026-02-12
- 3.0.0 — 2025-03-07
- 3.0.0-rc.0 — 2024-09-08
- 2.1.0 — 2022-09-26
- 2.0.1 — 2021-12-17
- 2.0.0 — 2021-12-15
- 1.0.1 — 2021-10-21
- 1.0.0 — 2021-10-20

## README

# ecpair
[![Github CI](https://github.com/bitcoinjs/ecpair/actions/workflows/main_ci.yml/badge.svg)](https://github.com/bitcoinjs/ecpair/actions/workflows/main_ci.yml) [![NPM](https://img.shields.io/npm/v/ecpair.svg)](https://www.npmjs.org/package/ecpair) [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier)

A library for managing SECP256k1 keypairs written in TypeScript with transpiled JavaScript committed to git.

**Note** `ECPair`.makeRandom() uses the `crypto.getRandomValues` if there is no custom `rng` function provided. This API currently is still an experimental feature as of Node.js 18.19.0. To work around this you can do one of the following:
1. Use a polyfill for crypto.getRandomValues()
2. Use the `--experimental-global-webcrypto` flag when running node.js.
3. Pass in a custom rng function to generate random values.

## Example

TypeScript

``` typescript
import { Signer, SignerAsync, ECPairInterface, ECPairFactory, ECPairAPI, TinySecp256k1Interface } from 'ecpair';
import * as crypto from 'crypto';

// You need to provide the ECC library. The ECC library must implement 
// all the methods of the `TinySecp256k1Interface` interface.
const tinysecp: TinySecp256k1Interface = require('tiny-secp256k1');
const ECPair: ECPairAPI = ECPairFactory(tinysecp);

// You don't need to explicitly write ECPairInterface, but just to show
// that the keyPair implements the interface this example includes it.

// From WIF
const keyPair1: ECPairInterface = ECPair.fromWIF('KynD8ZKdViVo5W82oyxvE18BbG6nZPVQ8Td8hYbwU94RmyUALUik');
// Random private key
const keyPair2 = ECPair.fromPrivateKey(crypto.randomBytes(32));
// OR (uses randombytes library, compatible with browser)
const keyPair3 = ECPair.makeRandom();
// OR use your own custom random buffer generator BE CAREFUL!!!!
const customRandomBufferFunc = (size: number): Buffer => crypto.randomBytes(size);
const keyPair4 = ECPair.makeRandom({ rng: customRandomBufferFunc });
// From pubkey (33 or 65 byte DER format public key)
const keyPair5 = ECPair.fromPublicKey(keyPair1.publicKey);

// Pass a custom network
const network = {}; // Your custom network object here
ECPair.makeRandom({ network });
ECPair.fromPrivateKey(crypto.randomBytes(32), { network });
ECPair.fromPublicKey(keyPair1.publicKey, { network });
// fromWIF will check the WIF version against the network you pass in
// pass in multiple networks if you are not sure
ECPair.fromWIF('wif key...', network);
const network2 = {}; // Your custom network object here
const network3 = {}; // Your custom network object here
ECPair.fromWIF('wif key...', [network, network2, network3]);
```

## LICENSE [MIT](LICENSE)
Written and tested by [bitcoinjs-lib](https://github.com/bitcoinjs/bitcoinjs-lib) contributors since 2014.

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