# @libp2p/mdns

> Node.js libp2p mDNS discovery implementation for peer discovery

Latest version **12.0.32** (published 2026-09-02) · Apache-2.0 OR MIT license · 0 weekly downloads

## Install

```sh
npm install @libp2p/mdns
pnpm add @libp2p/mdns
yarn add @libp2p/mdns
bun add @libp2p/mdns
```

## Health

**Score 75/100 (B)** — status: active.

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

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 12.0.32 |
| Published | 2026-09-02 |
| First published | 2022-02-06 |
| Weekly downloads | 0 |
| License | Apache-2.0 OR MIT |
| TypeScript types | bundled |
| Module format | ESM |
| Dependencies | 9 |
| Unpacked size | 1 MB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Provenance | attested (GitHub Actions) |
| GitHub stars | 2579 |
| Maintainers | daviddias, alanshaw, achingbrain, vascosantos, npm-service-account-libp2p, jacobheun |
| Keywords | IPFS |

## Links

- npm: https://www.npmjs.com/package/@libp2p/mdns
- Repository: https://github.com/libp2p/js-libp2p
- Homepage: https://github.com/libp2p/js-libp2p/tree/main/packages/peer-discovery-mdns#readme
- Issues: https://github.com/libp2p/js-libp2p/issues
- npm.io page: https://npm.io/package/@libp2p/mdns

## Dependencies (9)

- [dns-packet](https://npm.io/package/dns-packet.md) ^5.6.1
- [main-event](https://npm.io/package/main-event.md) ^1.0.1
- [@libp2p/utils](https://npm.io/package/@libp2p/utils.md) ^7.4.1
- [multicast-dns](https://npm.io/package/multicast-dns.md) ^7.2.5
- [@libp2p/peer-id](https://npm.io/package/@libp2p/peer-id.md) ^6.0.15
- [@libp2p/interface](https://npm.io/package/@libp2p/interface.md) ^3.3.0
- [@types/multicast-dns](https://npm.io/package/@types/multicast-dns.md) ^7.2.4
- [@multiformats/multiaddr](https://npm.io/package/@multiformats/multiaddr.md) ^13.0.3
- [@libp2p/interface-internal](https://npm.io/package/@libp2p/interface-internal.md) ^3.1.13

## Recent versions

- 12.0.32 (latest) — 2026-09-02
- 12.0.31-5cb617ae2 (next) — 2026-09-02
- 12.0.31-185d901cd — 2026-09-02
- 12.0.31 — 2026-08-31
- 12.0.30-cef4d32cf — 2026-08-31
- 12.0.30-ac7305ccf — 2026-08-31
- 12.0.30-87dca02b0 — 2026-08-27
- 12.0.30-4a6c5d11a — 2026-08-27
- 12.0.30 — 2026-08-23
- 12.0.29-947d304ed — 2026-08-22
- 12.0.29-0967e75f5 — 2026-08-22
- 12.0.29-4dae661b4 — 2026-08-22
- 12.0.29-8786aa8d0 — 2026-08-20
- 12.0.29-55d7a539a — 2026-08-20
- 12.0.29-d5534174d — 2026-08-13
- … 929 more at https://npm.io/package/@libp2p/mdns/versions

## README

# @libp2p/mdns

[![libp2p.io](https://img.shields.io/badge/project-libp2p-yellow.svg?style=flat-square)](http://libp2p.io/)
[![Discuss](https://img.shields.io/discourse/https/discuss.libp2p.io/posts.svg?style=flat-square)](https://discuss.libp2p.io)
[![codecov](https://img.shields.io/codecov/c/github/libp2p/js-libp2p.svg?style=flat-square)](https://codecov.io/gh/libp2p/js-libp2p)
[![CI](https://img.shields.io/github/actions/workflow/status/libp2p/js-libp2p/main.yml?branch=main\&style=flat-square)](https://github.com/libp2p/js-libp2p/actions/workflows/main.yml?query=branch%3Amain)

> Node.js libp2p mDNS discovery implementation for peer discovery

# About

<!--

!IMPORTANT!

Everything in this README between "# About" and "# Install" is automatically
generated and will be overwritten the next time the doc generator is run.

To make changes to this section, please update the @packageDocumentation section
of src/index.js or src/index.ts

To experiment with formatting, please run "npm run docs" from the root of this
repo and examine the changes made.

-->

A peer discover mechanism that uses [mDNS](https://datatracker.ietf.org/doc/html/rfc6762) to discover peers on the local network.

## Example - Use with libp2p

```TypeScript
import { createLibp2p } from 'libp2p'
import { mdns } from '@libp2p/mdns'

const libp2p = await createLibp2p({
  peerDiscovery: [
    mdns()
  ]
})

libp2p.addEventListener('peer:discovery', (evt) => {
  libp2p.dial(evt.detail.multiaddrs) // dial discovered peers
  console.log('found peer: ', evt.detail.toString())
})
```

## MDNS messages

A query is sent to discover the libp2p nodes on the local network

```JSON
{
   "type": "query",
   "questions": [{
     "name": "_p2p._udp.local",
     "type": "PTR"
   }]
}
```

When a query is detected, each libp2p node sends an answer about itself

```JSON
[{
  "name": "_p2p._udp.local",
  "type": "PTR",
  "class": "IN",
  "ttl": 120,
  "data": "QmNPubsDWATVngE3d5WDSNe7eVrFLuk38qb9t6vdLnu2aK._p2p._udp.local"
}, {
  "name": "QmNPubsDWATVngE3d5WDSNe7eVrFLuk38qb9t6vdLnu2aK._p2p._udp.local",
  "type": "SRV",
  "class": "IN",
  "ttl": 120,
  "data": {
    "priority": 10,
    "weight": 1,
    "port": "20002",
    "target": "LAPTOP-G5LJ7VN9"
  }
}, {
  "name": "QmNPubsDWATVngE3d5WDSNe7eVrFLuk38qb9t6vdLnu2aK._p2p._udp.local",
  "type": "TXT",
  "class": "IN",
  "ttl": 120,
  "data": ["QmNPubsDWATVngE3d5WDSNe7eVrFLuk38qb9t6vdLnu2aK"]
}, {
  "name": "LAPTOP-G5LJ7VN9",
  "type": "A",
  "class": "IN",
  "ttl": 120,
  "data": "127.0.0.1"
}, {
  "name": "LAPTOP-G5LJ7VN9",
  "type": "AAAA",
  "class": "IN",
  "ttl": 120,
  "data": "::1"
}]
```

# Install

```console
$ npm i @libp2p/mdns
```

# API Docs

- <https://libp2p.github.io/js-libp2p/modules/_libp2p_mdns.html>

# License

Licensed under either of

- Apache 2.0, ([LICENSE-APACHE](https://github.com/libp2p/js-libp2p/blob/main/packages/peer-discovery-mdns/LICENSE-APACHE) / <http://www.apache.org/licenses/LICENSE-2.0>)
- MIT ([LICENSE-MIT](https://github.com/libp2p/js-libp2p/blob/main/packages/peer-discovery-mdns/LICENSE-MIT) / <http://opensource.org/licenses/MIT>)

# Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

---
_Source: https://npm.io/package/@libp2p/mdns · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._