# @libp2p/dcutr

> Implementation of the DCUtR Protocol

Latest version **3.0.31** (published 2026-10-18) · Apache-2.0 OR MIT license · 0 weekly downloads

## Install

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

## Health

**Score 55/100 (C)** — status: active.

Positive: no vulnerabilities; recently updated; high maintenance score.

Warnings: low downloads; no types; no esm support.

## Facts

| | |
|---|---|
| Version | 3.0.31 |
| Published | 2026-10-18 |
| First published | 2023-11-09 |
| Weekly downloads | 0 |
| License | Apache-2.0 OR MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 2577 |
| Maintainers | daviddias, alanshaw, achingbrain, vascosantos, npm-service-account-libp2p, jacobheun |

## Links

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

## Recent versions

- 3.0.31 (latest) — 2026-10-18
- 3.0.31-7fa88999d (next) — 2026-10-19
- 3.0.31-c57bf6228 — 2026-10-19
- 3.0.31-3da8bab7c — 2026-10-19
- 3.0.31-b927d5921 — 2026-10-18
- 3.0.31-aa5ba42d0 — 2026-10-18
- 3.0.30-2d4c93ed6 — 2026-10-17
- 3.0.30-d1ce8bdbe — 2026-10-17
- 3.0.30-95392efdf — 2026-10-17
- 3.0.30-f0e64b9b8 — 2026-10-17
- 3.0.30-57c4b4456 — 2026-10-17
- 3.0.30-6d888970e — 2026-10-17
- 3.0.30 — 2026-10-17
- 3.0.29-be63a4416 — 2026-10-16
- 3.0.29-e48eabf67 — 2026-10-16
- … 759 more at https://npm.io/package/@libp2p/dcutr/versions

## README

# @libp2p/dcutr

[![libp2p.io](https://img.shields.io/badge/project-libp2p-yellow.svg?style=flat-square)](http://libp2p.io/)
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> Implementation of the DCUtR Protocol

# 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.

-->

Direct Connection Upgrade through Relay (DCUtR) is a protocol that allows two
nodes to connect to each other who would otherwise be prevented doing so due
to being behind NATed connections or firewalls.

The protocol involves making a relayed connection between the two peers and
using the relay to synchronize connection timings so that they dial each other
at precisely the same moment.

## Example

```TypeScript
import { createLibp2p } from 'libp2p'
import { circuitRelayTransport } from '@libp2p/circuit-relay-v2'
import { tcp } from '@libp2p/tcp'
import { identify } from '@libp2p/identify'
import { dcutr } from '@libp2p/dcutr'
import { multiaddr } from '@multiformats/multiaddr'

const node = await createLibp2p({
  transports: [
    circuitRelayTransport(),
    tcp()
  ],
  services: {
    identify: identify(),
    dcutr: dcutr()
  }
})

// QmTarget is a peer that is behind a NAT, supports TCP and has a relay
// reservation
const ma = multiaddr('/ip4/.../p2p/QmRelay/p2p-circuit/p2p/QmTarget')
await node.dial(ma)

// after a while the connection should automatically get upgraded to a
// direct connection (e.g. non-limited)
while (true) {
  const connections = node.getConnections()

  if (connections.find(conn => conn.limits == null)) {
    console.info('have direct connection')
    break
  } else {
    console.info('have relayed connection')

    // wait a few seconds to see if it's succeeded yet
    await new Promise<void>((resolve) => {
      setTimeout(() => resolve(), 5000)
    })
  }
}
```

# Install

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

## Browser `<script>` tag

Loading this module through a script tag will make its exports available as `Libp2pDcutr` in the global namespace.

```html
<script src="https://unpkg.com/@libp2p/dcutr/dist/index.min.js"></script>
```

# API Docs

- <https://libp2p.github.io/js-libp2p/modules/_libp2p_dcutr.html>

# License

Licensed under either of

- Apache 2.0, ([LICENSE-APACHE](https://github.com/libp2p/js-libp2p/blob/main/packages/protocol-dcutr/LICENSE-APACHE) / <http://www.apache.org/licenses/LICENSE-2.0>)
- MIT ([LICENSE-MIT](https://github.com/libp2p/js-libp2p/blob/main/packages/protocol-dcutr/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/dcutr · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._