# Using @dfinity/agent in node.js

**URL:** <https://forum.dfinity.org/t/using-dfinity-agent-in-node-js/6169>\
**Category:** Developers\
**Created:** [July 28, 2021, 12:46pm UTC](https://forum.dfinity.org/t/using-dfinity-agent-in-node-js/6169 "2021-07-28T12:46:12Z")\
**Posts on this page:** 1\
**Showing post:** 41

<div class="post-metadata">

**Author:** ![anon74414410](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@anon74414410](https://forum.dfinity.org/u/anon74414410)\
**Post date:** [February 25, 2022, 9:59pm UTC](https://forum.dfinity.org/t/using-dfinity-agent-in-node-js/6169/41 "2022-02-25T21:59:12Z")

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Update - @ericswanson helped me unblock this:

**seed.txt**

```auto
early cinnamon crucial teach mobile just toast real rebel around card priority spike aerobic result account marble hero action intact inside elbow wrestle oval

```

`$ keysmith principal` yields  
`bh66w-ffyze-maien-ejjje-wzhqi-crrjo-rcgs7-twjrh-kf2km-hbtia-eae`

**seed.js**

```javascript
const Identity = require("@dfinity/identity");
const hdkey = require("hdkey");
const fs = require("fs");

const { Secp256k1KeyIdentity } = Identity;

const bip39 = require("bip39");

const phrase = fs.readFileSync("seed.txt").toString().trim();

export const identityFromSeed = async (phrase) => {
  const seed = await bip39.mnemonicToSeed(phrase);
  const root = hdkey.fromMasterSeed(seed);
  const addrnode = root.derive("m/44'/223'/0'/0/0");

  return Secp256k1KeyIdentity.fromSecretKey(addrnode.privateKey);
};

identityFromSeed(phrase).then((identity) => {
  console.log(identity.getPrincipal().toString());
});

```

`$ node seed.js` yields  
`bh66w-ffyze-maien-ejjje-wzhqi-crrjo-rcgs7-twjrh-kf2km-hbtia-eae`

We still have to hunt down the implementation used by [rust-openssl/pkey.rs at master · sfackler/rust-openssl · GitHub](https://github.com/sfackler/rust-openssl/blob/master/openssl/src/pkey.rs#L518), but this should open up the possibility to use a single identity across JS and `dfx`, from a shared seed phrase!

Of course, this comes with some security caveats -

- Do not ever commit a seed phrase to your souce code.
- THIS PATTERN SHOULD NEVER BE USED IN A FRONTEND APPLICATION
- Use a different identity for each project to mitigate risk
- Dfinity does not officially endorse doing this

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_[View the full topic](https://forum.dfinity.org/t/using-dfinity-agent-in-node-js/6169)._