js-waku/README.md

# js-waku

A JavaScript implementation of the [Waku v2 protocol](https://rfc.vac.dev/spec/10/).

## Usage

Install `js-waku` package:

```shell
npm install js-waku
```

### Start a waku node

```ts
import { Waku } from 'js-waku';

const waku = await Waku.create();
```

### Connect to a new peer

```ts
// Directly dial a new peer
await waku.dial('/dns4/node-01.do-ams3.wakuv2.test.statusim.net/tcp/443/wss/p2p/16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ');

// Or, add peer to address book so it auto dials in the background
waku.addPeerToAddressBook(
  '16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ',
  ['/dns4/node-01.do-ams3.wakuv2.test.statusim.net/tcp/443/wss']
);
```

You can also use `getStatusFleetNodes` to connect to nodes run by Status:

```ts
import { getStatusFleetNodes } from 'js-waku';

getStatusFleetNodes().then((nodes) => {
  nodes.forEach((addr) => {
    waku.dial(addr);
  });
});
```

### Listen for messages

The `contentTopic` is a metadata `string` that allows categorization of messages on the waku network.
Depending on your use case, you can either create one (or several) new `contentTopic`(s) or look at the [RFCs](https://rfc.vac.dev/) and use an existing `contentTopic`.
See the [Waku v2 Topic Usage Recommendations](https://rfc.vac.dev/spec/23/) for more details.

For example, if you were to use a new `contentTopic` such as `/my-cool-app/1/my-use-case/proto`,
here is how to listen to new messages received via [Waku v2 Relay](https://rfc.vac.dev/spec/11/):

```ts
waku.relay.addObserver((msg) => {
  console.log("Message received:", msg.payloadAsUtf8)
}, ["/my-cool-app/1/my-use-case/proto"]);
```

The examples chat apps currently use content topic `"/toy-chat/2/huilong/proto"`.

### Send messages

There are two ways to send messages:

#### Waku Relay

[Waku Relay](https://rfc.vac.dev/spec/11/) is the most decentralized option,
peer receiving your messages are unlikely to know whether you are the originator or simply forwarding them.
However, it does not give you any delivery information.

```ts
import { WakuMessage } from 'js-waku';

const msg = await WakuMessage.fromUtf8String("Here is a message!", { contentTopic: "/my-cool-app/1/my-use-case/proto" })
await waku.relay.send(msg);
```

#### Waku Light Push

[Waku Light Push](https://rfc.vac.dev/spec/19/) gives you confirmation that the light push server node has
received your message.
However, it means that said node knows you are the originator of the message.
It cannot guarantee that the node will forward the message.

```ts
const ack = await waku.lightPush.push(message);
if (!ack?.isSuccess) {
  // Message was not sent
}
```

### Retrieve archived messages

The [Waku v2 Store protocol](https://rfc.vac.dev/spec/13/) enables more permanent nodes to store messages received via relay
and ephemeral clients to retrieve them (e.g. mobile phone resuming connectivity).
The protocol implements pagination meaning that it may take several queries to retrieve all messages.

Query a waku store peer to check historical messages:

```ts
// Process messages once they are all retrieved
const messages = await waku.store.queryHistory({ contentTopics: ["/my-cool-app/1/my-use-case/proto"] });
messages.forEach((msg) => {
  console.log("Message retrieved:", msg.payloadAsUtf8)
})

// Or, pass a callback function to be executed as pages are received:
waku.store.queryHistory({
    contentTopics: ["/my-cool-app/1/my-use-case/proto"],
    callback: (messages) => {
      messages.forEach((msg) => {
        console.log("Message retrieved:", msg.payloadAsUtf8);
      });
    }
  });
```

## Encryption & Signature

With js-waku, you can:

- Encrypt messages over the wire using public/private key pair (asymmetric encryption),
- Encrypt messages over the wire using a unique key to both encrypt and decrypt (symmetric encryption),
- Sign and verify your waku messages (must use encryption, compatible with both symmetric and asymmetric).

### Cryptographic Libraries

A quick note on the cryptographic libraries used as it is a not a straightforward affair:
- Asymmetric encryption:
  Uses [ecies-geth](https://github.com/cyrildever/ecies-geth/)
  which in turns uses [SubtleCrypto](https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto) Web API (browser),
  [secp256k1](https://www.npmjs.com/package/secp256k1) (native binding for node)
  or [elliptic](https://www.npmjs.com/package/elliptic) (pure JS if none of the other libraries are available).
- Symmetric encryption:
  Uses [SubtleCrypto](https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto) Web API (browser)
  or [NodeJS' crypto](https://nodejs.org/api/crypto.html) module.

### Create new keys

Asymmetric private keys and symmetric keys are expected to be 32 bytes arrays.

```ts
import { generatePrivateKey, getPublicKey } from 'js-waku';

// Asymmetric
const privateKey = generatePrivateKey();
const publicKey = getPublicKey(privateKey);

// Symmetric
const symKey = generatePrivateKey();
```

### Encrypt Waku Messages

To encrypt your waku messages, simply pass the encryption key when creating it:

```ts
import { WakuMessage } from 'js-waku';

// Asymmetric
const message = await WakuMessage.fromBytes(payload, {
    contentTopic: myAppContentTopic,
    encPublicKey: publicKey,
  });

// Symmetric
const message = await WakuMessage.fromBytes(payload, {
    contentTopic: myAppContentTopic,
    symKey: symKey,
  });
```

### Decrypt Waku Messages

#### Waku Relay

If you expect to receive encrypted messages then simply add private decryption key(s) to `WakuRelay`.
Waku Relay will attempt to decrypt incoming messages with each keys, both for symmetric and asymmetric encryption.
Messages that are successfully decrypted (or received in clear) will be passed to the observers, other messages will be omitted.

```ts
// Asymmetric
waku.relay.addDecryptionKey(privateKey);

// Symmetric
waku.relay.addDecryptionKey(symKey);

// Then add the observer
waku.relay.addObserver(callback, [contentTopic]);
```

Keys can be removed using `WakuMessage.deleteDecryptionKey`.

#### Waku Store

```ts
const messages = await waku.store.queryHistory({
  contentTopics: [],
  decryptionKeys: [privateKey, symKey],
});
```

Similarly to relay, only decrypted or clear messages will be returned.

### Sign Waku Messages

As per version 1`s [specs](https://rfc.vac.dev/spec/26/), signatures are only included in encrypted messages.
In the case where your app does not need encryption then you could use symmetric encryption with a trivial key, I intend to dig [more on the subject](https://github.com/status-im/js-waku/issues/74#issuecomment-880440186) and come back with recommendation and examples.

Signature keys can be generated the same way asymmetric keys for encryption are:

```ts
import { generatePrivateKey, getPublicKey, WakuMessage } from 'js-waku';

const signPrivateKey = generatePrivateKey();

// Asymmetric Encryption
const message = await WakuMessage.fromBytes(payload, {
    contentTopic: myAppContentTopic,
    encPublicKey: recipientPublicKey,
    sigPrivKey: signPrivateKey
  });

// Symmetric Encryption
const message = await WakuMessage.fromBytes(payload, {
    contentTopic: myAppContentTopic,
    encPublicKey: symKey,
    sigPrivKey: signPrivateKey
  });
```

### Verify Waku Message signatures

Two fields are available on `WakuMessage` regarding signatures:

- `signaturePublicKey`: If the message is signed, it holds the public key of the signature,
- `signature`: If the message is signed, it holds the actual signature.

Thus, if you expect messages to be signed by Alice,
you can simply compare `WakuMessage.signaturePublicKey` with Alice's public key.
As comparing hex string can lead to issues (is the `0x` prefix present?),
simply use helper function `equalByteArrays`.

```ts
import { equalByteArrays } from 'js-waku/lib/utils';

const sigPubKey = wakuMessage.signaturePublicKey;

const isSignedByAlice = sigPubKey && equalByteArrays(sigPubKey, alicePublicKey);
```

## More documentation

Find more [examples](#examples) below
or checkout the latest `main` branch documentation at [https://status-im.github.io/js-waku/docs/](https://status-im.github.io/js-waku/docs/).

Docs can also be generated locally using:

```shell
npm install
npm run doc
```

## Changelog

Release changelog can be found [here](https://github.com/status-im/js-waku/blob/main/CHANGELOG.md).

## Waku Protocol Support

You can track progress on the [project board](https://github.com/status-im/js-waku/projects/1).

- ✔: Supported
- 🚧: Implementation in progress
- ⛔: Support is not planned

| Spec | Implementation Status |
| ---- | -------------- |
|[6/WAKU1](https://rfc.vac.dev/spec/6)|⛔|
|[7/WAKU-DATA](https://rfc.vac.dev/spec/7)|⛔|
|[8/WAKU-MAIL](https://rfc.vac.dev/spec/8)|⛔|
|[9/WAKU-RPC](https://rfc.vac.dev/spec/9)|⛔|
|[10/WAKU2](https://rfc.vac.dev/spec/10)|🚧|
|[11/WAKU2-RELAY](https://rfc.vac.dev/spec/11)|✔|
|[12/WAKU2-FILTER](https://rfc.vac.dev/spec/12)||
|[13/WAKU2-STORE](https://rfc.vac.dev/spec/13)|✔ (querying node only)|
|[14/WAKU2-MESSAGE](https://rfc.vac.dev/spec/14)|✔|
|[15/WAKU2-BRIDGE](https://rfc.vac.dev/spec/15)||
|[16/WAKU2-RPC](https://rfc.vac.dev/spec/16)|⛔|
|[17/WAKU2-RLNRELAY](https://rfc.vac.dev/spec/17)||
|[18/WAKU2-SWAP](https://rfc.vac.dev/spec/18)||
|[19/WAKU2-LIGHTPUSH](https://rfc.vac.dev/spec/19/)|✔|

## Bugs, Questions & Features

If you encounter any bug or would like to propose new features, feel free to [open an issue](https://github.com/status-im/js-waku/issues/new/).

For support, questions & more general topics,
please join the discussion on the [Vac forum](https://forum.vac.dev/tag/js-waku) (use _\#js-waku_ tag)
or [\#waku-support on Status Community Discord](https://discord.gg/Q9aNS6Fg).

## Examples

## Web Chat App (ReactJS)

A ReactJS chat app is provided as a showcase of the library used in the browser.
It implements [Waku v2 Toy Chat](https://rfc.vac.dev/spec/22/) protocol.
A deployed version is available at https://status-im.github.io/js-waku/.

Find the code in the [examples folder](https://github.com/status-im/js-waku/tree/main/examples/web-chat).

To run a development version locally, do:

```shell
git clone https://github.com/status-im/js-waku/ ; cd js-waku
npm install   # Install dependencies for js-waku
npm run build # Build js-waku
cd examples/web-chat   
npm install   # Install dependencies for the web app
npm run start # Start development server to serve the web app on http://localhost:3000/js-waku
```

Use `/help` to see the available commands.

## CLI Chat App (NodeJS)

A node chat app is provided as a working example of the library.
It implements [Waku v2 Toy Chat](https://rfc.vac.dev/spec/22/) protocol.

Find the code in the [examples folder](https://github.com/status-im/js-waku/tree/main/examples/cli-chat).

To run the chat app, first ensure you have [Node.js](https://nodejs.org/en/) v14 or above:

```shell
node --version
```

Then, install and run:

```shell
git clone https://github.com/status-im/js-waku/ ; cd js-waku
npm install   # Install dependencies for js-waku
npm run build # Build js-waku
cd examples/cli-chat
npm install # Install dependencies for the cli app
npm run start -- --autoDial
```

You can also specify an optional `listenAddr` parameter (.e.g `--listenAddr /ip4/0.0.0.0/tcp/7777/ws`).
This is only useful if you want a remote node to dial to your chat app, 
it is not necessary in normal usage when you just connect to the fleet.

## Ethereum Direct Message

A PoC implementation of [20/ETH-DM](https://rfc.vac.dev/spec/20/).

Ethereum Direct Message, or Eth-DM, is a protocol that allows sending encrypted message to a recipient,
only knowing their Ethereum Address.

This is protocol has been created to demonstrated how encryption and signature could be added to messages
sent over the Waku v2 network.

The `main` branch's HEAD is deployed on GitHub Pages at https://status-im.github.io/js-waku/eth-dm/.

To run a development version locally, do:

```shell
git clone https://github.com/status-im/js-waku/ ; cd js-waku
npm install   # Install dependencies for js-waku
npm run build # Build js-waku
cd examples/eth-dm   
npm install   # Install dependencies for the web app
npm run start # Start development server to serve the web app on http://localhost:3000/js-waku/eth-dm
```

## Contributing

See [CONTRIBUTING.md](./CONTRIBUTING.md).

## License
Licensed and distributed under either of

* MIT license: [LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT

or

* Apache License, Version 2.0, ([LICENSE-APACHE-v2](LICENSE-APACHE-v2) or http://www.apache.org/licenses/LICENSE-2.0)

at your option. These files may not be copied, modified, or distributed except according to those terms.