@xmtp/grpc-api-client

GRPC API Client

An API Client that satisfies the xmtp-js ApiClient interface, to be used in Node.js applications.

Features

• Uses GRPC/Protobuf instead of HTTP/JSON for better performance
• Uses the XMTP Subscribe2 endpoint to allow updating subscriptions without closing the connection
• Configurable logger using pino

Usage

First, install the package in your project:

yarn add @xmtp/grpc-api-client

import { GrpcApiClient } from "@xmtp/grpc-api-client"
import { Client } from "@xmtp/xmtp-js"

const client = await Client.create(someWallet, {
  apiClientFactory: GrpcApiClient.fromOptions,
})

API Reference

subscribe(params: SubscribeParams, callback: SubscribeCallback, onConnectionLost: OnConnectionLostCallback): SubscriptionManager

This method is used to subscribe to a stream of new envelopes matching a predicate. It returns a SubscriptionManager which provides methods to unsubscribe and update content topics.

publish(messages: PublishParams[])`

This method is used to publish messages to the network. It takes an array of PublishParams as input.

query(params: QueryParams, options: QueryAllOptions): Promise<messageApi.Envelope[]>`

This method is used to query the store for messages. It returns a promise that resolves to an array of messageApi.Envelope.

Examples

Subscribing to a stream

let numEnvelopes = 0
const subscriptionManager = apiClient.subscribe(
  { contentTopics: [randomTopic] },
  () => {
    numEnvelopes++
  },
)

Publishing messages

await apiClient.publish([buildPublishParams({}), buildPublishParams({})])

Querying for messages

const results = await apiClient.query({ contentTopic: randomTopic }, {})

Please refer to the test files for more detailed examples and use cases