dfuse Firehose Node.js (JavaScript) Example

This simple program demonstrates how easy it is to stream full block details using StreamingFast gRPC API:

• Request a token from our authentication API
• Creates a gRPC connection with credentials
• Instantiates a BlockStream client
• Start a stream of blocks
• Prints the blocks received

Requirements

You will need to have Node.js 10+ as well as Yarn or NPM.

Quickstart

First of all, visit https://app.dfuse.io/ to get a free API key for your project.

First, clone this repository to your work folder:

git clone https://github.com/dfuse-io/example-firehose-eosio-nodejs.git
cd example-firehose-eosio-nodejs

Install all dependencies:

yarn install

Once your environment is setup properly, simply run the index.js script:

node index.js YOUR_API_KEY_HERE

By default it prints light details about the blocks, use the --full flag to print the full block in JSON:

node index.js YOUR_API_KEY_HERE --full

Note The default JSON.stringify will prints the various bytes type using base64 encoding, this is unfortunate as it makes reading it in the JSON harder. If you find a quick option to print it as hexadecimal, open a PR we will be happy to merge it in.

dfuse Community Edition

The dfuse Firehose service is also available via EOS Nation dfuse Community Edition. Access to the dfuse Community Edition does not require authentication, and is rate-limited. A higher rate limit is available to authenticatated users. The service being shared with the whole community, please be mindful of your requests. To create an API key for the dfuse Community Edition, visit EOS Nation Account Page.

Update the example createDfuseClient to looks like:

  const dfuse = createDfuseClient({
    apiKey: process.argv[2],
    network: "eos.firehose.eosnation.io",
  })

And bstreamService.BlockStreamV2 call to looks like:

  const client = new bstreamService.BlockStreamV2(
    "eos.firehose.eosnation.io:9000",
    grpc.credentials.createSsl()
  )