@waves/node-api-grpc

About

A client for Waves Node gRPC and Blockchain Updates.

How to use

Npm package: @waves/node-api-grpc.

We use:

• @grpc/proto-loader to load proto-files and the embedded app proto-loader-gen-types to generate definitions;
• @grpc/grpc-js to request the data from Waves Node gRPC API;
• long.js to represent 64-bit integers: int64, uint64, etc.

Examples

1. npm install --save @waves/node-api-grpc bs58

   bs58 here for encoding and decoding addresses and ids.

2. default usage with TypeScript looks like:

   import * as w from '@waves/node-api-grpc'
   import b58 from 'bs58'
   
   const grpcChannel = w.grpc.mkDefaultChannel('grpc.wavesnodes.com:6870')
   
   // Node gRPC API - a streaming example
   const transactionsApi = w.api.waves.node.grpc.mkTransactionsApi(grpcChannel)
   const txnId = '287XcMXPDY7pnw2tECbV86TZetPi2x9JBg9BVUsGaSJx';
   transactionsApi
       .getTransactions({transactionIds: [b58.decode(txnId)]}) // see TransactionsRequest
       .on("data", (item: w.api.waves.node.grpc.TransactionResponse) => console.log(`[getTransactions] The transaction '${txnId}' was on height of ${item.height}`))
       .on("end", () => console.log("[getTransactions] Stream ended"))
       .on("error", (e: Error) => console.error("[getTransactions] Failed", e))
   
   // Node gRPC API - an one-shot example
   const accountsApi = w.api.waves.node.grpc.mkAccountsApi(grpcChannel)
   const alias = 'likli'
   accountsApi.resolveAlias(
       {value: alias}, // Accepts google.protobuf.StringValue, that has "value" field
       (error, response) => {
           if (error === null) {
               const addressBytes = response?.value || new Buffer(0);
               console.log(`[resolveAlias] The address of '${alias}' is ${b58.encode(addressBytes)}`)
           } else console.error(`[resolveAlias] Can't determine address of '${alias}'`, error)
       }
   )
   
   // Blokchain updates gRPC API example
   // Note, we have to do another connection
   const blockchainUpdatesChannel = w.grpc.mkDefaultChannel('grpc.wavesnodes.com:6881') // 6881 instead of 6870
     
   const blockchainUpdatesApi = w.api.waves.events.grpc.mkBlockchainUpdatesApi(blockchainUpdatesChannel)
   blockchainUpdatesApi.getBlockUpdate(
       {height: 1},
       (error, response) => {
           if (error === null) {
               const txnIds = (response?.update?.append?.transactionIds || []).map(x => b58.encode(x));
               console.log(`[getBlockUpdate] Transactions of block 1: ${txnIds.join(", ")}`)
           } else console.error(`[getBlockUpdate] Can't get transactions of block 1`, error)
       }
   )

   With JavaScript looks similar:

   const w = require('@waves/node-api-grpc');
   const b58 = require('bs58');
   
   const channel = w.grpc.mkDefaultChannel('grpc.wavesnodes.com:6870')
   
   const transactionsApi = w.api.waves.node.grpc.mkTransactionsApi(channel)
   const txnId = '287XcMXPDY7pnw2tECbV86TZetPi2x9JBg9BVUsGaSJx';
   transactionsApi
       .getTransactions({transactionIds: [b58.decode(txnId)]})
       .on("data", (item) => console.log(`[getTransactions] The transaction '${txnId}' was on height of ${item.height}`))
       .on("end", () => console.log("[getTransactions] Stream ended"))
       .on("error", (e) => console.error("[getTransactions] Failed", e))

Types and API clients correlates with a structure of proto-files. For example:

• waves/node/grpc/transactions_api.proto relates to waves.node.grpc:

  package waves.node.grpc;

• It has the TransactionResponse message:

  // waves/node/grpc/transactions_api.proto
  message TransactionResponse {

• So we have waves.node.grpc.TransactionResponse;
• We used w.api.waves.node.grpc.TransactionResponse in the example.

If you want to create a client of API that isn't listed in the example, you need:

1. Find it among proto-files
2. Write w.api.{here.is.a.namespace.of.your.api}mk{Api name}
3. Then look at a method you are interested in: a. If you see stream in the response like:

   rpc GetTransactions (TransactionsRequest) returns (stream TransactionResponse)
   

   Then you need to register an event handler for "data" event (see the "Streaming" example) b. Otherwise, you need to provide only a callback (see the "One-shot" example)

How to build and test locally

$ npm run build && npm test