backend_skill

Overview

This skill provides expert backend patterns and implementations for MultiversX using Go, Python, and TypeScript. It focuses on microservices, off-chain logic, transaction lifecycle, and reliable blockchain integration. Use it to build performant APIs, background processors, and secure transaction pipelines that interact with MultiversX nodes and proxy APIs.

How this skill works

The skill inspects and documents server-side components: SDK usage (Go, TS, Python), proxy/observer access, transaction construction/signing, nonce handling, and data ingestion. It outlines concrete workflows for building, simulating, signing, broadcasting, and resubmitting transactions, plus reading contract state via VM queries or Elasticsearch. It also prescribes integration points for NestJS, Redis caching, and notifier-based push updates.

When to use it

• Building high-throughput microservices that send many signed transactions
• Implementing API backends or serverless endpoints for MultiversX dApps
• Automating on-chain data ingestion, indexing, and event-driven notifications
• Writing scripts or data pipelines for analytics and off-chain processing
• Integrating user login verification (NativeAuth) or ledger-based signing in backend flows

Best practices

• Choose SDK by workload: Go for performance, TypeScript for web backends, Python for scripting and analysis
• Manage nonces locally (NonceHandlerV3 pattern) for concurrency and throughput
• Always simulate gas costs before broadcast and estimate gas limits conservatively
• Reuse proxy/network clients, pass context with timeouts, and implement retry/resubmission logic
• Keep private keys out of code: use keystores, PEM, hardware wallets, or secure secret managers

Example use cases

• A Go microservice that constructs, signs, and batches ESDT transfers with local nonce handling
• A NestJS API that verifies NativeAuth tokens, exposes VM query endpoints, and caches network config in Redis
• A Python ETL that listens for SwapExecuted events, indexes them into Elasticsearch, and triggers notifications
• A relayer service that constructs inner user transactions, signs relayer envelopes, and manages resubmissions
• A monitoring tool using TransactionInteractor to detect and resolve stuck transactions