@fullstackhouse/opentelemetry-js-decorator

A TypeScript method decorator for OpenTelemetry tracing. Automatically creates spans for decorated methods with support for sync, async, generator, and async generator functions.

Installation

npm install @fullstackhouse/opentelemetry-js-decorator @opentelemetry/api
# or
pnpm add @fullstackhouse/opentelemetry-js-decorator @opentelemetry/api

Usage

import { Traced } from '@fullstackhouse/opentelemetry-js-decorator';

class UserService {
  @Traced()
  async getUser(id: string) {
    // Span automatically created: "UserService.getUser"
    return await this.repository.findById(id);
  }

  @Traced('fetch-user-profile')
  async getUserProfile(id: string) {
    // Span with custom name: "fetch-user-profile"
    return await this.fetchProfile(id);
  }

  @Traced({ name: 'db-query', op: 'database' })
  async queryDatabase(query: string) {
    // Span with custom name and operation type
    return await this.db.query(query);
  }
}

Features

• Automatic span creation with ClassName.methodName naming
• Custom span names via string argument or options
• Support for sync, async, Promise-returning, generator, and async generator methods
• Automatic error recording and span status setting
• Preserves method metadata (works with other decorators)
• Sets code.function and code.namespace attributes
• Optional op attribute for categorizing operations

API

@Traced()

Creates a span with auto-generated name (ClassName.methodName).

@Traced(name: string)

Creates a span with the specified name.

@Traced(options: TracedOptions)

Creates a span with the specified options.

interface TracedOptions extends SpanOptions {
  name?: string;  // Custom span name
  op?: string;    // Operation type (set as `code.op` attribute)
}

@Traced(name: string, options: TracedOptions)

Creates a span with the specified name and options.

Requirements

• @opentelemetry/api must be installed as a peer dependency
• TypeScript with experimentalDecorators enabled

License

MIT