@snapwyr/core

Internal package containing the core HTTP interception and event system for Snapwyr.

Overview

This is an internal package used by the snapwyr SDK. You should not install this package directly. Use snapwyr instead.

What It Does

• Patches globalThis.fetch to intercept outgoing requests (automatic)
• Patches axios when axios instance is provided in config
• Emits request events with method, URL, status, duration, and bodies
• Provides a global event emitter for cross-package communication

Architecture

@snapwyr/core
├── SnapWyrEmitter (global singleton)
│   ├── start() - Patch HTTP clients
│   ├── stop() - Restore original clients
│   ├── on('request', handler) - Listen for events
│   └── emitRequest(event) - Emit request events
├── Interceptors
│   ├── fetch.ts - Patches global fetch
│   └── axios.ts - Patches axios
└── Utilities
    ├── redactSensitiveData()
    ├── generateRequestId()
    ├── formatBytes()
    └── toCurl()

Exports

snapwyr

The global event emitter singleton.

import { snapwyr } from '@snapwyr/core';

// Log fetch requests (automatic)
snapwyr.start({ logBody: true });

// To log axios requests, pass your axios instance
import axios from 'axios';
snapwyr.start({
  axios: axios, // Required for axios interception
  logBody: true,
});

snapwyr.on('request', (event) => {
  console.log(event.method, event.url, event.status);
});

Types

interface RequestEvent {
  id: string;
  method: string;
  url: string;
  status?: number;
  duration: number;
  timestamp: number;
  requestBody?: string;
  responseBody?: string;
  error?: string;
  headers?: Record<string, string>;
  requestSize?: number;
  responseSize?: number;
  direction?: 'incoming' | 'outgoing';
}

interface SnapWyrConfig {
  enabled?: boolean;
  logBody?: boolean;
  bodySizeLimit?: number;
  format?: 'pretty' | 'json';
  emoji?: boolean;
  silent?: boolean;
  prefix?: string;
  showTimestamp?: boolean;
  slowThreshold?: number;
  errorsOnly?: boolean;
  methods?: string[];
  statusCodes?: number[];
  ignorePatterns?: (string | RegExp)[];
  redact?: (string | RegExp)[];
  requestId?: boolean;
  sizeTracking?: boolean;
  transport?: (entry: LogEntry) => void;
  axios?: any; // Axios instance to intercept (required for axios logging)
}

Installation

This package is installed automatically as a dependency of snapwyr. You typically don't need to install it directly.

npm install @snapwyr/core

License

AGPL-3.0