The kernel acts as a thin abstraction layer, mediating between high-level application logic and low-level platform implementations, similar to how operating system kernels abstract over hardware details. This helps the core Hoppscotch app be platform-agnostic while maintaining near native performance.

This codebase is minimal by design, providing just the building blocks for constructing features. If possible, always try composition before modifying the kernel directly.

Modules

IO Module

File system and external resource handling:

interface IoV1 {
  saveFileWithDialog(opts: SaveFileWithDialogOptions): Promise<SaveFileResponse>
  openExternalLink(opts: OpenExternalLinkOptions): Promise<OpenExternalLinkResponse>
  listen<T>(event: string, handler: EventCallback<T>): Promise<UnlistenFn>
}

Relay Module

Network operations with platform-specific optimizations:

interface RelayV1 {
  readonly capabilities: RelayCapabilities
  execute(request: RelayRequest): {
    cancel: () => Promise<void>
    emitter: RelayEventEmitter<RelayRequestEvents>
    response: Promise<Either<RelayError, RelayResponse>>
  }
}

Store Module

Cross-platform persistence with encryption support:

interface StoreV1 {
  readonly capabilities: Set<StoreCapability>
  set(namespace: string, key: string, value: unknown, options?: StorageOptions): Promise<Either<StoreError, void>>
  watch(namespace: string, key: string): Promise<StoreEventEmitter<StoreEvents>>
}

Usage

Kernel Initialization

import { initKernel } from '@hoppscotch/kernel'

// Platform-specific initialization
const kernel = initKernel('web' | 'desktop')

Network Operations

import { RelayRequest } from '@hoppscotch/kernel'

const request: RelayRequest = {
  id: 1,
  url: "https://api.example.com",
  method: "GET",
  version: "HTTP/1.1",
  headers: { 
    "Content-Type": "application/json" 
  }
}

// Execute with capability checks
const { response, cancel } = kernel.relay.execute(request)

Storage Operations

// Encrypted storage with compression
await kernel.store.set("collections", "team-a", data, {
  encrypt: true,
  compress: true
})

// Watch for changes
const watcher = await kernel.store.watch("collections", "team-a")
watcher.on("change", 
  (update) => console.log("Collection updated:", update)
)

File Operations

// Platform-agnostic file save
await kernel.io.saveFileWithDialog({
  data: new Uint8Array([...]),
  suggestedFilename: "export.json",
  contentType: "application/json"
})