Skip to content
Hakka

Breakpoints

What it does

Section titled “What it does”

BreakpointEngine holds a matching request or response Promise open until the overlay resolves it, letting a developer inspect and edit fields before the request is sent or the response is delivered to the caller. Rules match on URL substring + optional method filter, and can target the request phase, the response phase, or both.

Public API

Section titled “Public API”
import { breakpointEngine } from 'hakka-core'
import type { Breakpoint, BreakpointInput, BreakpointPhase, PausedEntry, PausedRequest, PausedResponse, ResumeAction, ResumeResponseAction } from 'hakka-core'


const id = breakpointEngine.addBreakpoint(input) // { pattern, method?, on?, enabled }
breakpointEngine.removeBreakpoint(id)
breakpointEngine.setEnabled(id, enabled)
breakpointEngine.getBreakpoints() // Breakpoint[]
breakpointEngine.clearBreakpoints()


breakpointEngine.getPaused() // PausedEntry[]
breakpointEngine.hasPaused() // boolean
breakpointEngine.resume(pauseId, edits?) // Partial<PausedRequest> | Partial<PausedResponse>
breakpointEngine.abort(pauseId)
breakpointEngine.resumeAll() // teardown — resumes every pending pause without edits
breakpointEngine.subscribe(listener) // () => void, fires on any rule/pause change

Interceptor-facing (called by capture/fetch.ts, not typical app code):

breakpointEngine.matches(url, method, phase) // boolean
breakpointEngine.pause(requestId, 'request', request: PausedRequest): Promise<ResumeAction>
breakpointEngine.pause(requestId, 'response', response: PausedResponse): Promise<ResumeResponseAction>

Config keys + defaults

Section titled “Config keys + defaults”

Not part of HakkaConfig — breakpoints are added imperatively. No global on/off flag; an empty rule list is a no-op.

Rule field Default Description
on 'request' Phase to pause on: 'request' | 'response' | 'both'.
method any HTTP method filter, case-insensitive.

Platform matrix

Section titled “Platform matrix”

SPEC §5 row “Breakpoints” (footnote 3):

Capability RN iOS Android Web
Breakpoints ● ● ● ●

Request and response-phase breakpoints, pause-and-edit, no proxy or cert. The shared TS breakpointEngine (hakka-core) is consumed by the web overlay today; iOS (Common/BreakpointEngine.swift) and Android (hakka-common/hakka-network-noop BreakpointEngine.kt) ship their own native ports of the same engine, driven by native panels and by control-channel breakpoint.add/breakpoint.remove commands.

Wire format

Section titled “Wire format”

Driven remotely as a breakpoint.add / breakpoint.remove ControlCommand — see Control channel. Aborting records the request with status: null and error: 'Aborted by Hakka'.

Test anchors

Section titled “Test anchors”
  • packages/hakka-core/src/engine/control.test.ts (breakpoint add/remove via ControlCommand)
  • packages/hakka-core/src/capture/rewrite.test.ts, packages/hakka-core/src/capture/xhr.test.ts
  • packages/hakka-browser/src/ui/Breakpoints.test.tsx
  • ios/Tests/HakkaTests/BreakpointEngineTests.swift
  • android/hakka-common/src/test/kotlin/com/noodleapps/hakka/BreakpointEngineTest.kt

Limits & non-goals

Section titled “Limits & non-goals”
  • On web, breakpoints apply to fetch only — XHR and WebSocket traffic passes through unpaused.
  • The response body is read to a string before a response-phase pause; binary responses are coerced to text.
  • Everything runs on the main thread — a pause holds the intercepted request Promise open until the overlay resolves it; there is no timeout, so resumeAll() must run on teardown to avoid dangling Promises.