diff --git a/cli/package.json b/cli/package.json
index 32ed8e460d..96fbef963c 100644
--- a/cli/package.json
+++ b/cli/package.json
@@ -83,6 +83,7 @@
     "test:build-zip-filter": "bun test/test-build-zip-filter.mjs",
     "test:checksum": "bun test/test-checksum-algorithm.mjs",
     "test:build-needed": "bun test/test-build-needed.mjs",
+    "test:build-cancellation": "bun test/test-build-cancellation.mjs",
     "test:ci-prompts": "bun test/test-ci-prompts.mjs",
     "test:ci-secrets": "bun test/test-ci-secrets.mjs",
     "test:android-onboarding-progress": "bun test/test-android-onboarding-progress.mjs",
@@ -174,7 +175,7 @@
     "test:android-version": "bun test/test-android-version.mjs",
     "test:platform-flow-contract": "bun test/test-platform-flow-contract.mjs",
     "test:tail-engine-shared": "bun test/test-tail-engine-shared.mjs",
-    "test": "bun run build && bun run test:helper-dce && bun run test:version-detection:setup && bun run test:bundle && bun run test:bundle-validation && bun run test:functional && bun run test:semver && bun run test:auto-bump-version && bun run test:auto-bump-ai-diff && bun run test:version-edge-cases && bun run test:regex && bun run test:upload && bun run test:fail-on-incompatible && bun run test:native-dependencies && bun run test:package-json-guard && bun run test:credentials && bun run test:credentials-export && bun run test:credentials-validation && bun run test:android-service-account-validation && bun run test:build-zip-filter && bun run test:checksum && bun run test:build-needed && bun run test:ci-prompts && bun run test:ci-secrets && bun run test:android-onboarding-progress && bun run test:onboarding-telemetry && bun run test:v2-event-migration && bun run test:analytics && bun run test:cli-headers && bun run test:min-cli-version && bun run test:authenticated-command-invocation && bun run test:analytics-error-category && bun run test:analytics-org-resolver && bun run test:supabase-perf && bun run test:preview-qr && bun run test:app-set-options && bun run test:mcp-analytics && bun run test:mcp-instructions && bun run test:mcp-live-update-onboarding && bun run test:mcp-stdout-guard && bun run test:mcp-platform-select && bun run test:mcp-explain-scopes && bun run test:mcp-oauth-reopen && bun run test:mcp-broker-oauth && bun run test:mcp-broker-session && bun run test:mcp-credentials-manage && bun run test:mcp-resume-prompt && bun run test:mcp-build-job && bun run test:mcp-build-tools && bun run test:app-created-source && bun run test:app-list-output-text && bun run test:doctor-analytics && bun run test:posthog-exception && bun run test:cli-recovery && bun run test:create-supabase-client && bun run test:build-platform-selection && bun run test:builder-project-discovery && bun run test:onboarding-recovery && bun run test:onboarding-progress && bun run test:onboarding-run-targets && bun run test:run-device-command && bun run test:init-monorepo-targeting && bun run test:init-app-conflict && bun run test:channel-add-exists && bun run test:wait-log && bun run test:init-guardrails && bun run test:init-replay && bun run test:init-telemetry && bun run test:prompt-preferences && bun run test:esm-sdk && bun run test:mcp && bun run test:mcp-no-key-handshake && bun run test:auth-session && bun run test:version-detection && bun run test:platform-paths && bun run test:project-type-detection && bun run test:payload-split && bun run test:manifest-path-encoding && bun run test:macos-signing && bun run test:asc-key-protocol && bun run test:apple-api-import-helpers && bun run test:apple-api-verify-key && bun run test:bundle-id-detector && bun run test:apple-api-app-list && bun run test:app-verification && bun run test:pbxproj-parser && bun run test:ai-log-capture && bun run test:ai-analyze-flow && bun run test:cicd-failure-help && bun run test:ai-sse-parser && bun run test:ai-render-markdown && bun run test:ai-stream-markdown && bun run test:ai-onboarding-mode && bun run test:ai-fit && bun run test:platform-layout && bun run test:frame-fit && bun run test:onboarding-min-size && bun run test:min-size-gate && bun run test:shell-size-gate && bun run test:build-log-sanitize && bun run test:build-output-viewport && bun run test:diff-viewer-viewport && bun run test:build-complete-exit && bun run test:ai-analyze-stream && bun run test:support-mailto && bun run test:support-redact && bun run test:support-internal-log && bun run test:support-help-menu && bun run test:support-contact && bun run test:support-upload-prompt && bun run test:support-bundle-files && bun run test:self-update && bun run test:update-prompt && bun run test:apple-api-cert-create && bun run test:android-tail-engine && bun run test:android-tail-render && bun run test:android-tail-routing && bun run test:dev-gate-stripped && bun run test:frame-fit-ios-shared && bun run test:ios-confirm-app-id && bun run test:ios-create-new && bun run test:ios-e2e && bun run test:ios-flow-contract && bun run test:ios-import-discovery && bun run test:ios-import-export && bun run test:ios-import-pickers && bun run test:ios-import-recovery && bun run test:ios-recovery && bun run test:ios-resume && bun run test:ios-tail-handoff && bun run test:ios-tui-render && bun run test:p8-error && bun run test:ios-tui-routing && bun run test:ios-updater-sync-validation && bun run test:ios-verify-app && bun run test:ios-marketing-version && bun run test:android-version && bun run test:platform-flow-contract && bun run test:tail-engine-shared && bun run test:prescan && bun run test:android-reporting-api && bun run test:android-app-verification && bun run test:android-rename && bun run test:appflow-auth && bun run test:appflow-api-map && bun run test:appflow-validate && bun run test:appflow-flow && bun run test:appflow-gapfill && bun run test:appflow-engine && bun run test:appflow-tail && bun run test:appflow-fetch && bun run test:appflow-sa-decode && bun run test:app-permission-helper && bun run test:2fa-compliance-network && bun run test:organization-set-api-host && bun run test:trial-warning && bun run test:plan-validation",
+    "test": "bun run build && bun run test:helper-dce && bun run test:version-detection:setup && bun run test:bundle && bun run test:bundle-validation && bun run test:functional && bun run test:semver && bun run test:auto-bump-version && bun run test:auto-bump-ai-diff && bun run test:version-edge-cases && bun run test:regex && bun run test:upload && bun run test:fail-on-incompatible && bun run test:native-dependencies && bun run test:package-json-guard && bun run test:credentials && bun run test:credentials-export && bun run test:credentials-validation && bun run test:android-service-account-validation && bun run test:build-zip-filter && bun run test:checksum && bun run test:build-needed && bun run test:build-cancellation && bun run test:ci-prompts && bun run test:ci-secrets && bun run test:android-onboarding-progress && bun run test:onboarding-telemetry && bun run test:v2-event-migration && bun run test:analytics && bun run test:cli-headers && bun run test:min-cli-version && bun run test:authenticated-command-invocation && bun run test:analytics-error-category && bun run test:analytics-org-resolver && bun run test:supabase-perf && bun run test:preview-qr && bun run test:app-set-options && bun run test:mcp-analytics && bun run test:mcp-instructions && bun run test:mcp-live-update-onboarding && bun run test:mcp-stdout-guard && bun run test:mcp-platform-select && bun run test:mcp-explain-scopes && bun run test:mcp-oauth-reopen && bun run test:mcp-broker-oauth && bun run test:mcp-broker-session && bun run test:mcp-credentials-manage && bun run test:mcp-resume-prompt && bun run test:mcp-build-job && bun run test:mcp-build-tools && bun run test:app-created-source && bun run test:app-list-output-text && bun run test:doctor-analytics && bun run test:posthog-exception && bun run test:cli-recovery && bun run test:create-supabase-client && bun run test:build-platform-selection && bun run test:builder-project-discovery && bun run test:onboarding-recovery && bun run test:onboarding-progress && bun run test:onboarding-run-targets && bun run test:run-device-command && bun run test:init-monorepo-targeting && bun run test:init-app-conflict && bun run test:channel-add-exists && bun run test:wait-log && bun run test:init-guardrails && bun run test:init-replay && bun run test:init-telemetry && bun run test:prompt-preferences && bun run test:esm-sdk && bun run test:mcp && bun run test:mcp-no-key-handshake && bun run test:auth-session && bun run test:version-detection && bun run test:platform-paths && bun run test:project-type-detection && bun run test:payload-split && bun run test:manifest-path-encoding && bun run test:macos-signing && bun run test:asc-key-protocol && bun run test:apple-api-import-helpers && bun run test:apple-api-verify-key && bun run test:bundle-id-detector && bun run test:apple-api-app-list && bun run test:app-verification && bun run test:pbxproj-parser && bun run test:ai-log-capture && bun run test:ai-analyze-flow && bun run test:cicd-failure-help && bun run test:ai-sse-parser && bun run test:ai-render-markdown && bun run test:ai-stream-markdown && bun run test:ai-onboarding-mode && bun run test:ai-fit && bun run test:platform-layout && bun run test:frame-fit && bun run test:onboarding-min-size && bun run test:min-size-gate && bun run test:shell-size-gate && bun run test:build-log-sanitize && bun run test:build-output-viewport && bun run test:diff-viewer-viewport && bun run test:build-complete-exit && bun run test:ai-analyze-stream && bun run test:support-mailto && bun run test:support-redact && bun run test:support-internal-log && bun run test:support-help-menu && bun run test:support-contact && bun run test:support-upload-prompt && bun run test:support-bundle-files && bun run test:self-update && bun run test:update-prompt && bun run test:apple-api-cert-create && bun run test:android-tail-engine && bun run test:android-tail-render && bun run test:android-tail-routing && bun run test:dev-gate-stripped && bun run test:frame-fit-ios-shared && bun run test:ios-confirm-app-id && bun run test:ios-create-new && bun run test:ios-e2e && bun run test:ios-flow-contract && bun run test:ios-import-discovery && bun run test:ios-import-export && bun run test:ios-import-pickers && bun run test:ios-import-recovery && bun run test:ios-recovery && bun run test:ios-resume && bun run test:ios-tail-handoff && bun run test:ios-tui-render && bun run test:p8-error && bun run test:ios-tui-routing && bun run test:ios-updater-sync-validation && bun run test:ios-verify-app && bun run test:ios-marketing-version && bun run test:android-version && bun run test:platform-flow-contract && bun run test:tail-engine-shared && bun run test:prescan && bun run test:android-reporting-api && bun run test:android-app-verification && bun run test:android-rename && bun run test:appflow-auth && bun run test:appflow-api-map && bun run test:appflow-validate && bun run test:appflow-flow && bun run test:appflow-gapfill && bun run test:appflow-engine && bun run test:appflow-tail && bun run test:appflow-fetch && bun run test:appflow-sa-decode && bun run test:app-permission-helper && bun run test:2fa-compliance-network && bun run test:organization-set-api-host && bun run test:trial-warning && bun run test:plan-validation",
     "test:build-platform-selection": "bun test/test-build-platform-selection.mjs",
     "test:builder-project-discovery": "bun test/test-builder-project-discovery.mjs",
     "test:ai-log-capture": "bun test/test-ai-log-capture.mjs",
diff --git a/cli/src/build/cancellation.ts b/cli/src/build/cancellation.ts
new file mode 100644
index 0000000000..4959d30a83
--- /dev/null
+++ b/cli/src/build/cancellation.ts
@@ -0,0 +1,73 @@
+export type BuildCancellationResult
+  = | { ok: true }
+    | { ok: false, message: string }
+
+// npx can deliver one physical Ctrl+C to the CLI twice: once through the
+// foreground process group and once when its wrapper forwards SIGINT.
+export const DUPLICATE_SIGINT_WINDOW_MS = 500
+
+export interface BuildCancellationRequestOptions {
+  url: string
+  headers: Record<string, string>
+  appId: string
+  fetchImpl?: typeof fetch
+  timeoutMs?: number
+}
+
+export async function requestBuildCancellation(options: BuildCancellationRequestOptions): Promise<BuildCancellationResult> {
+  const abortController = new AbortController()
+  const timeout = setTimeout(() => abortController.abort(), options.timeoutMs ?? 4_000)
+
+  try {
+    const response = await (options.fetchImpl ?? fetch)(options.url, {
+      method: 'POST',
+      headers: options.headers,
+      body: JSON.stringify({ app_id: options.appId }),
+      signal: abortController.signal,
+    })
+    if (!response.ok) {
+      const status = `${response.status}${response.statusText ? ` ${response.statusText}` : ''}`
+      return { ok: false, message: `Build cancellation request failed: HTTP ${status}` }
+    }
+    return { ok: true }
+  }
+  catch (error) {
+    const message = error instanceof Error ? error.message : String(error)
+    return { ok: false, message: `Build cancellation request failed: ${message}` }
+  }
+  finally {
+    clearTimeout(timeout)
+  }
+}
+
+export interface BuildCancellationSignalHandlerOptions {
+  requestCancellation: () => Promise<BuildCancellationResult>
+  onCancellationStarted: () => void
+  onCancellationResult: (result: BuildCancellationResult) => void
+  abortLogStream: () => void
+  forceExit: (code: number) => void
+  now?: () => number
+  duplicateSignalWindowMs?: number
+}
+
+export function createBuildCancellationSignalHandler(options: BuildCancellationSignalHandlerOptions): () => Promise<void> {
+  const now = options.now ?? Date.now
+  const duplicateSignalWindowMs = options.duplicateSignalWindowMs ?? DUPLICATE_SIGINT_WINDOW_MS
+  let firstSignalAt: number | null = null
+
+  return async () => {
+    const signalAt = now()
+    if (firstSignalAt !== null) {
+      if (signalAt - firstSignalAt <= duplicateSignalWindowMs)
+        return
+      options.forceExit(1)
+      return
+    }
+
+    firstSignalAt = signalAt
+    options.onCancellationStarted()
+    const result = await options.requestCancellation()
+    options.onCancellationResult(result)
+    options.abortLogStream()
+  }
+}
diff --git a/cli/src/build/request.ts b/cli/src/build/request.ts
index 9123e2107b..09d22ab6cd 100644
--- a/cli/src/build/request.ts
+++ b/cli/src/build/request.ts
@@ -68,6 +68,7 @@ import { offerSupportUploadBeforeAi } from '../support/support-upload-prompt.js'
 import { buildCliRequestHeaders } from '../analytics/cli-headers'
 import { assertCliPermission, canPromptInteractively, createSupabaseClient, findSavedKey, getConfig, getOrganizationId, getRemoteConfig, sendEvent, trimTrailingSlashes, TUS_UPLOAD_RETRY_DELAYS } from '../utils'
 import { syncAndroidVersion } from './android-version'
+import { createBuildCancellationSignalHandler, requestBuildCancellation } from './cancellation'
 import { mergeCredentials, MIN_OUTPUT_RETENTION_SECONDS, parseAndroidPlayStoreReleaseStatus, parseAndroidPlayStoreTrack, parseInAppUpdatePriority, parseOptionalBoolean, parseOutputRetentionSeconds } from './credentials'
 import { buildProvisioningMap } from './credentials-command'
 import { withCwd } from './cwd'
@@ -2212,46 +2213,29 @@ export async function requestBuildInternal(appId: string, options: BuildRequestO
       log.info('Streaming build logs...')
 
       const abortController = new AbortController()
-      let cancelRequested = false
-      const cancelBuild = async () => {
-        if (cancelRequested)
-          return
-        cancelRequested = true
-        const cancelAbort = new AbortController()
-        const timeout = setTimeout(() => cancelAbort.abort(), 4000)
-        try {
-          await fetch(`${host}/build/cancel/${buildRequest.job_id}`, {
-            method: 'POST',
-            headers: buildCliRequestHeaders({
-              'Content-Type': 'application/json',
-              authorization: options.apikey,
-            }),
-            body: JSON.stringify({ app_id: appId }),
-            signal: cancelAbort.signal,
-          })
-        }
-        catch (err) {
-          appendInternalLog(`build cancel request errored (ignored): ${err instanceof Error ? err.message : String(err)}`)
-          // ignore cancellation errors
-        }
-        finally {
-          clearTimeout(timeout)
-        }
-      }
-
-      const onSigint = async () => {
-        try {
-          if (cancelRequested) {
-            process.exit(1)
-          }
+      const onSigint = createBuildCancellationSignalHandler({
+        requestCancellation: () => requestBuildCancellation({
+          url: `${host}/build/cancel/${buildRequest.job_id}`,
+          headers: buildCliRequestHeaders({
+            'Content-Type': 'application/json',
+            authorization: options.apikey,
+          }),
+          appId,
+        }),
+        onCancellationStarted: () => {
           log.warn('Canceling build... (press Ctrl+C again to force quit)')
-          await cancelBuild()
-          abortController.abort()
-        }
-        catch {
-          // Prevent unhandled rejection from crashing the process
-        }
-      }
+        },
+        onCancellationResult: (result) => {
+          if (result.ok) {
+            log.success('Build cancellation requested.')
+            return
+          }
+          appendInternalLog(result.message)
+          log.warn(`${result.message}. The remote build may still be running.`)
+        },
+        abortLogStream: () => abortController.abort(),
+        forceExit: code => process.exit(code),
+      })
 
       process.on('SIGINT', onSigint)
 
diff --git a/cli/test/test-build-cancellation.mjs b/cli/test/test-build-cancellation.mjs
new file mode 100644
index 0000000000..60836da6eb
--- /dev/null
+++ b/cli/test/test-build-cancellation.mjs
@@ -0,0 +1,122 @@
+#!/usr/bin/env node
+
+import assert from 'node:assert/strict'
+
+console.log('🧪 Testing native build cancellation...\n')
+
+const cancellation = await import('../src/build/cancellation.ts').catch(() => null)
+
+let failures = 0
+
+async function test(name, fn) {
+  try {
+    await fn()
+    console.log(`✅ ${name}`)
+  }
+  catch (error) {
+    failures += 1
+    console.error(`❌ ${name}`)
+    console.error(error)
+  }
+}
+
+await test('ignores an immediate duplicate SIGINT while cancellation is in flight', async () => {
+  assert.ok(cancellation, 'build cancellation helper has not been implemented')
+
+  let resolveCancellation
+  const pendingCancellation = new Promise((resolve) => {
+    resolveCancellation = resolve
+  })
+  let now = 1_000
+  let started = 0
+  let aborted = 0
+  let forcedExits = 0
+
+  const onSigint = cancellation.createBuildCancellationSignalHandler({
+    requestCancellation: async () => pendingCancellation,
+    onCancellationStarted: () => { started += 1 },
+    onCancellationResult: () => {},
+    abortLogStream: () => { aborted += 1 },
+    forceExit: () => { forcedExits += 1 },
+    now: () => now,
+  })
+
+  const firstSignal = onSigint()
+  await Promise.resolve()
+  now += 1
+  await onSigint()
+
+  assert.equal(started, 1, 'only the first signal starts cancellation')
+  assert.equal(forcedExits, 0, 'the duplicate signal must not force-exit the process')
+  assert.equal(aborted, 0, 'log streaming stays active until cancellation settles')
+
+  resolveCancellation({ ok: true })
+  await firstSignal
+
+  assert.equal(aborted, 1, 'log streaming stops after cancellation settles')
+})
+
+await test('reports a rejected cancellation response instead of treating it as success', async () => {
+  assert.equal(typeof cancellation?.requestBuildCancellation, 'function', 'cancellation request helper has not been implemented')
+
+  const result = await cancellation.requestBuildCancellation({
+    url: 'https://api.capgo.app/build/cancel/job_test',
+    headers: { authorization: 'test-key' },
+    appId: 'com.demo.app',
+    fetchImpl: async () => new Response(null, { status: 401, statusText: 'Unauthorized' }),
+  })
+
+  assert.deepEqual(result, {
+    ok: false,
+    message: 'Build cancellation request failed: HTTP 401 Unauthorized',
+  })
+})
+
+await test('allows a later SIGINT to force-quit a stuck cancellation', async () => {
+  let now = 1_000
+  let forcedExitCode = null
+
+  const onSigint = cancellation.createBuildCancellationSignalHandler({
+    requestCancellation: async () => new Promise(() => {}),
+    onCancellationStarted: () => {},
+    onCancellationResult: () => {},
+    abortLogStream: () => {},
+    forceExit: (code) => { forcedExitCode = code },
+    now: () => now,
+    duplicateSignalWindowMs: 500,
+  })
+
+  void onSigint()
+  now += 501
+  await onSigint()
+
+  assert.equal(forcedExitCode, 1)
+})
+
+await test('sends the cancellation request with the app id and reports success', async () => {
+  let capturedUrl = null
+  let capturedInit = null
+
+  const result = await cancellation.requestBuildCancellation({
+    url: 'https://api.capgo.app/build/cancel/job_test',
+    headers: { authorization: 'test-key' },
+    appId: 'com.demo.app',
+    fetchImpl: async (url, init) => {
+      capturedUrl = url
+      capturedInit = init
+      return new Response(null, { status: 200 })
+    },
+  })
+
+  assert.deepEqual(result, { ok: true })
+  assert.equal(capturedUrl, 'https://api.capgo.app/build/cancel/job_test')
+  assert.equal(capturedInit.method, 'POST')
+  assert.equal(capturedInit.body, JSON.stringify({ app_id: 'com.demo.app' }))
+})
+
+if (failures > 0) {
+  console.error(`\n❌ ${failures} build cancellation test(s) failed`)
+  process.exit(1)
+}
+
+console.log('\n✅ Native build cancellation behaves correctly')