diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 142e179bb5..8dfd067f34 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -400,6 +400,21 @@ jobs:
           name: windows-native-inspection-fixture
           path: .cache/windows-native-inspection-fixture/
           if-no-files-found: error
+      # The process boundary observations are independent of the addon: they
+      # report the caller's and child's own token, environment and breakaway
+      # results from a separate executable. Cross-build it in the lane that
+      # already has MinGW so the Windows job can observe them too.
+      - name: Build Windows process boundary fixture
+        run: |
+          mkdir -p .cache/windows-process-boundary
+          x86_64-w64-mingw32-g++ -municode -std=c++17 -O2 -static -Wall -Wextra \
+            -o .cache/windows-process-boundary/process-boundary.exe \
+            tests/fixtures/windows/processBoundary.cc -ladvapi32
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: windows-process-boundary-fixture
+          path: .cache/windows-process-boundary/
+          if-no-files-found: error
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
           name: windows-native-controls
@@ -622,7 +637,16 @@ jobs:
           src/application/Update.test.ts
           tests/process-global/updateMaintenance.test.ts
           tests/conformance/providers/ghidra/realGhidraWindowsWorkflow.test.ts
-      - run: npm run verify:windows-native
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        with:
+          name: windows-process-boundary-fixture
+          path: .cache/windows-process-boundary/
+      # Passing the fixture adds the breakaway, caller/child token, environment
+      # semantics and ancestor reparse observations, which the lane skips
+      # entirely when it is absent.
+      - run: >-
+          npm run verify:windows-native -- .
+          "${{ github.workspace }}\.cache\windows-process-boundary\process-boundary.exe"
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           name: windows-native-inspection-fixture
diff --git a/.github/workflows/real-ghidra-windows.yml b/.github/workflows/real-ghidra-windows.yml
index db92cd0f84..ce14932063 100644
--- a/.github/workflows/real-ghidra-windows.yml
+++ b/.github/workflows/real-ghidra-windows.yml
@@ -36,6 +36,20 @@ jobs:
           name: real-ghidra-windows-native
           path: native/windows/build/
           if-no-files-found: error
+      # The boundary observations need a separate Windows executable, which the
+      # native lane skips when it is absent. Cross-build it here, where MinGW is
+      # already installed, so the proof run observes them too.
+      - name: Build Windows process boundary fixture
+        run: |
+          mkdir -p .cache/windows-process-boundary
+          x86_64-w64-mingw32-g++ -municode -std=c++17 -O2 -static -Wall -Wextra \
+            -o .cache/windows-process-boundary/process-boundary.exe \
+            tests/fixtures/windows/processBoundary.cc -ladvapi32
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: real-ghidra-windows-process-boundary
+          path: .cache/windows-process-boundary/
+          if-no-files-found: error
 
   verify:
     name: Real Ghidra 12.1.4 Windows x64 PE proof
@@ -55,7 +69,13 @@ jobs:
           name: real-ghidra-windows-native
           path: native/windows/build/
       - run: npm run verify:windows-native:artifact
-      - run: npm run verify:windows-native
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        with:
+          name: real-ghidra-windows-process-boundary
+          path: .cache/windows-process-boundary/
+      - run: >-
+          npm run verify:windows-native -- .
+          "${{ github.workspace }}\.cache\windows-process-boundary\process-boundary.exe"
       - name: Verify all admitted Windows Ghidra operations
         env:
           REA_ANALYSIS_PROVIDER: ghidra
diff --git a/native/windows/README.md b/native/windows/README.md
index e2543260f0..7432f15fd6 100644
--- a/native/windows/README.md
+++ b/native/windows/README.md
@@ -163,9 +163,14 @@ V8 heap flags cannot bound (limit notification, peak commit at the limit, all
 members settled, with the notification present in the first native exit report
 and the wrapper's exit event), and a control under the same limit that
 completes normally.
-An optional independently built
-`tests/fixtures/windows/processBoundary.cc` executable adds breakaway and
-caller/child token observations and an in-place ancestor reparse attempt:
+A separately built `tests/fixtures/windows/processBoundary.cc` executable adds
+breakaway, caller/child token and environment semantics observations and an
+in-place ancestor reparse attempt. The lane skips all of them when the
+executable is absent, so both Windows workflows cross-build it in the same
+MinGW job that builds their artifact and pass it: the capability and package
+lane in `.github/workflows/ci.yml`, and the real Ghidra proof run in
+`.github/workflows/real-ghidra-windows.yml`. Build it locally with any Windows
+C++ compiler, or the same way they do, and pass its path:
 
 ```powershell
 node scripts/verify-windows-native.mjs . C:\fixtures\process-boundary.exe