diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9ba5dcd..853839a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -34,42 +34,44 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: "3.11"
-
       - name: Install package and test deps
         run: |
           python -m pip install --upgrade pip
           python -m pip install -e ".[test]"
 
-      - name: Prepare qret stub for test (Unix)
-        if: runner.os != 'Windows'
-        run: |
-          mkdir -p .ci-bin
-          cat > .ci-bin/qret <<'EOF'
-          #!/usr/bin/env sh
-          echo "qret 0.0.0-ci"
-          EOF
-          cat > .ci-bin/gridsynth <<'EOF'
-          #!/usr/bin/env sh
-          echo "gridsynth 0.0.0-ci"
-          EOF
-          chmod +x .ci-bin/qret
-          chmod +x .ci-bin/gridsynth
-          echo "$GITHUB_WORKSPACE/.ci-bin" >> "$GITHUB_PATH"
 
-      - name: Prepare qret stub for test (Windows)
-        if: runner.os == 'Windows'
-        shell: pwsh
-        run: |
-          New-Item -ItemType Directory -Force -Path .ci-bin | Out-Null
-          @'
-          @echo off
-          echo qret 0.0.0-ci
-          '@ | Set-Content -Path .ci-bin/qret.cmd
-          @'
-          @echo off
-          echo gridsynth 0.0.0-ci
-          '@ | Set-Content -Path .ci-bin/gridsynth.cmd
-          "$env:GITHUB_WORKSPACE/.ci-bin" | Out-File -FilePath $env:GITHUB_PATH -Append
+      # - name: Prepare qret stub for test (Unix)
+      #   if: runner.os != 'Windows'
+      #   run: |
+      #     mkdir -p .ci-bin
+      #     cat > .ci-bin/qret <<'EOF'
+      #     #!/usr/bin/env sh
+      #     echo "qret 0.0.0-ci"
+      #     EOF
+      #     cat > .ci-bin/gridsynth <<'EOF'
+      #     #!/usr/bin/env sh
+      #     echo "gridsynth 0.0.0-ci"
+      #     EOF
+      #     chmod +x .ci-bin/qret
+      #     chmod +x .ci-bin/gridsynth
+      #     echo "$GITHUB_WORKSPACE/.ci-bin" >> "$GITHUB_PATH"
+
+      # - name: Prepare qret stub for test (Windows)
+      #   if: runner.os == 'Windows'
+      #   shell: pwsh
+      #   run: |
+      #     New-Item -ItemType Directory -Force -Path .ci-bin | Out-Null
+      #     @'
+      #     @echo off
+      #     echo qret 0.0.0-ci
+      #     '@ | Set-Content -Path .ci-bin/qret.cmd
+      #     @'
+      #     @echo off
+      #     echo gridsynth 0.0.0-ci
+      #     '@ | Set-Content -Path .ci-bin/gridsynth.cmd
+      #     "$env:GITHUB_WORKSPACE/.ci-bin" | Out-File -FilePath $env:GITHUB_PATH -Append
 
       - name: Run pytest
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
         run: pytest -q tests/test_qret_cli_bundle.py
diff --git a/qret_cli_bundle/__init__.py b/qret_cli_bundle/__init__.py
index 7b3a74a..341b99f 100644
--- a/qret_cli_bundle/__init__.py
+++ b/qret_cli_bundle/__init__.py
@@ -38,15 +38,25 @@ def _platform_asset_name() -> str:
     raise QretBundleError(f"Unsupported platform: {system} ({machine})")
 
 
+def _github_headers(accept: str) -> dict[str, str]:
+    headers = {"Accept": accept}
+    # Use a token in CI to avoid GitHub API rate limits; local environments can
+    # continue to fall back to unauthenticated requests when no token is set.
+    github_token = os.environ.get("GITHUB_TOKEN") or os.environ.get("GH_TOKEN")
+    if github_token:
+        headers["Authorization"] = f"Bearer {github_token}"
+    return headers
+
+
 def _release_json() -> dict:
     url = f"{API_BASE}/repos/{DEFAULT_REPO}/releases/latest"
-    req = urllib.request.Request(url, headers={"Accept": "application/vnd.github+json"})
+    req = urllib.request.Request(url, headers=_github_headers("application/vnd.github+json"))
     with urllib.request.urlopen(req, timeout=60) as response:
         return json.load(response)
 
 
 def _download_file(url: str, path: Path) -> None:
-    req = urllib.request.Request(url, headers={"Accept": "application/octet-stream"})
+    req = urllib.request.Request(url, headers=_github_headers("application/octet-stream"))
     with urllib.request.urlopen(req, timeout=300) as response:
         path.write_bytes(response.read())
 
@@ -90,6 +100,14 @@ def _append_env_path(var_name: str, entry: str) -> None:
     os.environ[var_name] = current + os.pathsep + entry if current else entry
 
 
+def _find_executable(bin_dir: Path, *names: str) -> Path | None:
+    for name in names:
+        candidate = bin_dir / name
+        if candidate.exists():
+            return candidate
+    return None
+
+
 def ensure_qret_on_path() -> None:
 
     install_root = Path(__file__).parent / "bundle"
@@ -98,8 +116,9 @@ def ensure_qret_on_path() -> None:
     _append_env_path("PATH", str(bin_dir))
     if platform.system() == "Linux":
         _append_env_path("LD_LIBRARY_PATH", str(lib_dir))
-    
-    if not (bin_dir / "qret").exists() or not (bin_dir / "gridsynth").exists():
+    elif platform.system() == "Darwin":
+        _append_env_path("DYLD_FALLBACK_LIBRARY_PATH", str(lib_dir))
+    if _find_executable(bin_dir, "qret", "qret.exe", "qret.cmd") is None or _find_executable(bin_dir, "gridsynth", "gridsynth.exe", "gridsynth.cmd") is None:
         asset_name = _platform_asset_name()
         release = _release_json()
         assets = {asset["name"]: asset["browser_download_url"] for asset in release.get("assets", [])}
@@ -118,8 +137,9 @@ def ensure_qret_on_path() -> None:
         _extract_archive(archive_path, install_root)
         archive_path.unlink(missing_ok=True)
 
-    if (bin_dir / "gridsynth").exists():
-        os.environ["GRIDSYNTH_PATH"] = str(bin_dir / "gridsynth")
+    gridsynth_path = _find_executable(bin_dir, "gridsynth", "gridsynth.exe", "gridsynth.cmd")
+    if gridsynth_path is not None:
+        os.environ["GRIDSYNTH_PATH"] = str(gridsynth_path)
 
 
 ensure_qret_on_path()