diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..86a82cd
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,34 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements-dev.txt
+
+      - name: Run regression tests
+        run: python -m unittest discover -s tests -p "test_*.py"
+
+      - name: Smoke test startup path resolution
+        run: |
+          python -c "import os; from components.globals import BUNDLE_DIR; assert os.path.isdir(BUNDLE_DIR), BUNDLE_DIR"
diff --git a/README.md b/README.md
index 5d13a81..faa67e2 100644
--- a/README.md
+++ b/README.md
@@ -42,16 +42,74 @@ Installers and standalone versions are available for Windows and macOS
 
 Instructions for using Reaper are available on [reaper.social](https://reaper.social)
 
-## Run source
-Reaper uses string formatting that was added in Python 3.6. You need to run Reaper with Python 3.6+ or download a pre-built version from the [releases](https://github.com/ScriptSmith/reaper/releases)
+## Quick Start
 
-Download
-```
+Reaper is easiest to run with Python 3.10-3.12.
+
+### Windows (PowerShell)
+```powershell
 git clone https://github.com/ScriptSmith/reaper.git
 cd reaper
+py -3.10 -m venv .venv
+.venv\Scripts\Activate.ps1
+python -m pip install --upgrade pip
+pip install -r requirements.txt
+python reaper.py
 ```
-Run
-```
-pip3 install -r requirements.txt
-python3 reaper.py
+
+### macOS / Linux
+```bash
+git clone https://github.com/ScriptSmith/reaper.git
+cd reaper
+python3 -m venv .venv
+source .venv/bin/activate
+python -m pip install --upgrade pip
+pip install -r requirements.txt
+python reaper.py
 ```
+
+## API Key Setup
+
+Reaper depends on external platform APIs. Before collecting data:
+
+1. Create API credentials for each provider you need (for example Reddit, YouTube, Tumblr, Pinterest, Twitter/X, Facebook).
+2. Open Reaper and go to the API keys page.
+3. Enter credentials for the enabled sources.
+4. Save keys and run a small test job first.
+
+## API Status Reality Check
+
+This project integrates external APIs that change over time. A source being listed in the UI does not guarantee the upstream endpoint is still available.
+
+Recommended validation workflow:
+
+1. Test each source with a minimal request before running large jobs.
+2. Watch the Error Manager output for auth/endpoint hints.
+3. Disable or hide sources that are no longer supported in your fork until updated.
+
+## Troubleshooting
+
+### RecursionError on startup (`maximum recursion depth exceeded`)
+
+If you saw this in older builds, upgrade to a version that includes Issue #13 fix.  
+The bug was in `components/globals.py` path resolution and was triggered by some Windows folder layouts.
+
+### `ModuleNotFoundError` or import failures
+
+1. Confirm your virtual environment is activated.
+2. Reinstall dependencies:
+   `pip install --upgrade pip && pip install -r requirements.txt`
+3. Verify Python version:
+   `python --version`
+
+### PyQt5 install problems
+
+1. Use a supported Python version (3.10-3.12 recommended).
+2. Upgrade pip before installing.
+3. On Linux, ensure Qt runtime/system packages are installed by your distro package manager.
+
+### Invalid API keys / source errors
+
+1. Re-check token permissions and expiry at the provider side.
+2. Test one source at a time to isolate failures.
+3. Check Reaper logs in your app data/log directory if startup succeeds but jobs fail.
diff --git a/components/globals.py b/components/globals.py
index 8e72d6c..b0d79e4 100644
--- a/components/globals.py
+++ b/components/globals.py
@@ -9,12 +9,31 @@
 LOG_DIR = appdirs.user_log_dir(APP_NAME, APP_AUTHOR)
 CACHE_DIR = appdirs.user_cache_dir(APP_NAME, APP_AUTHOR)
 
+
 def _calc_path(path):
-    head, tail = os.path.split(path)
-    if tail == 'reaper':
-        return path
-    else:
-        return _calc_path(head)
+    """
+    Resolve the project root directory without recursive parent traversal.
+
+    The original implementation recursively walked parent directories until it
+    found a folder named "reaper". On Windows this can loop forever when the
+    path reaches a drive boundary (e.g. "D:\\") and os.path.split() keeps
+    returning the same head.
+    """
+    current = os.path.abspath(path)
+    start = current
+
+    while True:
+        if (
+            os.path.isdir(os.path.join(current, "ui"))
+            and os.path.isdir(os.path.join(current, "components"))
+        ):
+            return current
+
+        head, _ = os.path.split(current)
+        if head == current or head == "":
+            return start
+
+        current = head
 
 BUNDLE_DIR = sys._MEIPASS if getattr(sys, "frozen", False) else \
     _calc_path(os.path.dirname(os.path.abspath(__file__)))
diff --git a/components/job_queue.py b/components/job_queue.py
index b13aef0..11cd1c0 100644
--- a/components/job_queue.py
+++ b/components/job_queue.py
@@ -14,6 +14,41 @@
 from components.globals import *
 
 
+def _api_error_hint(error):
+    message = str(error).lower()
+    hints = []
+
+    if any(
+        token in message
+        for token in (
+            "unauthorized",
+            "forbidden",
+            "invalid token",
+            "access token",
+            "oauth",
+            "401",
+            "403",
+            "bad authentication data",
+        )
+    ):
+        hints.append(
+            "Credentials appear invalid or expired. Re-check API keys for this source."
+        )
+
+    if any(
+        token in message
+        for token in ("deprecated", "unsupported", "endpoint", "410", "removed")
+    ):
+        hints.append(
+            "The provider endpoint may be deprecated or changed. Verify current API docs."
+        )
+
+    if not hints:
+        return None
+
+    return " ".join(hints)
+
+
 class QueueState(Enum):
     RUNNING = "running"
     STOPPED = "stopped"
@@ -341,6 +376,10 @@ def run(self):
                     self.job_error.emit(job)
                     job.pickle()
 
+                    hint = _api_error_hint(e)
+                    if hint:
+                        self.job_error_log.emit(hint)
+
                     if not isinstance(e, IterError):
                         self.job_error_log.emit(format_exc())
                 self.stop()
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..c3f7fbb
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,20 @@
+[build-system]
+requires = ["setuptools>=68", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "reaper"
+version = "2.5.4"
+description = "GUI social media data collection client powered by socialreaper."
+readme = "README.md"
+requires-python = ">=3.10,<3.13"
+authors = [{ name = "UQ" }]
+dependencies = [
+  "PyQt5>=5.15.9,<6",
+  "socialreaper @ git+https://github.com/ScriptSmith/socialreaper.git",
+  "appdirs>=1.4.4,<2",
+  "QDarkStyle>=3.2.3,<4",
+]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..a7e7e20
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,2 @@
+-r requirements.txt
+pytest>=8.3,<9
diff --git a/requirements.txt b/requirements.txt
index 860ca6f..ee0dd6f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,4 @@
-PyQt5==5.9.1
--e git+https://github.com/ScriptSmith/socialreaper.git#egg=socialreaper
-appdirs==1.4.3
-QDarkStyle==2.5.3 
-sip==4.19.8
+PyQt5>=5.15.9,<6
+socialreaper @ git+https://github.com/ScriptSmith/socialreaper.git
+appdirs>=1.4.4,<2
+QDarkStyle>=3.2.3,<4
diff --git a/tests/test_globals.py b/tests/test_globals.py
new file mode 100644
index 0000000..cc6e37f
--- /dev/null
+++ b/tests/test_globals.py
@@ -0,0 +1,40 @@
+import os
+import tempfile
+import unittest
+from unittest import mock
+
+from components.globals import _calc_path
+
+
+class CalcPathTests(unittest.TestCase):
+    def test_returns_project_root_when_layout_markers_exist(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            project_root = os.path.join(temp_dir, "reaper-master")
+            components_dir = os.path.join(project_root, "components")
+            ui_dir = os.path.join(project_root, "ui")
+
+            os.makedirs(components_dir)
+            os.makedirs(ui_dir)
+
+            self.assertEqual(_calc_path(components_dir), project_root)
+
+    def test_returns_start_path_when_project_root_not_found(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            nested = os.path.join(temp_dir, "a", "b", "c")
+            os.makedirs(nested)
+
+            self.assertEqual(_calc_path(nested), os.path.abspath(nested))
+
+    def test_stops_when_split_returns_same_path(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            start = os.path.abspath(temp_dir)
+
+            with mock.patch(
+                "components.globals.os.path.split",
+                side_effect=lambda p: (p, ""),
+            ):
+                self.assertEqual(_calc_path(start), start)
+
+
+if __name__ == "__main__":
+    unittest.main()