diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b10d1b0..46130f9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,3 @@
-# Continuous Integration workflow. For more information see:
 # https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-python
 # https://docs.astral.sh/ruff/integrations/#github-actions
 
@@ -17,20 +16,24 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: "3.12"
           cache: pip
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements.txt
+
       - name: Lint & format with ruff
         run: |
           ruff check --output-format github .
           ruff format --check .
+
+      - name: Test with pytest
+        run: pytest -v --ignore=purrr .
+
       - name: Verify README.md is up to date
         run: |
+          # If this check fails, run "python update_projects_table.py", and add "README.md" to this PR.
           python update_projects_table.py
           git diff --name-only --exit-code README.md
-      # (Enable this step once we have unit tests)
-      # - name: Test with pytest
-      #   run: pytest -v
diff --git a/Makefile b/Makefile
index c17e293..8a6245f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
-# Add "test" once we have unit tests
-all: deps format lint # test
+all: deps lint format test
 
 deps:
+	python -m pip install --upgrade pip
 	python -m pip install -r requirements.txt
 
 format: deps
@@ -11,6 +11,6 @@ lint: deps
 	ruff check --fix --output-format full .
 
 test: deps
-	pytest -v
+	pytest -v --ignore=purrr .
 
 .PHONY: all deps format lint test
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..3872c45
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,22 @@
+[tool.ruff]
+src = ["./**"]
+target-version = "py312"
+
+[tool.ruff.lint]
+# https://docs.astral.sh/ruff/rules/
+extend-select = ["B", "C4", "D101", "D2", "D3", "DTZ", "E5", "I", "N", "PTH", "Q", "S", "UP", "W"]
+ignore = ["D213", "S113", "S311", "S314", "S4"]
+# TODO: BLE, D100, S113
+# MAYBE: D4, ANN, S314, FBT, CPY, TRY
+
+[tool.ruff.lint.isort]
+force-sort-within-sections = true
+lines-after-imports = 2
+order-by-type = false
+known-third-party = ["discord", "github"]
+
+force-single-line = true
+single-line-exclusions = ["autokitteh.atlassian", "autokitteh.google", "datetime", "typing"]
+
+[tool.ruff.lint.pydocstyle]
+convention = "google"
diff --git a/requirements.txt b/requirements.txt
index e8e7661..71cc539 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
-pytest ~= 8.2
-ruff ~= 0.5
+pytest
+ruff