diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 00000000..4faecbb2
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,8 @@
+# `pre-commit install` once, then ruff runs on every commit, as in CI.
+repos:
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.17.3
+    hooks:
+      - id: ruff-check
+        args: [simple, tests]
+        pass_filenames: false
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 38846dfd..83d46e3f 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -29,10 +29,15 @@ git clone https://github.com/<your-username>/OpenVerifiableLLM
 cd OpenVerifiableLLM
 pip install --require-hashes -r requirements/preparation.lock   # the same CPU environment as CI
 pip install pytest gguf safetensors ruff
-OVL_DEVICE=cpu OVL_TIMESTAMP=0 python -m pytest -q tests        # runs on a CPU, about 15 s
+OVL_DEVICE=cpu OVL_TIMESTAMP=0 python -m pytest -q tests        # runs on a CPU, about 25 s
 ruff check simple tests
 ```
 
+With `make`, the same steps are `make setup` and `make check` (`make help` lists the rest). Run
+`pre-commit install` once to run ruff on every commit. With `uv` instead of pip, install the lock
+with `uv pip install --index-strategy unsafe-best-match --require-hashes -r requirements/preparation.lock`:
+the lock takes PyTorch from the PyTorch index and everything else from PyPI.
+
 Training and segment checks need an RTX 5090. Everything in `tests/` runs on a CPU. To add a
 dependency, add it to the lock file, so that every install stays pinned by hash.
 
diff --git a/Makefile b/Makefile
new file mode 100644
index 00000000..da19f0b6
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,25 @@
+# Everyday commands. The environment is the one CI uses: see CONTRIBUTING.md.
+PYTHON ?= python
+export OVL_DEVICE ?= cpu
+export OVL_TIMESTAMP ?= 0
+export TOKENIZERS_PARALLELISM ?= false
+
+.PHONY: help setup test lint check check-release
+
+help:  ## list the commands
+	@grep -E '^[a-z-]+:.*## ' $(MAKEFILE_LIST) | sed 's/:.*## /\t/'
+
+setup:  ## install the hash-locked CPU environment and the dev tools into the current Python
+	$(PYTHON) -m pip install --require-hashes -r requirements/preparation.lock
+	$(PYTHON) -m pip install pytest pytest-cov ruff gguf safetensors pre-commit
+
+test:  ## run the tests (CPU, about 25 s)
+	$(PYTHON) -m pytest -q tests
+
+lint:  ## run ruff, as CI does
+	$(PYTHON) -m ruff check simple tests
+
+check: lint test  ## everything CI runs
+
+check-release:  ## check the published release on this computer (about 2 minutes)
+	bash simple/check_release.sh
diff --git a/pyproject.toml b/pyproject.toml
index 493f2f08..899aca9d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,9 @@ version = "1.1.0"
 description = "Train a small language model on English Wikipedia so that anyone can recompute it bit for bit."
 readme = "README.md"
 requires-python = ">=3.12"
-# Pinned with hashes in requirements/preparation.lock, which CI installs.
+# For the tools and the CPU checks; pinned with hashes in requirements/preparation.lock, which CI
+# installs. Training and segment checks don't use these: they run in the training image
+# (PyTorch 2.8.0, CUDA 12.8), the only setup that reproduces the published bits.
 dependencies = ["torch>=2.10.0,<3.0", "numpy>=2.4,<3.0", "tokenizers==0.23.2"]
 
 [project.optional-dependencies]