diff --git a/lefthook.yml b/lefthook.yml
new file mode 100644
index 00000000..58f346f6
--- /dev/null
+++ b/lefthook.yml
@@ -0,0 +1,27 @@
+# Autofix-only: these commands never block a commit. Unfixable lint errors are
+# printed for visibility, but `|| true` keeps the hook green. CI is what gates.
+#
+# `glob` scopes each tool to the file types it handles, so a commit touching
+# only e.g. Markdown skips all three commands instead of spawning no-op
+# processes. Lefthook already skips a command when its file list comes out
+# empty, so the globs are for clarity and speed, not safety.
+pre-commit:
+    commands:
+        lint:
+            priority: 1
+            # oxlint reads .astro too, and CI's bare `oxlint` discovers them.
+            glob: '*.{js,jsx,mjs,cjs,mts,cts,ts,tsx,astro}'
+            run: pnpm exec oxlint --fix {staged_files} || true
+            stage_fixed: true
+        fmt:
+            priority: 2
+            # Must cover every type oxfmt handles, or the hook stays silent on a
+            # file that `pnpm run check` then fails on in CI.
+            glob: '*.{js,jsx,mjs,cjs,mts,cts,ts,tsx,json,jsonc,yaml,yml,md,mdx,html}'
+            run: pnpm exec oxfmt {staged_files} || true
+            stage_fixed: true
+        fmt-astro:
+            priority: 2
+            glob: '*.astro'
+            run: pnpm exec prettier --write {staged_files} || true
+            stage_fixed: true
diff --git a/package.json b/package.json
index 12e0bbc5..626adb08 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,7 @@
         "@vitest/coverage-istanbul": "4.1.1",
         "buffer": "6.0.3",
         "git-cliff": "2.13.1",
+        "lefthook": "2.1.10",
         "parcel": "2.16.4",
         "process": "0.11.10",
         "typescript": "5.9.3",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 175f885b..a423bc94 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -23,6 +23,9 @@ importers:
       git-cliff:
         specifier: 2.13.1
         version: 2.13.1
+      lefthook:
+        specifier: 2.1.10
+        version: 2.1.10
       oxfmt:
         specifier: 0.61.0
         version: 0.61.0
@@ -2951,6 +2954,60 @@ packages:
     resolution: {integrity: sha512-dhG34DXATL5hSxJbIexCft8FChFXtmskoZYnoPWjXQuebWYCNkVeV3KkGegCK9CP1oswI/vQibS2GY7Em/sJJA==}
     engines: {node: '>= 8'}
 
+  lefthook-darwin-arm64@2.1.10:
+    resolution: {integrity: sha512-nw+X8wRNDoUUV6WSteyKBbcLySq+fsmZt5WV/s50ZJpysmsDKJOUMln6SllNfP+60dzUahAO7REco/2633BsLg==}
+    cpu: [arm64]
+    os: [darwin]
+
+  lefthook-darwin-x64@2.1.10:
+    resolution: {integrity: sha512-KQ/bHmvpkFdHMn4pZnUdTf+GuSC+aBBgBTxZT4GW+6cSf+qbErKZBhK7cH6BmILsvx43+VzEArvHYY7YOfRFOQ==}
+    cpu: [x64]
+    os: [darwin]
+
+  lefthook-freebsd-arm64@2.1.10:
+    resolution: {integrity: sha512-8su6DwydP7+pv7kG0zCtjphqsw4ouOnfexRUErapy5GTxYBoUOhYz3RSHTSWNRsK6W4jva7FPUh2Lp5/PSn30w==}
+    cpu: [arm64]
+    os: [freebsd]
+
+  lefthook-freebsd-x64@2.1.10:
+    resolution: {integrity: sha512-GeAJEFxko3Lk+AsnS3NleAFrpyMLFUKOlgJvPKuU0xHwVEI/z+ZoCcmuO0BX+4CS0NLbZhC/YQAvBASqDvvVdQ==}
+    cpu: [x64]
+    os: [freebsd]
+
+  lefthook-linux-arm64@2.1.10:
+    resolution: {integrity: sha512-1sHTCmpTWjVMs+yKPBLRNT1kuuIr1yjietlk7rCB6wFPVOS6Ph3o2zPFH2AvW1UymHlqwyHXzBr9EtDpQ7j1mQ==}
+    cpu: [arm64]
+    os: [linux]
+
+  lefthook-linux-x64@2.1.10:
+    resolution: {integrity: sha512-z/VlRB3bh6mBvW3r1rwnJ5vP8z+Krx5gJzkZ4veDXh+6FlRTx8wtd3g3fllOv/yZMxkgmL3fQoFXv05Esa7vBQ==}
+    cpu: [x64]
+    os: [linux]
+
+  lefthook-openbsd-arm64@2.1.10:
+    resolution: {integrity: sha512-430zL8sSIKw5P0YXGG6PB+eAhHa06n0PXuaERaAQE4Ss3odfqwnl5Mq9hQmkEnOS1EGiQEKkd0UHv/i4PtMNIQ==}
+    cpu: [arm64]
+    os: [openbsd]
+
+  lefthook-openbsd-x64@2.1.10:
+    resolution: {integrity: sha512-bgkO8PphGZVDhQgCJ524aYYPI5491pVmCiLPGjBIo1AvOSlIyw4N1Y+1C3QfqwEmechzw+Aq16SNc8pqv6UuXg==}
+    cpu: [x64]
+    os: [openbsd]
+
+  lefthook-windows-arm64@2.1.10:
+    resolution: {integrity: sha512-5Q6etF0Fla2DDA4ilDySrdNgiR5+W7cJZwnZ69Je3kvWCaWm4wnkuc8FEdjp3kiL2x3ZXipdI00f5vpO8aWmog==}
+    cpu: [arm64]
+    os: [win32]
+
+  lefthook-windows-x64@2.1.10:
+    resolution: {integrity: sha512-c/XH8YZtylG4XaxzqFfXluvq2LXq2W/p54Bnzn3+Z7E5X2Fk3JlFJAibulMbIt2+w8T7UI/r97ok5GqE4kGaeA==}
+    cpu: [x64]
+    os: [win32]
+
+  lefthook@2.1.10:
+    resolution: {integrity: sha512-K7mM4WoqMwqfXYK11EHy+lSH1uW8XHni3Yn/bSqyerPkUPygGdf3xn18JoV5HyA06xuQL3ofGAOjG01QX9oJ4w==}
+    hasBin: true
+
   lightningcss-android-arm64@1.30.2:
     resolution: {integrity: sha512-BH9sEdOCahSgmkVhBLeU7Hc9DWeZ1Eb6wNS6Da8igvUwAe0sqROHddIlvU06q3WyXVEOYDZ6ykBZQnjTbmo4+A==}
     engines: {node: '>= 12.0.0'}
@@ -7208,6 +7265,49 @@ snapshots:
 
   klona@2.0.6: {}
 
+  lefthook-darwin-arm64@2.1.10:
+    optional: true
+
+  lefthook-darwin-x64@2.1.10:
+    optional: true
+
+  lefthook-freebsd-arm64@2.1.10:
+    optional: true
+
+  lefthook-freebsd-x64@2.1.10:
+    optional: true
+
+  lefthook-linux-arm64@2.1.10:
+    optional: true
+
+  lefthook-linux-x64@2.1.10:
+    optional: true
+
+  lefthook-openbsd-arm64@2.1.10:
+    optional: true
+
+  lefthook-openbsd-x64@2.1.10:
+    optional: true
+
+  lefthook-windows-arm64@2.1.10:
+    optional: true
+
+  lefthook-windows-x64@2.1.10:
+    optional: true
+
+  lefthook@2.1.10:
+    optionalDependencies:
+      lefthook-darwin-arm64: 2.1.10
+      lefthook-darwin-x64: 2.1.10
+      lefthook-freebsd-arm64: 2.1.10
+      lefthook-freebsd-x64: 2.1.10
+      lefthook-linux-arm64: 2.1.10
+      lefthook-linux-x64: 2.1.10
+      lefthook-openbsd-arm64: 2.1.10
+      lefthook-openbsd-x64: 2.1.10
+      lefthook-windows-arm64: 2.1.10
+      lefthook-windows-x64: 2.1.10
+
   lightningcss-android-arm64@1.30.2:
     optional: true
 
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index db3a0b79..52ba6f88 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -9,6 +9,8 @@ allowBuilds:
     '@parcel/watcher': false
     '@swc/core': false
     esbuild: false
+    # lefthook's postinstall is what installs the git hooks.
+    lefthook: true
     lmdb: false
     msgpackr-extract: false
     sharp: false