diff --git a/.prettierignore b/.prettierignore
new file mode 100644
index 0000000..e7349ba
--- /dev/null
+++ b/.prettierignore
@@ -0,0 +1,5 @@
+legal/THIRD_PARTY.md
+CHANGELOG.md
+**/graphql/schema.json
+package-lock.json
+/doc/
diff --git a/.prettierrc.json b/.prettierrc.json
new file mode 100644
index 0000000..e55558a
--- /dev/null
+++ b/.prettierrc.json
@@ -0,0 +1,10 @@
+{
+  "overrides": [
+    {
+      "files": ["*.md", "*.markdown"],
+      "options": {
+        "tabWidth": 4
+      }
+    }
+  ]
+}
diff --git a/package.json b/package.json
index c52bbce..aedef89 100644
--- a/package.json
+++ b/package.json
@@ -61,7 +61,8 @@
     "skill:bundle": "atm-skill bundle --minify --source-map",
     "skill:package": "atm-skill package",
     "skill:register": "atm-skill register",
-    "atm:lint:eslint": "eslint --fix"
+    "atm:lint:eslint": "eslint --fix",
+    "atm:lint:prettier": "prettier --write"
   },
   "husky": {
     "hooks": {
@@ -69,6 +70,7 @@
     }
   },
   "lint-staged": {
-    "**/*.ts": "npm run atm:lint:eslint"
+    "**/*.ts": "npm run atm:lint:eslint",
+    "**/*.@(graphql|json|markdown|yaml|yml|md)": "npm run atm:lint:prettier"
   }
 }