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+---
+title: Enable Strict Template Checking
+impact: HIGH
+impactDescription: catches undefined components and props at compile time
+type: capability
+tags: vue-tsc, typescript, type-checking, templates, vueCompilerOptions
+---
+
+# Enable Strict Template Checking
+
+**Impact: HIGH** - catches undefined components and props at compile time
+
+By default, vue-tsc does not report errors for undefined components in templates. Enable `strictTemplates` to catch these issues during type checking.
+
+## Which tsconfig?
+
+Add `vueCompilerOptions` to the tsconfig that includes Vue source files. In projects with multiple tsconfigs (like those created with `create-vue`), this is typically `tsconfig.app.json`, not the root `tsconfig.json` or `tsconfig.node.json`.
+
+**Incorrect (missing strict checking):**
+
+```json
+{
+  "compilerOptions": {
+    "strict": true
+  }
+  // vueCompilerOptions not configured - undefined components won't error
+}
+```
+
+**Correct (strict template checking enabled):**
+
+```json
+{
+  "compilerOptions": {
+    "strict": true
+  },
+  "vueCompilerOptions": {
+    "strictTemplates": true
+  }
+}
+```
+
+## Available Options
+
+| Option | Default | Effect |
+|--------|---------|--------|
+| `strictTemplates` | `false` | Enables all checkUnknown* options below |
+| `checkUnknownComponents` | `false` | Error on undefined/unregistered components |
+| `checkUnknownProps` | `false` | Error on props not declared in component definition |
+| `checkUnknownEvents` | `false` | Error on events not declared via `defineEmits` |
+| `checkUnknownDirectives` | `false` | Error on unregistered custom directives |
+
+## Granular Control
+
+If `strictTemplates` is too strict, enable individual checks:
+
+```json
+{
+  "vueCompilerOptions": {
+    "checkUnknownComponents": true,
+    "checkUnknownProps": false
+  }
+}
+```
+
+## Reference
+
+- [Vue Compiler Options](https://github.com/vuejs/language-tools/wiki/Vue-Compiler-Options)
+- [Vite Vue+TS Template](https://github.com/vitejs/vite/tree/main/packages/create-vite/template-vue-ts)