diff --git a/packages/app/src/core/component-path.ts b/packages/app/src/core/component-path.ts
index 8198c00..52451de 100644
--- a/packages/app/src/core/component-path.ts
+++ b/packages/app/src/core/component-path.ts
@@ -1,5 +1,34 @@
 const jsxFilePattern = /\.(tsx|jsx)(\?.*)?$/u
 
+/**
+ * Normalizes a module ID by stripping query parameters.
+ *
+ * Vite and other bundlers may append query parameters to module IDs
+ * (e.g., "src/App.tsx?import" or "src/App.tsx?v=123"). This function
+ * returns the clean file path without query string.
+ *
+ * @param id - Module ID (may include query parameters).
+ * @returns Clean path without query string.
+ *
+ * @pure true
+ * @invariant ∀ id: normalizeModuleId(id) does not contain '?'
+ * @complexity O(n) time / O(1) space where n = |id|
+ */
+// CHANGE: centralize query stripping as a pure function in core.
+// WHY: unify module ID normalization in one place as requested in issue #18.
+// QUOTE(ТЗ): "Вынести stripQuery() (или normalizeModuleId()) в core, использовать в Vite и (при желании) в isJsxFile."
+// REF: REQ-18 (issue #18)
+// SOURCE: n/a
+// FORMAT THEOREM: ∀ id: normalizeModuleId(id) = id.split('?')[0]
+// PURITY: CORE
+// EFFECT: n/a
+// INVARIANT: result contains no query string
+// COMPLEXITY: O(n)/O(1)
+export const normalizeModuleId = (id: string): string => {
+  const queryIndex = id.indexOf("?")
+  return queryIndex === -1 ? id : id.slice(0, queryIndex)
+}
+
 // CHANGE: rename attribute from "path" to "data-path" for HTML5 compliance.
 // WHY: data-* attributes are standard HTML5 custom data attributes, improving compatibility.
 // QUOTE(issue-14): "Rename attribute path → data-path (breaking change)"
@@ -24,7 +53,7 @@ export const componentPathAttributeName = "data-path"
  */
 // CHANGE: centralize JSX file detection as a pure predicate.
 // WHY: keep file filtering in the functional core for testability.
-// QUOTE(TZ): "\u0421\u0430\u043c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442 \u0434\u043e\u043b\u0436\u0435\u043d \u0431\u044b\u0442\u044c \u0432 \u0442\u0435\u043a\u0443\u0449\u0435\u043c app \u043d\u043e \u0432\u043e\u0442 \u0447\u0442\u043e \u0431\u044b \u0435\u0433\u043e \u043f\u0440\u043e\u0442\u0435\u0441\u0442\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u043d\u0430\u0434\u043e \u0441\u043e\u0437\u0434\u0430\u0442\u044c \u0435\u0449\u0451 \u043e\u0434\u0438\u043d \u043f\u0440\u043e\u0435\u043a\u0442 \u043a\u043e\u0442\u043e\u0440\u044b\u0439 \u043d\u0430\u0448 \u0442\u0435\u043a\u0443\u0449\u0438\u0439 \u0430\u043f\u043f \u0431\u0443\u0434\u0435\u0442 \u043f\u043e\u0434\u043a\u043b\u044e\u0447\u0430\u0442\u044c"
+// QUOTE(TZ): "Сам компонент должен быть в текущем app но вот что бы его протестировать надо создать ещё один проект который наш текущий апп будет подключать"
 // REF: user-2026-01-14-frontend-consumer
 // SOURCE: n/a
 // FORMAT THEOREM: forall id in ModuleId: isJsxFile(id) -> matches(id, jsxFilePattern)
@@ -48,7 +77,7 @@ export const isJsxFile = (id: string): boolean => jsxFilePattern.test(id)
  */
 // CHANGE: provide a pure formatter for component location payloads.
 // WHY: reuse a single, deterministic encoding for UI metadata.
-// QUOTE(TZ): "\u0421\u0430\u043c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442 \u0434\u043e\u043b\u0436\u0435\u043d \u0431\u044b\u0442\u044c \u0432 \u0442\u0435\u043a\u0443\u0449\u0435\u043c app \u043d\u043e \u0432\u043e\u0442 \u0447\u0442\u043e \u0431\u044b \u0435\u0433\u043e \u043f\u0440\u043e\u0442\u0435\u0441\u0442\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u043d\u0430\u0434\u043e \u0441\u043e\u0437\u0434\u0430\u0442\u044c \u0435\u0449\u0451 \u043e\u0434\u0438\u043d \u043f\u0440\u043e\u0435\u043a\u0442 \u043a\u043e\u0442\u043e\u0440\u044b\u0439 \u043d\u0430\u0448 \u0442\u0435\u043a\u0443\u0449\u0438\u0439 \u0430\u043f\u043f \u0431\u0443\u0434\u0435\u0442 \u043f\u043e\u0434\u043a\u043b\u044e\u0447\u0430\u0442\u044c"
+// QUOTE(TZ): "Сам компонент должен быть в текущем app но вот что бы его протестировать надо создать ещё один проект который наш текущий апп будет подключать"
 // REF: user-2026-01-14-frontend-consumer
 // SOURCE: n/a
 // FORMAT THEOREM: forall p,l,c: formatComponentPathValue(p,l,c) = concat(p, ":", l, ":", c)
diff --git a/packages/app/src/index.ts b/packages/app/src/index.ts
index eb188ee..97afcd9 100644
--- a/packages/app/src/index.ts
+++ b/packages/app/src/index.ts
@@ -8,7 +8,12 @@
 // EFFECT: n/a
 // INVARIANT: exports remain stable for consumers
 // COMPLEXITY: O(1)/O(1)
-export { componentPathAttributeName, formatComponentPathValue, isJsxFile } from "./core/component-path.js"
+export {
+  componentPathAttributeName,
+  formatComponentPathValue,
+  isJsxFile,
+  normalizeModuleId
+} from "./core/component-path.js"
 export {
   attrExists,
   createJsxTaggerVisitor,
diff --git a/packages/app/src/shell/component-tagger.ts b/packages/app/src/shell/component-tagger.ts
index 2558ca6..0d18ae2 100644
--- a/packages/app/src/shell/component-tagger.ts
+++ b/packages/app/src/shell/component-tagger.ts
@@ -3,7 +3,7 @@ import type { Path } from "@effect/platform/Path"
 import { Effect, pipe } from "effect"
 import type { PluginOption } from "vite"
 
-import { componentPathAttributeName, isJsxFile } from "../core/component-path.js"
+import { componentPathAttributeName, isJsxFile, normalizeModuleId } from "../core/component-path.js"
 import { createJsxTaggerVisitor, type JsxTaggerContext } from "../core/jsx-tagger.js"
 import { NodePathLayer, relativeFromRoot } from "../core/path-service.js"
 
@@ -33,11 +33,6 @@ class ComponentTaggerError extends Error {
   }
 }
 
-const stripQuery = (id: string): string => {
-  const queryIndex = id.indexOf("?")
-  return queryIndex === -1 ? id : id.slice(0, queryIndex)
-}
-
 const toViteResult = (result: BabelTransformResult): ViteTransformResult | null => {
   if (result === null || result.code === null || result.code === undefined) {
     return null
@@ -105,7 +100,7 @@ const runTransform = (
   rootDir: string,
   attributeName: string
 ): Effect.Effect<ViteTransformResult | null, ComponentTaggerError, Path> => {
-  const cleanId = stripQuery(id)
+  const cleanId = normalizeModuleId(id)
 
   return pipe(
     relativeFromRoot(rootDir, cleanId),
diff --git a/packages/app/tests/core/component-path.test.ts b/packages/app/tests/core/component-path.test.ts
index 4e327c8..62b39d0 100644
--- a/packages/app/tests/core/component-path.test.ts
+++ b/packages/app/tests/core/component-path.test.ts
@@ -1,7 +1,12 @@
 import { describe, expect, it } from "@effect/vitest"
 import { Effect } from "effect"
 
-import { componentPathAttributeName, formatComponentPathValue, isJsxFile } from "../../src/core/component-path.js"
+import {
+  componentPathAttributeName,
+  formatComponentPathValue,
+  isJsxFile,
+  normalizeModuleId
+} from "../../src/core/component-path.js"
 
 describe("component-path", () => {
   it.effect("exposes the data-path attribute name", () =>
@@ -21,4 +26,21 @@ describe("component-path", () => {
       expect(isJsxFile("src/App.jsx?import")).toBe(true)
       expect(isJsxFile("src/App.ts")).toBe(false)
     }))
+
+  it.effect("normalizes module id by stripping query string", () =>
+    Effect.sync(() => {
+      // With query parameter
+      expect(normalizeModuleId("src/App.tsx?import")).toBe("src/App.tsx")
+      expect(normalizeModuleId("src/App.jsx?v=123")).toBe("src/App.jsx")
+      expect(normalizeModuleId("src/App.tsx?import&v=abc")).toBe("src/App.tsx")
+
+      // Without query parameter (idempotent)
+      expect(normalizeModuleId("src/App.tsx")).toBe("src/App.tsx")
+      expect(normalizeModuleId("src/App.jsx")).toBe("src/App.jsx")
+
+      // Edge cases
+      expect(normalizeModuleId("")).toBe("")
+      expect(normalizeModuleId("?")).toBe("")
+      expect(normalizeModuleId("file?")).toBe("file")
+    }))
 })