diff --git a/README.md b/README.md
index 82172db..0418471 100644
--- a/README.md
+++ b/README.md
@@ -10,12 +10,21 @@ Searchs for usage of `$t` and writes keys to JSON files.
 Input from source code
 ```javascript
 $t('some_key')
+
+// with namespace to split into separate files
+$t('common:some_key')
+
+// nested key
+$t('messages.success')
 ```
 
 Output to translation file
 ```json
 {
-  "some_key": "__MISSING_TRANSLATION__"
+  "some_key": "__MISSING_TRANSLATION__",
+  "messages": {
+    "success": "__MISSING_TRANSLATION__"
+  }
 }
 ```
 
@@ -61,7 +70,12 @@ module.exports = {
   // Optional: Default value for new translations
   defaultValue: '__MISSING_TRANSLATION__',
   // Optional: Regex to extract transations from source code
+  // The translation key must be the first match
   parseRegex: /\B\$t\s*\(\s*['"]([\w/: ._-]+)['"]/g,
+  // Optional: Parser function, receives file content as string and should return list of found translation keys
+  // Type: (filePath: string, content: string) => string[]
+  parser: (filePath, content) =>
+    [...content.matchAll(/\B\$t\s*\(\s*['"]([\w/: ._-]+)['"]/g)].map((matches) => matches[1]),
   // Optional: Keep missing translations and not delete them
   keepMissing: false
 }
diff --git a/src/parse.ts b/src/parse.ts
index f2c1abe..e4d9b4f 100644
--- a/src/parse.ts
+++ b/src/parse.ts
@@ -44,21 +44,22 @@ export const getFileList = async (
  */
 export const parseFile = async (options: I18nExtractOptions, filePath: string): Promise<TranslationKeyList> => {
   const content = readFileSync(filePath, { encoding: 'utf8' })
-  return parseContent(options, content)
+  return parseContent(options, filePath, content)
 }
 
 /**
  * Parse content and return found translation keys
  */
-export const parseContent = async (options: I18nExtractOptions, content: string): Promise<TranslationKeyList> => {
-  const regex = options.parseRegex ?? /\B\$t\s*\(\s*['"]([\w/: ._-]+)['"]/g
-  const matches: TranslationKeyList = new Set()
-  let match
-  do {
-    match = regex.exec(content)
-    if (match) {
+export const parseContent = async (options: I18nExtractOptions, filePath: string, content: string): Promise<TranslationKeyList> => {
+  if (options.parser) {
+    const results = options.parser(filePath, content)
+    return results instanceof Set ? results : new Set(results)
+  } else {
+    const regex = options.parseRegex ?? /\B\$t\s*\(\s*['"]([\w/: ._-]+)['"]/g
+    const matches: TranslationKeyList = new Set()
+    for (const match of content.matchAll(regex)) {
       matches.add(match[1])
     }
-  } while (match != null)
-  return matches
+    return matches
+  }
 }
diff --git a/src/types.ts b/src/types.ts
index 54b6634..202c0d0 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -20,6 +20,8 @@ export type TranslationMap <T extends TranslationResult = TranslationResult> = R
 export type TranslationMapLoad = TranslationMap
 export type TranslationMapWrite = TranslationMap<TranslationResultWrite>
 
+export type CustomParser = (filePath: string, content: string) => (string[] | Set<string>)
+
 export interface I18nExtractOptions {
   input: string[]
   output: string
@@ -28,5 +30,6 @@ export interface I18nExtractOptions {
   namespaces?: Namespace[]
   defaultValue?: string
   parseRegex?: RegExp
+  parser?: CustomParser
   keepMissing?: boolean
 }
diff --git a/tests/parse.spec.ts b/tests/parse.spec.ts
index 5c40fc1..439614a 100644
--- a/tests/parse.spec.ts
+++ b/tests/parse.spec.ts
@@ -1,7 +1,8 @@
-import { describe, expect, it } from 'vitest'
+import { describe, expect, it, vi } from 'vitest'
 import path from 'node:path'
 import { getFileList, parseContent, parseFile, parseFiles } from '@/parse'
-import type { I18nExtractOptions } from '@/types'
+import { CustomParser, I18nExtractOptions } from '@/types'
+import { readFileSync } from 'fs'
 
 const options: I18nExtractOptions = {
   input: [
@@ -9,10 +10,11 @@ const options: I18nExtractOptions = {
     'examples/namespaces/src/**/*.ts',
     '!**/__tests__/**'
   ],
-  output: 'examples/default/locales/{{lng}}.json',
+  output: 'examples/namespaces/locales/{{lng}}.json',
   languages: ['de', 'en-GB'],
   defaultNamespace: 'common'
 }
+const getFileContent = (filePath: string) => readFileSync(filePath, { encoding: 'utf8' })
 
 /**
  * parseFiles
@@ -61,6 +63,43 @@ describe('parseFiles', () => {
       'other_key'
     ])
   })
+
+  it('should parse all files with custom parser', async () => {
+    const parser = vi.fn<CustomParser>((_, content) =>
+      [...content.matchAll(/\B\$t\s*\('([\w/: _-]+)'/g)].map((matches) => matches[1]))
+    const results = await parseFiles({
+      input: [
+        'examples/default/src/**/*.vue',
+        'examples/default/src/**/*.ts',
+        '!**/__tests__/**'
+      ],
+      output: 'examples/default/locales/{{lng}}.json',
+      languages: ['de', 'en-GB'],
+      parser
+    })
+
+    expect(Object.keys(results).sort()).toStrictEqual(['default'])
+    expect(results.default).toStrictEqual([
+      'key_1',
+      'key_2',
+      'key_4',
+      'new_key'
+    ])
+
+    expect(parser).toHaveBeenCalledTimes(3)
+    expect(parser).toHaveBeenCalledWith(
+      'examples/default/src/i18n.ts',
+      getFileContent('examples/default/src/i18n.ts')
+    )
+    expect(parser).toHaveBeenCalledWith(
+      'examples/default/src/typescript-file.ts',
+      getFileContent('examples/default/src/typescript-file.ts')
+    )
+    expect(parser).toHaveBeenCalledWith(
+      'examples/default/src/vue-file.vue',
+      getFileContent('examples/default/src/vue-file.vue')
+    )
+  })
 })
 
 /**
@@ -140,7 +179,7 @@ describe('parseFile', () => {
  * parseContent
  */
 describe('parseContent', () => {
-  const parseToArray = async (content: string) => Array.from(await parseContent(options, content))
+  const parseToArray = async (content: string) => Array.from(await parseContent(options, 'some-file.txt', content))
 
   it('should find translations from content', async () => {
     expect(await parseToArray('$t("key_1")')).toStrictEqual(['key_1'])
@@ -185,7 +224,19 @@ describe('parseContent', () => {
     expect(Array.from(await parseContent({
       ...options,
       parseRegex: /\B\$tc\s*\(\s*['"]([\w/: ._-]+)['"]/g
-    }, '$tc("key_1")'))).toStrictEqual(['key_1'])
+    }, 'some-file.txt', '$tc("key_1")'))).toStrictEqual(['key_1'])
   })
-})
 
+  it('should parse with parser function', async () => {
+    const parser = vi.fn<CustomParser>((_, content) =>
+      [...content.matchAll(/\B\$tx\s*\(\s*['"]([\w/: ._-]+)['"]/g)].map((matches) => matches[1]))
+
+    expect(Array.from(await parseContent({
+      ...options,
+      parser
+    }, 'some-file.txt', '$tx("key_1")'))).toStrictEqual(['key_1'])
+
+    expect(parser).toHaveBeenCalledTimes(1)
+    expect(parser).toHaveBeenCalledWith('some-file.txt', '$tx("key_1")')
+  })
+})