diff --git a/.changeset/fifty-ants-argue.md b/.changeset/fifty-ants-argue.md
new file mode 100644
index 000000000..ddbd65356
--- /dev/null
+++ b/.changeset/fifty-ants-argue.md
@@ -0,0 +1,5 @@
+---
+'vite-plugin-kit-routes': patch
+---
+
+fix group routes management
diff --git a/.changeset/popular-bears-tan.md b/.changeset/popular-bears-tan.md
new file mode 100644
index 000000000..90d05e386
--- /dev/null
+++ b/.changeset/popular-bears-tan.md
@@ -0,0 +1,5 @@
+---
+'vite-plugin-kit-routes': patch
+---
+
+manage optional params
diff --git a/.changeset/wet-insects-retire.md b/.changeset/wet-insects-retire.md
new file mode 100644
index 000000000..9bd98544b
--- /dev/null
+++ b/.changeset/wet-insects-retire.md
@@ -0,0 +1,5 @@
+---
+'vite-plugin-kit-routes': patch
+---
+
+manage matchers
diff --git a/packages/vite-plugin-kit-routes/src/lib/ROUTES.ts b/packages/vite-plugin-kit-routes/src/lib/ROUTES.ts
index 0fd15dc93..6b572702d 100644
--- a/packages/vite-plugin-kit-routes/src/lib/ROUTES.ts
+++ b/packages/vite-plugin-kit-routes/src/lib/ROUTES.ts
@@ -1,38 +1,50 @@
 export const PAGES = {
-  _ROOT: (sp?: Record<string, string>) => {
+  _ROOT: (sp?: Record<string, string | number>) => {
     return `/${appendSp(sp)}`
   },
-  contract: (sp?: Record<string, string>) => {
+  contract: (sp?: Record<string, string | number>) => {
     return `/contract${appendSp(sp)}`
   },
-  contract_id: (params: { id: string }, sp?: Record<string, string>) => {
+  contract_id: (params: { id: string | number }, sp?: Record<string, string | number>) => {
     return `/contract/${params.id}${appendSp(sp)}`
   },
-  site: (sp?: Record<string, string>) => {
+  gp_logged_one: (sp?: Record<string, string | number>) => {
+    return `/gp/one${appendSp(sp)}`
+  },
+  gp_public_two: (sp?: Record<string, string | number>) => {
+    return `/gp/two${appendSp(sp)}`
+  },
+  lang_lang: (params?: { lang?: string | number }, sp?: Record<string, string | number>) => {
+    return `/lang/${params?.lang ?? ''}${appendSp(sp)}`
+  },
+  match_id_int: (params: { id: string | number }, sp?: Record<string, string | number>) => {
+    return `/match/${params.id}${appendSp(sp)}`
+  },
+  site: (sp?: Record<string, string | number>) => {
     return `/site${appendSp(sp)}`
   },
-  site_id: (params: { id: string }, sp?: Record<string, string>) => {
+  site_id: (params: { id: string | number }, sp?: Record<string, string | number>) => {
     return `/site/${params.id}${appendSp(sp)}`
   },
   site_contract_siteId_contractId: (
-    params: { siteId: string; contractId: string },
-    sp?: Record<string, string>,
+    params: { siteId: string | number; contractId: string | number },
+    sp?: Record<string, string | number>,
   ) => {
     return `/site_contract/${params.siteId}-${params.contractId}${appendSp(sp)}`
   },
 }
 
 export const SERVERS = {
-  contract: (method: 'GET' | 'POST', sp?: Record<string, string>) => {
+  contract: (method: 'GET' | 'POST', sp?: Record<string, string | number>) => {
     return `/contract${appendSp(sp)}`
   },
-  site: (method: 'GET', sp?: Record<string, string>) => {
+  site: (method: 'GET', sp?: Record<string, string | number>) => {
     return `/site${appendSp(sp)}`
   },
 }
 
 export const ACTIONS = {
-  contract_id: (params: { id: string }) => {
+  contract_id: (params: { id: string | number }) => {
     return `/contract/${params.id}`
   },
   site: (action: 'action1' | 'action2') => {
@@ -40,13 +52,13 @@ export const ACTIONS = {
   },
   site_contract_siteId_contractId: (
     action: 'sendSomething',
-    params: { siteId: string; contractId: string },
+    params: { siteId: string | number; contractId: string | number },
   ) => {
     return `/site_contract/${params.siteId}-${params.contractId}?/${action}`
   },
 }
 
-const appendSp = (sp?: Record<string, string>) => {
+const appendSp = (sp?: Record<string, string | number>) => {
   if (sp === undefined) return ''
-  return `?${new URLSearchParams(sp || {}).toString()}`
+  return `?${new URLSearchParams((sp as Record<string, string>) || {}).toString()}`
 }
diff --git a/packages/vite-plugin-kit-routes/src/lib/index.ts b/packages/vite-plugin-kit-routes/src/lib/index.ts
index 6bac8ff61..f3f3bd387 100644
--- a/packages/vite-plugin-kit-routes/src/lib/index.ts
+++ b/packages/vite-plugin-kit-routes/src/lib/index.ts
@@ -42,7 +42,7 @@ export function formatKey(key: string, options?: Options) {
     return key
   }
 
-  const toReplace = ['/', '[', ']', '(', ')', '-']
+  const toReplace = ['/', '[', ']', '(', ')', '-', '=']
   let toRet = key
     .split('')
     .map(c => (toReplace.includes(c) ? '_' : c))
@@ -74,6 +74,7 @@ const log = new Log('Kit Routes')
 const getFileKeys = (
   lookFor: '+page.svelte' | '+page.server.ts' | '+server.ts',
   options?: Options,
+  withAppendSp?: boolean,
 ) => {
   const files = readdirSync(routes_path(), { recursive: true }) as string[]
   return (
@@ -83,29 +84,56 @@ const getFileKeys = (
       // Keep the sorting at this level, it will make more sense
       .sort()
       .map(file => {
-        return { toUse: formatKey(file, options), original: file }
+        const paramsFromPath = extractParamsFromPath(file)
+        const href = file.replace(/\([^)]*\)/g, '').replace(/\/+/g, '/')
+        let toRet = href
+        paramsFromPath.params.forEach(c => {
+          const sMatcher = `${c.matcher ? `=${c.matcher}` : ''}`
+          if (c.optional) {
+            toRet = toRet.replaceAll(`[[${c.name + sMatcher}]]`, `\${params?.${c.name} ?? ''}`)
+          } else {
+            toRet = toRet.replaceAll(`[${c.name + sMatcher}]`, `\${params.${c.name}}`)
+          }
+        })
+        return {
+          toUse: formatKey(file, options),
+          original: file,
+          paramsFromPath,
+          toReturn: `${toRet}${withAppendSp ? `\${appendSp(sp)}` : ``}`,
+        }
       })
   )
 }
 
-function formatExtractParamsFromPath(file_path: string) {
-  return extractParamsFromPath(file_path).map(c => `${c}: string`)
-}
-
-export function extractParamsFromPath(path: string): string[] {
-  // Use a regular expression to match parameter placeholders like '[param]'
-  const paramPattern = /\[([^\]]+)]/g
+export function extractParamsFromPath(path: string): {
+  params: { name: string; optional: boolean; matcher?: string }[]
+  formatArgs: string[]
+  isAllOptional: boolean
+} {
+  const paramPattern = /\[+([^\]]+)]+/g
   const params = []
 
   let match
   while ((match = paramPattern.exec(path)) !== null) {
-    // The matched parameter name is in the first capturing group
-    params.push(match[1])
+    // Check if it's surrounded by double brackets indicating an optional parameter
+    const isOptional = match[0].startsWith('[[')
+    const matcher = match[1].split('=')
+    if (matcher.length === 2) {
+      params.push({
+        // name: `${matcher[0]}_${matcher[1]}`,
+        name: matcher[0],
+        optional: isOptional,
+        matcher: matcher[1],
+      })
+    } else {
+      params.push({ name: match[1], optional: isOptional })
+    }
   }
 
-  return params
+  const format = params.map(c => `${c.name}${c.optional ? '?' : ''}: string | number`)
+  const isAllOptional = params.filter(c => !c.optional).length === 0
+  return { params, formatArgs: format, isAllOptional }
 }
-
 const getMethodsOfServerFiles = (path: string) => {
   const code = read(`${routes_path()}/${path}/${'+server.ts'}`)
 
@@ -164,55 +192,51 @@ const getActionsOfServerPages = (path: string) => {
 }
 
 const run = (options?: Options) => {
-  const pages = getFileKeys('+page.svelte', options)
-  const server = getFileKeys('+page.server.ts', options)
-  const files_server = getFileKeys('+server.ts', options)
+  const pages = getFileKeys('+page.svelte', options, true)
+  const servers = getFileKeys('+server.ts', options, true)
+  const pages_server = getFileKeys('+page.server.ts', options)
 
   const result = write(generated_file_path(options), [
     `export const PAGES = {
   ${pages
     .map(key => {
       const params = []
-      const pFormPath = formatExtractParamsFromPath(key.original)
-      if (pFormPath.length > 0) {
-        params.push(`params: {${pFormPath}}`)
+      if (key.paramsFromPath.params.length > 0) {
+        params.push(
+          `params${key.paramsFromPath.isAllOptional ? '?' : ''}: {${
+            key.paramsFromPath.formatArgs
+          }}`,
+        )
       }
-      params.push(`sp?: Record<string, string>`)
-      return (
-        `"${key.toUse}": (${params.join(', ')}) => ` +
-        `{ return \`${key.original
-          .replaceAll('[', '${params.')
-          .replaceAll(']', '}')}\${appendSp(sp)}\` }`
-      )
+      params.push(`sp?: Record<string, string | number>`)
+      return `"${key.toUse}": (${params.join(', ')}) =>  { return \`${key.toReturn}\` }`
     })
     .join(',\n  ')}
 }
 
 export const SERVERS = {
-  ${files_server
+  ${servers
     .map(key => {
       const params = []
       const methods = getMethodsOfServerFiles(key.original)
       if (methods.length > 0) {
         params.push(`method: ${methods.map(c => `'${c}'`).join(' | ')}`)
       }
-      const pFormPath = formatExtractParamsFromPath(key.original)
-      if (pFormPath.length > 0) {
-        params.push(`params: {${pFormPath}}`)
+      if (key.paramsFromPath.params.length > 0) {
+        params.push(
+          `params${key.paramsFromPath.isAllOptional ? '?' : ''}: {${
+            key.paramsFromPath.formatArgs
+          }}`,
+        )
       }
-      params.push(`sp?: Record<string, string>`)
-      return (
-        `"${key.toUse}": (${params.join(', ')}) => ` +
-        `{ return \`${key.original
-          .replaceAll('[', '${params.')
-          .replaceAll(']', '}')}\${appendSp(sp)}\` }`
-      )
+      params.push(`sp?: Record<string, string | number>`)
+      return `"${key.toUse}": (${params.join(', ')}) =>  { return \`${key.toReturn}\` }`
     })
     .join(',\n  ')}
 }
 
 export const ACTIONS = {
-  ${server
+  ${pages_server
     .map(key => {
       const params = []
       const actions = getActionsOfServerPages(key.original)
@@ -222,26 +246,25 @@ export const ACTIONS = {
       } else {
         params.push(`action: ${actions.map(c => `'${c}'`).join(' | ')}`)
         actionsFormat = `?/\${action}`
-        // actionsFormat = `coucou`
       }
-      const pFormPath = formatExtractParamsFromPath(key.original)
-      if (pFormPath.length > 0) {
-        params.push(`params: {${pFormPath}}`)
+      if (key.paramsFromPath.params.length > 0) {
+        params.push(
+          `params${key.paramsFromPath.isAllOptional ? '?' : ''}: {${
+            key.paramsFromPath.formatArgs
+          }}`,
+        )
       }
       return (
         `"${key.toUse}": (${params.join(', ')}) => ` +
-        `{ return \`` +
-        `${key.original.replaceAll('[', '${params.').replaceAll(']', '}')}` +
-        `${actionsFormat}` +
-        `\`}`
+        ` { return \`${key.toReturn}${actionsFormat}\` }`
       )
     })
     .join(',\n  ')}
 }
 
-const appendSp = (sp?: Record<string, string>) => {
+const appendSp = (sp?: Record<string, string | number>) => {
   if (sp === undefined) return ''
-  return \`?\${new URLSearchParams(sp || {}).toString()}\`
+  return \`?\${new URLSearchParams(sp as Record<string, string> || {}).toString()}\`
 }
 `,
   ])
diff --git a/packages/vite-plugin-kit-routes/src/lib/plugins.spec.ts b/packages/vite-plugin-kit-routes/src/lib/plugins.spec.ts
index 74eaf4d42..b72548a64 100644
--- a/packages/vite-plugin-kit-routes/src/lib/plugins.spec.ts
+++ b/packages/vite-plugin-kit-routes/src/lib/plugins.spec.ts
@@ -4,28 +4,84 @@ import { extractParamsFromPath, formatKey } from './index.js'
 describe('vite-plugin-kit-routes', () => {
   it('get id', async () => {
     expect(extractParamsFromPath('/site/[id]')).toMatchInlineSnapshot(`
-      [
-        "id",
-      ]
+      {
+        "formatArgs": [
+          "id: string | number",
+        ],
+        "isAllOptional": false,
+        "params": [
+          {
+            "name": "id",
+            "optional": false,
+          },
+        ],
+      }
     `)
   })
 
   it('get params & id', async () => {
     expect(extractParamsFromPath('/site/[param]/[id]')).toMatchInlineSnapshot(`
-      [
-        "param",
-        "id",
-      ]
+      {
+        "formatArgs": [
+          "param: string | number",
+          "id: string | number",
+        ],
+        "isAllOptional": false,
+        "params": [
+          {
+            "name": "param",
+            "optional": false,
+          },
+          {
+            "name": "id",
+            "optional": false,
+          },
+        ],
+      }
     `)
   })
 
   it('get params & id', async () => {
     expect(extractParamsFromPath('/[param]site/[yop](group)/[id]')).toMatchInlineSnapshot(`
-      [
-        "param",
-        "yop",
-        "id",
-      ]
+      {
+        "formatArgs": [
+          "param: string | number",
+          "yop: string | number",
+          "id: string | number",
+        ],
+        "isAllOptional": false,
+        "params": [
+          {
+            "name": "param",
+            "optional": false,
+          },
+          {
+            "name": "yop",
+            "optional": false,
+          },
+          {
+            "name": "id",
+            "optional": false,
+          },
+        ],
+      }
+    `)
+  })
+
+  it('get optional param', async () => {
+    expect(extractParamsFromPath('/lang/[[lang]]')).toMatchInlineSnapshot(`
+      {
+        "formatArgs": [
+          "lang?: string | number",
+        ],
+        "isAllOptional": true,
+        "params": [
+          {
+            "name": "lang",
+            "optional": true,
+          },
+        ],
+      }
     `)
   })
 
diff --git a/packages/vite-plugin-kit-routes/src/params/int.ts b/packages/vite-plugin-kit-routes/src/params/int.ts
new file mode 100644
index 000000000..b8c1f374c
--- /dev/null
+++ b/packages/vite-plugin-kit-routes/src/params/int.ts
@@ -0,0 +1,5 @@
+import type { ParamMatcher } from '@sveltejs/kit'
+
+export const match: ParamMatcher = param => {
+  return /^\d+$/.test(param)
+}
diff --git a/packages/vite-plugin-kit-routes/src/routes/+layout.svelte b/packages/vite-plugin-kit-routes/src/routes/+layout.svelte
index edb17d01b..688b51392 100644
--- a/packages/vite-plugin-kit-routes/src/routes/+layout.svelte
+++ b/packages/vite-plugin-kit-routes/src/routes/+layout.svelte
@@ -13,12 +13,31 @@
 <ul>
   <li><a href={PAGES._ROOT()}>Home</a></li>
   <li><a href={PAGES.site()}>Sites</a></li>
+  <li><a href={PAGES.site({ limit: 2 })}>Sites (with Search Param)</a></li>
   <li><a href={PAGES.site_id({ id: 'Paris' })}>Site Paris</a></li>
   <li>
     <a href={PAGES.site_contract_siteId_contractId({ siteId: 'Paris', contractId: 'First' })}>
       Site Paris & Contract First
     </a>
   </li>
+  <li>
+    <a href={PAGES.lang_lang()}>Lang ??</a>
+  </li>
+  <li>
+    <a href={PAGES.lang_lang({ lang: 'fr' })}>Lang fr</a>
+  </li>
+  <li>
+    <a href={PAGES.match_id_int({ id: 1 })}>match int 1</a>
+  </li>
+  <li>
+    <a href={PAGES.match_id_int({ id: 'a' })}>match int a (expect 404)</a>
+  </li>
+  <li>
+    <a href={PAGES.gp_logged_one()}>gp One</a>
+  </li>
+  <li>
+    <a href="/gp/two">gp Two</a>
+  </li>
 </ul>
 
 <hr />
diff --git a/packages/vite-plugin-kit-routes/src/routes/gp/(logged)/one/+page.svelte b/packages/vite-plugin-kit-routes/src/routes/gp/(logged)/one/+page.svelte
new file mode 100644
index 000000000..94160746e
--- /dev/null
+++ b/packages/vite-plugin-kit-routes/src/routes/gp/(logged)/one/+page.svelte
@@ -0,0 +1 @@
+<h2>Logged One</h2>
diff --git a/packages/vite-plugin-kit-routes/src/routes/gp/(public)/two/+page.svelte b/packages/vite-plugin-kit-routes/src/routes/gp/(public)/two/+page.svelte
new file mode 100644
index 000000000..feda6d904
--- /dev/null
+++ b/packages/vite-plugin-kit-routes/src/routes/gp/(public)/two/+page.svelte
@@ -0,0 +1 @@
+<h2>Public Two</h2>
diff --git a/packages/vite-plugin-kit-routes/src/routes/lang/[[lang]]/+page.svelte b/packages/vite-plugin-kit-routes/src/routes/lang/[[lang]]/+page.svelte
new file mode 100644
index 000000000..78f5961ca
--- /dev/null
+++ b/packages/vite-plugin-kit-routes/src/routes/lang/[[lang]]/+page.svelte
@@ -0,0 +1,5 @@
+<script>
+  import { page } from '$app/stores'
+</script>
+
+<h2>Lang [{$page.params.lang}]</h2>
diff --git a/packages/vite-plugin-kit-routes/src/routes/match/[id=int]/+page.svelte b/packages/vite-plugin-kit-routes/src/routes/match/[id=int]/+page.svelte
new file mode 100644
index 000000000..702f5640d
--- /dev/null
+++ b/packages/vite-plugin-kit-routes/src/routes/match/[id=int]/+page.svelte
@@ -0,0 +1,5 @@
+<script>
+  import { page } from '$app/stores'
+</script>
+
+<h2>Match id [{$page.params.id}]</h2>
diff --git a/packages/vite-plugin-kit-routes/src/routes/site/+page.svelte b/packages/vite-plugin-kit-routes/src/routes/site/+page.svelte
index c10c6a1a5..4171f95b9 100644
--- a/packages/vite-plugin-kit-routes/src/routes/site/+page.svelte
+++ b/packages/vite-plugin-kit-routes/src/routes/site/+page.svelte
@@ -1 +1,7 @@
+<script>
+  import { page } from '$app/stores'
+</script>
+
 <h2>Sites</h2>
+
+<pre>limit: {$page.url.searchParams.get('limit')}</pre>