diff --git a/README.md b/README.md
index 256637c..1fbdb9a 100644
--- a/README.md
+++ b/README.md
@@ -20,3 +20,6 @@ Our new telegram bot.
    ```sh
    pnpm run dev
    ```
+
+### Maybe useful references
+- [How to send private messages](https://github.com/PoliNetworkOrg/PoliNetworkBot_CSharp/blob/03c7434f06323ffdec301cb105d1d3b2c1ed4a95/PoliNetworkBot_CSharp/Code/Utils/SendMessage.cs#L90)
diff --git a/TODO.md b/TODO.md
index 927a400..a7434bf 100644
--- a/TODO.md
+++ b/TODO.md
@@ -29,7 +29,7 @@
   - [ ] exception to send our whatsapp links?
   - [ ] do not delete Direttivo's allowed messages
   - [x] check if user has username
-  - [ ] group-specific moderation (eg. #cerco #vendo in polihouse) see [here](https://github.com/PoliNetworkOrg/PoliNetworkBot_CSharp/blob/03c7434f06323ffdec301cb105d1d3b2c1ed4a95/PoliNetworkBot_CSharp/Code/Bots/Moderation/Blacklist/Blacklist.cs#L84)
+  - [x] group-specific moderation (eg. #cerco #vendo in polihouse) see [here](https://github.com/PoliNetworkOrg/PoliNetworkBot_CSharp/blob/03c7434f06323ffdec301cb105d1d3b2c1ed4a95/PoliNetworkBot_CSharp/Code/Bots/Moderation/Blacklist/Blacklist.cs#L84)
 - [x] role management
   - [x] setrole: set role for some username (only Direttivo, maybe HR)
   - [x] getrole: get user role
diff --git a/src/bot.ts b/src/bot.ts
index 6cfd4da..ef6df2c 100644
--- a/src/bot.ts
+++ b/src/bot.ts
@@ -12,6 +12,7 @@ import { logger } from "./logger"
 import { AutoModerationStack } from "./middlewares/auto-moderation-stack"
 import { BotMembershipHandler } from "./middlewares/bot-membership-handler"
 import { checkUsername } from "./middlewares/check-username"
+import { GroupSpecificActions } from "./middlewares/group-specific-actions"
 import { messageLink } from "./middlewares/message-link"
 import { MessageUserStorage } from "./middlewares/message-user-storage"
 import { UIActionsLogger } from "./middlewares/ui-actions-logger"
@@ -76,6 +77,7 @@ bot.use(MenuGenerator.getInstance())
 bot.use(commands)
 bot.use(new BotMembershipHandler())
 bot.use(new AutoModerationStack())
+bot.use(new GroupSpecificActions())
 bot.use(new UIActionsLogger())
 
 bot.on("message", async (ctx, next) => {
diff --git a/src/middlewares/group-specific-actions.ts b/src/middlewares/group-specific-actions.ts
new file mode 100644
index 0000000..b9334bb
--- /dev/null
+++ b/src/middlewares/group-specific-actions.ts
@@ -0,0 +1,119 @@
+import { Composer, type Filter, type MiddlewareObj } from "grammy"
+import { err, ok, type Result } from "neverthrow"
+import { api } from "@/backend"
+import { logger } from "@/logger"
+import { modules } from "@/modules"
+import { fmt, fmtUser } from "@/utils/format"
+import type { Context } from "@/utils/types"
+import { wait } from "@/utils/wait"
+
+const TARGET_GROUPS: Record<string, number> = {
+  alloggi: -1001175999519,
+  ripetizioni: -1001495422899,
+  books: -1001164044303,
+} as const
+
+const TARGET_GROUP_IDS_SET = new Set(Object.values(TARGET_GROUPS));
+
+export class GroupSpecificActions<C extends Context> implements MiddlewareObj<C> {
+  private composer = new Composer<C>()
+
+  constructor() {
+    this.composer
+      .filter((ctx) => !!ctx.chatId && TARGET_GROUP_IDS_SET.has(ctx.chatId))
+      .on("message", async (ctx, next) => {
+        if (ctx.from.id === ctx.me.id) return next() // skip if bot
+        const { roles } = await api.tg.permissions.getRoles.query({ userId: ctx.from.id })
+        if (roles && roles.length > 0) return next() // skip if admin or other roles
+
+        const chatMember = await ctx.getChatMember(ctx.from.id)
+        if (chatMember.status === "administrator" || chatMember.status === "creator") return next() // skip if group-admin
+
+        let check: Result<void, string>
+        switch (ctx.chatId) {
+          case TARGET_GROUPS.alloggi:
+            check = this.checkAlloggi(ctx)
+            break
+
+          case TARGET_GROUPS.ripetizioni:
+            check = this.checkRipetizioni(ctx)
+            break
+
+          case TARGET_GROUPS.books:
+            check = this.checkBooks(ctx)
+            break
+
+          default:
+            logger.error(
+              { chatId: ctx.chatId, targetGroupsMap: TARGET_GROUPS },
+              "GroupSpecificActions: target group matched, but no handler set. This is an unimplemented feature"
+            )
+            return next()
+        }
+
+        if (check.isOk()) return next()
+
+        modules.get("tgLogger").delete([ctx.message], `User did not follow group rules:\n${check.error}`, ctx.me)
+        const reply = await ctx.reply(
+          fmt(({ b, n }) => [b`${fmtUser(ctx.from)} you sent an invalid message`, b`Reason:`, n`${check.error}`], {
+            sep: "\n",
+          }),
+          { disable_notification: false, reply_markup: { force_reply: true } }
+        )
+
+        // delete error msg after 2 min without blocking the middleware stack
+        void wait(120_000)
+          .then(() => reply.delete())
+          .catch(() => {})
+      })
+  }
+
+  checkAlloggi(ctx: Filter<C, "message">): Result<void, string> {
+    const hashtags = ctx.entities("hashtag").map((e) => e.text.toLowerCase())
+
+    if (
+      !hashtags.includes("#cerco") &&
+      !hashtags.includes("#searching") &&
+      !hashtags.includes("#search") &&
+      !hashtags.includes("#offro") &&
+      !hashtags.includes("#offering") &&
+      !hashtags.includes("#offer")
+    )
+      return err(
+        "You must include one of the following hashtags in your message:\n #cerco #searching #offro #offering \nCheck rules for more info."
+      )
+
+    return ok()
+  }
+
+  checkRipetizioni(ctx: Filter<C, "message">): Result<void, string> {
+    const hashtags = ctx.entities("hashtag").map((e) => e.text.toLowerCase())
+
+    if (
+      !hashtags.includes("#richiesta") &&
+      !hashtags.includes("#offerta") &&
+      !hashtags.includes("#request") &&
+      !hashtags.includes("#offer")
+    )
+      return err(
+        "You must include one of the following hashtags in your message:\n #richiesta #request #offerta #offer \nCheck rules for more info."
+      )
+
+    return ok()
+  }
+
+  checkBooks(ctx: Filter<C, "message">): Result<void, string> {
+    const hashtags = ctx.entities("hashtag").map((e) => e.text.toLowerCase())
+
+    if (!hashtags.includes("#cerco") && !hashtags.includes("#vendo"))
+      return err(
+        "Devi includere uno di questi hashtags nel tuo messaggio:\n #cerco #vendo \nControlla le regole per maggiori indicazioni."
+      )
+
+    return ok()
+  }
+
+  middleware() {
+    return this.composer.middleware()
+  }
+}