diff --git a/openapi.yml b/openapi.yml
index 250a86d..3e49d44 100644
--- a/openapi.yml
+++ b/openapi.yml
@@ -8,7 +8,7 @@ servers:
 security:
   # This makes every route by default auth protected
   - BearerAuthHeader: [] # Authorization header
-  - BearerAuthCookie: [] # Token in cookie 
+  - BearerAuthCookie: [] # Token in cookie
 components:
   securitySchemes:
     BearerAuthHeader:
@@ -59,15 +59,16 @@ components:
                 type: string
               members:
                 type: array
-                $ref: "#/components/schemas/Member"
+                items:
+                  $ref: "#/components/schemas/Member"
               items:
                 type: array
-                $ref: "#/components/schemas/Item"
+                items:
+                  $ref: "#/components/schemas/Item"
               money_balance:
                 type: integer
             required:
               - name
-              - members
               - money_balance
   requestBodies:
     register:
@@ -93,7 +94,7 @@ components:
       content:
         application/json:
           schema:
-            $ref: '#/components/schemas/Item'
+            $ref: "#/components/schemas/Item"
   schemas:
     UserCredentials:
       type: object
@@ -127,7 +128,7 @@ components:
       properties:
         id:
           type: integer
-          # readOnly: true # TODO unfortunately ogen doesn't support readOnly marker. But we want to reuse this schema for posting 
+          # readOnly: true # TODO unfortunately ogen doesn't support readOnly marker. But we want to reuse this schema for posting
           # as well as getting for simplicity. So for now, the convention would be to set the id to 0 as it will get ignored either way.
         timestamp:
           type: integer
@@ -142,6 +143,12 @@ components:
           type: integer
         reimbursement:
           type: boolean
+        # New participant list should be returned from expense_participants schema
+        participants:
+          type: array
+          items:
+            $ref: "#/components/schemas/Member"
+
       required:
         - id
         - timestamp
@@ -153,7 +160,7 @@ components:
       type: object
       properties:
         id:
-          type: string
+          type: integer
         name:
           type: string
         displayName:
diff --git a/server/main.go b/server/main.go
index b1d4125..a03b6d1 100644
--- a/server/main.go
+++ b/server/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"database/sql"
+	"fmt"
 	"log"
 	"net/http"
 	"os"
@@ -71,8 +72,79 @@ func (h *Handler) GroupsNonauthedGet(ctx context.Context) ([]api.Group, error) {
 }
 
 func (h *Handler) GroupsIDGet(ctx context.Context, params api.GroupsIDGetParams) (*api.GroupOverview, error) {
-	// TODO task #4
-	return nil, nil
+	//IDs
+	g_id := int64(params.ID)
+	userid := ctx.Value("user_id").(int64)
+
+	//authorID
+	group, _ := qs.GetGroupByID(ctx, g_id)
+
+	// Fetch members of the group
+	members, _ := qs.GetMembersOfGroup(ctx, g_id)
+
+	var apiMembers []api.Member
+
+	for _, member := range members {
+		apiMembers = append(apiMembers, api.Member{
+			ID:   int(member.ID),
+			Name: member.Username,
+		})
+	}
+	// new schema EP added converting to of type memeber th query of Expense_participants
+	eps, _ := qs.Expense_participants(ctx, 1)
+	var ep_members []api.Member
+
+	for _, ep := range eps {
+		ep_members = append(ep_members, api.Member{
+			ID:          int(ep.MemberID),
+			Name:        ep.Username,
+			DisplayName: ep.Displayname,
+		})
+
+	}
+	// Fetch items of the group
+	items, _ := qs.GetItemsOfGroup(ctx, g_id)
+
+	var apiItems []api.Item
+
+	for _, item := range items {
+		apiItems = append(apiItems, api.Item{
+			ID:        int(item.ID),
+			Timestamp: int(item.Timestamp),
+			Name:      item.Name,
+			Price:     item.Price,
+			AuthorID:  int(item.AuthorID),
+			GroupID:   int(g_id),
+			// The new participant list!!!!!!
+			Participants: ep_members,
+		})
+	}
+	// Calculate money balance for the group
+	netAmountParams := data.GetNetAmountForUserInGroupParams{
+		AuthorID: userid,
+		GroupID:  g_id,
+	}
+
+	netAmount, err := qs.GetNetAmountForUserInGroup(ctx, netAmountParams)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch net amount: %w", err)
+	}
+	var balance int
+
+	if netAmount.Valid {
+		balance = int(netAmount.Float64)
+	} else {
+		balance = 0
+	}
+
+	groupOverview := &api.GroupOverview{
+		Name:         group.Name,
+		Members:      apiMembers,
+		Items:        apiItems,
+		MoneyBalance: balance,
+	}
+
+	return groupOverview, nil
 }
 
 func (h *Handler) GroupsIDMembersPost(ctx context.Context, req *api.GroupsIDMembersPostReq, params api.GroupsIDMembersPostParams) error {
@@ -98,7 +170,8 @@ func (h *Handler) GroupsIDItemsGet(ctx context.Context, params api.GroupsIDItems
 }
 
 func (h *Handler) GroupsIDItemsPost(ctx context.Context, req *api.Item, params api.GroupsIDItemsPostParams) (int, error) {
-	g, _ := qs.AddItemToGroup(ctx, data.AddItemToGroupParams{
+	// Add the new item to the 'items' table
+	g, err := qs.AddItemToGroup(ctx, data.AddItemToGroupParams{
 		Name:          req.Name,
 		Timestamp:     int64(req.Timestamp),
 		Price:         req.Price,
@@ -106,6 +179,25 @@ func (h *Handler) GroupsIDItemsPost(ctx context.Context, req *api.Item, params a
 		AuthorID:      int64(req.AuthorID),
 		Reimbursement: sql.NullBool{Bool: req.Reimbursement.Value, Valid: req.Reimbursement.Set},
 	})
+	if err != nil {
+		return 0, err
+	}
+
+	// Ensure participants are passed in the request
+	if len(req.Participants) == 0 {
+		return 0, fmt.Errorf("no participants provided")
+	}
+
+	// Add participants to the 'expense_participants' table
+	for _, member := range req.Participants {
+		err := qs.AddExpenseParticipant(ctx, data.AddExpenseParticipantParams{
+			ItemID:   g,                // The ID of the item that was just added
+			MemberID: int64(member.ID), // The ID of the participant to add
+		})
+		if err != nil {
+			return 0, err
+		}
+	}
 
 	return int(g), nil
 }
diff --git a/server/query.sql b/server/query.sql
index ae09b19..f352954 100644
--- a/server/query.sql
+++ b/server/query.sql
@@ -42,3 +42,29 @@ FROM member_groups mg1
 INNER JOIN member_groups mg2 ON mg1.group_id = mg2.group_id
 WHERE mg1.member_id = ? AND mg2.member_id <> 3
 GROUP BY mg2.member_id;
+
+
+-- name: GetGroupByID :one
+SELECT 
+    id, 
+    name 
+FROM 
+    groups 
+WHERE 
+    id = ?;
+
+-- name: Expense_participants :many
+SELECT 
+    ep.member_id, 
+    i.name AS item_name, 
+    m.username, 
+    m.displayName
+FROM expense_participants ep
+JOIN items i ON ep.item_id = i.id
+JOIN members m ON ep.member_id = m.id
+WHERE ep.item_id = ?;
+
+-- name: AddExpenseParticipant :exec
+INSERT INTO expense_participants (item_id, member_id) VALUES (?, ?);
+
+
diff --git a/server/schema.sql b/server/schema.sql
index 2c1aa03..502a7f5 100644
--- a/server/schema.sql
+++ b/server/schema.sql
@@ -28,3 +28,11 @@ CREATE TABLE items ( --bs: medium
         FOREIGN KEY (group_id) REFERENCES groups (id),
         FOREIGN KEY (author_id) REFERENCES members (id)
 );
+
+CREATE TABLE expense_participants ( --bs: medium
+    item_id INTEGER NOT NULL, --bs: rel
+    member_id INTEGER NOT NULL, --bs: rel
+    PRIMARY KEY (item_id, member_id), -- Composite primary key (ensures unique pairs)
+    FOREIGN KEY (item_id) REFERENCES items (id), -- Foreign key constraint to items table
+    FOREIGN KEY (member_id) REFERENCES members (id) -- Foreign key constraint to members table
+);
diff --git a/web/src/routes/g/[slug]/+page.svelte b/web/src/routes/g/[slug]/+page.svelte
index 0c08425..2779a5a 100644
--- a/web/src/routes/g/[slug]/+page.svelte
+++ b/web/src/routes/g/[slug]/+page.svelte
@@ -6,12 +6,12 @@
   import shoppingBagIcon from "@ktibow/iconset-material-symbols/shopping-bag";
   import priceIcon from "@ktibow/iconset-material-symbols/price-check";
   import check from "@ktibow/iconset-material-symbols/check";
-    import { PUBLIC_SERVER_URL } from "$env/static/public";
+  import { PUBLIC_SERVER_URL } from "$env/static/public";
   export let data;
   let name = "";
   let price = "";
 
-  let addItem = (e : Event) => {
+  let addItem = (e: Event) => {
     e.preventDefault();
     const item = {
       id: 14,
@@ -24,12 +24,10 @@
       method: "POST",
       body: JSON.stringify(item),
     }).then((_) => {
-      data.items = [item, ...data.items]
-      
+      data.items = [item, ...data.items];
     });
   };
   let open = true;
-
 </script>
 
 <div class="screen">
@@ -68,6 +66,12 @@
         <div class="fabpos">
           <FAB icon={check} size="large"></FAB>
         </div>
+        <div>
+          <h2>
+            Balance:
+            {data.balance}
+          </h2>
+        </div>
       </form>
     </SideSheet>
   {/if}
@@ -78,7 +82,7 @@
     display: flex;
     align-items: flex-start;
     height: 100%;
-    gap:1rem;
+    gap: 1rem;
   }
   .contents {
     padding: 1rem;
diff --git a/web/src/routes/g/[slug]/+page.ts b/web/src/routes/g/[slug]/+page.ts
index 283fc62..3222f1b 100644
--- a/web/src/routes/g/[slug]/+page.ts
+++ b/web/src/routes/g/[slug]/+page.ts
@@ -1,16 +1,18 @@
-import api from '$lib/api/api';
-import { error as errorOut } from '@sveltejs/kit';
+import api from "$lib/api/api";
+import { error as errorOut } from "@sveltejs/kit";
 
 export async function load({ params }) {
-        const {
-                data, // only present if 2XX response
-                error, // only present if 4XX or 5XX response
-                response
-        } = await api.GET("/groups/{id}/items", {params:{path: { id: params.slug}}})
-        if (response.status != 200) {
-                errorOut(response.status, response.statusText);
-        }
-
-        return { group_id: params.slug, items: data }
-
+  const {
+    data, // only present if 2XX response
+    error,
+    response,
+  } = await api.GET("/groups/{id}", { params: { path: { id: params.slug } } });
+  if (response.status != 200) {
+    errorOut(response.status, response.statusText);
+  }
+  return {
+    items: data!.items,
+    group_id: params.slug,
+    balance: data?.money_balance,
+  };
 }