diff --git a/src/modules/project/models/project.model.js b/src/modules/project/models/project.model.js
index 8eb9c40..b4f7410 100644
--- a/src/modules/project/models/project.model.js
+++ b/src/modules/project/models/project.model.js
@@ -88,10 +88,33 @@ const updateProjectModel = joi.object().keys({
 });
 
 const getAllProjectsModel = joi.object().keys({
-  status: joi.string().valid(...PROJECT_STATUS_VALUES).optional().messages({
-    'string.base': 'Project status must be a string.',
-    'any.only': `Project status must be one of: ${PROJECT_STATUS_VALUES.join(', ')}.`,
-  }),
+  status: joi
+    .alternatives()
+    .try(
+      joi.string(),
+      joi.array().items(joi.string())
+    )
+    .optional()
+    .custom((value, helpers) => {
+      const statuses = Array.isArray(value)
+        ? value.flatMap((status) => String(status).split(','))
+        : String(value).split(',');
+
+      const invalidStatuses = statuses
+        .map((status) => status.trim().toLowerCase())
+        .filter(Boolean)
+        .filter((status) => !PROJECT_STATUS_VALUES.includes(status));
+
+      if (invalidStatuses.length > 0) {
+        return helpers.error('any.only');
+      }
+
+      return value;
+    })
+    .messages({
+      'alternatives.types': 'Project status must be a string or an array of strings.',
+      'any.only': `Project status must be one of: ${PROJECT_STATUS_VALUES.join(', ')}.`,
+    }),
 });
 
 module.exports = {
diff --git a/src/modules/project/repositories/project.repository.js b/src/modules/project/repositories/project.repository.js
index e140deb..43ebc2a 100644
--- a/src/modules/project/repositories/project.repository.js
+++ b/src/modules/project/repositories/project.repository.js
@@ -58,11 +58,13 @@ class ProjectRepository {
     });
   }
 
-  async findAll({ status, actor }) {
+  async findAll({ statuses, actor }) {
     const where = {};
 
-    if (status) {
-      where.status = status;
+    if (statuses && statuses.length > 0) {
+      where.status = {
+        in: statuses,
+      };
     }
 
     if (actor?.role === "intern") {
@@ -428,6 +430,9 @@ class ProjectRepository {
           in: userIds.map((id) => parseInt(id)),
         },
         status: "active",
+        project: {
+          status: "active"
+        }
       },
       include: {
         user: {
diff --git a/src/modules/project/services/project.service.js b/src/modules/project/services/project.service.js
index f49bed2..1e21a5f 100644
--- a/src/modules/project/services/project.service.js
+++ b/src/modules/project/services/project.service.js
@@ -109,8 +109,13 @@ class ProjectService {
 
   async getAllProjects(query = {}, actor = {}) {
     try {
+      const statusFilter = this.parseProjectStatusFilter(query.status);
+      if (statusFilter.err) {
+        return statusFilter;
+      }
+
       const projects = await projectRepository.findAll({
-        status: query.status,
+        statuses: statusFilter.data,
         actor,
       });
 
@@ -293,6 +298,40 @@ class ProjectService {
     return new ForbiddenError("Access denied: invalid role");
   }
 
+  parseProjectStatusFilter(rawStatus) {
+    if (!rawStatus) {
+      return data(null);
+    }
+
+    const allowedStatuses = ["active", "completed", "archived"];
+
+    const statuses = Array.isArray(rawStatus)
+      ? rawStatus.flatMap((status) => String(status).split(","))
+      : String(rawStatus).split(",");
+
+    const cleanedStatuses = [
+      ...new Set(
+        statuses
+          .map((status) => status.trim().toLowerCase())
+          .filter(Boolean)
+      ),
+    ];
+
+    const invalidStatuses = cleanedStatuses.filter(
+      (status) => !allowedStatuses.includes(status)
+    );
+
+    if (invalidStatuses.length > 0) {
+      return error(
+        new BadRequestError(
+          `Invalid project status: ${invalidStatuses.join(", ")}`
+        )
+      );
+    }
+
+    return data(cleanedStatuses);
+  }
+
   normalizeEmails(emails = []) {
     return [
       ...new Set(
@@ -534,13 +573,16 @@ class ProjectService {
       const { id_project, id_user } = payload;
 
       if (!id_project || !id_user) {
-        return error(new BadRequestError("Project ID and User ID are required"));
+        return error(new BadRequestError("Project ID/slug and User ID are required"));
       }
 
-      const project = await projectRepository.findById(id_project);
+      const project = await projectRepository.findByIdOrSlug(id_project);
       if (!project) {
         return error(new NotFoundError("Project not found"));
       }
+      if (project.status !== "active") {
+        return error(new ConflictError("Cannot assign member to a non-active project"));
+      }
 
       const user = await projectRepository.findUserByIdAndActive(id_user);
       if (!user) {
@@ -556,7 +598,7 @@ class ProjectService {
       const activeMemberships = await projectRepository.findActiveMembershipsByUserIds([id_user]);
       if (activeMemberships.length > 0) {
         const activeProj = activeMemberships[0].project;
-        if (activeMemberships[0].id_project === parseInt(id_project)) {
+        if (activeMemberships[0].id_project === project.id) {
           return error(new ConflictError("User is already an active member of this project"));
         } else {
           return error(
@@ -567,13 +609,13 @@ class ProjectService {
         }
       }
 
-      const existingMembership = await projectRepository.findMembership(id_project, id_user);
+      const existingMembership = await projectRepository.findMembership(project.id, id_user);
 
       let membership;
       if (existingMembership) {
         membership = await projectRepository.updateMembershipStatus(existingMembership.id, 'active');
       } else {
-        membership = await projectRepository.assignMember(id_project, id_user);
+        membership = await projectRepository.assignMember(project.id, id_user);
       }
 
       await notificationService.createNotificationForIntern(
@@ -603,10 +645,10 @@ class ProjectService {
       const { id_project, id_user } = payload;
 
       if (!id_project || !id_user) {
-        return error(new BadRequestError("Project ID and User ID are required"));
+        return error(new BadRequestError("Project ID/slug and User ID are required"));
       }
 
-      const project = await projectRepository.findById(id_project);
+      const project = await projectRepository.findByIdOrSlug(id_project);
       if (!project) {
         return error(new NotFoundError("Project not found"));
       }
@@ -616,7 +658,13 @@ class ProjectService {
         return error(new NotFoundError("User not found or inactive"));
       }
 
-      const existingMembership = await projectRepository.findMembership(id_project, id_user);
+      if (user.role !== "intern") {
+        return error(
+          new ForbiddenError("Access denied: only interns can be removed from projects")
+        );
+      }
+
+      const existingMembership = await projectRepository.findMembership(project.id, id_user);
 
       if (!existingMembership || existingMembership.status !== 'active') {
         return error(new BadRequestError("User is not an active member of this project"));
diff --git a/src/routes/project.routes.js b/src/routes/project.routes.js
index 4146f0a..f5ac657 100644
--- a/src/routes/project.routes.js
+++ b/src/routes/project.routes.js
@@ -125,7 +125,7 @@ const router = express.Router();
  *            type: string
  *            nullable: true
  *            example: Senior Program Manager at Internify.
- *     ProjectListItem:
+ *     ProjectBaseItem:
  *       type: object
  *       properties:
  *         id:
@@ -136,6 +136,7 @@ const router = express.Router();
  *           example: internify-platform-dev
  *         project_icon:
  *           type: string
+ *           enum: [code, chart, cloud, mobile, gear, users, clipboard, speedometer, lightbulb, shield]
  *           example: code
  *         background_color:
  *           type: string
@@ -146,6 +147,10 @@ const router = express.Router();
  *         description:
  *           type: string
  *           example: Upgrading the core Internify platform backend and web client.
+ *         certificate_template:
+ *           type: string
+ *           nullable: true
+ *           example: /uploads/certificate-template.png
  *         start_date:
  *           type: string
  *           format: date-time
@@ -156,6 +161,7 @@ const router = express.Router();
  *           example: 2026-10-15T00:00:00.000Z
  *         status:
  *           type: string
+ *           enum: [active, completed, archived]
  *           example: active
  *         admin:
  *           $ref: '#/components/schemas/ProjectAdminSummary'
@@ -165,10 +171,6 @@ const router = express.Router();
  *         total_tasks:
  *           type: integer
  *           example: 3
- *         task_done:
- *           type: integer
- *           example: 2
- *           description: Number of completed tasks. For interns, this counts tasks submitted by the logged-in intern. For admin/mentor, this counts tasks submitted by all active project members.
  *         created_at:
  *           type: string
  *           format: date-time
@@ -177,6 +179,15 @@ const router = express.Router();
  *           type: string
  *           format: date-time
  *           example: 2026-06-10T10:00:00.000Z
+ *     ProjectListItem:
+ *       allOf:
+ *         - $ref: '#/components/schemas/ProjectBaseItem'
+ *         - type: object
+ *           properties:
+ *             task_done:
+ *               type: integer
+ *               example: 2
+ *               description: Number of completed tasks. For interns, this counts tasks submitted by the logged-in intern. For admin/mentor, this counts tasks submitted by all active project members.
  *     ProjectMemberUser:
  *       type: object
  *       properties:
@@ -256,7 +267,7 @@ const router = express.Router();
  *           example: 2026-06-10T10:00:00.000Z
  *     ProjectDetail:
  *       allOf:
- *         - $ref: '#/components/schemas/ProjectListItem'
+ *         - $ref: '#/components/schemas/ProjectBaseItem'
  *         - type: object
  *           properties:
  *             members:
@@ -523,10 +534,10 @@ router.post('/add', verifyJWT, isMentorOrAdmin, projectController.createProject)
  *         name: status
  *         schema:
  *           type: string
- *           enum: [active, completed, archived]
+ *           example: 'active,completed'
  *         required: false
- *         description: Filter projects by status
- *         example: active
+ *         description: Filter projects by one or more statuses. Use comma-separated values, for example active,completed. Values are **active, completed, archived**
+ *         example: active,completed
  *     responses:
  *       200:
  *         description: Projects retrieved successfully
@@ -534,6 +545,8 @@ router.post('/add', verifyJWT, isMentorOrAdmin, projectController.createProject)
  *           application/json:
  *             schema:
  *               $ref: '#/components/schemas/ProjectListResponse'
+ *       400:
+ *         description: Invalid project status
  *       401:
  *         description: Unauthorized
  *       417:
@@ -825,8 +838,15 @@ router.get('/interns', verifyJWT, isMentorOrAdmin, projectController.getInterns)
  *               - id_user
  *             properties:
  *               id_project:
- *                 type: integer
- *                 example: 1
+ *                 oneOf:
+ *                   - type: integer
+ *                     example: 1
+ *                     description: Project ID
+ *                   - type: string
+ *                     example: internify-lms
+ *                     description: Project slug
+ *                 description: Project ID or project slug
+ *                 example: internify-platform-dev
  *               id_user:
  *                 type: integer
  *                 example: 2
@@ -846,7 +866,7 @@ router.get('/interns', verifyJWT, isMentorOrAdmin, projectController.getInterns)
  *       404:
  *         description: Project or User not found
  *       409:
- *         description: Conflict (User is already an active member of this project)
+ *         description: Conflict (User is already an active member of this project or target project is not active)
  *       500:
  *         description: Internal server error
  */
@@ -872,8 +892,15 @@ router.post('/assign-member', verifyJWT, isMentorOrAdmin, projectController.assi
  *               - id_user
  *             properties:
  *               id_project:
- *                 type: integer
- *                 example: 1
+ *                 oneOf:
+ *                   - type: integer
+ *                     example: 1
+ *                     description: Project ID
+ *                   - type: string
+ *                     example: internify-lms
+ *                     description: Project slug
+ *                 description: Project ID or slug
+ *                 example: internify-lms
  *               id_user:
  *                 type: integer
  *                 example: 2