diff --git a/app/main.py b/app/main.py
index afd2405..8fcdb32 100644
--- a/app/main.py
+++ b/app/main.py
@@ -249,3 +249,45 @@ def get_user(user_id: int, db: Session = Depends(get_db)):
 def startup():
     from app.core.config import Base, engine
     Base.metadata.create_all(bind=engine)
+
+
+# ============ Project Members API ============
+
+@app.post("/projects/{project_id}/members", response_model=schemas.ProjectMemberResponse, status_code=status.HTTP_201_CREATED)
+def add_project_member(project_id: int, member: schemas.ProjectMemberCreate, db: Session = Depends(get_db)):
+    project = db.query(models.Project).filter(models.Project.id == project_id).first()
+    if not project:
+        raise HTTPException(status_code=404, detail="Project not found")
+    user = db.query(models.User).filter(models.User.id == member.user_id).first()
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found")
+    existing = db.query(models.ProjectMember).filter(
+        models.ProjectMember.project_id == project_id,
+        models.ProjectMember.user_id == member.user_id
+    ).first()
+    if existing:
+        raise HTTPException(status_code=400, detail="User already a member")
+    db_member = models.ProjectMember(project_id=project_id, user_id=member.user_id, role=member.role)
+    db.add(db_member)
+    db.commit()
+    db.refresh(db_member)
+    return db_member
+
+
+@app.get("/projects/{project_id}/members", response_model=List[schemas.ProjectMemberResponse])
+def list_project_members(project_id: int, db: Session = Depends(get_db)):
+    members = db.query(models.ProjectMember).filter(models.ProjectMember.project_id == project_id).all()
+    return members
+
+
+@app.delete("/projects/{project_id}/members/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
+def remove_project_member(project_id: int, user_id: int, db: Session = Depends(get_db)):
+    member = db.query(models.ProjectMember).filter(
+        models.ProjectMember.project_id == project_id,
+        models.ProjectMember.user_id == user_id
+    ).first()
+    if not member:
+        raise HTTPException(status_code=404, detail="Member not found")
+    db.delete(member)
+    db.commit()
+    return None