diff --git a/mateclaw-server/src/main/java/vip/mate/config/WorkspaceAccessInterceptor.java b/mateclaw-server/src/main/java/vip/mate/config/WorkspaceAccessInterceptor.java
index 9f3b7fea..5421d1ad 100644
--- a/mateclaw-server/src/main/java/vip/mate/config/WorkspaceAccessInterceptor.java
+++ b/mateclaw-server/src/main/java/vip/mate/config/WorkspaceAccessInterceptor.java
@@ -9,12 +9,17 @@ import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Component;
 import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.servlet.HandlerInterceptor;
+import org.springframework.web.servlet.HandlerMapping;
+import vip.mate.agent.model.AgentEntity;
+import vip.mate.agent.repository.AgentMapper;
 import vip.mate.auth.model.UserEntity;
 import vip.mate.auth.service.AuthService;
 import vip.mate.workspace.core.annotation.RequireGlobalAdmin;
 import vip.mate.workspace.core.annotation.RequireWorkspaceRole;
 import vip.mate.workspace.core.service.WorkspaceService;
 
+import java.util.Map;
+
 /**
  * Workspace 访问拦截器
  * <p>
@@ -34,6 +39,7 @@ public class WorkspaceAccessInterceptor implements HandlerInterceptor {
 
     private final WorkspaceService workspaceService;
     private final AuthService authService;
+    private final AgentMapper agentMapper;
 
     /** 默认 workspace ID（未传 header 时使用） */
     private static final long DEFAULT_WORKSPACE_ID = 1L;
@@ -91,9 +97,50 @@ public class WorkspaceAccessInterceptor implements HandlerInterceptor {
             return false;
         }
 
+        // The role check above only proves the user belongs to the *header*
+        // workspace — not that a path-bound {agentId} actually lives there.
+        // Without this a member of workspace A could read workspace B's agent
+        // memory / context files by supplying B's agent id with their own header.
+        if (!agentBelongsToWorkspace(request, workspaceId)) {
+            log.warn("Cross-workspace agent access denied: user={}, workspaceId={}, path={}",
+                    username, workspaceId, request.getRequestURI());
+            sendForbidden(response, "Agent does not belong to the current workspace");
+            return false;
+        }
+
         return true;
     }
 
+    /**
+     * When the matched route carries an {@code {agentId}} path variable, verify
+     * that agent belongs to the resolved workspace. Allows the request through
+     * when there is no agent id, the id is unparseable, the agent does not
+     * exist (so the handler can return its own 404), or the agent has not been
+     * assigned a workspace.
+     */
+    @SuppressWarnings("unchecked")
+    private boolean agentBelongsToWorkspace(HttpServletRequest request, long workspaceId) {
+        Object attr = request.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE);
+        if (!(attr instanceof Map)) {
+            return true;
+        }
+        Object rawAgentId = ((Map<String, String>) attr).get("agentId");
+        if (rawAgentId == null) {
+            return true;
+        }
+        long agentId;
+        try {
+            agentId = Long.parseLong(rawAgentId.toString());
+        } catch (NumberFormatException e) {
+            return true;
+        }
+        AgentEntity agent = agentMapper.selectById(agentId);
+        if (agent == null || agent.getWorkspaceId() == null) {
+            return true;
+        }
+        return agent.getWorkspaceId() == workspaceId;
+    }
+
     private long resolveWorkspaceId(HttpServletRequest request) {
         String header = request.getHeader("X-Workspace-Id");
         if (header != null && !header.isBlank()) {
diff --git a/mateclaw-server/src/main/java/vip/mate/workspace/document/controller/WorkspaceFileController.java b/mateclaw-server/src/main/java/vip/mate/workspace/document/controller/WorkspaceFileController.java
index 004cc177..0f049fb7 100644
--- a/mateclaw-server/src/main/java/vip/mate/workspace/document/controller/WorkspaceFileController.java
+++ b/mateclaw-server/src/main/java/vip/mate/workspace/document/controller/WorkspaceFileController.java
@@ -39,6 +39,7 @@ public class WorkspaceFileController {
      * 列出 Agent 的所有工作区文件（不含内容）
      */
     @Operation(summary = "列出工作区文件")
+    @RequireWorkspaceRole("viewer")
     @GetMapping("/files")
     public R<List<WorkspaceFileEntity>> listFiles(@PathVariable Long agentId) {
         return R.ok(workspaceFileService.listFiles(agentId));
@@ -48,6 +49,7 @@ public class WorkspaceFileController {
      * 读取单个文件内容（支持子目录，如 memory/2026-04-03.md）
      */
     @Operation(summary = "读取工作区文件")
+    @RequireWorkspaceRole("viewer")
     @GetMapping("/files/**")
     public R<WorkspaceFileEntity> getFile(@PathVariable Long agentId, HttpServletRequest request) {
         String filename = extractFilename(request);
@@ -62,6 +64,7 @@ public class WorkspaceFileController {
      * 创建或更新文件（支持子目录）
      */
     @Operation(summary = "保存工作区文件")
+    @RequireWorkspaceRole("member")
     @PutMapping("/files/**")
     public R<WorkspaceFileEntity> saveFile(@PathVariable Long agentId,
                                            HttpServletRequest httpRequest,
@@ -74,6 +77,7 @@ public class WorkspaceFileController {
      * 删除文件（支持子目录）
      */
     @Operation(summary = "删除工作区文件")
+    @RequireWorkspaceRole("member")
     @DeleteMapping("/files/**")
     public R<Void> deleteFile(@PathVariable Long agentId, HttpServletRequest request) {
         String filename = extractFilename(request);
@@ -94,6 +98,7 @@ public class WorkspaceFileController {
      * 获取启用的系统提示文件列表（有序）
      */
     @Operation(summary = "获取系统提示文件列表")
+    @RequireWorkspaceRole("viewer")
     @GetMapping("/prompt-files")
     public R<List<String>> getPromptFiles(@PathVariable Long agentId) {
         return R.ok(workspaceFileService.getPromptFiles(agentId));
@@ -103,6 +108,7 @@ public class WorkspaceFileController {
      * 设置启用的系统提示文件列表（有序）
      */
     @Operation(summary = "设置系统提示文件列表")
+    @RequireWorkspaceRole("member")
     @PutMapping("/prompt-files")
     public R<Void> setPromptFiles(@PathVariable Long agentId,
                                    @RequestBody PromptFilesRequest request) {