diff --git a/codex-rs/app-server-protocol/schema/json/ClientRequest.json b/codex-rs/app-server-protocol/schema/json/ClientRequest.json
index 0ccf453020..23e2512031 100644
--- a/codex-rs/app-server-protocol/schema/json/ClientRequest.json
+++ b/codex-rs/app-server-protocol/schema/json/ClientRequest.json
@@ -1933,6 +1933,9 @@
               "default": false,
               "type": "boolean"
             },
+            "readAccess": {
+              "$ref": "#/definitions/WorkspaceReadAccess"
+            },
             "type": {
               "enum": [
                 "workspaceWrite"
@@ -2037,6 +2040,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess2"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -3097,6 +3108,95 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
+    },
+    "WorkspaceReadAccess2": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccess2Type",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess2",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccess2Type",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess2",
+          "type": "object"
+        }
+      ]
     }
   },
   "description": "Request from the client to the server.",
diff --git a/codex-rs/app-server-protocol/schema/json/EventMsg.json b/codex-rs/app-server-protocol/schema/json/EventMsg.json
index f399912e03..7ebb8c4908 100644
--- a/codex-rs/app-server-protocol/schema/json/EventMsg.json
+++ b/codex-rs/app-server-protocol/schema/json/EventMsg.json
@@ -4303,6 +4303,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -5044,6 +5052,52 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "description": "Response event from the agent NOTE: Make sure none of these values have optional types, as it will mess up the extension code-gen.",
diff --git a/codex-rs/app-server-protocol/schema/json/ServerNotification.json b/codex-rs/app-server-protocol/schema/json/ServerNotification.json
index 0e2f94f4d8..2a035c538d 100644
--- a/codex-rs/app-server-protocol/schema/json/ServerNotification.json
+++ b/codex-rs/app-server-protocol/schema/json/ServerNotification.json
@@ -5343,6 +5343,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -7365,6 +7373,52 @@
         "samplePaths"
       ],
       "type": "object"
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "description": "Notification sent from the server to the client.",
diff --git a/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json b/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
index 3b6e61fc23..71f6916474 100644
--- a/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
+++ b/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
@@ -7548,6 +7548,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -9684,6 +9692,52 @@
         }
       ]
     },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
+    },
     "v2": {
       "AbsolutePathBuf": {
         "description": "A path that is guaranteed to be absolute and normalized (though it is not guaranteed to be canonicalized or exist on the filesystem).\n\nIMPORTANT: When deserializing an `AbsolutePathBuf`, a base path must be set using [AbsolutePathBufGuard::new]. If no base path is set, the deserialization will fail unless the path being deserialized is already absolute.",
@@ -13464,6 +13518,9 @@
                 "default": false,
                 "type": "boolean"
               },
+              "readAccess": {
+                "$ref": "#/definitions/v2/WorkspaceReadAccess"
+              },
               "type": {
                 "enum": [
                   "workspaceWrite"
@@ -13501,6 +13558,9 @@
             "default": false,
             "type": "boolean"
           },
+          "read_access": {
+            "$ref": "#/definitions/v2/WorkspaceReadAccess"
+          },
           "writable_roots": {
             "default": [],
             "items": {
@@ -16055,6 +16115,49 @@
         "title": "WindowsWorldWritableWarningNotification",
         "type": "object"
       },
+      "WorkspaceReadAccess": {
+        "oneOf": [
+          {
+            "properties": {
+              "type": {
+                "enum": [
+                  "fullReadAccess"
+                ],
+                "title": "FullReadAccessWorkspaceReadAccessType",
+                "type": "string"
+              }
+            },
+            "required": [
+              "type"
+            ],
+            "title": "FullReadAccessWorkspaceReadAccess",
+            "type": "object"
+          },
+          {
+            "properties": {
+              "readableRoots": {
+                "default": [],
+                "items": {
+                  "$ref": "#/definitions/v2/AbsolutePathBuf"
+                },
+                "type": "array"
+              },
+              "type": {
+                "enum": [
+                  "restrictedReadAccess"
+                ],
+                "title": "RestrictedReadAccessWorkspaceReadAccessType",
+                "type": "string"
+              }
+            },
+            "required": [
+              "type"
+            ],
+            "title": "RestrictedReadAccessWorkspaceReadAccess",
+            "type": "object"
+          }
+        ]
+      },
       "WriteStatus": {
         "enum": [
           "ok",
diff --git a/codex-rs/app-server-protocol/schema/json/v1/ExecOneOffCommandParams.json b/codex-rs/app-server-protocol/schema/json/v1/ExecOneOffCommandParams.json
index a325704be4..ae3104f573 100644
--- a/codex-rs/app-server-protocol/schema/json/v1/ExecOneOffCommandParams.json
+++ b/codex-rs/app-server-protocol/schema/json/v1/ExecOneOffCommandParams.json
@@ -94,6 +94,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -116,6 +124,52 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v1/ForkConversationResponse.json b/codex-rs/app-server-protocol/schema/json/v1/ForkConversationResponse.json
index a5838e89e7..7d8e3a3275 100644
--- a/codex-rs/app-server-protocol/schema/json/v1/ForkConversationResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v1/ForkConversationResponse.json
@@ -4303,6 +4303,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -5044,6 +5052,52 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v1/ResumeConversationResponse.json b/codex-rs/app-server-protocol/schema/json/v1/ResumeConversationResponse.json
index 718b17aa28..8224ae8e0d 100644
--- a/codex-rs/app-server-protocol/schema/json/v1/ResumeConversationResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v1/ResumeConversationResponse.json
@@ -4303,6 +4303,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -5044,6 +5052,52 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v1/SendUserTurnParams.json b/codex-rs/app-server-protocol/schema/json/v1/SendUserTurnParams.json
index d56ae933bd..cc0cb4611e 100644
--- a/codex-rs/app-server-protocol/schema/json/v1/SendUserTurnParams.json
+++ b/codex-rs/app-server-protocol/schema/json/v1/SendUserTurnParams.json
@@ -255,6 +255,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -324,6 +332,52 @@
         "byteRange"
       ],
       "type": "object"
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v1/SessionConfiguredNotification.json b/codex-rs/app-server-protocol/schema/json/v1/SessionConfiguredNotification.json
index a85b78281b..2d3251feb2 100644
--- a/codex-rs/app-server-protocol/schema/json/v1/SessionConfiguredNotification.json
+++ b/codex-rs/app-server-protocol/schema/json/v1/SessionConfiguredNotification.json
@@ -4303,6 +4303,14 @@
               "description": "When set to `true`, outbound network access is allowed. `false` by default.",
               "type": "boolean"
             },
+            "read_access": {
+              "allOf": [
+                {
+                  "$ref": "#/definitions/WorkspaceReadAccess"
+                }
+              ],
+              "description": "Controls whether the workspace-write policy has full read access or an explicit read allowlist."
+            },
             "type": {
               "enum": [
                 "workspace-write"
@@ -5044,6 +5052,52 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "description": "Controls read access semantics for `workspace-write` sandbox policies.",
+      "oneOf": [
+        {
+          "description": "Preserve current behavior where all file-system paths are readable.",
+          "properties": {
+            "type": {
+              "enum": [
+                "full-read-access"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "description": "Restrict reads to an explicit allowlist plus implicitly readable paths.",
+          "properties": {
+            "readable_roots": {
+              "description": "Additional folders that should be readable from inside the sandbox.",
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restricted-read-access"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v2/CommandExecParams.json b/codex-rs/app-server-protocol/schema/json/v2/CommandExecParams.json
index 6dd8fb7bc8..a66fa12758 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/CommandExecParams.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/CommandExecParams.json
@@ -84,6 +84,9 @@
               "default": false,
               "type": "boolean"
             },
+            "readAccess": {
+              "$ref": "#/definitions/WorkspaceReadAccess"
+            },
             "type": {
               "enum": [
                 "workspaceWrite"
@@ -106,6 +109,49 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v2/ConfigReadResponse.json b/codex-rs/app-server-protocol/schema/json/v2/ConfigReadResponse.json
index 96ce16be09..156fa2d58e 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/ConfigReadResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/ConfigReadResponse.json
@@ -530,6 +530,9 @@
           "default": false,
           "type": "boolean"
         },
+        "read_access": {
+          "$ref": "#/definitions/WorkspaceReadAccess"
+        },
         "writable_roots": {
           "default": [],
           "items": {
@@ -573,6 +576,49 @@
         "live"
       ],
       "type": "string"
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v2/ThreadForkResponse.json b/codex-rs/app-server-protocol/schema/json/v2/ThreadForkResponse.json
index 61b12ceff3..c5a4de38d2 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/ThreadForkResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/ThreadForkResponse.json
@@ -571,6 +571,9 @@
               "default": false,
               "type": "boolean"
             },
+            "readAccess": {
+              "$ref": "#/definitions/WorkspaceReadAccess"
+            },
             "type": {
               "enum": [
                 "workspaceWrite"
@@ -1538,6 +1541,49 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v2/ThreadResumeResponse.json b/codex-rs/app-server-protocol/schema/json/v2/ThreadResumeResponse.json
index 0534f6e16e..964af14de2 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/ThreadResumeResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/ThreadResumeResponse.json
@@ -571,6 +571,9 @@
               "default": false,
               "type": "boolean"
             },
+            "readAccess": {
+              "$ref": "#/definitions/WorkspaceReadAccess"
+            },
             "type": {
               "enum": [
                 "workspaceWrite"
@@ -1538,6 +1541,49 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v2/ThreadStartResponse.json b/codex-rs/app-server-protocol/schema/json/v2/ThreadStartResponse.json
index c85d7ce97a..b4464ec4c7 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/ThreadStartResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/ThreadStartResponse.json
@@ -571,6 +571,9 @@
               "default": false,
               "type": "boolean"
             },
+            "readAccess": {
+              "$ref": "#/definitions/WorkspaceReadAccess"
+            },
             "type": {
               "enum": [
                 "workspaceWrite"
@@ -1538,6 +1541,49 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/json/v2/TurnStartParams.json b/codex-rs/app-server-protocol/schema/json/v2/TurnStartParams.json
index be351a48ea..e9ac2f147f 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/TurnStartParams.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/TurnStartParams.json
@@ -176,6 +176,9 @@
               "default": false,
               "type": "boolean"
             },
+            "readAccess": {
+              "$ref": "#/definitions/WorkspaceReadAccess"
+            },
             "type": {
               "enum": [
                 "workspaceWrite"
@@ -369,6 +372,49 @@
           "type": "object"
         }
       ]
+    },
+    "WorkspaceReadAccess": {
+      "oneOf": [
+        {
+          "properties": {
+            "type": {
+              "enum": [
+                "fullReadAccess"
+              ],
+              "title": "FullReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "FullReadAccessWorkspaceReadAccess",
+          "type": "object"
+        },
+        {
+          "properties": {
+            "readableRoots": {
+              "default": [],
+              "items": {
+                "$ref": "#/definitions/AbsolutePathBuf"
+              },
+              "type": "array"
+            },
+            "type": {
+              "enum": [
+                "restrictedReadAccess"
+              ],
+              "title": "RestrictedReadAccessWorkspaceReadAccessType",
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ],
+          "title": "RestrictedReadAccessWorkspaceReadAccess",
+          "type": "object"
+        }
+      ]
     }
   },
   "properties": {
diff --git a/codex-rs/app-server-protocol/schema/typescript/SandboxPolicy.ts b/codex-rs/app-server-protocol/schema/typescript/SandboxPolicy.ts
index 103a6863f4..d2b504794c 100644
--- a/codex-rs/app-server-protocol/schema/typescript/SandboxPolicy.ts
+++ b/codex-rs/app-server-protocol/schema/typescript/SandboxPolicy.ts
@@ -3,6 +3,7 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { AbsolutePathBuf } from "./AbsolutePathBuf";
 import type { NetworkAccess } from "./NetworkAccess";
+import type { WorkspaceReadAccess } from "./WorkspaceReadAccess";
 
 /**
  * Determines execution restrictions for model shell commands.
@@ -32,4 +33,9 @@ exclude_tmpdir_env_var: boolean,
  * When set to `true`, will NOT include the `/tmp` among the default
  * writable roots on UNIX. Defaults to `false`.
  */
-exclude_slash_tmp: boolean, };
+exclude_slash_tmp: boolean, 
+/**
+ * Controls whether the workspace-write policy has full read access or
+ * an explicit read allowlist.
+ */
+read_access?: WorkspaceReadAccess, };
diff --git a/codex-rs/app-server-protocol/schema/typescript/WorkspaceReadAccess.ts b/codex-rs/app-server-protocol/schema/typescript/WorkspaceReadAccess.ts
new file mode 100644
index 0000000000..06c279b70e
--- /dev/null
+++ b/codex-rs/app-server-protocol/schema/typescript/WorkspaceReadAccess.ts
@@ -0,0 +1,13 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { AbsolutePathBuf } from "./AbsolutePathBuf";
+
+/**
+ * Controls read access semantics for `workspace-write` sandbox policies.
+ */
+export type WorkspaceReadAccess = { "type": "full-read-access" } | { "type": "restricted-read-access", 
+/**
+ * Additional folders that should be readable from inside the sandbox.
+ */
+readable_roots?: Array<AbsolutePathBuf>, };
diff --git a/codex-rs/app-server-protocol/schema/typescript/index.ts b/codex-rs/app-server-protocol/schema/typescript/index.ts
index a6ff6fbaf1..1ae5d2bfae 100644
--- a/codex-rs/app-server-protocol/schema/typescript/index.ts
+++ b/codex-rs/app-server-protocol/schema/typescript/index.ts
@@ -219,4 +219,5 @@ export type { WebSearchBeginEvent } from "./WebSearchBeginEvent";
 export type { WebSearchEndEvent } from "./WebSearchEndEvent";
 export type { WebSearchItem } from "./WebSearchItem";
 export type { WebSearchMode } from "./WebSearchMode";
+export type { WorkspaceReadAccess } from "./WorkspaceReadAccess";
 export * as v2 from "./v2";
diff --git a/codex-rs/app-server-protocol/schema/typescript/v2/SandboxPolicy.ts b/codex-rs/app-server-protocol/schema/typescript/v2/SandboxPolicy.ts
index 199d7f2a52..30b19ad7f7 100644
--- a/codex-rs/app-server-protocol/schema/typescript/v2/SandboxPolicy.ts
+++ b/codex-rs/app-server-protocol/schema/typescript/v2/SandboxPolicy.ts
@@ -3,5 +3,6 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { AbsolutePathBuf } from "../AbsolutePathBuf";
 import type { NetworkAccess } from "./NetworkAccess";
+import type { WorkspaceReadAccess } from "./WorkspaceReadAccess";
 
-export type SandboxPolicy = { "type": "dangerFullAccess" } | { "type": "readOnly" } | { "type": "externalSandbox", networkAccess: NetworkAccess, } | { "type": "workspaceWrite", writableRoots: Array<AbsolutePathBuf>, networkAccess: boolean, excludeTmpdirEnvVar: boolean, excludeSlashTmp: boolean, };
+export type SandboxPolicy = { "type": "dangerFullAccess" } | { "type": "readOnly" } | { "type": "externalSandbox", networkAccess: NetworkAccess, } | { "type": "workspaceWrite", writableRoots: Array<AbsolutePathBuf>, networkAccess: boolean, excludeTmpdirEnvVar: boolean, excludeSlashTmp: boolean, readAccess?: WorkspaceReadAccess, };
diff --git a/codex-rs/app-server-protocol/schema/typescript/v2/SandboxWorkspaceWrite.ts b/codex-rs/app-server-protocol/schema/typescript/v2/SandboxWorkspaceWrite.ts
index cd19d83f1f..0afc3d871b 100644
--- a/codex-rs/app-server-protocol/schema/typescript/v2/SandboxWorkspaceWrite.ts
+++ b/codex-rs/app-server-protocol/schema/typescript/v2/SandboxWorkspaceWrite.ts
@@ -1,5 +1,6 @@
 // GENERATED CODE! DO NOT MODIFY BY HAND!
 
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { WorkspaceReadAccess } from "./WorkspaceReadAccess";
 
-export type SandboxWorkspaceWrite = { writable_roots: Array<string>, network_access: boolean, exclude_tmpdir_env_var: boolean, exclude_slash_tmp: boolean, };
+export type SandboxWorkspaceWrite = { writable_roots: Array<string>, network_access: boolean, exclude_tmpdir_env_var: boolean, exclude_slash_tmp: boolean, read_access?: WorkspaceReadAccess, };
diff --git a/codex-rs/app-server-protocol/schema/typescript/v2/WorkspaceReadAccess.ts b/codex-rs/app-server-protocol/schema/typescript/v2/WorkspaceReadAccess.ts
new file mode 100644
index 0000000000..fed75f3379
--- /dev/null
+++ b/codex-rs/app-server-protocol/schema/typescript/v2/WorkspaceReadAccess.ts
@@ -0,0 +1,6 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { AbsolutePathBuf } from "../AbsolutePathBuf";
+
+export type WorkspaceReadAccess = { "type": "fullReadAccess" } | { "type": "restrictedReadAccess", readableRoots: Array<AbsolutePathBuf>, };
diff --git a/codex-rs/app-server-protocol/schema/typescript/v2/index.ts b/codex-rs/app-server-protocol/schema/typescript/v2/index.ts
index 65a12daa34..000f1b1ba7 100644
--- a/codex-rs/app-server-protocol/schema/typescript/v2/index.ts
+++ b/codex-rs/app-server-protocol/schema/typescript/v2/index.ts
@@ -185,4 +185,5 @@ export type { TurnSteerResponse } from "./TurnSteerResponse";
 export type { UserInput } from "./UserInput";
 export type { WebSearchAction } from "./WebSearchAction";
 export type { WindowsWorldWritableWarningNotification } from "./WindowsWorldWritableWarningNotification";
+export type { WorkspaceReadAccess } from "./WorkspaceReadAccess";
 export type { WriteStatus } from "./WriteStatus";
diff --git a/codex-rs/app-server-protocol/src/protocol/v2.rs b/codex-rs/app-server-protocol/src/protocol/v2.rs
index a978fec6db..0806628cfa 100644
--- a/codex-rs/app-server-protocol/src/protocol/v2.rs
+++ b/codex-rs/app-server-protocol/src/protocol/v2.rs
@@ -329,6 +329,8 @@ pub struct SandboxWorkspaceWrite {
     pub exclude_tmpdir_env_var: bool,
     #[serde(default)]
     pub exclude_slash_tmp: bool,
+    #[serde(default, skip_serializing_if = "WorkspaceReadAccess::is_full")]
+    pub read_access: WorkspaceReadAccess,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -595,6 +597,27 @@ pub enum NetworkAccess {
     Enabled,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS, Default)]
+#[serde(tag = "type", rename_all = "camelCase")]
+#[ts(tag = "type")]
+#[ts(export_to = "v2/")]
+pub enum WorkspaceReadAccess {
+    #[default]
+    FullReadAccess,
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    RestrictedReadAccess {
+        #[serde(default)]
+        readable_roots: Vec<AbsolutePathBuf>,
+    },
+}
+
+impl WorkspaceReadAccess {
+    pub fn is_full(&self) -> bool {
+        matches!(self, WorkspaceReadAccess::FullReadAccess)
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
 #[serde(tag = "type", rename_all = "camelCase")]
 #[ts(tag = "type")]
@@ -619,6 +642,8 @@ pub enum SandboxPolicy {
         exclude_tmpdir_env_var: bool,
         #[serde(default)]
         exclude_slash_tmp: bool,
+        #[serde(default, skip_serializing_if = "WorkspaceReadAccess::is_full")]
+        read_access: WorkspaceReadAccess,
     },
 }
 
@@ -642,11 +667,22 @@ impl SandboxPolicy {
                 network_access,
                 exclude_tmpdir_env_var,
                 exclude_slash_tmp,
+                read_access,
             } => codex_protocol::protocol::SandboxPolicy::WorkspaceWrite {
                 writable_roots: writable_roots.clone(),
                 network_access: *network_access,
                 exclude_tmpdir_env_var: *exclude_tmpdir_env_var,
                 exclude_slash_tmp: *exclude_slash_tmp,
+                read_access: match read_access {
+                    WorkspaceReadAccess::FullReadAccess => {
+                        codex_protocol::protocol::WorkspaceReadAccess::FullReadAccess
+                    }
+                    WorkspaceReadAccess::RestrictedReadAccess { readable_roots } => {
+                        codex_protocol::protocol::WorkspaceReadAccess::RestrictedReadAccess {
+                            readable_roots: readable_roots.clone(),
+                        }
+                    }
+                },
             },
         }
     }
@@ -672,11 +708,20 @@ impl From<codex_protocol::protocol::SandboxPolicy> for SandboxPolicy {
                 network_access,
                 exclude_tmpdir_env_var,
                 exclude_slash_tmp,
+                read_access,
             } => SandboxPolicy::WorkspaceWrite {
                 writable_roots,
                 network_access,
                 exclude_tmpdir_env_var,
                 exclude_slash_tmp,
+                read_access: match read_access {
+                    codex_protocol::protocol::WorkspaceReadAccess::FullReadAccess => {
+                        WorkspaceReadAccess::FullReadAccess
+                    }
+                    codex_protocol::protocol::WorkspaceReadAccess::RestrictedReadAccess {
+                        readable_roots,
+                    } => WorkspaceReadAccess::RestrictedReadAccess { readable_roots },
+                },
             },
         }
     }
@@ -3143,6 +3188,34 @@ mod tests {
         assert_eq!(back_to_v2, v2_policy);
     }
 
+    #[test]
+    fn sandbox_policy_round_trips_workspace_write_restricted_read_access() {
+        let readable_root = if cfg!(windows) {
+            AbsolutePathBuf::from_absolute_path("C:\\repo\\readable").expect("absolute path")
+        } else {
+            AbsolutePathBuf::from_absolute_path("/repo/readable").expect("absolute path")
+        };
+        let writable_root = if cfg!(windows) {
+            AbsolutePathBuf::from_absolute_path("C:\\repo\\writable").expect("absolute path")
+        } else {
+            AbsolutePathBuf::from_absolute_path("/repo/writable").expect("absolute path")
+        };
+
+        let v2_policy = SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![writable_root],
+            network_access: false,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+            read_access: WorkspaceReadAccess::RestrictedReadAccess {
+                readable_roots: vec![readable_root],
+            },
+        };
+
+        let core_policy = v2_policy.to_core();
+        let back_to_v2 = SandboxPolicy::from(core_policy);
+        assert_eq!(back_to_v2, v2_policy);
+    }
+
     #[test]
     fn core_turn_item_into_thread_item_converts_supported_variants() {
         let user_item = TurnItem::UserMessage(UserMessageItem {
diff --git a/codex-rs/app-server/README.md b/codex-rs/app-server/README.md
index a6d49f2e4c..d4db344d31 100644
--- a/codex-rs/app-server/README.md
+++ b/codex-rs/app-server/README.md
@@ -288,7 +288,11 @@ You can optionally specify config overrides on the new turn. If specified, these
     "sandboxPolicy": {
         "type": "workspaceWrite",
         "writableRoots": ["/Users/me/project"],
-        "networkAccess": true
+        "networkAccess": true,
+        "readAccess": {
+            "type": "restrictedReadAccess",
+            "readableRoots": ["/Users/me/project", "/Users/me/project/.cache"]
+        }
     },
     "model": "gpt-5.1-codex",
     "effort": "medium",
@@ -468,7 +472,7 @@ Run a standalone command (argv vector) in the server’s sandbox without creatin
 Notes:
 
 - Empty `command` arrays are rejected.
-- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags, `externalSandbox` with `networkAccess` `restricted|enabled`).
+- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags including optional `readAccess`, `externalSandbox` with `networkAccess` `restricted|enabled`).
 - When omitted, `timeoutMs` falls back to the server default.
 
 ## Events
diff --git a/codex-rs/app-server/tests/suite/codex_message_processor_flow.rs b/codex-rs/app-server/tests/suite/codex_message_processor_flow.rs
index 2debbda653..b09710f630 100644
--- a/codex-rs/app-server/tests/suite/codex_message_processor_flow.rs
+++ b/codex-rs/app-server/tests/suite/codex_message_processor_flow.rs
@@ -447,6 +447,7 @@ async fn test_send_user_turn_updates_sandbox_and_cwd_between_turns() -> Result<(
                 network_access: false,
                 exclude_tmpdir_env_var: false,
                 exclude_slash_tmp: false,
+                read_access: Default::default(),
             },
             model: model.clone(),
             effort: Some(ReasoningEffort::Medium),
diff --git a/codex-rs/app-server/tests/suite/v2/turn_start.rs b/codex-rs/app-server/tests/suite/v2/turn_start.rs
index 395561f69a..f09d4c4523 100644
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -1102,6 +1102,7 @@ async fn turn_start_updates_sandbox_and_cwd_between_turns_v2() -> Result<()> {
                 network_access: false,
                 exclude_tmpdir_env_var: false,
                 exclude_slash_tmp: false,
+                read_access: Default::default(),
             }),
             model: Some("mock-model".to_string()),
             effort: Some(ReasoningEffort::Medium),
diff --git a/codex-rs/common/src/sandbox_summary.rs b/codex-rs/common/src/sandbox_summary.rs
index 45520b11a0..b19a783ad2 100644
--- a/codex-rs/common/src/sandbox_summary.rs
+++ b/codex-rs/common/src/sandbox_summary.rs
@@ -1,5 +1,6 @@
 use codex_core::protocol::NetworkAccess;
 use codex_core::protocol::SandboxPolicy;
+use codex_core::protocol::WorkspaceReadAccess;
 
 pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
     match sandbox_policy {
@@ -17,6 +18,7 @@ pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
             network_access,
             exclude_tmpdir_env_var,
             exclude_slash_tmp,
+            read_access,
         } => {
             let mut summary = "workspace-write".to_string();
 
@@ -35,6 +37,18 @@ pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
             );
 
             summary.push_str(&format!(" [{}]", writable_entries.join(", ")));
+            if let WorkspaceReadAccess::RestrictedReadAccess { readable_roots } = read_access {
+                summary.push_str(" (restricted read access");
+                if !readable_roots.is_empty() {
+                    let roots = readable_roots
+                        .iter()
+                        .map(|path| path.to_string_lossy().to_string())
+                        .collect::<Vec<_>>()
+                        .join(", ");
+                    summary.push_str(&format!(": {roots}"));
+                }
+                summary.push(')');
+            }
             if *network_access {
                 summary.push_str(" (network access enabled)");
             }
@@ -74,6 +88,7 @@ mod tests {
             network_access: true,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: true,
+            read_access: Default::default(),
         });
         assert_eq!(
             summary,
@@ -83,4 +98,29 @@ mod tests {
             )
         );
     }
+
+    #[test]
+    fn workspace_write_summary_includes_restricted_read_access() {
+        let read_root = if cfg!(windows) {
+            AbsolutePathBuf::try_from("C:\\read").unwrap()
+        } else {
+            AbsolutePathBuf::try_from("/read").unwrap()
+        };
+        let summary = summarize_sandbox_policy(&SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![],
+            network_access: false,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+            read_access: WorkspaceReadAccess::RestrictedReadAccess {
+                readable_roots: vec![read_root.clone()],
+            },
+        });
+        assert_eq!(
+            summary,
+            format!(
+                "workspace-write [workdir] (restricted read access: {})",
+                read_root.to_string_lossy()
+            )
+        );
+    }
 }
diff --git a/codex-rs/core/src/config/mod.rs b/codex-rs/core/src/config/mod.rs
index 7de6f00ea8..87b096ed7a 100644
--- a/codex-rs/core/src/config/mod.rs
+++ b/codex-rs/core/src/config/mod.rs
@@ -1175,6 +1175,7 @@ impl ConfigToml {
                     network_access: *network_access,
                     exclude_tmpdir_env_var: *exclude_tmpdir_env_var,
                     exclude_slash_tmp: *exclude_slash_tmp,
+                    read_access: Default::default(),
                 },
                 None => SandboxPolicy::new_workspace_write_policy(),
             },
@@ -2092,6 +2093,7 @@ exclude_slash_tmp = true
                         network_access: false,
                         exclude_tmpdir_env_var: true,
                         exclude_slash_tmp: true,
+                        read_access: Default::default(),
                     },
                     forced_auto_mode_downgraded_on_windows: false,
                 }
@@ -2142,6 +2144,7 @@ trust_level = "trusted"
                         network_access: false,
                         exclude_tmpdir_env_var: true,
                         exclude_slash_tmp: true,
+                        read_access: Default::default(),
                     },
                     forced_auto_mode_downgraded_on_windows: false,
                 }
diff --git a/codex-rs/core/src/config_loader/config_requirements.rs b/codex-rs/core/src/config_loader/config_requirements.rs
index b3e6043288..aa5dcfa097 100644
--- a/codex-rs/core/src/config_loader/config_requirements.rs
+++ b/codex-rs/core/src/config_loader/config_requirements.rs
@@ -715,6 +715,7 @@ mod tests {
                     network_access: false,
                     exclude_tmpdir_env_var: false,
                     exclude_slash_tmp: false,
+                    read_access: Default::default(),
                 })
                 .is_ok()
         );
diff --git a/codex-rs/core/src/config_loader/tests.rs b/codex-rs/core/src/config_loader/tests.rs
index d68093c30f..c1f2195695 100644
--- a/codex-rs/core/src/config_loader/tests.rs
+++ b/codex-rs/core/src/config_loader/tests.rs
@@ -415,6 +415,7 @@ allowed_sandbox_modes = ["read-only"]
                 network_access: false,
                 exclude_tmpdir_env_var: false,
                 exclude_slash_tmp: false,
+                read_access: Default::default(),
             })
             .is_err()
     );
diff --git a/codex-rs/core/src/safety.rs b/codex-rs/core/src/safety.rs
index 47a12e029e..cb762d6db3 100644
--- a/codex-rs/core/src/safety.rs
+++ b/codex-rs/core/src/safety.rs
@@ -198,6 +198,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: true,
+            read_access: Default::default(),
         };
 
         assert!(is_write_patch_constrained_to_writable_paths(
@@ -219,6 +220,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: true,
+            read_access: Default::default(),
         };
         assert!(is_write_patch_constrained_to_writable_paths(
             &add_outside,
diff --git a/codex-rs/core/src/seatbelt.rs b/codex-rs/core/src/seatbelt.rs
index a15ebb177b..99a2edccef 100644
--- a/codex-rs/core/src/seatbelt.rs
+++ b/codex-rs/core/src/seatbelt.rs
@@ -13,6 +13,8 @@ use crate::spawn::spawn_child_async;
 
 const MACOS_SEATBELT_BASE_POLICY: &str = include_str!("seatbelt_base_policy.sbpl");
 const MACOS_SEATBELT_NETWORK_POLICY: &str = include_str!("seatbelt_network_policy.sbpl");
+const MACOS_SEATBELT_RESTRICTED_READ_BASE_POLICY: &str =
+    include_str!("seatbelt_restricted_read_base_policy.sbpl");
 
 /// When working with `sandbox-exec`, only consider `sandbox-exec` in `/usr/bin`
 /// to defend against an attacker trying to inject a malicious version on the
@@ -48,6 +50,8 @@ pub(crate) fn create_seatbelt_command_args(
     sandbox_policy: &SandboxPolicy,
     sandbox_policy_cwd: &Path,
 ) -> Vec<String> {
+    let has_full_disk_read_access = sandbox_policy.has_full_disk_read_access();
+
     let (file_write_policy, file_write_dir_params) = {
         if sandbox_policy.has_full_disk_write_access() {
             // Allegedly, this is more permissive than `(allow file-write*)`.
@@ -105,10 +109,39 @@ pub(crate) fn create_seatbelt_command_args(
         }
     };
 
-    let file_read_policy = if sandbox_policy.has_full_disk_read_access() {
-        "; allow read-only file operations\n(allow file-read*)"
+    let (file_read_policy, file_read_dir_params) = if has_full_disk_read_access {
+        (
+            "; allow read-only file operations\n(allow file-read*)".to_string(),
+            Vec::new(),
+        )
     } else {
+        let readable_roots = sandbox_policy.get_readable_roots_with_cwd(sandbox_policy_cwd);
+        let mut readable_folder_policies: Vec<String> = Vec::new();
+        let mut file_read_params = Vec::new();
+
+        for (index, root) in readable_roots.iter().enumerate() {
+            // Canonicalize to avoid mismatches like /var vs /private/var on macOS.
+            let canonical_root = root
+                .as_path()
+                .canonicalize()
+                .unwrap_or_else(|_| root.to_path_buf());
+            let root_param = format!("READABLE_ROOT_{index}");
+            file_read_params.push((root_param.clone(), canonical_root));
+            readable_folder_policies.push(format!(
+                "(allow file-read* file-map-executable (subpath (param \"{root_param}\")))"
+            ));
+            readable_folder_policies.push(format!(
+                "(allow file-read-metadata file-test-existence (path-ancestors (param \"{root_param}\")))"
+            ));
+        }
+
+        (readable_folder_policies.join("\n"), file_read_params)
+    };
+
+    let restricted_read_base_policy = if has_full_disk_read_access {
         ""
+    } else {
+        MACOS_SEATBELT_RESTRICTED_READ_BASE_POLICY
     };
 
     // TODO(mbolin): apply_patch calls must also honor the SandboxPolicy.
@@ -118,11 +151,24 @@ pub(crate) fn create_seatbelt_command_args(
         ""
     };
 
-    let full_policy = format!(
-        "{MACOS_SEATBELT_BASE_POLICY}\n{file_read_policy}\n{file_write_policy}\n{network_policy}"
-    );
+    let full_policy = [
+        MACOS_SEATBELT_BASE_POLICY,
+        restricted_read_base_policy,
+        file_read_policy.as_str(),
+        file_write_policy.as_str(),
+        network_policy,
+    ]
+    .into_iter()
+    .filter(|policy| !policy.is_empty())
+    .collect::<Vec<_>>()
+    .join("\n");
 
-    let dir_params = [file_write_dir_params, macos_dir_params()].concat();
+    let dir_params = [
+        file_write_dir_params,
+        file_read_dir_params,
+        macos_dir_params(),
+    ]
+    .concat();
 
     let mut seatbelt_args: Vec<String> = vec!["-p".to_string(), full_policy];
     let definition_args = dir_params
@@ -166,6 +212,7 @@ mod tests {
     use super::create_seatbelt_command_args;
     use super::macos_dir_params;
     use crate::protocol::SandboxPolicy;
+    use crate::protocol::WorkspaceReadAccess;
     use crate::seatbelt::MACOS_PATH_TO_SEATBELT_EXECUTABLE;
     use pretty_assertions::assert_eq;
     use std::fs;
@@ -210,6 +257,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: true,
+            read_access: Default::default(),
         };
 
         // Create the Seatbelt command to wrap a shell command that tries to
@@ -240,8 +288,7 @@ mod tests {
 (allow file-read*)
 (allow file-write*
 (require-all (subpath (param "WRITABLE_ROOT_0")) (require-not (subpath (param "WRITABLE_ROOT_0_RO_0"))) (require-not (subpath (param "WRITABLE_ROOT_0_RO_1"))) ) (subpath (param "WRITABLE_ROOT_1")) (subpath (param "WRITABLE_ROOT_2"))
-)
-"#,
+)"#,
         );
 
         let mut expected_args = vec![
@@ -371,6 +418,48 @@ mod tests {
         );
     }
 
+    #[test]
+    fn create_seatbelt_args_with_restricted_read_roots() {
+        let tmp = TempDir::new().expect("tempdir");
+        let cwd = tmp.path().join("cwd");
+        fs::create_dir_all(&cwd).expect("create cwd");
+        let readable_root = tmp.path().join("readable");
+        fs::create_dir_all(&readable_root).expect("create readable root");
+        let readable_root_canonical = readable_root.canonicalize().expect("canonicalize root");
+
+        let policy = SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![],
+            network_access: false,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+            read_access: WorkspaceReadAccess::RestrictedReadAccess {
+                readable_roots: vec![readable_root.try_into().expect("absolute path")],
+            },
+        };
+
+        let args = create_seatbelt_command_args(vec!["/usr/bin/true".to_string()], &policy, &cwd);
+        let policy_text = args
+            .get(1)
+            .expect("seatbelt policy arg should be present")
+            .to_string();
+
+        assert!(
+            policy_text.contains("(allow file-map-executable"),
+            "restricted read baseline should include file-map-executable rules"
+        );
+        assert!(
+            policy_text.contains("(param \"READABLE_ROOT_0\")"),
+            "restricted read policy should include parameterized readable roots"
+        );
+        assert!(
+            args.contains(&format!(
+                "-DREADABLE_ROOT_0={}",
+                readable_root_canonical.to_string_lossy()
+            )),
+            "expected readable root parameter in args: {args:?}"
+        );
+    }
+
     #[test]
     fn create_seatbelt_args_with_read_only_git_pointer_file() {
         let tmp = TempDir::new().expect("tempdir");
@@ -394,6 +483,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: true,
+            read_access: Default::default(),
         };
 
         let shell_command: Vec<String> = [
@@ -477,6 +567,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: false,
             exclude_slash_tmp: false,
+            read_access: Default::default(),
         };
 
         let shell_command: Vec<String> = [
@@ -518,8 +609,7 @@ mod tests {
 (allow file-read*)
 (allow file-write*
 (require-all (subpath (param "WRITABLE_ROOT_0")) (require-not (subpath (param "WRITABLE_ROOT_0_RO_0"))) (require-not (subpath (param "WRITABLE_ROOT_0_RO_1"))) ) (subpath (param "WRITABLE_ROOT_1")){tempdir_policy_entry}
-)
-"#,
+)"#,
         );
 
         let mut expected_args = vec![
diff --git a/codex-rs/core/src/seatbelt_restricted_read_base_policy.sbpl b/codex-rs/core/src/seatbelt_restricted_read_base_policy.sbpl
new file mode 100644
index 0000000000..4e9a23010d
--- /dev/null
+++ b/codex-rs/core/src/seatbelt_restricted_read_base_policy.sbpl
@@ -0,0 +1,49 @@
+; baseline read access for restricted-read workspace-write policies
+; keeps the runtime and dynamic loader functional without globally allowing
+; file-read* on all paths.
+
+; shell/runtime binaries
+(allow file-read-data file-read-metadata
+  (subpath "/bin")
+  (subpath "/sbin")
+  (subpath "/usr/bin")
+  (subpath "/usr/sbin")
+  (subpath "/usr/libexec"))
+
+; standard shell configuration loaded by /bin/zsh
+(allow file-read-data file-read-metadata
+  (literal "/etc/zshenv")
+  (literal "/etc/zprofile")
+  (literal "/etc/zlogin"))
+
+; dynamic loader + frameworks
+(allow file-read* file-test-existence
+  (subpath "/Library/Apple")
+  (subpath "/System")
+  (subpath "/usr/lib")
+  (subpath "/usr/share"))
+
+(allow file-map-executable
+  (subpath "/Library/Apple/System/Library/Frameworks")
+  (subpath "/Library/Apple/System/Library/PrivateFrameworks")
+  (subpath "/Library/Apple/usr/lib")
+  (subpath "/System/Library/Frameworks")
+  (subpath "/System/Library/PrivateFrameworks")
+  (subpath "/System/Library/SubFrameworks")
+  (subpath "/usr/lib"))
+
+; allow path traversal for common symlinked roots
+(allow file-read-metadata file-test-existence
+  (literal "/")
+  (literal "/etc")
+  (literal "/tmp")
+  (literal "/var")
+  (literal "/private/etc/localtime")
+  (path-ancestors "/System/Volumes/Data/private"))
+
+; resolver / service metadata commonly read at startup
+(allow file-read* file-test-existence
+  (literal "/private/etc/master.passwd")
+  (literal "/private/etc/passwd")
+  (literal "/private/etc/protocols")
+  (literal "/private/etc/services"))
diff --git a/codex-rs/core/tests/suite/apply_patch_cli.rs b/codex-rs/core/tests/suite/apply_patch_cli.rs
index ccfa9fe654..7ddbbab5ed 100644
--- a/codex-rs/core/tests/suite/apply_patch_cli.rs
+++ b/codex-rs/core/tests/suite/apply_patch_cli.rs
@@ -581,6 +581,7 @@ async fn apply_patch_cli_rejects_path_traversal_outside_workspace(
         network_access: false,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
     harness
         .submit_with_policy(
@@ -637,6 +638,7 @@ async fn apply_patch_cli_rejects_move_path_traversal_outside_workspace(
         network_access: false,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
     harness
         .submit_with_policy("attempt move traversal via apply_patch", sandbox_policy)
diff --git a/codex-rs/core/tests/suite/approvals.rs b/codex-rs/core/tests/suite/approvals.rs
index 1b295964e8..df994fcf73 100644
--- a/codex-rs/core/tests/suite/approvals.rs
+++ b/codex-rs/core/tests/suite/approvals.rs
@@ -631,6 +631,7 @@ fn scenarios() -> Vec<ScenarioSpec> {
         network_access,
         exclude_tmpdir_env_var: false,
         exclude_slash_tmp: false,
+        read_access: Default::default(),
     };
 
     vec![
@@ -1576,6 +1577,7 @@ async fn approving_apply_patch_for_session_skips_future_prompts_for_same_file()
         network_access: false,
         exclude_tmpdir_env_var: false,
         exclude_slash_tmp: false,
+        read_access: Default::default(),
     };
     let sandbox_policy_for_config = sandbox_policy.clone();
 
diff --git a/codex-rs/core/tests/suite/permissions_messages.rs b/codex-rs/core/tests/suite/permissions_messages.rs
index fc1f0fa0b6..580a39f6dc 100644
--- a/codex-rs/core/tests/suite/permissions_messages.rs
+++ b/codex-rs/core/tests/suite/permissions_messages.rs
@@ -460,6 +460,7 @@ async fn permissions_message_includes_writable_roots() -> Result<()> {
         network_access: false,
         exclude_tmpdir_env_var: false,
         exclude_slash_tmp: false,
+        read_access: Default::default(),
     };
     let sandbox_policy_for_config = sandbox_policy.clone();
 
diff --git a/codex-rs/core/tests/suite/prompt_caching.rs b/codex-rs/core/tests/suite/prompt_caching.rs
index 9b1548591b..69eea847cc 100644
--- a/codex-rs/core/tests/suite/prompt_caching.rs
+++ b/codex-rs/core/tests/suite/prompt_caching.rs
@@ -377,6 +377,7 @@ async fn overrides_turn_context_but_keeps_cached_prefix_and_key_constant() -> an
         network_access: true,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
     codex
         .submit(Op::OverrideTurnContext {
@@ -618,6 +619,7 @@ async fn per_turn_overrides_keep_cached_prefix_and_key_constant() -> anyhow::Res
         network_access: true,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
     codex
         .submit(Op::UserTurn {
diff --git a/codex-rs/core/tests/suite/seatbelt.rs b/codex-rs/core/tests/suite/seatbelt.rs
index 286bc8791b..eff95f4a4e 100644
--- a/codex-rs/core/tests/suite/seatbelt.rs
+++ b/codex-rs/core/tests/suite/seatbelt.rs
@@ -80,6 +80,7 @@ async fn if_parent_of_repo_is_writable_then_dot_git_folder_is_writable() {
         network_access: false,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
 
     test_scenario
@@ -106,6 +107,7 @@ async fn if_git_repo_is_writable_root_then_dot_git_folder_is_read_only() {
         network_access: false,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
 
     test_scenario
diff --git a/codex-rs/exec-server/tests/common/lib.rs b/codex-rs/exec-server/tests/common/lib.rs
index 66bb4b7f9c..b6da9a373a 100644
--- a/codex-rs/exec-server/tests/common/lib.rs
+++ b/codex-rs/exec-server/tests/common/lib.rs
@@ -116,6 +116,7 @@ where
             // strict about what is writable.
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: true,
+            read_access: Default::default(),
         },
         codex_linux_sandbox_exe,
         sandbox_cwd: writable_folder.as_ref().to_path_buf(),
diff --git a/codex-rs/exec/tests/suite/sandbox.rs b/codex-rs/exec/tests/suite/sandbox.rs
index ab8d3868d9..b15b7ff902 100644
--- a/codex-rs/exec/tests/suite/sandbox.rs
+++ b/codex-rs/exec/tests/suite/sandbox.rs
@@ -135,6 +135,7 @@ async fn python_multiprocessing_lock_works_under_sandbox() {
         network_access: false,
         exclude_tmpdir_env_var: false,
         exclude_slash_tmp: false,
+        read_access: Default::default(),
     };
 
     let python_code = r#"import multiprocessing
@@ -248,6 +249,7 @@ async fn sandbox_distinguishes_command_and_policy_cwds() {
         network_access: false,
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
 
     // Attempt to write inside the command cwd, which is outside of the sandbox policy cwd.
diff --git a/codex-rs/linux-sandbox/tests/suite/landlock.rs b/codex-rs/linux-sandbox/tests/suite/landlock.rs
index 52cd402a13..c8ce98243a 100644
--- a/codex-rs/linux-sandbox/tests/suite/landlock.rs
+++ b/codex-rs/linux-sandbox/tests/suite/landlock.rs
@@ -92,6 +92,7 @@ async fn run_cmd_result_with_writable_roots(
         // writing to in the sandbox.
         exclude_tmpdir_env_var: true,
         exclude_slash_tmp: true,
+        read_access: Default::default(),
     };
     let sandbox_program = env!("CARGO_BIN_EXE_codex-linux-sandbox");
     let codex_linux_sandbox_exe = Some(PathBuf::from(sandbox_program));
diff --git a/codex-rs/protocol/src/models.rs b/codex-rs/protocol/src/models.rs
index ae38a7890c..8730453d9a 100644
--- a/codex-rs/protocol/src/models.rs
+++ b/codex-rs/protocol/src/models.rs
@@ -1216,6 +1216,7 @@ mod tests {
             network_access: true,
             exclude_tmpdir_env_var: false,
             exclude_slash_tmp: false,
+            read_access: Default::default(),
         };
 
         let instructions = DeveloperInstructions::from_policy(
diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index 078ea31d18..9a101e411f 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -376,6 +376,29 @@ impl NetworkAccess {
     }
 }
 
+/// Controls read access semantics for `workspace-write` sandbox policies.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Display, Default, JsonSchema, TS)]
+#[strum(serialize_all = "kebab-case")]
+#[serde(tag = "type", rename_all = "kebab-case")]
+pub enum WorkspaceReadAccess {
+    /// Preserve current behavior where all file-system paths are readable.
+    #[default]
+    FullReadAccess,
+
+    /// Restrict reads to an explicit allowlist plus implicitly readable paths.
+    RestrictedReadAccess {
+        /// Additional folders that should be readable from inside the sandbox.
+        #[serde(default, skip_serializing_if = "Vec::is_empty")]
+        readable_roots: Vec<AbsolutePathBuf>,
+    },
+}
+
+impl WorkspaceReadAccess {
+    pub fn is_full(&self) -> bool {
+        matches!(self, WorkspaceReadAccess::FullReadAccess)
+    }
+}
+
 /// Determines execution restrictions for model shell commands.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Display, JsonSchema, TS)]
 #[strum(serialize_all = "kebab-case")]
@@ -422,6 +445,11 @@ pub enum SandboxPolicy {
         /// writable roots on UNIX. Defaults to `false`.
         #[serde(default)]
         exclude_slash_tmp: bool,
+
+        /// Controls whether the workspace-write policy has full read access or
+        /// an explicit read allowlist.
+        #[serde(default, skip_serializing_if = "WorkspaceReadAccess::is_full")]
+        read_access: WorkspaceReadAccess,
     },
 }
 
@@ -479,12 +507,48 @@ impl SandboxPolicy {
             network_access: false,
             exclude_tmpdir_env_var: false,
             exclude_slash_tmp: false,
+            read_access: WorkspaceReadAccess::FullReadAccess,
         }
     }
 
-    /// Always returns `true`; restricting read access is not supported.
     pub fn has_full_disk_read_access(&self) -> bool {
-        true
+        match self {
+            SandboxPolicy::DangerFullAccess => true,
+            SandboxPolicy::ExternalSandbox { .. } => true,
+            SandboxPolicy::ReadOnly => true,
+            SandboxPolicy::WorkspaceWrite { read_access, .. } => {
+                matches!(read_access, WorkspaceReadAccess::FullReadAccess)
+            }
+        }
+    }
+
+    /// Returns readable roots tailored to cwd when read access is restricted.
+    /// Returns an empty list when the policy has full disk read access.
+    pub fn get_readable_roots_with_cwd(&self, cwd: &Path) -> Vec<AbsolutePathBuf> {
+        match self {
+            SandboxPolicy::DangerFullAccess => Vec::new(),
+            SandboxPolicy::ExternalSandbox { .. } => Vec::new(),
+            SandboxPolicy::ReadOnly => Vec::new(),
+            SandboxPolicy::WorkspaceWrite { read_access, .. } => match read_access {
+                WorkspaceReadAccess::FullReadAccess => Vec::new(),
+                WorkspaceReadAccess::RestrictedReadAccess { readable_roots } => {
+                    let mut roots = readable_roots.clone();
+                    roots.extend(
+                        self.get_writable_roots_with_cwd(cwd)
+                            .into_iter()
+                            .map(|root| root.root),
+                    );
+
+                    let mut deduped = Vec::new();
+                    for root in roots {
+                        if !deduped.iter().any(|existing| existing == &root) {
+                            deduped.push(root);
+                        }
+                    }
+                    deduped
+                }
+            },
+        }
     }
 
     pub fn has_full_disk_write_access(&self) -> bool {
@@ -517,6 +581,7 @@ impl SandboxPolicy {
                 writable_roots,
                 exclude_tmpdir_env_var,
                 exclude_slash_tmp,
+                read_access: _,
                 network_access: _,
             } => {
                 // Start from explicitly configured writable roots.
@@ -2482,6 +2547,7 @@ mod tests {
     use crate::items::UserMessageItem;
     use crate::items::WebSearchItem;
     use anyhow::Result;
+    use codex_utils_absolute_path::AbsolutePathBuf;
     use pretty_assertions::assert_eq;
     use serde_json::json;
     use tempfile::NamedTempFile;
@@ -2501,6 +2567,52 @@ mod tests {
         assert!(enabled.has_full_network_access());
     }
 
+    #[test]
+    fn workspace_write_restricted_read_reports_not_full_read_access() {
+        let policy = SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![],
+            network_access: false,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+            read_access: WorkspaceReadAccess::RestrictedReadAccess {
+                readable_roots: vec![],
+            },
+        };
+
+        assert!(!policy.has_full_disk_read_access());
+    }
+
+    #[test]
+    fn workspace_write_restricted_readable_roots_include_writable_roots() -> Result<()> {
+        let (cwd, writable_root, readable_root) = if cfg!(windows) {
+            (
+                AbsolutePathBuf::from_absolute_path("C:\\repo\\cwd")?,
+                AbsolutePathBuf::from_absolute_path("C:\\repo\\writable")?,
+                AbsolutePathBuf::from_absolute_path("C:\\repo\\readable")?,
+            )
+        } else {
+            (
+                AbsolutePathBuf::from_absolute_path("/repo/cwd")?,
+                AbsolutePathBuf::from_absolute_path("/repo/writable")?,
+                AbsolutePathBuf::from_absolute_path("/repo/readable")?,
+            )
+        };
+
+        let policy = SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![writable_root.clone()],
+            network_access: false,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+            read_access: WorkspaceReadAccess::RestrictedReadAccess {
+                readable_roots: vec![readable_root.clone()],
+            },
+        };
+
+        let readable_roots = policy.get_readable_roots_with_cwd(cwd.as_path());
+        assert_eq!(readable_roots, vec![readable_root, writable_root, cwd]);
+        Ok(())
+    }
+
     #[test]
     fn item_started_event_from_web_search_emits_begin_event() {
         let event = ItemStartedEvent {
diff --git a/codex-rs/tui/src/chatwidget/tests.rs b/codex-rs/tui/src/chatwidget/tests.rs
index f49493b6a1..a167f6c2df 100644
--- a/codex-rs/tui/src/chatwidget/tests.rs
+++ b/codex-rs/tui/src/chatwidget/tests.rs
@@ -3490,6 +3490,7 @@ async fn preset_matching_ignores_extra_writable_roots() {
         network_access: false,
         exclude_tmpdir_env_var: false,
         exclude_slash_tmp: false,
+        read_access: Default::default(),
     };
 
     assert!(
diff --git a/codex-rs/tui/src/status/tests.rs b/codex-rs/tui/src/status/tests.rs
index c8844904ab..0835e387da 100644
--- a/codex-rs/tui/src/status/tests.rs
+++ b/codex-rs/tui/src/status/tests.rs
@@ -103,6 +103,7 @@ async fn status_snapshot_includes_reasoning_details() {
             network_access: false,
             exclude_tmpdir_env_var: false,
             exclude_slash_tmp: false,
+            read_access: Default::default(),
         })
         .expect("set sandbox policy");
 
diff --git a/codex-rs/windows-sandbox-rs/src/allow.rs b/codex-rs/windows-sandbox-rs/src/allow.rs
index 83d72f7e55..91f96e277e 100644
--- a/codex-rs/windows-sandbox-rs/src/allow.rs
+++ b/codex-rs/windows-sandbox-rs/src/allow.rs
@@ -111,6 +111,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: false,
             exclude_slash_tmp: false,
+        read_access: Default::default(),
         };
 
         let paths = compute_allow_paths(&policy, &command_cwd, &command_cwd, &HashMap::new());
@@ -137,6 +138,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: false,
+        read_access: Default::default(),
         };
         let mut env_map = HashMap::new();
         env_map.insert("TEMP".into(), temp_dir.to_string_lossy().to_string());
@@ -164,6 +166,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: false,
+        read_access: Default::default(),
         };
 
         let paths = compute_allow_paths(&policy, &command_cwd, &command_cwd, &HashMap::new());
@@ -191,6 +194,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: false,
+        read_access: Default::default(),
         };
 
         let paths = compute_allow_paths(&policy, &command_cwd, &command_cwd, &HashMap::new());
@@ -216,6 +220,7 @@ mod tests {
             network_access: false,
             exclude_tmpdir_env_var: true,
             exclude_slash_tmp: false,
+        read_access: Default::default(),
         };
 
         let paths = compute_allow_paths(&policy, &command_cwd, &command_cwd, &HashMap::new());
diff --git a/codex-rs/windows-sandbox-rs/src/elevated_impl.rs b/codex-rs/windows-sandbox-rs/src/elevated_impl.rs
index ecd5732c09..463e98efa6 100644
--- a/codex-rs/windows-sandbox-rs/src/elevated_impl.rs
+++ b/codex-rs/windows-sandbox-rs/src/elevated_impl.rs
@@ -472,6 +472,7 @@ mod windows_impl {
                 network_access,
                 exclude_tmpdir_env_var: false,
                 exclude_slash_tmp: false,
+                read_access: Default::default(),
             }
         }
 
diff --git a/codex-rs/windows-sandbox-rs/src/lib.rs b/codex-rs/windows-sandbox-rs/src/lib.rs
index 4a97efaaf8..e681a7819d 100644
--- a/codex-rs/windows-sandbox-rs/src/lib.rs
+++ b/codex-rs/windows-sandbox-rs/src/lib.rs
@@ -513,6 +513,7 @@ mod windows_impl {
                 network_access,
                 exclude_tmpdir_env_var: false,
                 exclude_slash_tmp: false,
+                read_access: Default::default(),
             }
         }
 
diff --git a/skyshield_base_policy.txt b/skyshield_base_policy.txt
new file mode 100644
index 0000000000..5fe713fe7b
--- /dev/null
+++ b/skyshield_base_policy.txt
@@ -0,0 +1,351 @@
+private func baseSandboxPolicy(
+  temporaryDirectory: URL,
+  allowedReadFolders: [URL],
+  allowedWriteFolders: [URL],
+  sandboxPolicyOptions: TinyskySandboxPolicyOptions?,
+) -> String {
+  // Sandbox policies require fully-resolved paths
+  var temporaryPath = temporaryDirectory.resolvingSymlinksInPath().path
+
+  // Per documentation, URL.resolveSymlinksInPath() strips /private from /var paths; we re-add it
+  if temporaryPath.hasPrefix("/var") {
+    temporaryPath = "/private" + temporaryDirectory.path
+  }
+
+  let allowedReadOnlyFolderRules = allowedReadOnlyFolderRules(for: allowedReadFolders)
+  let allowedWriteOnlyFolderRules = allowedWriteFolderRules(for: allowedWriteFolders)
+  let sandboxPolicyOptionsRules = rules(for: sandboxPolicyOptions) ?? ""
+
+  return """
+    (version 1)
+
+    ; inspired by Chrome's sandbox policy:
+    ; https://source.chromium.org/chromium/chromium/src/+/main:sandbox/policy/mac/common.sb;l=273-319;drc=7b3962fe2e5fc9e2ee58000dc8fbf3429d84d3bd
+    ; https://source.chromium.org/chromium/chromium/src/+/main:sandbox/policy/mac/renderer.sb;l=64;drc=7b3962fe2e5fc9e2ee58000dc8fbf3429d84d3bd
+
+    ; start with closed-by-default
+    (deny default)
+
+    ; Read access to standard system paths
+    (allow file-read* file-test-existence
+           (subpath "/Library/Apple")
+           (subpath "/Library/Filesystems/NetFSPlugins")
+           (subpath "/Library/Preferences/Logging")
+           (subpath "/System")
+           (literal "/private/var/db/DarwinDirectory/local/recordStore.data")
+           (subpath "/private/var/db/timezone")
+           (subpath "/usr/lib")
+           (subpath "/usr/share"))
+
+    ; Map system frameworks + dylibs
+    (allow file-map-executable
+           (subpath "/Library/Apple/System/Library/Frameworks")
+           (subpath "/Library/Apple/System/Library/PrivateFrameworks")
+           (subpath "/Library/Apple/usr/lib")
+           (subpath "/System/Library/Extensions")
+           (subpath "/System/Library/Frameworks")
+           (subpath "/System/Library/PrivateFrameworks")
+           (subpath "/System/Library/SubFrameworks")
+           (subpath "/System/iOSSupport/System/Library/Frameworks")
+           (subpath "/System/iOSSupport/System/Library/PrivateFrameworks")
+           (subpath "/System/iOSSupport/System/Library/SubFrameworks")
+           (subpath "/usr/lib"))
+
+    ; Allow guarded vnodes.
+    (allow system-mac-syscall (mac-policy-name "vnguard"))
+
+    ; Determine whether a container is expected.
+    (allow system-mac-syscall
+           (require-all
+             (mac-policy-name "Sandbox")
+             (mac-syscall-number 67)))
+
+    ; Allow resolution of standard system symlinks.
+    (allow file-read-metadata file-test-existence
+           (literal "/etc")
+           (literal "/tmp")
+           (literal "/var")
+           (literal "/private/etc/localtime"))
+
+    ; Allow stat'ing of path components of firmlink targets.
+    (allow file-read-metadata file-test-existence
+           (path-ancestors "/System/Volumes/Data/private"))
+
+    ; Allow processes to get their current working directory.
+    (allow file-read* file-test-existence
+           (literal "/"))
+
+    ; Allow FSIOC_CAS_BSDFLAGS as an alternate chflags(2).
+    (allow system-fsctl (fsctl-command FSIOC_CAS_BSDFLAGS))
+
+    ; Allow access to standard special files.
+    (allow file-read* file-test-existence
+           (literal "/dev/autofs_nowait")
+           (literal "/dev/random")
+           (literal "/dev/urandom")
+           (literal "/private/etc/master.passwd")
+           (literal "/private/etc/passwd")
+           (literal "/private/etc/protocols")
+           (literal "/private/etc/services"))
+
+    (allow file-read* file-test-existence file-write-data
+           (literal "/dev/null")
+           (literal "/dev/zero"))
+
+    ; Allow read/write access to the file descriptors.
+    (allow file-read-data file-test-existence file-write-data
+           (subpath "/dev/fd"))
+
+    (allow file-read* file-test-existence file-write-data file-ioctl
+           (literal "/dev/dtracehelper"))
+
+    ; Regulatory domain support
+    (allow file-read*
+           (literal "/private/var/db/eligibilityd/eligibility.plist"))
+
+    ; Allow IPC to standard system agents.
+    (allow network-outbound
+           (literal "/private/var/run/syslog"))
+
+    (allow ipc-posix-shm-read*
+           (ipc-posix-name "apple.shm.notification_center")
+           (ipc-posix-name-prefix "apple.cfprefs."))
+
+    (allow mach-lookup
+           (global-name "com.apple.analyticsd")
+           (global-name "com.apple.analyticsd.messagetracer")
+           (global-name "com.apple.appsleep")
+           (global-name "com.apple.bsd.dirhelper")
+           (global-name "com.apple.cfprefsd.agent")
+           (global-name "com.apple.cfprefsd.daemon")
+           (global-name "com.apple.diagnosticd")
+           (global-name "com.apple.dt.automationmode.reader")
+           (global-name "com.apple.espd")
+           (global-name "com.apple.logd")
+           (global-name "com.apple.logd.events")
+           (global-name "com.apple.runningboard")
+           (global-name "com.apple.secinitd")
+           (global-name "com.apple.system.DirectoryService.libinfo_v1")
+           (global-name "com.apple.system.logger")
+           (global-name "com.apple.system.notification_center")
+           (global-name "com.apple.system.opendirectoryd.libinfo")
+           (global-name "com.apple.system.opendirectoryd.membership")
+           (global-name "com.apple.trustd")
+           (global-name "com.apple.trustd.agent")
+           (global-name "com.apple.xpc.activity.unmanaged")
+           (local-name "com.apple.cfprefsd.agent"))
+
+    ; Allow mostly harmless operations.
+    (allow sysctl-read)
+    (allow sysctl-write
+           (sysctl-name "kern.grade_cputype"
+                        "kern.wq_limit_cooperative_threads"))
+
+    ; (system-graphics)
+    (define (system-graphics)
+      (allow user-preference-read
+             (preference-domain "com.apple.gpu")
+             (preference-domain "com.apple.opengl")
+             (preference-domain "com.nvidia.OpenGL"))
+      (allow mach-lookup
+             (global-name "com.apple.gpumemd.source"))
+      (allow mach-lookup
+             (global-name "com.apple.lsd.mapdb"))
+      (allow mach-lookup
+             (global-name "com.apple.CARenderServer")
+             (global-name "com.apple.CoreDisplay.master")
+             (global-name "com.apple.CoreDisplay.Notification"))
+      (allow mach-lookup
+             (global-name "com.apple.cvmsServ"))
+      (allow file-read*
+             (subpath "/private/var/db/CVMS"))
+      (allow iokit-open-service
+             (iokit-registry-entry-class "IOAccelerator"
+                                         "IOSurfaceRoot"))
+      (allow iokit-open-user-client
+             (iokit-connection "IOAccelerator")
+             (iokit-user-client-class "IOAccelerationUserClient"
+                                      "IOSurfaceAcceleratorClient"
+                                      "IOSurfaceRootUserClient"
+                                      "IOSurfaceSendRight"))
+      (allow iokit-open-service
+             (iokit-registry-entry-class "IOFramebuffer"))
+      (allow iokit-open-user-client
+             (iokit-user-client-class "IOFramebufferSharedUserClient"))
+      (allow iokit-open-service
+             (iokit-connection "AppleGraphicsDeviceControl"))
+      (allow iokit-open-user-client
+             (iokit-user-client-class "AppleIntelMEUserClient"
+                                      "AppleSNBFBUserClient"))
+      (allow iokit-open-service
+             (iokit-registry-entry-class "AGPM"
+                                         "AppleGraphicsControl"
+                                         "AppleGraphicsPolicy"))
+      (allow iokit-open-user-client
+             (iokit-user-client-class "AGPMClient"
+                                      "AppleGraphicsControlClient"
+                                      "AppleGraphicsPolicyClient"))
+      (allow iokit-open-user-client
+             (iokit-user-client-class "AppleMGPUPowerControlClient"))
+      (allow file-read* file-test-existence
+             (subpath "/Library/GPUBundles"))
+      (allow iokit-set-properties
+             (require-all
+               (iokit-connection "IODisplay")
+               (require-any
+                 (iokit-property "brightness"
+                                 "linear-brightness"
+                                 "commit"
+                                 "rgcs"
+                                 "ggcs"
+                                 "bgcs")))))
+
+    ; OOPJIT support
+    (define (oopjit-runner)
+      (allow file-read* file-map-executable file-write-unlink
+             (extension "com.apple.sandbox.oopjit")))
+
+    ; child processes inherit the policy of their parent
+    (allow process-exec)
+    (allow process-fork)
+    (allow signal (target same-sandbox))
+
+    ; Allow cf prefs to work.
+    (allow user-preference-read)
+
+    ; process-info
+    (allow process-info* (target same-sandbox))
+
+    (allow file-write-data
+      (require-all
+        (path "/dev/null")
+        (vnode-type CHARACTER-DEVICE)))
+
+    ; --- Allow reading the minimum system runtime so exec works ---
+    (allow file-read-data (subpath "/bin"))
+    (allow file-read-metadata (subpath "/bin"))
+    (allow file-read-data (subpath "/sbin"))
+    (allow file-read-metadata (subpath "/sbin"))
+    (allow file-read-data (subpath "/usr/bin"))
+    (allow file-read-metadata (subpath "/usr/bin"))
+    (allow file-read-data (subpath "/usr/sbin"))
+    (allow file-read-metadata (subpath "/usr/sbin"))
+    (allow file-read-data (subpath "/usr/libexec"))
+    (allow file-read-metadata (subpath "/usr/libexec"))
+
+    ; zsh system config
+    (allow file-read-data (literal "/etc/zshenv"))
+    (allow file-read-metadata (literal "/etc/zshenv"))
+    (allow file-read-data (literal "/etc/zprofile"))
+    (allow file-read-metadata (literal "/etc/zprofile"))
+    (allow file-read-data (literal "/etc/zlogin"))
+    (allow file-read-metadata (literal "/etc/zlogin"))
+
+    (allow file-read* (subpath "/Library/Preferences"))
+    (allow file-read* (subpath "/var/db"))
+    (allow file-read* (subpath "/private/var/db"))
+
+    ; dyld cache metadata outside /System
+    (allow file-read* (subpath "/private/var/db/dyld"))
+    (allow file-read* (subpath "/var/db/dyld"))
+
+    ; common 3rd-party dylib / framework locations
+    ; Homebrew
+    (allow file-read* (subpath "/opt/homebrew/lib"))
+    (allow file-read* (subpath "/usr/local/lib"))
+
+    ; App bundles
+    (allow file-read* (subpath "/Applications"))
+
+    ; terminal basics
+    (allow file-read*  (regex "^/dev/fd/(0|1|2)$"))
+    (allow file-write* (regex "^/dev/fd/(1|2)$"))
+    (allow file-read* file-write* (literal "/dev/null"))
+    (allow file-read* file-write* (literal "/dev/tty"))
+    (allow file-read-metadata (literal "/dev"))
+    (allow file-read-metadata (regex "^/dev/.*$"))
+    (allow file-read-metadata (literal "/dev/stdin"))
+    (allow file-read-metadata (literal "/dev/stdout"))
+    (allow file-read-metadata (literal "/dev/stderr"))
+    (allow file-read-metadata (regex "^/dev/tty[^/]*$"))
+    (allow file-read-metadata (regex "^/dev/pty[^/]*$"))
+    (allow file-read* file-write* (regex "^/dev/ttys[0-9]+$"))
+    (allow file-read* file-write* (literal "/dev/ptmx"))
+
+    ; scratch space (so tools can create temp files)
+    (allow file-read* file-write* (subpath "/tmp"))
+    (allow file-read* file-write* (subpath "/private/tmp"))
+    (allow file-read* file-write* (subpath "/var/tmp"))
+    (allow file-read* file-write* (subpath "/private/var/tmp"))
+
+    (allow file-read* (subpath "/etc"))
+    (allow file-read* (subpath "/private/etc"))
+
+    ; Some processes read /var metadata during startup
+    (allow file-read-metadata (subpath "/var"))
+    (allow file-read-metadata (subpath "/private/var"))
+
+    ; IOKit
+    (allow iokit-open
+      (iokit-registry-entry-class "RootDomainUserClient")
+    )
+
+    ; needed to look up user info, see https://crbug.com/792228
+    (allow mach-lookup
+      (global-name "com.apple.system.opendirectoryd.libinfo")
+    )
+
+    ; Unified logging (os_log) needs logd
+    (allow mach-lookup
+      (global-name-prefix "com.apple.logd")
+      (global-name "com.apple.system.logger")
+    )
+
+    ; Diagnostics daemon (sometimes queried on startup)
+    (allow mach-lookup
+      (global-name "com.apple.diagnosticd")
+      (global-name-prefix "com.apple.diagnosticd")
+    )
+
+    ; Needed for python multiprocessing on MacOS for the SemLock
+    (allow ipc-posix-sem)
+
+    (allow mach-lookup
+      (global-name "com.apple.PowerManagement.control")
+    )
+
+    ; allow openpty()
+    (allow pseudo-tty)
+    (allow file-read* file-write* file-ioctl (literal "/dev/ptmx"))
+    (allow file-read* file-write*
+      (require-all
+        (regex #"^/dev/ttys[0-9]+")))
+    ; PTYs created before entering seatbelt may lack the extension; allow ioctl
+    ; on those slave ttys so interactive shells detect a TTY and remain functional.
+    (allow file-ioctl (regex #"^/dev/ttys[0-9]+"))
+
+    (allow mach-lookup (global-name "com.apple.audio.audiohald"))
+    (allow mach-lookup (global-name "com.apple.audio.AudioComponentRegistrar"))
+    (allow file-read-data (subpath "/etc"))
+    (allow file-read-metadata (subpath "/etc"))
+    (allow file-read-data (subpath "/usr"))
+    (allow file-read-metadata (subpath "/usr"))
+
+    ; allow metadata traversal for firmlink parents
+    (allow file-read-metadata (literal "/System/Volumes") (vnode-type DIRECTORY))
+    (allow file-read-metadata (literal "/System/Volumes/Data") (vnode-type DIRECTORY))
+    (allow file-read-metadata (literal "/System/Volumes/Data/Users") (vnode-type DIRECTORY))
+
+    \(allowedReadOnlyFolderRules)
+    \(allowedWriteOnlyFolderRules)
+    \(sandboxPolicyOptionsRules)
+    (allow file-read* file-write* (subpath "\(temporaryPath)"))
+
+    (allow mach-lookup (global-name "\(SkyShieldCommandProxyIPCServer.messagePortName)"))
+    (allow mach-lookup (global-name "\(SkyShieldSandboxExtensionIPCServer.messagePortName)"))
+
+    ; Allow app-sandbox file extensions to grant access
+    (allow file-read* (extension "com.apple.app-sandbox.read"))
+    (allow file-read* file-write* (extension "com.apple.app-sandbox.read-write"))
+    """
+}