agentclientprotocol · fscarponi · Feb 19, 2026
@@ -22,6 +22,7 @@ unstable = [
     "unstable_session_model",
     "unstable_session_resume",
     "unstable_session_usage",
+    "unstable_boolean_config",
 ]
 unstable_cancel_request = []
 unstable_session_fork = []
@@ -30,6 +31,7 @@ unstable_session_list = []
 unstable_session_model = []
 unstable_session_resume = []
 unstable_session_usage = []
+unstable_boolean_config = []
 
 [[bin]]
 name = "generate"

@@ -720,8 +720,9 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/exte
 <ResponseField name="sessionId" type={<a href="#sessionid">SessionId</a>} required>
   The ID of the session to set the configuration option for.
 </ResponseField>
-<ResponseField name="value" type={<a href="#sessionconfigvalueid">SessionConfigValueId</a>} required>
-  The ID of the configuration option value to set.
+<ResponseField name="value" type={<a href="#sessionconfigoptionvalue">SessionConfigOptionValue</a>} required>
+  The value to set. For `select` options, this is a `SessionConfigValueId` string.
+For `boolean` options, this is a boolean.
 </ResponseField>
 
 #### <span class="font-mono">SetSessionConfigOptionResponse</span>
@@ -2969,6 +2970,22 @@ Whether the agent supports `session/resume`.
 
 </ResponseField>
 
+## <span class="font-mono">SessionConfigBoolean</span>
+
+**UNSTABLE**
+
+This capability is not part of the spec yet, and may be removed or changed at any point.
+
+A boolean on/off toggle session configuration option payload.
+
+**Type:** Object
+
+**Properties:**
+
+<ResponseField name="currentValue" type={"boolean"} required>
+  The current value of the boolean option.
+</ResponseField>
+
 ## <span class="font-mono">SessionConfigGroupId</span>
 
 Unique identifier for a session configuration option value group.
@@ -3011,6 +3028,23 @@ Single-value selector (dropdown).
 </Expandable>
 </ResponseField>
 
+<ResponseField name="boolean" type="object">
+**UNSTABLE**
+
+This capability is not part of the spec yet, and may be removed or changed at any point.
+
+Boolean on/off toggle.
+
+<Expandable title="Properties">
+
+<ResponseField name="currentValue" type={"boolean"} required>
+  The current value of the boolean option.
+</ResponseField>
+<ResponseField name="type" type={"string"} required></ResponseField>
+
+</Expandable>
+</ResponseField>
+
 ## <span class="font-mono">SessionConfigOptionCategory</span>
 
 Semantic category for a session configuration option.
@@ -3041,6 +3075,23 @@ Category names that do not begin with `_` are reserved for the ACP spec.
   Unknown / uncategorized selector.
 </ResponseField>
 
+## <span class="font-mono">SessionConfigOptionValue</span>
+
+The value to set for a session configuration option.
+
+For `select` options, the value is a `SessionConfigValueId` string.
+For `boolean` options, the value is a boolean.
+
+**Type:** Union
+
+<ResponseField name="String">
+  A string value (used by `select` options).
+</ResponseField>
+
+<ResponseField name="Bool" type="boolean">
+  A boolean value (used by `boolean` options).
+</ResponseField>
+
 ## <span class="font-mono">SessionConfigSelect</span>
 
 A single-value selector (dropdown) session configuration option payload.

@@ -448,8 +448,9 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/exte
 <ResponseField name="sessionId" type={<a href="#sessionid">SessionId</a>} required>
   The ID of the session to set the configuration option for.
 </ResponseField>
-<ResponseField name="value" type={<a href="#sessionconfigvalueid">SessionConfigValueId</a>} required>
-  The ID of the configuration option value to set.
+<ResponseField name="value" type={<a href="#sessionconfigoptionvalue">SessionConfigOptionValue</a>} required>
+  The value to set. For `select` options, this is a `SessionConfigValueId` string.
+For `boolean` options, this is a boolean.
 </ResponseField>
 
 #### <span class="font-mono">SetSessionConfigOptionResponse</span>
@@ -2559,6 +2560,23 @@ Category names that do not begin with `_` are reserved for the ACP spec.
   Unknown / uncategorized selector.
 </ResponseField>
 
+## <span class="font-mono">SessionConfigOptionValue</span>
+
+The value to set for a session configuration option.
+
+For `select` options, the value is a `SessionConfigValueId` string.
+For `boolean` options, the value is a boolean.
+
+**Type:** Union
+
+<ResponseField name="String">
+  A string value (used by `select` options).
+</ResponseField>
+
+<ResponseField name="Bool" type="boolean">
+  A boolean value (used by `boolean` options).
+</ResponseField>
+
 ## <span class="font-mono">SessionConfigSelect</span>
 
 A single-value selector (dropdown) session configuration option payload.

@@ -61,6 +61,13 @@ During [Session Setup](./session-setup) the Agent **MAY** return a list of confi
             "description": "The most powerful model"
           }
         ]
+      },
+      {
+        "id": "brave_mode",
+        "name": "Brave Mode",
+        "description": "Skip confirmation prompts and act autonomously",
+        "type": "boolean",
+        "currentValue": false
       }
     ]
   }
@@ -93,9 +100,13 @@ During [Session Setup](./session-setup) the Agent **MAY** return a list of confi
 </ResponseField>
 
 <ResponseField name="type" type="ConfigOptionType" required>
-  The type of input control. Currently only `select` is supported.
+  The type of input control. Supported types are `select` and `boolean`.
 </ResponseField>
 
+### Select Options
+
+When `type` is `select`, the following fields are used:
+
 <ResponseField name="currentValue" type="string" required>
   The currently selected value for this option
 </ResponseField>
@@ -104,6 +115,16 @@ During [Session Setup](./session-setup) the Agent **MAY** return a list of confi
   The available values for this option
 </ResponseField>
 
+### Boolean Options
+
+When `type` is `boolean`, the following fields are used:
+
+<ResponseField name="currentValue" type="boolean" required>
+  The current boolean state of the option (`true` for on, `false` for off)
+</ResponseField>
+
+Boolean options are intended for simple on/off toggles such as "Brave Mode", "Produce Report", or "Read Only". Clients **SHOULD** render them as toggle switches or checkboxes.
+
 ### ConfigOptionValue
 
 <ResponseField name="value" type="string" required>
@@ -186,9 +207,10 @@ Clients can change a config option value by calling the `session/set_config_opti
   The `id` of the configuration option to change
 </ParamField>
 
-<ParamField path="value" type="string" required>
-  The new value to set. Must be one of the values listed in the option's
-  `options` array.
+<ParamField path="value" type="string | boolean" required>
+  The new value to set. For `select` options, this must be one of the values
+  listed in the option's `options` array. For `boolean` options, this must be a
+  boolean (`true` or `false`).
 </ParamField>
 
 The Agent **MUST** respond with the complete list of all configuration options and their current values:

@@ -2333,6 +2333,25 @@
       ],
       "description": "Semantic category for a session configuration option.\n\nThis is intended to help Clients distinguish broadly common selectors (e.g. model selector vs\nsession mode selector vs thought/reasoning level) for UX purposes (keyboard shortcuts, icons,\nplacement). It MUST NOT be required for correctness. Clients MUST handle missing or unknown\ncategories gracefully.\n\nCategory names beginning with `_` are free for custom use, like other ACP extension methods.\nCategory names that do not begin with `_` are reserved for the ACP spec."
     },
+    "SessionConfigOptionValue": {
+      "anyOf": [
+        {
+          "allOf": [
+            {
+              "$ref": "#/$defs/SessionConfigValueId"
+            }
+          ],
+          "description": "A string value (used by `select` options).",
+          "title": "String"
+        },
+        {
+          "description": "A boolean value (used by `boolean` options).",
+          "title": "Bool",
+          "type": "boolean"
+        }
+      ],
+      "description": "The value to set for a session configuration option.\n\nFor `select` options, the value is a `SessionConfigValueId` string.\nFor `boolean` options, the value is a boolean."
+    },
     "SessionConfigSelect": {
       "description": "A single-value selector (dropdown) session configuration option payload.",
       "properties": {
@@ -2705,10 +2724,10 @@
         "value": {
           "allOf": [
             {
-              "$ref": "#/$defs/SessionConfigValueId"
+              "$ref": "#/$defs/SessionConfigOptionValue"
             }
           ],
-          "description": "The ID of the configuration option value to set."
+          "description": "The value to set. For `select` options, this is a `SessionConfigValueId` string.\nFor `boolean` options, this is a boolean."
         }
       },
       "required": ["sessionId", "configId", "value"],

@@ -2656,6 +2656,17 @@
       },
       "type": "object"
     },
+    "SessionConfigBoolean": {
+      "description": "**UNSTABLE**\n\nThis capability is not part of the spec yet, and may be removed or changed at any point.\n\nA boolean on/off toggle session configuration option payload.",
+      "properties": {
+        "currentValue": {
+          "description": "The current value of the boolean option.",
+          "type": "boolean"
+        }
+      },
+      "required": ["currentValue"],
+      "type": "object"
+    },
     "SessionConfigGroupId": {
       "description": "Unique identifier for a session configuration option value group.",
       "type": "string"
@@ -2685,6 +2696,22 @@
           },
           "required": ["type"],
           "type": "object"
+        },
+        {
+          "allOf": [
+            {
+              "$ref": "#/$defs/SessionConfigBoolean"
+            }
+          ],
+          "description": "**UNSTABLE**\n\nThis capability is not part of the spec yet, and may be removed or changed at any point.\n\nBoolean on/off toggle.",
+          "properties": {
+            "type": {
+              "const": "boolean",
+              "type": "string"
+            }
+          },
+          "required": ["type"],
+          "type": "object"
         }
       ],
       "properties": {
@@ -2749,6 +2776,25 @@
       ],
       "description": "Semantic category for a session configuration option.\n\nThis is intended to help Clients distinguish broadly common selectors (e.g. model selector vs\nsession mode selector vs thought/reasoning level) for UX purposes (keyboard shortcuts, icons,\nplacement). It MUST NOT be required for correctness. Clients MUST handle missing or unknown\ncategories gracefully.\n\nCategory names beginning with `_` are free for custom use, like other ACP extension methods.\nCategory names that do not begin with `_` are reserved for the ACP spec."
     },
+    "SessionConfigOptionValue": {
+      "anyOf": [
+        {
+          "allOf": [
+            {
+              "$ref": "#/$defs/SessionConfigValueId"
+            }
+          ],
+          "description": "A string value (used by `select` options).",
+          "title": "String"
+        },
+        {
+          "description": "A boolean value (used by `boolean` options).",
+          "title": "Bool",
+          "type": "boolean"
+        }
+      ],
+      "description": "The value to set for a session configuration option.\n\nFor `select` options, the value is a `SessionConfigValueId` string.\nFor `boolean` options, the value is a boolean."
+    },
     "SessionConfigSelect": {
       "description": "A single-value selector (dropdown) session configuration option payload.",
       "properties": {
@@ -3264,10 +3310,10 @@
         "value": {
           "allOf": [
             {
-              "$ref": "#/$defs/SessionConfigValueId"
+              "$ref": "#/$defs/SessionConfigOptionValue"
             }
           ],
-          "description": "The ID of the configuration option value to set."
+          "description": "The value to set. For `select` options, this is a `SessionConfigValueId` string.\nFor `boolean` options, this is a boolean."
         }
       },
       "required": ["sessionId", "configId", "value"],