Complete the child-customization model (per-child enable/disable + invocation matrix)

CHANGELOG.md

@@ -27,6 +27,23 @@ changes accumulate. Track in-flight protocol changes via PRs touching
 
 Spec version: `0.5.2`
 
+### Added
+
+- Optional `enabled` flag on the child customizations (`AgentCustomization`,
+  `SkillCustomization`, `PromptCustomization`, `RuleCustomization`,
+  `HookCustomization`) so an individual child can be turned off independently of
+  its container; absent means enabled.
+- `disableUserInvocation` on `SkillCustomization`, plus `disableModelInvocation`
+  and `disableUserInvocation` on `AgentCustomization`, giving custom agents and
+  skills a symmetric user/model invocation matrix.
+
+### Changed
+
+- `session/customizationToggled` now targets any top-level customization
+  (`plugin`, `directory`, or top-level `mcpServer`) or an individual child by
+  `id` and sets that entry's `enabled`; the effective state of a child is
+  `container.enabled && (child.enabled ?? true)`.
+
 ## [0.5.1] — 2026-07-02
 
 Spec version: `0.5.1`

clients/go/CHANGELOG.md

@@ -14,6 +14,24 @@ tag whose matching `## [X.Y.Z]` heading is missing from this file.
 
 ## [Unreleased]
 
+## [0.5.2] — Unreleased
+
+Implements AHP 0.5.2.
+
+### Added
+
+- Optional `Enabled` field on the child customization types
+  (`AgentCustomization`, `SkillCustomization`, `PromptCustomization`,
+  `RuleCustomization`, `HookCustomization`).
+- `DisableUserInvocation` on `SkillCustomization`, plus `DisableModelInvocation`
+  and `DisableUserInvocation` on `AgentCustomization`.
+
+### Changed
+
+- The `session/customizationToggled` reducer now toggles any top-level
+  customization (`plugin`, `directory`, or top-level `mcpServer`) or an
+  individual child by `id`, setting that entry's `Enabled`.
+
 ## [0.5.1] — 2026-07-02
 
 Implements AHP 0.5.1.

clients/go/ahp/reducers.go

@@ -324,6 +324,23 @@ func setContainerEnabled(c *ahptypes.Customization, enabled bool) {
 	}
 }
 
+func setChildEnabled(c *ahptypes.ChildCustomization, enabled bool) {
+	switch v := c.Value.(type) {
+	case *ahptypes.AgentCustomization:
+		v.Enabled = &enabled
+	case *ahptypes.SkillCustomization:
+		v.Enabled = &enabled
+	case *ahptypes.PromptCustomization:
+		v.Enabled = &enabled
+	case *ahptypes.RuleCustomization:
+		v.Enabled = &enabled
+	case *ahptypes.HookCustomization:
+		v.Enabled = &enabled
+	case *ahptypes.McpServerCustomization:
+		v.Enabled = enabled
+	}
+}
+
 func applyToggle(list []ahptypes.Customization, id string, enabled bool) bool {
 	for i := range list {
 		got, ok := customizationID(list[i])
@@ -332,6 +349,19 @@ func applyToggle(list []ahptypes.Customization, id string, enabled bool) bool {
 			return true
 		}
 	}
+	for i := range list {
+		children := containerChildren(&list[i])
+		if children == nil {
+			continue
+		}
+		for j := range *children {
+			got, ok := childCustomizationID((*children)[j])
+			if ok && got == id {
+				setChildEnabled(&(*children)[j], enabled)
+				return true
+			}
+		}
+	}
 	return false
 }
 

clients/go/ahptypes/actions.generated.go

@@ -824,17 +824,21 @@ type SessionCustomizationsChangedAction struct {
 	Customizations []Customization `json:"customizations"`
 }
 
-// A client toggled a container customization on or off.
-//
-// Targets a top-level container (plugin or directory) by `id`. Only
-// containers have an `enabled` flag; children are always active when
-// their container is enabled. Is a no-op when no matching container is
-// found.
+// A client toggled a customization on or off.
+//
+// Matches `id` against every top-level customization first — a plugin or
+// directory container, or a bare top-level MCP server — then against the
+// children inside each container (a skill, agent, or other entry), and
+// sets the matched entry's `enabled` flag. Disabling a container still
+// disables all of its children — the effective state of a child is
+// `container.enabled && (child.enabled ?? true)` — so toggling a child
+// only matters while its container is enabled. Is a no-op when no
+// customization has the given `id`.
 type SessionCustomizationToggledAction struct {
 	Type ActionType `json:"type"`
-	// The id of the container to toggle.
+	// The id of the container or child to toggle.
 	Id string `json:"id"`
-	// Whether to enable or disable the container.
+	// Whether to enable or disable the targeted customization.
 	Enabled bool `json:"enabled"`
 }
 

clients/go/ahptypes/state.generated.go

@@ -2206,8 +2206,20 @@ type AgentCustomization struct {
 	// customization is a subset of a larger file (for example, one entry
 	// in an inline `mcpServers` block of a `plugins.json` manifest).
 	// Absent when the customization covers the whole resource.
-	Range *TextRange        `json:"range,omitempty"`
-	Type  CustomizationType `json:"type"`
+	Range *TextRange `json:"range,omitempty"`
+	// Whether this child is individually enabled. Absent means enabled, so a
+	// producer only needs to set it to surface a child that exists but is
+	// turned off on its own.
+	//
+	// This flag is independent of the parent container's: the **effective**
+	// enabled state of a child is
+	// `container.enabled && (child.enabled ?? true)`, so a disabled container
+	// disables every child regardless of each child's own flag.
+	//
+	// A child is turned on or off by id with
+	// {@link SessionCustomizationToggledAction | `session/customizationToggled`}.
+	Enabled *bool             `json:"enabled,omitempty"`
+	Type    CustomizationType `json:"type"`
 	// Short description of what the agent specializes in and when to
 	// invoke it. Sourced from the agent file's frontmatter `description`.
 	Description *string `json:"description,omitempty"`
@@ -2223,6 +2235,14 @@ type AgentCustomization struct {
 	// field rather than sending an empty array, so an empty list carries no
 	// meaning distinct from absence.
 	Tools []string `json:"tools,omitempty"`
+	// When `true`, the agent will not auto-delegate to this custom agent
+	// as a sub-agent; it can only be selected by the user. Absent or
+	// `false` means the agent may delegate to it.
+	DisableModelInvocation *bool `json:"disableModelInvocation,omitempty"`
+	// When `true`, the user cannot select this custom agent (for example,
+	// in a picker); it remains available for the agent to auto-delegate
+	// to. Absent or `false` means the user may select it.
+	DisableUserInvocation *bool `json:"disableUserInvocation,omitempty"`
 	// Additional provider-specific metadata for this custom agent.
 	//
 	// Mirrors the MCP `_meta` convention.
@@ -2256,15 +2276,31 @@ type SkillCustomization struct {
 	// customization is a subset of a larger file (for example, one entry
 	// in an inline `mcpServers` block of a `plugins.json` manifest).
 	// Absent when the customization covers the whole resource.
-	Range *TextRange        `json:"range,omitempty"`
-	Type  CustomizationType `json:"type"`
+	Range *TextRange `json:"range,omitempty"`
+	// Whether this child is individually enabled. Absent means enabled, so a
+	// producer only needs to set it to surface a child that exists but is
+	// turned off on its own.
+	//
+	// This flag is independent of the parent container's: the **effective**
+	// enabled state of a child is
+	// `container.enabled && (child.enabled ?? true)`, so a disabled container
+	// disables every child regardless of each child's own flag.
+	//
+	// A child is turned on or off by id with
+	// {@link SessionCustomizationToggledAction | `session/customizationToggled`}.
+	Enabled *bool             `json:"enabled,omitempty"`
+	Type    CustomizationType `json:"type"`
 	// Short description used for help text and auto-invocation matching.
 	// Sourced from the skill's frontmatter `description`.
 	Description *string `json:"description,omitempty"`
 	// When `true`, only the user can invoke this skill — the agent will not
 	// auto-invoke it. Sourced from the command skill's frontmatter
 	// `disable-model-invocation` flag.
 	DisableModelInvocation *bool `json:"disableModelInvocation,omitempty"`
+	// When `true`, the user cannot directly invoke this skill (for example,
+	// as a slash command); it remains available for the agent to
+	// auto-invoke. Absent or `false` means the user may invoke it.
+	DisableUserInvocation *bool `json:"disableUserInvocation,omitempty"`
 }
 
 // A prompt contributed by a plugin or directory.
@@ -2289,8 +2325,20 @@ type PromptCustomization struct {
 	// customization is a subset of a larger file (for example, one entry
 	// in an inline `mcpServers` block of a `plugins.json` manifest).
 	// Absent when the customization covers the whole resource.
-	Range *TextRange        `json:"range,omitempty"`
-	Type  CustomizationType `json:"type"`
+	Range *TextRange `json:"range,omitempty"`
+	// Whether this child is individually enabled. Absent means enabled, so a
+	// producer only needs to set it to surface a child that exists but is
+	// turned off on its own.
+	//
+	// This flag is independent of the parent container's: the **effective**
+	// enabled state of a child is
+	// `container.enabled && (child.enabled ?? true)`, so a disabled container
+	// disables every child regardless of each child's own flag.
+	//
+	// A child is turned on or off by id with
+	// {@link SessionCustomizationToggledAction | `session/customizationToggled`}.
+	Enabled *bool             `json:"enabled,omitempty"`
+	Type    CustomizationType `json:"type"`
 	// Short description of what the prompt does.
 	Description *string `json:"description,omitempty"`
 }
@@ -2325,8 +2373,20 @@ type RuleCustomization struct {
 	// customization is a subset of a larger file (for example, one entry
 	// in an inline `mcpServers` block of a `plugins.json` manifest).
 	// Absent when the customization covers the whole resource.
-	Range *TextRange        `json:"range,omitempty"`
-	Type  CustomizationType `json:"type"`
+	Range *TextRange `json:"range,omitempty"`
+	// Whether this child is individually enabled. Absent means enabled, so a
+	// producer only needs to set it to surface a child that exists but is
+	// turned off on its own.
+	//
+	// This flag is independent of the parent container's: the **effective**
+	// enabled state of a child is
+	// `container.enabled && (child.enabled ?? true)`, so a disabled container
+	// disables every child regardless of each child's own flag.
+	//
+	// A child is turned on or off by id with
+	// {@link SessionCustomizationToggledAction | `session/customizationToggled`}.
+	Enabled *bool             `json:"enabled,omitempty"`
+	Type    CustomizationType `json:"type"`
 	// Description of what the rule enforces.
 	Description *string `json:"description,omitempty"`
 	// When `true`, the rule is always active (subject to `globs` if any).
@@ -2360,8 +2420,20 @@ type HookCustomization struct {
 	// customization is a subset of a larger file (for example, one entry
 	// in an inline `mcpServers` block of a `plugins.json` manifest).
 	// Absent when the customization covers the whole resource.
-	Range *TextRange        `json:"range,omitempty"`
-	Type  CustomizationType `json:"type"`
+	Range *TextRange `json:"range,omitempty"`
+	// Whether this child is individually enabled. Absent means enabled, so a
+	// producer only needs to set it to surface a child that exists but is
+	// turned off on its own.
+	//
+	// This flag is independent of the parent container's: the **effective**
+	// enabled state of a child is
+	// `container.enabled && (child.enabled ?? true)`, so a disabled container
+	// disables every child regardless of each child's own flag.
+	//
+	// A child is turned on or off by id with
+	// {@link SessionCustomizationToggledAction | `session/customizationToggled`}.
+	Enabled *bool             `json:"enabled,omitempty"`
+	Type    CustomizationType `json:"type"`
 }
 
 // An MCP server contributed by a plugin or directory.

clients/kotlin/CHANGELOG.md

@@ -15,6 +15,24 @@ versions (`*-SNAPSHOT`) are explicitly rejected by the publish pipeline; bump
 
 ## [Unreleased]
 
+## [0.5.2] — Unreleased
+
+Implements AHP 0.5.2.
+
+### Added
+
+- Optional `enabled` field on the child customization types
+  (`AgentCustomization`, `SkillCustomization`, `PromptCustomization`,
+  `RuleCustomization`, `HookCustomization`).
+- `disableUserInvocation` on `SkillCustomization`, plus `disableModelInvocation`
+  and `disableUserInvocation` on `AgentCustomization`.
+
+### Changed
+
+- The `session/customizationToggled` reducer now toggles any top-level
+  customization (`plugin`, `directory`, or top-level `mcpServer`) or an
+  individual child by `id`, setting that entry's `enabled`.
+
 ## [0.5.1] — 2026-07-02
 
 Implements AHP 0.5.1.

clients/kotlin/src/main/kotlin/com/microsoft/agenthostprotocol/Reducers.kt

@@ -235,6 +235,16 @@ private fun withCustomizationEnabled(c: Customization, enabled: Boolean): Custom
     is CustomizationUnknown -> c
 }
 
+private fun withChildCustomizationEnabled(c: ChildCustomization, enabled: Boolean): ChildCustomization = when (c) {
+    is ChildCustomizationAgent -> ChildCustomizationAgent(c.value.copy(enabled = enabled))
+    is ChildCustomizationSkill -> ChildCustomizationSkill(c.value.copy(enabled = enabled))
+    is ChildCustomizationPrompt -> ChildCustomizationPrompt(c.value.copy(enabled = enabled))
+    is ChildCustomizationRule -> ChildCustomizationRule(c.value.copy(enabled = enabled))
+    is ChildCustomizationHook -> ChildCustomizationHook(c.value.copy(enabled = enabled))
+    is ChildCustomizationMcpServer -> ChildCustomizationMcpServer(c.value.copy(enabled = enabled))
+    is ChildCustomizationUnknown -> c
+}
+
 private fun childCustomizationId(c: ChildCustomization): String? = when (c) {
     is ChildCustomizationAgent -> c.value.id
     is ChildCustomizationSkill -> c.value.id
@@ -597,10 +607,22 @@ public fun sessionReducer(state: SessionState, action: StateAction): SessionStat
         val list = state.customizations
         if (list == null) state else {
             val idx = list.indexOfFirst { customizationId(it) == a.id }
-            if (idx < 0) state else {
+            if (idx >= 0) {
                 val updated = list.toMutableList()
                 updated[idx] = withCustomizationEnabled(updated[idx], a.enabled)
                 state.copy(customizations = updated)
+            } else run {
+                for (i in list.indices) {
+                    val children = customizationChildren(list[i]) ?: continue
+                    val childIdx = children.indexOfFirst { childCustomizationId(it) == a.id }
+                    if (childIdx < 0) continue
+                    val newChildren = children.toMutableList()
+                    newChildren[childIdx] = withChildCustomizationEnabled(newChildren[childIdx], a.enabled)
+                    val updated = list.toMutableList()
+                    updated[i] = withCustomizationChildren(list[i], newChildren)
+                    return@run state.copy(customizations = updated)
+                }
+                state
             }
         }
     }

clients/kotlin/src/main/kotlin/com/microsoft/agenthostprotocol/generated/Actions.generated.kt

@@ -915,11 +915,11 @@ data class SessionCustomizationsChangedAction(
 data class SessionCustomizationToggledAction(
     val type: ActionType,
     /**
-     * The id of the container to toggle.
+     * The id of the container or child to toggle.
      */
     val id: String,
     /**
-     * Whether to enable or disable the container.
+     * Whether to enable or disable the targeted customization.
      */
     val enabled: Boolean
 )