sessions: add session-level inputNeeded aggregate

CHANGELOG.md

@@ -32,6 +32,18 @@ changes accumulate. Track in-flight protocol changes via PRs touching
 - `JsonPrimitive` type alias (`string | number | boolean | null`) in `types/common/state.ts`.
 - `session/activeClientRemoved` action to release a single active client from a
   session by `clientId`.
+- `SessionState.inputNeeded` — a session-level aggregate of outstanding input
+  requests across all chats, so a client can discover and answer elicitations,
+  tool confirmations, and client-tool execution requests from the session
+  channel without subscribing to individual chats. Each entry
+  (`SessionChatInputRequest`, `SessionToolConfirmationRequest`,
+  `SessionToolClientExecutionRequest`, unioned as `SessionInputRequest`) carries
+  the owning chat URI plus the identifiers needed to respond.
+- `session/inputNeededSet` and `session/inputNeededRemoved` actions for the host
+  to upsert and remove `SessionState.inputNeeded` entries.
+- `ToolCallConfirmationState` union (`ToolCallPendingConfirmationState |
+  ToolCallPendingResultConfirmationState`) for the tool call carried by
+  `SessionToolConfirmationRequest`.
 
 ### Changed
 

clients/go/CHANGELOG.md

@@ -22,6 +22,13 @@ tag whose matching `## [X.Y.Z]` heading is missing from this file.
   lightweight session-list presentation hints.
 - `SessionActiveClientRemovedAction` (wire `session/activeClientRemoved`) to
   release a single active client by `ClientId`.
+- `SessionState.InputNeeded` — a session-level aggregate of outstanding input
+  requests across all chats (`SessionInputRequest` union with
+  `SessionChatInputRequest`, `SessionToolConfirmationRequest`, and
+  `SessionToolClientExecutionRequest`), plus the `SessionInputNeededSetAction`
+  (wire `session/inputNeededSet`) and `SessionInputNeededRemovedAction` (wire
+  `session/inputNeededRemoved`) actions and the `ToolCallConfirmationState`
+  union.
 
 ### Changed
 

clients/go/ahp/reducers.go

@@ -263,6 +263,18 @@ func customizationID(c ahptypes.Customization) (string, bool) {
 	return "", false
 }
 
+func sessionInputRequestID(r ahptypes.SessionInputRequest) (string, bool) {
+	switch v := r.Value.(type) {
+	case *ahptypes.SessionChatInputRequest:
+		return v.Id, true
+	case *ahptypes.SessionToolConfirmationRequest:
+		return v.Id, true
+	case *ahptypes.SessionToolClientExecutionRequest:
+		return v.Id, true
+	}
+	return "", false
+}
+
 func childCustomizationID(c ahptypes.ChildCustomization) (string, bool) {
 	switch v := c.Value.(type) {
 	case *ahptypes.AgentCustomization:
@@ -743,6 +755,27 @@ func ApplyActionToSession(state *ahptypes.SessionState, action ahptypes.StateAct
 			}
 		}
 		return ReduceOutcomeNoOp
+	case *ahptypes.SessionInputNeededSetAction:
+		id, ok := sessionInputRequestID(a.Request)
+		if !ok {
+			return ReduceOutcomeNoOp
+		}
+		for i := range state.InputNeeded {
+			if got, ok := sessionInputRequestID(state.InputNeeded[i]); ok && got == id {
+				state.InputNeeded[i] = a.Request
+				return ReduceOutcomeApplied
+			}
+		}
+		state.InputNeeded = append(state.InputNeeded, a.Request)
+		return ReduceOutcomeApplied
+	case *ahptypes.SessionInputNeededRemovedAction:
+		for i := range state.InputNeeded {
+			if got, ok := sessionInputRequestID(state.InputNeeded[i]); ok && got == a.Id {
+				state.InputNeeded = append(state.InputNeeded[:i], state.InputNeeded[i+1:]...)
+				return ReduceOutcomeApplied
+			}
+		}
+		return ReduceOutcomeNoOp
 	case *ahptypes.SessionCustomizationsChangedAction:
 		state.Customizations = append([]ahptypes.Customization(nil), a.Customizations...)
 		return ReduceOutcomeApplied

clients/go/ahptypes/actions.generated.go

@@ -48,6 +48,8 @@ const (
 	ActionTypeSessionServerToolsChanged         ActionType = "session/serverToolsChanged"
 	ActionTypeSessionActiveClientSet            ActionType = "session/activeClientSet"
 	ActionTypeSessionActiveClientRemoved        ActionType = "session/activeClientRemoved"
+	ActionTypeSessionInputNeededSet             ActionType = "session/inputNeededSet"
+	ActionTypeSessionInputNeededRemoved         ActionType = "session/inputNeededRemoved"
 	ActionTypeChatPendingMessageSet             ActionType = "chat/pendingMessageSet"
 	ActionTypeChatPendingMessageRemoved         ActionType = "chat/pendingMessageRemoved"
 	ActionTypeChatQueuedMessagesReordered       ActionType = "chat/queuedMessagesReordered"
@@ -754,6 +756,38 @@ type SessionActiveClientRemovedAction struct {
 	ClientId string `json:"clientId"`
 }
 
+// A session-level input request was added or updated.
+//
+// Upsert semantics keyed by {@link SessionInputRequest.id | `request.id`}: the
+// host dispatches this with the full {@link SessionInputRequest} to append a new
+// entry to {@link SessionState.inputNeeded} or replace the existing entry with
+// the same `id`.
+//
+// Server-originated: the host mirrors chat-level requests (elicitations, tool
+// confirmations, client-tool executions) into the session aggregate so clients
+// subscribed only to the session channel can discover them. Clients respond by
+// dispatching the ordinary `chat/*` action to the entry's `chat` channel — see
+// {@link SessionInputRequest}.
+type SessionInputNeededSetAction struct {
+	Type ActionType `json:"type"`
+	// The input request to add or update, matched by `id`.
+	Request SessionInputRequest `json:"request"`
+}
+
+// A session-level input request was removed.
+//
+// Removes the entry identified by `id` from
+// {@link SessionState.inputNeeded}; a no-op when no entry matches.
+//
+// Server-originated: the host dispatches this once the underlying request
+// resolves (the user answers, the tool call is confirmed, or the client
+// reports its result).
+type SessionInputNeededRemovedAction struct {
+	Type ActionType `json:"type"`
+	// The `id` of the input request to remove.
+	Id string `json:"id"`
+}
+
 // The session's customizations have changed.
 //
 // Full-replacement semantics: the `customizations` array replaces the
@@ -1241,6 +1275,8 @@ func (*SessionChangesetsChangedAction) isStateAction()          {}
 func (*SessionServerToolsChangedAction) isStateAction()         {}
 func (*SessionActiveClientSetAction) isStateAction()            {}
 func (*SessionActiveClientRemovedAction) isStateAction()        {}
+func (*SessionInputNeededSetAction) isStateAction()             {}
+func (*SessionInputNeededRemovedAction) isStateAction()         {}
 func (*SessionCustomizationsChangedAction) isStateAction()      {}
 func (*SessionCustomizationToggledAction) isStateAction()       {}
 func (*SessionCustomizationUpdatedAction) isStateAction()       {}
@@ -1534,6 +1570,18 @@ func (u *StateAction) UnmarshalJSON(data []byte) error {
 			return err
 		}
 		u.Value = &value
+	case "session/inputNeededSet":
+		var value SessionInputNeededSetAction
+		if err := json.Unmarshal(data, &value); err != nil {
+			return err
+		}
+		u.Value = &value
+	case "session/inputNeededRemoved":
+		var value SessionInputNeededRemovedAction
+		if err := json.Unmarshal(data, &value); err != nil {
+			return err
+		}
+		u.Value = &value
 	case "session/customizationsChanged":
 		var value SessionCustomizationsChangedAction
 		if err := json.Unmarshal(data, &value); err != nil {