feat: gate session cleanup by runtime capabilities

src/client/src/api.ts

@@ -1,3 +1,3 @@
 export { activityApi, api, configApi, filesApi, gitApi, machinesApi, piWebApi, pluginsApi, projectsApi, sessionsApi, terminalsApi, workspacesApi } from "./api/clients";
 export { globalSessionEvents, realtimeEvents, sessionEvents, terminalSocket } from "./api/sockets";
-export type { ArchiveSessionsResponse, AuthProviderOption, AuthProviderStatus, AuthProvidersResponse, AuthStatusSource, AuthType, CommandOption, CommandResult, FileContentMediaType, FileContentResponse, FileSuggestion, FileTreeEntry, FileTreeResponse, GitDiffResponse, GitFileState, GitStatusFile, GitStatusResponse, Machine, MachineHealth, MachineKind, MachineStatus, MessagePage, ModelSelectionResponse, OAuthFlowState, PiWebComponentStatus, PiWebConfigEnvOverrides, PiWebConfigResponse, PiWebConfigValues, PiWebInstallationInfo, PiWebPluginConfig, PiWebPluginConfigMap, PiWebPluginInfo, PiWebPluginsResponse, PiWebPluginScope, PiWebPluginSettings, PiWebReleaseStatus, PiWebShortcutConfig, PiWebStatusMessage, PiWebStatusResponse, Project, QueuedSessionMessage, RealtimeEvent, RunTerminalCommandInput, SessionActivity, SessionInfo, SessionModel, SessionStatus, SlashCommand, SessionUiEvent, TerminalCommandRun, TerminalCommandRunFilter, TerminalCommandRunHandle, TerminalCommandRunStatus, TerminalInfo, TerminalUiEvent, ThinkingLevel, ThinkingLevelsResponse, Workspace, WorkspaceActivity, WorkspaceActivityResponse, WorkspaceActivityUiEvent } from "../../shared/apiTypes";
+export type { ArchiveSessionsResponse, AuthProviderOption, AuthProviderStatus, AuthProvidersResponse, AuthStatusSource, AuthType, CommandOption, CommandResult, FileContentMediaType, FileContentResponse, FileSuggestion, FileTreeEntry, FileTreeResponse, GitDiffResponse, GitFileState, GitStatusFile, GitStatusResponse, Machine, MachineHealth, MachineKind, MachineRuntime, MachineStatus, MessagePage, ModelSelectionResponse, OAuthFlowState, PiWebCapability, PiWebComponentStatus, PiWebConfigEnvOverrides, PiWebConfigResponse, PiWebConfigValues, PiWebInstallationInfo, PiWebPluginConfig, PiWebPluginConfigMap, PiWebPluginInfo, PiWebPluginsResponse, PiWebPluginScope, PiWebPluginSettings, PiWebReleaseStatus, PiWebRuntimeComponent, PiWebRuntimeResponse, PiWebShortcutConfig, PiWebStatusMessage, PiWebStatusResponse, Project, QueuedSessionMessage, RealtimeEvent, RunTerminalCommandInput, SessionActivity, SessionInfo, SessionModel, SessionStatus, SlashCommand, SessionUiEvent, TerminalCommandRun, TerminalCommandRunFilter, TerminalCommandRunHandle, TerminalCommandRunStatus, TerminalInfo, TerminalUiEvent, ThinkingLevel, ThinkingLevelsResponse, Workspace, WorkspaceActivity, WorkspaceActivityResponse, WorkspaceActivityUiEvent } from "../../shared/apiTypes";

src/client/src/api/clients.test.ts

@@ -1,6 +1,7 @@
 import { afterEach, describe, expect, it, vi } from "vitest";
+import { PI_WEB_CAPABILITIES } from "../../../shared/capabilities";
 import type { TerminalCommandRun, Workspace } from "../../../shared/apiTypes";
-import { terminalsApi, workspacesApi } from "./clients";
+import { machinesApi, terminalsApi, workspacesApi } from "./clients";
 
 const workspace: Workspace = {
   id: "w/1",
@@ -29,6 +30,17 @@ afterEach(() => {
   vi.unstubAllGlobals();
 });
 
+describe("machine-scoped runtime API", () => {
+  it("reads machine runtime through the gateway route", async () => {
+    const fetchMock = stubJsonFetch({ machineId: "remote a", ok: true, checkedAt: "now", capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] });
+
+    await machinesApi.runtime("remote a");
+
+    expect(fetchMock).toHaveBeenCalledOnce();
+    expect(fetchCall(fetchMock, 0)[0]).toBe("/api/machines/remote%20a/runtime");
+  });
+});
+
 describe("machine-scoped terminal command-run API", () => {
   it("deletes workspaces through the selected machine scope", async () => {
     const fetchMock = stubJsonFetch(commandRun);

src/client/src/api/clients.ts

@@ -17,12 +17,14 @@ import {
   parseGitStatusResponse,
   parseMachine,
   parseMachineHealth,
+  parseMachineRuntime,
   parseMachinesResponse,
   parseMessagePage,
   parseModelSelectionResponse,
   parseOAuthFlowState,
   parsePiWebConfigResponse,
   parsePiWebPluginsResponse,
+  parsePiWebRuntimeResponse,
   parsePiWebStatusResponse,
   parseProject,
   parseRestored,
@@ -42,6 +44,7 @@ const machinePrefix = (machineId = "local") => `/api/machines/${encodeURICompone
 
 export const piWebApi = {
   piWebStatus: () => request("/api/pi-web/status", parsePiWebStatusResponse),
+  piWebRuntime: () => request("/api/pi-web/runtime", parsePiWebRuntimeResponse),
 };
 
 export const machinesApi = {
@@ -49,6 +52,7 @@ export const machinesApi = {
   addMachine: (input: { name: string; baseUrl: string; token?: string }) => request("/api/machines", parseMachine, { method: "POST", body: JSON.stringify(input) }),
   deleteMachine: (machineId: string) => request(`/api/machines/${encodeURIComponent(machineId)}`, (value) => value, { method: "DELETE" }),
   health: (machineId: string) => request(`/api/machines/${encodeURIComponent(machineId)}/health`, parseMachineHealth),
+  runtime: (machineId: string) => request(`/api/machines/${encodeURIComponent(machineId)}/runtime`, parseMachineRuntime),
 };
 
 export const configApi = {

src/client/src/api/parsers.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
-import { parseCommandResult, parseFileContentResponse, parseFileSuggestion, parseGitStatusResponse, parseMessagePage, parsePiWebConfigResponse, parsePiWebPluginsResponse, parseSessionStatus, parseSlashCommand, parseTerminalCommandRun, parseTerminalInfo, parseWorkspaceActivityResponse } from "./parsers";
+import { PI_WEB_CAPABILITIES } from "../../../shared/capabilities";
+import { parseCommandResult, parseFileContentResponse, parseFileSuggestion, parseGitStatusResponse, parseMessagePage, parsePiWebConfigResponse, parsePiWebPluginsResponse, parsePiWebRuntimeResponse, parseSessionStatus, parseSlashCommand, parseTerminalCommandRun, parseTerminalInfo, parseWorkspaceActivityResponse } from "./parsers";
 
 describe("API parsers", () => {
   it("parses PI WEB config responses", () => {
@@ -18,6 +19,18 @@ describe("API parsers", () => {
     });
   });
 
+  it("parses PI WEB runtime responses", () => {
+    expect(parsePiWebRuntimeResponse({
+      packageName: "@jmfederico/pi-web",
+      generatedAt: "now",
+      components: {
+        web: { component: "web", label: "Web/UI", runtimeVersion: "1.0.0", available: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] },
+        sessiond: { component: "sessiond", label: "Session daemon", runtimeVersion: "1.0.0", available: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] },
+      },
+      capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived],
+    })).toMatchObject({ capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] });
+  });
+
   it("parses PI WEB plugin status responses", () => {
     expect(parsePiWebPluginsResponse({
       plugins: [{ id: "info", module: "/pi-web-plugins/info/pi-web-plugin.js?v=1", source: "bundled", scope: "bundled", enabled: false }],

src/client/src/api/parsers.ts

@@ -1,4 +1,5 @@
-import type { ArchiveSessionsResponse, AuthProviderOption, AuthProviderStatus, AuthProvidersResponse, AuthStatusSource, AuthType, CommandOption, CommandResult, FileContentResponse, FileSuggestion, FileTreeEntry, FileTreeResponse, GitDiffResponse, GitFileState, GitStatusFile, GitStatusResponse, Machine, MachineHealth, MachineKind, MachineStatus, MessagePage, ModelSelectionResponse, OAuthFlowState, PiWebComponentStatus, PiWebConfigEnvOverrides, PiWebConfigResponse, PiWebConfigValues, PiWebInstallationInfo, PiWebPluginConfigMap, PiWebPluginInfo, PiWebPluginsResponse, PiWebPluginScope, PiWebReleaseStatus, PiWebServiceComponent, PiWebShortcutConfig, PiWebStatusMessage, PiWebStatusResponse, PiWebStatusSeverity, Project, QueuedSessionMessage, SessionInfo, SessionModel, SessionStatus, SlashCommand, TerminalCommandRun, TerminalCommandRunStatus, TerminalInfo, ThinkingLevel, ThinkingLevelsResponse, Workspace, WorkspaceActivity, WorkspaceActivityResponse } from "../../../shared/apiTypes";
+import type { ArchiveSessionsResponse, AuthProviderOption, AuthProviderStatus, AuthProvidersResponse, AuthStatusSource, AuthType, CommandOption, CommandResult, FileContentResponse, FileSuggestion, FileTreeEntry, FileTreeResponse, GitDiffResponse, GitFileState, GitStatusFile, GitStatusResponse, Machine, MachineHealth, MachineKind, MachineRuntime, MachineStatus, MessagePage, ModelSelectionResponse, OAuthFlowState, PiWebCapability, PiWebComponentStatus, PiWebConfigEnvOverrides, PiWebConfigResponse, PiWebConfigValues, PiWebInstallationInfo, PiWebPluginConfigMap, PiWebPluginInfo, PiWebPluginsResponse, PiWebPluginScope, PiWebReleaseStatus, PiWebRuntimeComponent, PiWebRuntimeResponse, PiWebServiceComponent, PiWebShortcutConfig, PiWebStatusMessage, PiWebStatusResponse, PiWebStatusSeverity, Project, QueuedSessionMessage, SessionInfo, SessionModel, SessionStatus, SlashCommand, TerminalCommandRun, TerminalCommandRunStatus, TerminalInfo, ThinkingLevel, ThinkingLevelsResponse, Workspace, WorkspaceActivity, WorkspaceActivityResponse } from "../../../shared/apiTypes";
+import { isPiWebCapability } from "../../../shared/capabilities";
 
 function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null;
@@ -95,6 +96,21 @@ export function parseMachineHealth(value: unknown): MachineHealth {
   };
 }
 
+export function parseMachineRuntime(value: unknown): MachineRuntime {
+  const record = requireRecord(value);
+  const error = optionalString(record, "error");
+  return {
+    machineId: requireString(record, "machineId"),
+    ok: requireBoolean(record, "ok"),
+    checkedAt: requireString(record, "checkedAt"),
+    ...optionalField("packageName", optionalString(record, "packageName")),
+    ...optionalField("generatedAt", optionalString(record, "generatedAt")),
+    ...(record["components"] === undefined ? {} : { components: parsePiWebRuntimeComponents(record["components"]) }),
+    ...(record["capabilities"] === undefined ? {} : { capabilities: parsePiWebCapabilities(record["capabilities"]) }),
+    ...(error === undefined ? {} : { error }),
+  };
+}
+
 function requireMachineKind(record: Record<string, unknown>, key: string): MachineKind {
   const value = requireString(record, key);
   if (value !== "local" && value !== "remote") throw new Error(`Expected machine kind field: ${key}`);
@@ -497,11 +513,38 @@ export function parsePiWebStatusResponse(value: unknown): PiWebStatusResponse {
   };
 }
 
+export function parsePiWebRuntimeResponse(value: unknown): PiWebRuntimeResponse {
+  const record = requireRecord(value);
+  return {
+    packageName: requireString(record, "packageName"),
+    generatedAt: requireString(record, "generatedAt"),
+    components: parsePiWebRuntimeComponents(record["components"]),
+    capabilities: parsePiWebCapabilities(record["capabilities"]),
+  };
+}
+
 function parsePiWebComponents(value: unknown): PiWebStatusResponse["components"] {
   const record = requireRecord(value);
   return { web: parsePiWebComponentStatus(record["web"]), sessiond: parsePiWebComponentStatus(record["sessiond"]) };
 }
 
+function parsePiWebRuntimeComponents(value: unknown): PiWebRuntimeResponse["components"] {
+  const record = requireRecord(value);
+  return { web: parsePiWebRuntimeComponent(record["web"]), sessiond: parsePiWebRuntimeComponent(record["sessiond"]) };
+}
+
+function parsePiWebRuntimeComponent(value: unknown): PiWebRuntimeComponent {
+  const record = requireRecord(value);
+  return {
+    component: parsePiWebServiceComponent(record["component"]),
+    label: requireString(record, "label"),
+    ...optionalField("runtimeVersion", optionalString(record, "runtimeVersion")),
+    available: requireBoolean(record, "available"),
+    capabilities: parsePiWebCapabilities(record["capabilities"]),
+    ...optionalField("error", optionalString(record, "error")),
+  };
+}
+
 function parsePiWebComponentStatus(value: unknown): PiWebComponentStatus {
   const record = requireRecord(value);
   return {
@@ -571,6 +614,11 @@ function parsePiWebServiceComponent(value: unknown): PiWebServiceComponent {
   return value;
 }
 
+function parsePiWebCapabilities(value: unknown): PiWebCapability[] {
+  if (!Array.isArray(value) || !value.every(isPiWebCapability)) throw new Error("Invalid PI WEB capabilities");
+  return value;
+}
+
 function parsePiWebStatusSeverity(value: unknown): PiWebStatusSeverity {
   if (value !== "info" && value !== "warning" && value !== "error") throw new Error("Invalid PI WEB status severity");
   return value;

src/client/src/appState.ts

@@ -1,4 +1,4 @@
-import type { AuthProviderOption, CommandOption, CommandResult, FileContentResponse, FileTreeEntry, GitDiffResponse, GitStatusResponse, Machine, MachineHealth, OAuthFlowState, PiWebStatusResponse, Project, SessionActivity, SessionInfo, SessionStatus, TerminalCommandRun, Workspace, WorkspaceActivity } from "./api";
+import type { AuthProviderOption, CommandOption, CommandResult, FileContentResponse, FileTreeEntry, GitDiffResponse, GitStatusResponse, Machine, MachineHealth, MachineRuntime, OAuthFlowState, PiWebStatusResponse, Project, SessionActivity, SessionInfo, SessionStatus, TerminalCommandRun, Workspace, WorkspaceActivity } from "./api";
 import type { ChatLine } from "./components/shared";
 import type { QualifiedContributionId } from "./plugins/ids";
 
@@ -7,6 +7,7 @@ export interface AppState {
   selectedMachine: Machine | undefined;
   isLoadingMachines: boolean;
   machineStatuses: Record<string, MachineHealth>;
+  machineRuntimes: Record<string, MachineRuntime>;
   projects: Project[];
   workspaces: Workspace[];
   sessions: SessionInfo[];
@@ -102,6 +103,7 @@ export function initialAppState(): AppState {
     selectedMachine: undefined,
     isLoadingMachines: false,
     machineStatuses: {},
+    machineRuntimes: {},
     projects: [],
     workspaces: [],
     sessions: [],

src/client/src/components/PiWebApp.ts

@@ -4,6 +4,7 @@ import { configApi, piWebApi, terminalsApi, workspacesApi, type Machine, type Ma
 import type { AppAction } from "../actions";
 import { initialAppState, type AppState } from "../appState";
 import { isSessionActive } from "../../../shared/activity";
+import { PI_WEB_CAPABILITIES, supportsPiWebCapability } from "../../../shared/capabilities";
 import { ActivityController } from "../controllers/activityController";
 import { AuthController } from "../controllers/authController";
 import { FileExplorerController } from "../controllers/fileExplorerController";
@@ -847,6 +848,22 @@ export class PiWebApp extends LitElement {
     this.panelResize.resetPanels();
   }
 
+  private canDeleteArchivedSessions(): boolean {
+    const runtime = this.selectedMachineRuntime();
+    return runtime?.ok === true && supportsPiWebCapability(runtime, PI_WEB_CAPABILITIES.sessionsDeleteArchived);
+  }
+
+  private archivedDeleteUnavailableMessage(): string {
+    const machineName = this.state.selectedMachine?.name ?? "this machine";
+    const runtime = this.selectedMachineRuntime();
+    if (runtime?.ok === false && runtime.error !== undefined) return `Update and restart Pi-Web on ${machineName} to delete archived sessions. Runtime check failed: ${runtime.error}`;
+    return `Update and restart Pi-Web on ${machineName} to delete archived sessions.`;
+  }
+
+  private selectedMachineRuntime() {
+    return this.state.machineRuntimes[selectedMachineId(this.state)];
+  }
+
   private renderNavigationPanel() {
     return html`
       <app-navigation-panel
@@ -870,6 +887,8 @@ export class PiWebApp extends LitElement {
         .sessionActivities=${this.state.sessionActivities}
         .selectedSession=${this.state.selectedSession}
         .canStartSession=${!!this.state.selectedWorkspace}
+        .canDeleteArchivedSessions=${this.canDeleteArchivedSessions()}
+        .archivedDeleteUnavailableMessage=${this.archivedDeleteUnavailableMessage()}
         .collapsible=${true}
         .compact=${this.appShell.isMobileNavigationLayout}
         .projectsCollapsed=${this.navigationSections.isCollapsed("projects")}
@@ -1206,7 +1225,9 @@ export class PiWebApp extends LitElement {
       focusPrompt: () => { void this.focusChatComposer(); },
       addProject: () => { this.setState({ projectDialogOpen: true }); },
       addMachine: () => { this.openMachineDialog(); },
-      refreshSelectedMachine: () => this.machines.refreshMachineHealth(),
+      refreshSelectedMachine: async () => {
+        await Promise.all([this.machines.refreshMachineHealth(), this.machines.refreshMachineRuntime()]);
+      },
       removeSelectedMachine: () => this.removeMachine(),
       openSelectedMachine: () => { this.openSelectedMachine(); },
       configureAuth: () => this.auth.openLogin(),

src/client/src/components/SessionList.ts

@@ -29,6 +29,8 @@ export class SessionList extends LitElement implements KeyboardNavigableSection
   @property({ attribute: false }) activities: Record<string, SessionActivity> = {};
   @property({ attribute: false }) selected?: SessionInfo;
   @property({ type: Boolean }) canStart = false;
+  @property({ type: Boolean }) canDeleteArchived = false;
+  @property({ type: String }) archivedDeleteUnavailableMessage = "Update and restart Pi-Web on this machine to delete archived sessions.";
   @property({ type: Boolean, reflect: true }) collapsible = false;
   @property({ type: Boolean, reflect: true }) collapsed = false;
   @property({ attribute: false }) onSelect?: (session: SessionInfo) => void;
@@ -180,7 +182,7 @@ export class SessionList extends LitElement implements KeyboardNavigableSection
       <div class="bulk-row selecting">
         <button ?disabled=${visibleSessions.length === 0} @click=${() => { this.toggleVisibleSelection(visibleSessions, !allVisibleSelected); }}>${allVisibleSelected ? "Clear visible" : "Select visible"}</button>
         <small>${selectedSessions.length} selected${visibleSelectedCount !== selectedSessions.length ? html` · ${visibleSelectedCount} visible` : null}</small>
-        <button class="danger" ?disabled=${selectedSessions.length === 0} @click=${() => { this.confirmDeleteSelectedArchived(); }}>Delete selected</button>
+        <button class="danger" title=${this.canDeleteArchived ? "Permanently delete selected archived sessions" : this.archivedDeleteUnavailableMessage} ?disabled=${selectedSessions.length === 0 || !this.canDeleteArchived} @click=${() => { this.confirmDeleteSelectedArchived(); }}>Delete selected</button>
         <button @click=${() => { this.clearSelection("archived"); }}>Clear</button>
         <button @click=${() => { this.closeSelection("archived"); }}>Done</button>
       </div>
@@ -215,7 +217,7 @@ export class SessionList extends LitElement implements KeyboardNavigableSection
                 : session.archived === true
                   ? html`
                     <button title="Restore session" @click=${() => { this.openMenuSessionId = undefined; this.onRestore?.(session); }}>Restore</button>
-                    <button class="danger" title="Permanently delete archived session" @click=${() => { this.openMenuSessionId = undefined; this.confirmDeleteArchived(session); }}>Delete archived session</button>
+                    <button class="danger" title=${this.canDeleteArchived ? "Permanently delete archived session" : this.archivedDeleteUnavailableMessage} ?disabled=${!this.canDeleteArchived} @click=${() => { this.openMenuSessionId = undefined; this.confirmDeleteArchived(session); }}>Delete archived session</button>
                   `
                   : html`
                     ${session.parentSessionPath !== undefined ? html`<button title="Detach from parent" @click=${() => { this.openMenuSessionId = undefined; this.onDetachParent?.(session); }}>Detach from parent</button>` : null}
@@ -252,10 +254,12 @@ export class SessionList extends LitElement implements KeyboardNavigableSection
   }
 
   private confirmDeleteArchived(session: SessionInfo): void {
+    if (!this.canDeleteArchived) return;
     if (confirm(`Permanently delete archived session “${sessionLabel(session)}”? This cannot be undone.`)) void this.onDeleteArchived?.(session);
   }
 
   private confirmDeleteSelectedArchived(): void {
+    if (!this.canDeleteArchived) return;
     const archived = this.selectedSessions("archived");
     if (archived.length === 0) return;
     const noun = archived.length === 1 ? "archived session" : "archived sessions";

src/client/src/components/appShell/AppNavigationPanel.ts

@@ -39,6 +39,8 @@ export class AppNavigationPanel extends LitElement {
   @property({ type: Boolean }) workspacesCollapsed = false;
   @property({ type: Boolean }) sessionsCollapsed = false;
   @property({ type: Boolean }) canStartSession = false;
+  @property({ type: Boolean }) canDeleteArchivedSessions = false;
+  @property({ type: String }) archivedDeleteUnavailableMessage = "Update and restart Pi-Web on this machine to delete archived sessions.";
   @property({ attribute: false }) onShowActions?: () => void;
   @property({ attribute: false }) onToggleMachines?: () => void;
   @property({ attribute: false }) onToggleProjects?: () => void;
@@ -151,6 +153,8 @@ export class AppNavigationPanel extends LitElement {
         .activities=${this.sessionActivities}
         .selected=${this.selectedSession}
         .canStart=${this.canStartSession}
+        .canDeleteArchived=${this.canDeleteArchivedSessions}
+        .archivedDeleteUnavailableMessage=${this.archivedDeleteUnavailableMessage}
         .collapsible=${this.collapsible}
         .collapsed=${this.sessionsCollapsed}
         .onToggleCollapsed=${() => { this.onToggleSessions?.(); }}

src/client/src/controllers/machineController.ts

@@ -12,8 +12,9 @@ export class MachineController {
       const machines = await api.machines();
       const selectedMachine = await this.selectInitialMachine(machines, routeMachineId);
       const machineIds = new Set(machines.map((machine) => machine.id));
-      this.setState({ machines, selectedMachine, machineActivities: filterKeys(this.getState().machineActivities, machineIds) });
+      this.setState({ machines, selectedMachine, machineActivities: filterKeys(this.getState().machineActivities, machineIds), machineRuntimes: filterKeys(this.getState().machineRuntimes, machineIds) });
       void this.refreshMachineHealthFor(machines);
+      void this.refreshMachineRuntimeFor(machines);
     } catch (error) {
       this.setState({ error: String(error) });
     } finally {
@@ -47,6 +48,7 @@ export class MachineController {
     if (options.updateUrl !== false) this.updateUrl();
     await this.projects.loadProjects();
     void this.refreshMachineHealth(machine.id);
+    void this.refreshMachineRuntime(machine.id);
   }
 
   async addMachine(input: { name: string; baseUrl: string; token?: string }): Promise<Machine | undefined> {
@@ -73,7 +75,7 @@ export class MachineController {
       await api.deleteMachine(machine.id);
       const machines = this.getState().machines.filter((candidate) => candidate.id !== machine.id);
       const local = machines.find((candidate) => candidate.id === "local") ?? machines[0];
-      this.setState({ machines, machineStatuses: omitKey(this.getState().machineStatuses, machine.id), machineActivities: omitKey(this.getState().machineActivities, machine.id) });
+      this.setState({ machines, machineStatuses: omitKey(this.getState().machineStatuses, machine.id), machineRuntimes: omitKey(this.getState().machineRuntimes, machine.id), machineActivities: omitKey(this.getState().machineActivities, machine.id) });
       if (wasSelected && local !== undefined) {
         if (options.selectFallback === false) return local;
         await this.selectMachine(local);
@@ -95,6 +97,15 @@ export class MachineController {
     }
   }
 
+  async refreshMachineRuntime(machineId = this.getState().selectedMachine?.id ?? "local"): Promise<void> {
+    try {
+      const runtime = await api.runtime(machineId);
+      this.setState({ machineRuntimes: { ...this.getState().machineRuntimes, [runtime.machineId]: runtime } });
+    } catch (error) {
+      this.setState({ error: String(error) });
+    }
+  }
+
   private async selectInitialMachine(machines: Machine[], routeMachineId?: string): Promise<Machine | undefined> {
     const requestedMachine = machines.find((machine) => machine.id === (routeMachineId ?? "local"));
     if (requestedMachine?.kind !== "remote") return requestedMachine ?? this.localMachine(machines);
@@ -133,6 +144,12 @@ export class MachineController {
     const health = Object.fromEntries(results.flatMap((result) => result.status === "fulfilled" ? [[result.value.machineId, result.value] as const] : []));
     if (Object.keys(health).length > 0) this.setState({ machineStatuses: { ...this.getState().machineStatuses, ...health } });
   }
+
+  private async refreshMachineRuntimeFor(machines: Machine[]): Promise<void> {
+    const results = await Promise.allSettled(machines.map((machine) => api.runtime(machine.id)));
+    const runtimes = Object.fromEntries(results.flatMap((result) => result.status === "fulfilled" ? [[result.value.machineId, result.value] as const] : []));
+    if (Object.keys(runtimes).length > 0) this.setState({ machineRuntimes: { ...this.getState().machineRuntimes, ...runtimes } });
+  }
 }
 
 function omitKey<T>(record: Record<string, T>, keyToOmit: string): Record<string, T> {

src/client/src/controllers/sessionController.test.ts

@@ -3,6 +3,7 @@ import { api as defaultApi, type MessagePage, type SessionActivity, type Session
 import { isCachedNewSessionInfo, loadCachedNewSessions, markCachedNewSessionInfo, rememberCachedNewSession } from "../cachedNewSessions";
 import { initialAppState, type AppState } from "../appState";
 import { machineSessionKey } from "../machineKeys";
+import { PI_WEB_CAPABILITIES } from "../../../shared/capabilities";
 import { loadDraft, saveDraft } from "../promptDraftStorage";
 import { SessionController, type SessionEventSocket } from "./sessionController";
 import { InMemorySessionSelectionMemory } from "./sessionSelection";
@@ -325,7 +326,13 @@ describe("SessionController", () => {
     const archivedSession = { ...oldSession, archived: true, archivedAt: "later" };
     const nextSession = { ...oldSession, id: "next-session", path: "/tmp/next-session.jsonl" };
     const deletedIds: string[] = [];
-    let state: AppState = { ...initialAppState(), selectedWorkspace: workspace, selectedSession: archivedSession, sessions: [archivedSession, nextSession] };
+    let state: AppState = {
+      ...initialAppState(),
+      selectedWorkspace: workspace,
+      selectedSession: archivedSession,
+      sessions: [archivedSession, nextSession],
+      machineRuntimes: { local: { machineId: "local", ok: true, checkedAt: "now", capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] } },
+    };
     const api: typeof defaultApi = {
       ...defaultApi,
       deleteArchived: (sessionId) => {
@@ -350,6 +357,32 @@ describe("SessionController", () => {
     expect(state.selectedSession?.id).toBe(nextSession.id);
   });
 
+  it("does not delete archived sessions when the selected machine runtime does not support it", async () => {
+    const archivedSession = { ...oldSession, archived: true, archivedAt: "later" };
+    const deletedIds: string[] = [];
+    let state: AppState = { ...initialAppState(), selectedWorkspace: workspace, sessions: [archivedSession] };
+    const api: typeof defaultApi = {
+      ...defaultApi,
+      deleteArchived: (sessionId) => {
+        deletedIds.push(sessionId);
+        return Promise.resolve({ deleted: true });
+      },
+    };
+    const controller = new SessionController(
+      () => state,
+      (patch) => { state = { ...state, ...patch }; },
+      () => undefined,
+      new InMemorySessionSelectionMemory(),
+      { api, socket: new FakeSocket() },
+    );
+
+    await controller.deleteArchivedSessions([archivedSession]);
+
+    expect(deletedIds).toEqual([]);
+    expect(state.sessions).toEqual([archivedSession]);
+    expect(state.error).toContain("requires an updated Pi-Web runtime");
+  });
+
   it("forgets archived selections when the archived section collapse clears selection", async () => {
     const archivedSession = { ...oldSession, archived: true, archivedAt: "later" };
     let state: AppState = { ...initialAppState(), selectedWorkspace: workspace, sessions: [archivedSession] };

src/client/src/controllers/sessionController.ts

@@ -8,6 +8,7 @@ import { ChatTranscriptStore } from "../chatTranscriptStore";
 import { isShellInput } from "../inputModes";
 import { SessionSocket, type GlobalSessionEvent, type SessionUiEvent } from "../sessionSocket";
 import { isSessionActive } from "../../../shared/activity";
+import { PI_WEB_CAPABILITIES, supportsPiWebCapability } from "../../../shared/capabilities";
 import { InMemorySessionSelectionMemory, markSessionArchived, markSessionsArchived, selectPreferredSession, selectionAfterArchivingSession, selectionAfterArchivingSessions, shouldDeselectAfterArchivedCollapse, type SessionSelectionMemory } from "./sessionSelection";
 import { selectedMachineId, type GetState, type SetState, type UpdateUrl } from "./types";
 
@@ -288,6 +289,11 @@ export class SessionController {
     if (candidates.length === 0) return;
 
     const machineId = selectedMachineId(this.getState());
+    const runtime = this.getState().machineRuntimes[machineId];
+    if (runtime?.ok !== true || !supportsPiWebCapability(runtime, PI_WEB_CAPABILITIES.sessionsDeleteArchived)) {
+      this.setState({ error: "Deleting archived sessions requires an updated Pi-Web runtime on this machine." });
+      return;
+    }
     const results = await Promise.allSettled(candidates.map(async (session) => {
       await this.api.deleteArchived(session.id, machineId);
       return session.id;

src/server/app.test.ts

@@ -12,6 +12,7 @@ import { MachineService } from "./machines/machineService.js";
 import { MachineStore } from "./machines/machineStore.js";
 import { WorkspaceService } from "./workspaces/workspaceService.js";
 import type { SessionProxyDaemon } from "./sessiond/sessionProxyRoutes.js";
+import { PI_WEB_CAPABILITIES } from "../shared/capabilities.js";
 import { machineScopedPluginId } from "../shared/machinePluginIds.js";
 import { MAX_IMAGE_PREVIEW_BYTES } from "../shared/workspaceFiles.js";
 import type { Project, Workspace } from "./types.js";
@@ -47,6 +48,15 @@ beforeEach(async () => {
         commands: { update: "", restart: "", restartSystemd: "", restartDev: "" },
         messages: [],
       }),
+      localRuntime: () => Promise.resolve({
+        packageName: "@jmfederico/pi-web",
+        generatedAt: "2026-05-25T00:00:00.000Z",
+        components: {
+          web: { component: "web", label: "PI WEB", available: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] },
+          sessiond: { component: "sessiond", label: "PI WEB Session Daemon", available: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] },
+        },
+        capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived],
+      }),
     }),
     sessionDaemon: fakeSessionDaemon(),
     piWebPlugins: {
@@ -109,6 +119,31 @@ describe("buildApp", () => {
     expect(remoteHealth.json()).toMatchObject({ machineId: remote.id, ok: true, status: "online" });
   });
 
+  it("reports effective machine runtime capabilities for remote machines", async () => {
+    const addResponse = await app.inject({ method: "POST", url: "/api/machines", payload: { name: "Remote", baseUrl: "https://remote.example.test/" } });
+    const remote = addResponse.json<{ id: string }>();
+    const requestJson = vi.fn<MachineClient["requestJson"]>(() => Promise.resolve({
+      statusCode: 200,
+      headers: { "content-type": "application/json" },
+      body: {
+        packageName: "@jmfederico/pi-web",
+        generatedAt: "2026-05-25T00:00:00.000Z",
+        components: {
+          web: { component: "web", label: "Remote Web", runtimeVersion: "1.0.0", available: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] },
+          sessiond: { component: "sessiond", label: "Remote Sessiond", runtimeVersion: "1.0.0", available: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] },
+        },
+        capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived],
+      },
+    }));
+    remoteClient = fakeRemoteClient({ requestJson });
+
+    const runtime = await app.inject({ method: "GET", url: `/api/machines/${remote.id}/runtime` });
+
+    expect(runtime.statusCode).toBe(200);
+    expect(runtime.json()).toMatchObject({ machineId: remote.id, ok: true, capabilities: [PI_WEB_CAPABILITIES.sessionsDeleteArchived] });
+    expect(requestJson).toHaveBeenCalledWith("GET", "/api/pi-web/runtime", undefined, { timeoutMs: 3000 });
+  });
+
   it("proxies allowlisted remote HTTP routes through the selected machine", async () => {
     const addResponse = await app.inject({ method: "POST", url: "/api/machines", payload: { name: "Remote", baseUrl: "https://remote.example.test/" } });
     const remote = addResponse.json<{ id: string }>();

src/server/app.ts

@@ -17,7 +17,7 @@ import { registerTerminalProxyRoutes } from "./terminalProxyRoutes.js";
 import { registerWorkspaceDeletionRoutes } from "./workspaces/workspaceDeletionRoutes.js";
 import { registerConfigRoutes, type PiWebConfigService } from "./configRoutes.js";
 import { PiWebPluginService } from "./piWebPluginService.js";
-import { getPiWebStatus, getPiWebVersionStatus } from "./piWebStatus.js";
+import { getPiWebRuntime, getPiWebStatus, getPiWebVersionStatus } from "./piWebStatus.js";
 import { MachineService } from "./machines/machineService.js";
 import { registerMachineRoutes } from "./machines/machineRoutes.js";
 import { registerMachineProxyRoutes } from "./machines/machineProxyRoutes.js";
@@ -91,8 +91,11 @@ export async function buildApp(deps: AppDependencies = {}): Promise<FastifyInsta
   const projects = deps.projects ?? new ProjectService(new ProjectStore());
   const workspaces = deps.workspaces ?? new WorkspaceService();
   const piWebPlugins = deps.piWebPlugins ?? new PiWebPluginService();
-  const machines = deps.machines ?? new MachineService();
   const sessionDaemon = deps.sessionDaemon ?? new SessionDaemonClient();
+  const machines = deps.machines ?? new MachineService(undefined, {
+    localRuntime: () => getPiWebRuntime(sessionDaemon),
+    localStatus: () => getPiWebStatus(sessionDaemon),
+  });
 
   app.get("/pi-web-plugins/manifest.json", async () => piWebPlugins.manifest());
 
@@ -104,8 +107,9 @@ export async function buildApp(deps: AppDependencies = {}): Promise<FastifyInsta
     return reply.type(asset.contentType).send(asset.content);
   });
 
-  app.get("/api/pi-web/status", async () => getPiWebStatus());
-  app.get("/api/pi-web/version", async () => getPiWebVersionStatus());
+  app.get("/api/pi-web/status", async () => getPiWebStatus(sessionDaemon));
+  app.get("/api/pi-web/version", async () => getPiWebVersionStatus(sessionDaemon));
+  app.get("/api/pi-web/runtime", async () => getPiWebRuntime(sessionDaemon));
   app.get("/api/plugins", async () => piWebPlugins.plugins());
   registerConfigRoutes(app, deps.config);
 

src/server/machines/machineRoutes.ts

@@ -18,6 +18,12 @@ export function registerMachineRoutes(app: FastifyInstance, machines = new Machi
     return health;
   });
 
+  app.get<{ Params: { machineId: string } }>("/api/machines/:machineId/runtime", async (request, reply) => {
+    const runtime = await machines.runtime(request.params.machineId);
+    if (runtime === undefined) return reply.code(404).send({ error: "Machine not found" });
+    return runtime;
+  });
+
   app.get<{ Params: { machineId: string } }>("/api/machines/:machineId", async (request, reply) => {
     const machine = await machines.get(request.params.machineId);
     if (machine === undefined) return reply.code(404).send({ error: "Machine not found" });

src/server/machines/machineService.ts

@@ -1,5 +1,6 @@
-import type { Machine, MachineHealth, PiWebComponentStatus, PiWebStatusResponse } from "../../shared/apiTypes.js";
-import { getPiWebStatus } from "../piWebStatus.js";
+import type { Machine, MachineHealth, MachineRuntime, PiWebComponentStatus, PiWebRuntimeResponse, PiWebStatusResponse } from "../../shared/apiTypes.js";
+import { isPiWebCapability } from "../../shared/capabilities.js";
+import { getPiWebRuntime, getPiWebStatus } from "../piWebStatus.js";
 import { DEFAULT_REMOTE_HEALTH_TIMEOUT_MS, RemoteMachineClient, type MachineClient, validateConfiguredMachineHeaders } from "./machineClient.js";
 import { MachineStore, type StoredMachine } from "./machineStore.js";
 
@@ -14,9 +15,11 @@ export type UpdateMachineInput = Partial<CreateMachineInput>;
 
 export interface MachineServiceDependencies {
   localStatus?: () => Promise<PiWebStatusResponse>;
+  localRuntime?: () => Promise<PiWebRuntimeResponse>;
   remoteClientFactory?: (machine: StoredMachine) => MachineClient;
   now?: () => Date;
   healthCacheTtlMs?: number;
+  runtimeCacheTtlMs?: number;
 }
 
 const LOCAL_MACHINE_TIMESTAMP = "1970-01-01T00:00:00.000Z";
@@ -24,6 +27,7 @@ const DEFAULT_HEALTH_CACHE_TTL_MS = 5_000;
 
 export class MachineService {
   private readonly healthCache = new Map<string, { expiresAt: number; health: MachineHealth }>();
+  private readonly runtimeCache = new Map<string, { expiresAt: number; runtime: MachineRuntime }>();
 
   constructor(private readonly store = new MachineStore(), private readonly deps: MachineServiceDependencies = {}) {}
 
@@ -52,14 +56,20 @@ export class MachineService {
     if (input.token !== undefined) patch.token = input.token;
     if (input.headers !== undefined) patch.headers = validateHeaders(input.headers);
     const stored = await this.store.update(id, patch);
-    if (stored !== undefined) this.healthCache.delete(id);
+    if (stored !== undefined) {
+      this.healthCache.delete(id);
+      this.runtimeCache.delete(id);
+    }
     return stored === undefined ? undefined : publicMachine(stored);
   }
 
   async remove(id: string): Promise<boolean> {
     if (id === "local") throw new Error("Local machine cannot be deleted");
     const removed = await this.store.remove(id);
-    if (removed) this.healthCache.delete(id);
+    if (removed) {
+      this.healthCache.delete(id);
+      this.runtimeCache.delete(id);
+    }
     return removed;
   }
 
@@ -84,6 +94,17 @@ export class MachineService {
     return health;
   }
 
+  async runtime(id: string): Promise<MachineRuntime | undefined> {
+    const cached = this.runtimeCache.get(id);
+    const now = this.now().getTime();
+    if (cached !== undefined && cached.expiresAt > now) return cached.runtime;
+
+    const runtime = id === "local" ? await this.localRuntime() : await this.remoteRuntime(id);
+    if (runtime === undefined) return undefined;
+    this.runtimeCache.set(id, { expiresAt: now + (this.deps.runtimeCacheTtlMs ?? DEFAULT_HEALTH_CACHE_TTL_MS), runtime });
+    return runtime;
+  }
+
   private async localHealth(): Promise<MachineHealth> {
     const checkedAt = this.now().toISOString();
     try {
@@ -109,6 +130,28 @@ export class MachineService {
     }
   }
 
+  private async localRuntime(): Promise<MachineRuntime> {
+    const checkedAt = this.now().toISOString();
+    try {
+      return machineRuntime("local", checkedAt, await (this.deps.localRuntime ?? getPiWebRuntime)());
+    } catch (error) {
+      return { machineId: "local", ok: false, checkedAt, error: errorMessage(error) };
+    }
+  }
+
+  private async remoteRuntime(id: string): Promise<MachineRuntime | undefined> {
+    const machine = await this.storedRemote(id);
+    if (machine === undefined) return undefined;
+    const checkedAt = this.now().toISOString();
+    try {
+      const response = await this.clientFor(machine).requestJson("GET", "/api/pi-web/runtime", undefined, { timeoutMs: DEFAULT_REMOTE_HEALTH_TIMEOUT_MS });
+      if (response.statusCode >= 200 && response.statusCode < 300 && isPiWebRuntimeResponse(response.body)) return machineRuntime(id, checkedAt, response.body);
+      return { machineId: id, ok: false, checkedAt, error: `Remote runtime returned HTTP ${String(response.statusCode)}` };
+    } catch (error) {
+      return { machineId: id, ok: false, checkedAt, error: errorMessage(error) };
+    }
+  }
+
   private clientFor(machine: StoredMachine): MachineClient {
     return this.deps.remoteClientFactory?.(machine) ?? new RemoteMachineClient(machine);
   }
@@ -162,6 +205,18 @@ function errorMessage(error: unknown): string {
   return error instanceof Error ? error.message : String(error);
 }
 
+function machineRuntime(machineId: string, checkedAt: string, runtime: PiWebRuntimeResponse): MachineRuntime {
+  return {
+    machineId,
+    ok: true,
+    checkedAt,
+    packageName: runtime.packageName,
+    generatedAt: runtime.generatedAt,
+    components: runtime.components,
+    capabilities: runtime.capabilities,
+  };
+}
+
 function isPiWebStatusResponse(value: unknown): value is PiWebStatusResponse {
   if (!isRecord(value)) return false;
   const components = value["components"];
@@ -169,6 +224,16 @@ function isPiWebStatusResponse(value: unknown): value is PiWebStatusResponse {
   return isPiWebComponentStatus(components["web"]) && isPiWebComponentStatus(components["sessiond"]);
 }
 
+function isPiWebRuntimeResponse(value: unknown): value is PiWebRuntimeResponse {
+  if (!isRecord(value)) return false;
+  const packageName = value["packageName"];
+  const generatedAt = value["generatedAt"];
+  const components = value["components"];
+  const capabilities = value["capabilities"];
+  if (typeof packageName !== "string" || typeof generatedAt !== "string" || !isRecord(components) || !isPiWebCapabilityArray(capabilities)) return false;
+  return isPiWebRuntimeComponent(components["web"]) && isPiWebRuntimeComponent(components["sessiond"]);
+}
+
 function isPiWebComponentStatus(value: unknown): value is PiWebComponentStatus {
   if (!isRecord(value)) return false;
   const component = value["component"];
@@ -178,6 +243,19 @@ function isPiWebComponentStatus(value: unknown): value is PiWebComponentStatus {
     && typeof value["available"] === "boolean";
 }
 
+function isPiWebRuntimeComponent(value: unknown): boolean {
+  if (!isRecord(value)) return false;
+  const component = value["component"];
+  return (component === "web" || component === "sessiond")
+    && typeof value["label"] === "string"
+    && typeof value["available"] === "boolean"
+    && isPiWebCapabilityArray(value["capabilities"]);
+}
+
+function isPiWebCapabilityArray(value: unknown): boolean {
+  return Array.isArray(value) && value.every(isPiWebCapability);
+}
+
 function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null && !Array.isArray(value);
 }

src/server/piWebStatus.ts

@@ -5,8 +5,9 @@ import { homedir } from "node:os";
 import { dirname, join, relative, resolve, sep } from "node:path";
 import { fileURLToPath } from "node:url";
 import { DefaultPackageManager, getAgentDir, SettingsManager } from "@earendil-works/pi-coding-agent";
-import type { PiWebComponentStatus, PiWebInstallationInfo, PiWebReleaseStatus, PiWebServiceComponent, PiWebStatusMessage, PiWebStatusResponse, PiWebVersionResponse } from "../shared/apiTypes.js";
-import { parsePiWebComponentStatus } from "../shared/piWebStatusParsing.js";
+import type { PiWebCapability, PiWebComponentStatus, PiWebInstallationInfo, PiWebReleaseStatus, PiWebRuntimeComponent, PiWebRuntimeResponse, PiWebServiceComponent, PiWebStatusMessage, PiWebStatusResponse, PiWebVersionResponse } from "../shared/apiTypes.js";
+import { effectivePiWebCapabilities, WEB_RUNTIME_CAPABILITIES } from "../shared/capabilities.js";
+import { parsePiWebComponentStatus, parsePiWebRuntimeComponent } from "../shared/piWebStatusParsing.js";
 import { SessionDaemonClient } from "../sessiond/sessionDaemonClient.js";
 
 const PI_WEB_PACKAGE_NAME = "@jmfederico/pi-web";
@@ -61,10 +62,35 @@ interface PackageInfo {
   path: string;
 }
 
+interface PiWebStatusDaemon {
+  request(method: string, path: string, body?: unknown): Promise<{ statusCode: number; headers: Record<string, string>; body: string }>;
+}
+
 let latestReleaseCache: { checkedAtMs: number; latestVersion?: string; error?: string } | undefined;
 
 const runtimePackageInfo = readPackageInfoSync();
 
+export function getPiWebRuntimeComponent(component: PiWebServiceComponent, capabilities: readonly PiWebCapability[] = []): PiWebRuntimeComponent {
+  return {
+    component,
+    label: component === "web" ? "Web/UI" : "Session daemon",
+    runtimeVersion: runtimePackageInfo?.version ?? DEFAULT_VERSION,
+    available: true,
+    capabilities: [...capabilities],
+  };
+}
+
+export async function getPiWebRuntime(daemon: PiWebStatusDaemon = new SessionDaemonClient()): Promise<PiWebRuntimeResponse> {
+  const web = getPiWebRuntimeComponent("web", WEB_RUNTIME_CAPABILITIES);
+  const sessiond = await getSessiondRuntimeComponent(daemon);
+  return {
+    packageName: PI_WEB_PACKAGE_NAME,
+    generatedAt: new Date().toISOString(),
+    components: { web, sessiond },
+    capabilities: effectivePiWebCapabilities({ web, sessiond }),
+  };
+}
+
 export async function getPiWebComponentStatus(component: PiWebServiceComponent): Promise<PiWebComponentStatus> {
   const [installed, installation] = await Promise.all([
     readInstalledPackageInfo(),
@@ -83,7 +109,7 @@ export async function getPiWebComponentStatus(component: PiWebServiceComponent):
   };
 }
 
-export async function getPiWebVersionStatus(daemon = new SessionDaemonClient()): Promise<PiWebVersionResponse> {
+export async function getPiWebVersionStatus(daemon: PiWebStatusDaemon = new SessionDaemonClient()): Promise<PiWebVersionResponse> {
   const [web, sessiond] = await Promise.all([
     getPiWebComponentStatus("web"),
     getSessiondComponentStatus(daemon),
@@ -95,7 +121,7 @@ export async function getPiWebVersionStatus(daemon = new SessionDaemonClient()):
   };
 }
 
-export async function getPiWebStatus(daemon = new SessionDaemonClient()): Promise<PiWebStatusResponse> {
+export async function getPiWebStatus(daemon: PiWebStatusDaemon = new SessionDaemonClient()): Promise<PiWebStatusResponse> {
   const versionStatus = await getPiWebVersionStatus(daemon);
   const { web, sessiond } = versionStatus.components;
   const release = await getLatestReleaseStatus(web.installedVersion ?? web.runtimeVersion ?? DEFAULT_VERSION);
@@ -214,21 +240,78 @@ function isSameOrWithin(parent: string, candidate: string): boolean {
   return rel === "" || (!rel.startsWith("..") && !rel.startsWith(sep));
 }
 
-async function getSessiondComponentStatus(daemon: SessionDaemonClient): Promise<PiWebComponentStatus> {
+async function getSessiondRuntimeComponent(daemon: PiWebStatusDaemon): Promise<PiWebRuntimeComponent> {
   try {
-    const upstream = await daemon.request("GET", "/health");
+    const upstream = await daemon.request("GET", "/runtime");
     if (upstream.statusCode < 200 || upstream.statusCode >= 300) {
-      return unavailableSessiond(`health check returned HTTP ${String(upstream.statusCode)}`);
+      return await legacySessiondRuntimeComponent(daemon) ?? unavailableSessiondRuntime(`runtime check returned HTTP ${String(upstream.statusCode)}`);
     }
     const parsed: unknown = upstream.body === "" ? undefined : JSON.parse(upstream.body);
-    const version = isRecord(parsed) ? parsed["version"] : undefined;
-    const component = parsePiWebComponentStatus(version);
-    return component ?? unavailableSessiond("health response did not include version information");
+    const runtime = parsePiWebRuntimeComponent(parsed);
+    if (runtime !== undefined) return runtime;
+    const legacyVersion = isRecord(parsed) ? parsePiWebComponentStatus(parsed["version"]) : undefined;
+    if (legacyVersion !== undefined) return runtimeComponentFromStatus(legacyVersion);
+    return await legacySessiondRuntimeComponent(daemon) ?? unavailableSessiondRuntime("runtime response did not include valid runtime information");
+  } catch (error) {
+    return unavailableSessiondRuntime(error instanceof Error ? error.message : String(error));
+  }
+}
+
+async function getSessiondComponentStatus(daemon: PiWebStatusDaemon): Promise<PiWebComponentStatus> {
+  try {
+    const upstream = await daemon.request("GET", "/runtime");
+    if (upstream.statusCode < 200 || upstream.statusCode >= 300) {
+      return await legacySessiondComponentStatus(daemon) ?? unavailableSessiond(`runtime check returned HTTP ${String(upstream.statusCode)}`);
+    }
+    const parsed: unknown = upstream.body === "" ? undefined : JSON.parse(upstream.body);
+    const legacyVersion = isRecord(parsed) ? parsePiWebComponentStatus(parsed["version"]) : undefined;
+    if (legacyVersion !== undefined) return legacyVersion;
+    const runtime = parsePiWebRuntimeComponent(parsed);
+    if (runtime?.available !== true) return await legacySessiondComponentStatus(daemon) ?? unavailableSessiond(runtime?.error ?? "runtime response did not include valid runtime information");
+    const status = await getPiWebComponentStatus("sessiond");
+    return { ...status, ...(runtime.runtimeVersion === undefined ? {} : { runtimeVersion: runtime.runtimeVersion }), available: true };
   } catch (error) {
     return unavailableSessiond(error instanceof Error ? error.message : String(error));
   }
 }
 
+async function legacySessiondRuntimeComponent(daemon: PiWebStatusDaemon): Promise<PiWebRuntimeComponent | undefined> {
+  const status = await legacySessiondComponentStatus(daemon);
+  return status === undefined ? undefined : runtimeComponentFromStatus(status);
+}
+
+async function legacySessiondComponentStatus(daemon: PiWebStatusDaemon): Promise<PiWebComponentStatus | undefined> {
+  try {
+    const upstream = await daemon.request("GET", "/health");
+    if (upstream.statusCode < 200 || upstream.statusCode >= 300) return undefined;
+    const parsed: unknown = upstream.body === "" ? undefined : JSON.parse(upstream.body);
+    return isRecord(parsed) ? parsePiWebComponentStatus(parsed["version"]) : undefined;
+  } catch {
+    return undefined;
+  }
+}
+
+function runtimeComponentFromStatus(status: PiWebComponentStatus): PiWebRuntimeComponent {
+  return {
+    component: status.component,
+    label: status.label,
+    ...(status.runtimeVersion === undefined ? {} : { runtimeVersion: status.runtimeVersion }),
+    available: status.available,
+    capabilities: [],
+    ...(status.error === undefined ? {} : { error: status.error }),
+  };
+}
+
+function unavailableSessiondRuntime(error: string): PiWebRuntimeComponent {
+  return {
+    component: "sessiond",
+    label: "Session daemon",
+    available: false,
+    capabilities: [],
+    error,
+  };
+}
+
 function unavailableSessiond(error: string): PiWebComponentStatus {
   return {
     component: "sessiond",

src/server/sessiond.ts

@@ -13,7 +13,8 @@ import { registerSessionRoutes } from "./sessions/sessionRoutes.js";
 import { sessiondSocketPath } from "../sessiond/config.js";
 import { TerminalService } from "./terminals/terminalService.js";
 import { registerTerminalRoutes } from "./terminals/terminalRoutes.js";
-import { getPiWebComponentStatus } from "./piWebStatus.js";
+import { getPiWebRuntimeComponent } from "./piWebStatus.js";
+import { SESSIOND_RUNTIME_CAPABILITIES } from "../shared/capabilities.js";
 
 const app = Fastify({ logger: true });
 await app.register(fastifyWebsocket);
@@ -29,12 +30,23 @@ registerAuthRoutes(app, auth);
 registerSessionRoutes(app, sessions, eventHub);
 registerTerminalRoutes(app, terminals);
 
-app.get("/health", async () => ({
-  ok: true,
-  activeSessions: sessions.activeCount(),
-  checkedAt: new Date().toISOString(),
-  version: await getPiWebComponentStatus("sessiond"),
-}));
+app.get("/health", () => {
+  const runtime = getPiWebRuntimeComponent("sessiond", SESSIOND_RUNTIME_CAPABILITIES);
+  return {
+    ok: true,
+    activeSessions: sessions.activeCount(),
+    checkedAt: new Date().toISOString(),
+    version: {
+      component: runtime.component,
+      label: runtime.label,
+      ...(runtime.runtimeVersion === undefined ? {} : { runtimeVersion: runtime.runtimeVersion }),
+      stale: false,
+      available: runtime.available,
+    },
+  };
+});
+
+app.get("/runtime", () => getPiWebRuntimeComponent("sessiond", SESSIOND_RUNTIME_CAPABILITIES));
 
 let shuttingDown = false;
 async function shutdown(signal: NodeJS.Signals): Promise<void> {

src/server/sessiond/sessionProxyRoutes.ts

@@ -22,6 +22,7 @@ export function registerSessionProxyRoutes(app: FastifyInstance, daemon: Session
   };
 
   app.get(`${prefix}/sessiond/health`, (_request, reply) => proxy({ method: "GET", url: `${prefix}/health` }, reply));
+  app.get(`${prefix}/sessiond/runtime`, (_request, reply) => proxy({ method: "GET", url: `${prefix}/runtime` }, reply));
 
   app.get<{ Params: { sessionId: string } }>(`${prefix}/sessions/:sessionId/events`, { websocket: true }, (socket, request) => {
     bridgeSockets(socket, daemon.connectWebSocket(`/sessions/${request.params.sessionId}/events`));

src/shared/apiTypes.ts

@@ -1,6 +1,12 @@
 export type MachineKind = "local" | "remote";
 export type MachineStatus = "unknown" | "online" | "offline" | "error";
 
+export const PI_WEB_CAPABILITIES = {
+  sessionsDeleteArchived: "sessions.deleteArchived",
+} as const;
+
+export type PiWebCapability = typeof PI_WEB_CAPABILITIES[keyof typeof PI_WEB_CAPABILITIES];
+
 export interface Machine {
   id: string;
   name: string;
@@ -22,6 +28,17 @@ export interface MachineHealth {
   error?: string;
 }
 
+export interface MachineRuntime {
+  machineId: string;
+  ok: boolean;
+  checkedAt: string;
+  packageName?: string;
+  generatedAt?: string;
+  components?: PiWebRuntimeResponse["components"];
+  capabilities?: PiWebCapability[];
+  error?: string;
+}
+
 export type PiWebShortcutConfig = Record<string, string | null>;
 export type PiWebPluginSettings = Record<string, unknown>;
 export type PiWebPluginConfigMap = Record<string, PiWebPluginConfig>;
@@ -337,6 +354,15 @@ export interface PiWebComponentStatus {
   error?: string;
 }
 
+export interface PiWebRuntimeComponent {
+  component: PiWebServiceComponent;
+  label: string;
+  runtimeVersion?: string;
+  available: boolean;
+  capabilities: PiWebCapability[];
+  error?: string;
+}
+
 export interface PiWebReleaseStatus {
   packageName: string;
   latestVersion?: string;
@@ -363,6 +389,16 @@ export interface PiWebVersionResponse {
   };
 }
 
+export interface PiWebRuntimeResponse {
+  packageName: string;
+  generatedAt: string;
+  components: {
+    web: PiWebRuntimeComponent;
+    sessiond: PiWebRuntimeComponent;
+  };
+  capabilities: PiWebCapability[];
+}
+
 export interface PiWebStatusResponse extends PiWebVersionResponse {
   release: PiWebReleaseStatus;
   commands: {

src/shared/capabilities.ts

@@ -0,0 +1,32 @@
+import { PI_WEB_CAPABILITIES, type PiWebCapability, type PiWebRuntimeComponent, type PiWebServiceComponent } from "./apiTypes.js";
+
+export { PI_WEB_CAPABILITIES };
+export type { PiWebCapability };
+
+export const KNOWN_PI_WEB_CAPABILITIES = Object.values(PI_WEB_CAPABILITIES);
+const knownPiWebCapabilities: ReadonlySet<string> = new Set(KNOWN_PI_WEB_CAPABILITIES);
+
+export const WEB_RUNTIME_CAPABILITIES = [PI_WEB_CAPABILITIES.sessionsDeleteArchived] as const satisfies readonly PiWebCapability[];
+export const SESSIOND_RUNTIME_CAPABILITIES = [PI_WEB_CAPABILITIES.sessionsDeleteArchived] as const satisfies readonly PiWebCapability[];
+
+const EFFECTIVE_CAPABILITY_REQUIREMENTS = {
+  [PI_WEB_CAPABILITIES.sessionsDeleteArchived]: ["web", "sessiond"],
+} as const satisfies Record<PiWebCapability, readonly PiWebServiceComponent[]>;
+
+export function isPiWebCapability(value: unknown): value is PiWebCapability {
+  return typeof value === "string" && knownPiWebCapabilities.has(value);
+}
+
+export function supportsPiWebCapability(source: { capabilities?: readonly PiWebCapability[] } | undefined, capability: PiWebCapability): boolean {
+  return source?.capabilities?.includes(capability) === true;
+}
+
+export function effectivePiWebCapabilities(components: Partial<Record<PiWebServiceComponent, Pick<PiWebRuntimeComponent, "available" | "capabilities">>>): PiWebCapability[] {
+  return KNOWN_PI_WEB_CAPABILITIES.filter((capability) => {
+    const requiredComponents = EFFECTIVE_CAPABILITY_REQUIREMENTS[capability];
+    return requiredComponents.every((component) => {
+      const runtime = components[component];
+      return runtime?.available === true && supportsPiWebCapability(runtime, capability);
+    });
+  });
+}

src/shared/piWebStatusParsing.ts

@@ -1,4 +1,5 @@
-import type { PiWebComponentStatus, PiWebInstallationInfo, PiWebVersionResponse } from "./apiTypes.js";
+import type { PiWebCapability, PiWebComponentStatus, PiWebInstallationInfo, PiWebRuntimeComponent, PiWebRuntimeResponse, PiWebVersionResponse } from "./apiTypes.js";
+import { isPiWebCapability } from "./capabilities.js";
 
 export function parsePiWebVersionResponse(value: unknown): PiWebVersionResponse | undefined {
   if (!isRecord(value)) return undefined;
@@ -12,6 +13,39 @@ export function parsePiWebVersionResponse(value: unknown): PiWebVersionResponse
   return { packageName, generatedAt, components: { web, sessiond } };
 }
 
+export function parsePiWebRuntimeResponse(value: unknown): PiWebRuntimeResponse | undefined {
+  if (!isRecord(value)) return undefined;
+  const packageName = value["packageName"];
+  const generatedAt = value["generatedAt"];
+  const components = value["components"];
+  if (typeof packageName !== "string" || packageName === "" || typeof generatedAt !== "string" || generatedAt === "" || !isRecord(components)) return undefined;
+  const web = parsePiWebRuntimeComponent(components["web"]);
+  const sessiond = parsePiWebRuntimeComponent(components["sessiond"]);
+  const capabilities = parsePiWebCapabilities(value["capabilities"]);
+  if (web === undefined || sessiond === undefined || capabilities === undefined) return undefined;
+  return { packageName, generatedAt, components: { web, sessiond }, capabilities };
+}
+
+export function parsePiWebRuntimeComponent(value: unknown): PiWebRuntimeComponent | undefined {
+  if (!isRecord(value)) return undefined;
+  const component = value["component"];
+  const label = value["label"];
+  const runtimeVersion = value["runtimeVersion"];
+  const available = value["available"];
+  const capabilities = parsePiWebCapabilities(value["capabilities"]);
+  const error = value["error"];
+  if (component !== "web" && component !== "sessiond") return undefined;
+  if (typeof label !== "string" || label === "" || typeof available !== "boolean" || capabilities === undefined) return undefined;
+  return {
+    component,
+    label,
+    ...(typeof runtimeVersion === "string" ? { runtimeVersion } : {}),
+    available,
+    capabilities,
+    ...(typeof error === "string" ? { error } : {}),
+  };
+}
+
 export function parsePiWebComponentStatus(value: unknown): PiWebComponentStatus | undefined {
   if (!isRecord(value)) return undefined;
   const component = value["component"];
@@ -36,6 +70,11 @@ export function parsePiWebComponentStatus(value: unknown): PiWebComponentStatus
   };
 }
 
+function parsePiWebCapabilities(value: unknown): PiWebCapability[] | undefined {
+  if (!Array.isArray(value) || !value.every(isPiWebCapability)) return undefined;
+  return value;
+}
+
 export function parsePiWebInstallationInfo(value: unknown): PiWebInstallationInfo | undefined {
   if (!isRecord(value)) return undefined;
   const kind = value["kind"];