fix(dashboard): dispatch plugin routes dynamically per request

Plugin-defined HTTP routes were a boot-time snapshot of the launch
project's PluginLoader, while dashboard views/UI slots resolve a
project-scoped loader live per request. Two failure modes survived the
961edf214 no-engine mount fix: a plugin enabled after boot rendered its
view while every API route 404'd until restart, and a plugin enabled
only in a non-launch project never got routes mounted at all (Compound
Engineering "Failed to load sessions: Not found" on v0.73.0-beta.3).

Routes are now dispatched per request through the same
getProjectPluginLoader cache (moved from the plugins registrar into
routes/context.ts) that serves dashboard-views and enable/disable, with
the host loader + PluginRunner tables unioned in (project entries win,
loader beats runner). The compiled dispatch sub-router is cached per
resolved loader and rebuilt only when the route signature changes, so
views and routes agree by construction.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.changeset/dynamic-plugin-route-dispatch.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Plugin API routes now work for plugins enabled after startup or enabled only in a non-launch project.
+category: fix
+dev: Plugin-defined HTTP routes are dispatched per request through the shared project-scoped PluginLoader resolution (routes/context.ts getProjectPluginLoader) instead of a boot-time snapshot of the launch project's loader. Fixes Compound Engineering "Failed to load sessions/artifacts: Not found" persisting on v0.73.0-beta.3.

packages/dashboard/src/__tests__/plugin-routes-wiring.test.ts

@@ -185,4 +185,117 @@ describe("createPluginRouter wiring under /api/plugins", () => {
     expect(started.body).toEqual({ session: { id: "ce-1", status: "launching" } });
     expect(startHandler).toHaveBeenCalled();
   });
+
+  /*
+  FNXC:PluginRoutes 2026-07-22-20:30:
+  Plugin routes were a boot-time snapshot of the launch loader. Two failure modes survived
+  the loader-mount fix above: a plugin enabled AFTER boot rendered its dashboard view
+  (served live) while its API routes 404'd until restart, and a plugin enabled only in a
+  NON-LAUNCH project never got routes at all. Dispatch is per-request now — these tests
+  pin both invariants.
+  */
+  it("serves routes for a plugin enabled after the router was created (no restart)", async () => {
+    const helloHandler = vi.fn(async () => ({ ok: true }));
+    const routeTable: Array<{ pluginId: string; route: { method: string; path: string; handler: unknown } }> = [];
+
+    const pluginStore = {
+      listPlugins: vi.fn(async () => []),
+      getPlugin: vi.fn(async (id: string) => ({ id, settings: {}, enabled: true, manifest: { id, name: id, version: "1.0.0", description: "" } })),
+      enablePlugin: vi.fn(),
+      disablePlugin: vi.fn(),
+      registerPlugin: vi.fn(),
+      unregisterPlugin: vi.fn(),
+      updatePluginSettings: vi.fn(),
+      updatePluginState: vi.fn(),
+    } as any;
+
+    const pluginLoader = {
+      getPlugin: vi.fn((id: string) => (id === "late-plugin" && routeTable.length > 0 ? { manifest: { id } } : undefined)),
+      getPluginRoutes: vi.fn(() => [...routeTable]),
+      createRouteContext: vi.fn(async () => ({
+        pluginId: "late-plugin",
+        taskStore: {},
+        settings: {},
+        logger: { info: vi.fn(), warn: vi.fn(), error: vi.fn(), debug: vi.fn() },
+        emitEvent: vi.fn(),
+      })),
+      loadPlugin: vi.fn(),
+      stopPlugin: vi.fn(),
+    } as any;
+
+    const app = express();
+    app.use(express.json());
+    app.use("/api/plugins", createPluginRouter(pluginStore, pluginLoader, undefined, {} as any));
+    app.use((_req, res) => res.status(404).json({ error: "Not found" }));
+
+    // Before enable: no routes exist for the plugin.
+    const before = await performGet(app, "/api/plugins/late-plugin/hello");
+    expect(before.status).toBe(404);
+
+    // Enable-after-boot: the loader's route table grows; no router rebuild or restart.
+    routeTable.push({ pluginId: "late-plugin", route: { method: "GET", path: "/hello", handler: helloHandler } });
+
+    const after = await performGet(app, "/api/plugins/late-plugin/hello");
+    expect(after.status).toBe(200);
+    expect(after.body).toEqual({ ok: true });
+    expect(helloHandler).toHaveBeenCalled();
+  });
+
+  it("serves routes from the request's project-scoped loader and executes against it", async () => {
+    const projectHandler = vi.fn(async () => ({ project: true }));
+
+    const pluginStore = {
+      listPlugins: vi.fn(async () => []),
+      getPlugin: vi.fn(async (id: string) => ({ id, settings: {}, enabled: true, manifest: { id, name: id, version: "1.0.0", description: "" } })),
+      enablePlugin: vi.fn(),
+      disablePlugin: vi.fn(),
+      registerPlugin: vi.fn(),
+      unregisterPlugin: vi.fn(),
+      updatePluginSettings: vi.fn(),
+      updatePluginState: vi.fn(),
+    } as any;
+
+    // Launch/host loader has NO plugins — mirrors a daemon launched from a project
+    // where the plugin is not enabled.
+    const hostLoader = {
+      getPlugin: vi.fn(() => undefined),
+      getPluginRoutes: vi.fn(() => []),
+      createRouteContext: vi.fn(),
+      loadPlugin: vi.fn(),
+      stopPlugin: vi.fn(),
+    } as any;
+
+    const projectRouteContext = {
+      pluginId: "project-only-plugin",
+      taskStore: {},
+      settings: {},
+      logger: { info: vi.fn(), warn: vi.fn(), error: vi.fn(), debug: vi.fn() },
+      emitEvent: vi.fn(),
+    };
+    const projectLoader = {
+      getPlugin: vi.fn((id: string) => (id === "project-only-plugin" ? { manifest: { id } } : undefined)),
+      getPluginRoutes: vi.fn(() => [
+        { pluginId: "project-only-plugin", route: { method: "GET", path: "/data", handler: projectHandler } },
+      ]),
+      createRouteContext: vi.fn(async () => projectRouteContext),
+      loadPlugin: vi.fn(),
+      stopPlugin: vi.fn(),
+    } as any;
+
+    const resolveProjectPluginLoader = vi.fn(async () => projectLoader);
+
+    const app = express();
+    app.use(express.json());
+    app.use("/api/plugins", createPluginRouter(pluginStore, hostLoader, undefined, {} as any, resolveProjectPluginLoader));
+    app.use((_req, res) => res.status(404).json({ error: "Not found" }));
+
+    const res = await performGet(app, "/api/plugins/project-only-plugin/data");
+    expect(res.status).toBe(200);
+    expect(res.body).toEqual({ project: true });
+    expect(projectHandler).toHaveBeenCalled();
+    expect(resolveProjectPluginLoader).toHaveBeenCalled();
+    // Execution resolved through the project loader, never the host loader.
+    expect(projectLoader.createRouteContext).toHaveBeenCalledWith("project-only-plugin", expect.anything());
+    expect(hostLoader.createRouteContext).not.toHaveBeenCalled();
+  });
 });

packages/dashboard/src/__tests__/plugin-routes.routes.test.ts

@@ -1326,10 +1326,14 @@ describe("DELETE /plugins/:id", () => {
 });
 
 describe("plugin-defined route dispatch", () => {
-  it("registers PATCH routes from plugins", () => {
+  it("dispatches PATCH routes from plugins", async () => {
+    // FNXC:PluginRoutes 2026-07-22-20:30: plugin routes are dispatched dynamically per
+    // request now, so assert observable dispatch behavior instead of inspecting the
+    // boot-time Express router stack (which no longer contains plugin routes).
+    const patchHandler = vi.fn().mockResolvedValue({ patched: true });
     const pluginRunner = {
       getPluginRoutes: vi.fn().mockReturnValue([
-        { pluginId: "fusion-plugin-roadmap", route: { method: "PATCH", path: "/roadmaps/x", handler: vi.fn() } },
+        { pluginId: "fusion-plugin-roadmap", route: { method: "PATCH", path: "/roadmaps/x", handler: patchHandler } },
       ]),
     };
 
@@ -1345,9 +1349,14 @@ describe("plugin-defined route dispatch", () => {
       getPlugin: vi.fn().mockReturnValue({ manifest: { id: "fusion-plugin-roadmap" } }),
     } as any), pluginRunner as any, createMockTaskStore());
 
-    const stack = (router as any).stack as Array<{ route?: { path: string; methods: Record<string, boolean> } }>;
-    const patchRoute = stack.find((layer) => layer.route?.path === "/fusion-plugin-roadmap/roadmaps/x");
-    expect(patchRoute?.route?.methods.patch).toBe(true);
+    const app = express();
+    app.use(express.json());
+    app.use("/api/plugins", router);
+
+    const res = await REQUEST(app, "PATCH", "/api/plugins/fusion-plugin-roadmap/roadmaps/x", {});
+    expect(res.status).toBe(200);
+    expect(res.body).toEqual({ patched: true });
+    expect(patchHandler).toHaveBeenCalled();
   });
 
   it("passes scoped taskStore and createAiSession through pluginLoader.createRouteContext", async () => {

packages/dashboard/src/plugin-routes.ts

@@ -322,12 +322,17 @@ async function readAndValidateManifest(
  * @param pluginStore - Plugin store for persistence
  * @param pluginLoader - Plugin loader for lifecycle management
  * @param pluginRunner - Optional plugin runner for plugin-defined routes
+ * @param defaultTaskStore - Task store used when a request carries no projectId
+ * @param resolveProjectPluginLoader - Per-request project-scoped loader resolution
+ *   (routes/context.ts getProjectPluginLoader); when absent, dispatch falls back to
+ *   the host pluginLoader + pluginRunner route tables only.
  */
 export function createPluginRouter(
   pluginStore: PluginStore,
   pluginLoader: PluginLoader,
   pluginRunner?: PluginRunner,
   defaultTaskStore?: import("@fusion/core").TaskStore,
+  resolveProjectPluginLoader?: (req: Request) => Promise<PluginLoader | undefined>,
 ): Router {
   const router = Router();
 
@@ -703,29 +708,67 @@ export function createPluginRouter(
   "Failed to load sessions/artifacts: Not found" (catch-all 404) on every CE API
   call while the stage cards painted normally. Prefer loader entries on key
   collisions so handlers resolve against the same pluginLoader instance.
+
+  FNXC:PluginRoutes 2026-07-22-20:30:
+  Plugin routes are now dispatched DYNAMICALLY per request, not registered once at
+  boot. The boot-time snapshot had two live failure modes on v0.73.0-beta.3 even
+  after the fix above: (1) a plugin enabled after boot rendered its dashboard view
+  (served live via the project-scoped loader) while its routes stayed unmounted
+  until restart; (2) a plugin enabled only in a non-launch project NEVER got routes
+  mounted because the snapshot came from the launch project's loader. Dispatch
+  resolves the request's project-scoped loader (same routes/context.ts
+  getProjectPluginLoader cache the dashboard-views/enable endpoints use), unions in
+  the host loader + PluginRunner tables (project entries win, loader beats runner),
+  and executes each entry against the loader that owns its plugin instance. The
+  matching sub-router is cached per resolved loader and rebuilt only when the route
+  signature changes, so views and routes agree by construction.
   */
   type PluginRouteEntry = { pluginId: string; route: import("@fusion/core").PluginRouteDefinition };
-  const pluginRoutesByKey = new Map<string, PluginRouteEntry>();
-  const addPluginRoutes = (entries: PluginRouteEntry[]) => {
-    for (const entry of entries) {
-      const key = `${entry.pluginId}\0${entry.route.method}\0${entry.route.path}`;
-      pluginRoutesByKey.set(key, entry);
-    }
-  };
-  if (pluginRunner && typeof pluginRunner.getPluginRoutes === "function") {
-    addPluginRoutes(pluginRunner.getPluginRoutes());
-  }
-  const loaderRoutes = (pluginLoader as { getPluginRoutes?: () => PluginRouteEntry[] }).getPluginRoutes?.();
-  if (loaderRoutes) {
-    addPluginRoutes(loaderRoutes);
-  }
+  type DispatchEntry = PluginRouteEntry & { execLoader: PluginLoader };
 
-  for (const { pluginId, route } of pluginRoutesByKey.values()) {
+  const collectDispatchEntries = (resolvedLoader?: PluginLoader): Map<string, DispatchEntry> => {
+    const byKey = new Map<string, DispatchEntry>();
+    // First writer wins: project-scoped loader, then host loader, then runner.
+    const addPluginRoutes = (entries: PluginRouteEntry[] | undefined, execLoader: PluginLoader) => {
+      if (!entries) return;
+      for (const entry of entries) {
+        const key = `${entry.pluginId}\0${entry.route.method}\0${entry.route.path}`;
+        if (!byKey.has(key)) {
+          byKey.set(key, { ...entry, execLoader });
+        }
+      }
+    };
+    if (resolvedLoader && resolvedLoader !== pluginLoader) {
+      addPluginRoutes((resolvedLoader as { getPluginRoutes?: () => PluginRouteEntry[] }).getPluginRoutes?.(), resolvedLoader);
+    }
+    addPluginRoutes((pluginLoader as { getPluginRoutes?: () => PluginRouteEntry[] }).getPluginRoutes?.(), pluginLoader);
+    if (pluginRunner && typeof pluginRunner.getPluginRoutes === "function") {
+      // Runner entries execute against the host loader, matching the pre-dynamic
+      // behavior where handlers always resolved through pluginLoader.
+      addPluginRoutes(pluginRunner.getPluginRoutes(), pluginLoader);
+    }
+    return byKey;
+  };
+
+  const buildDispatchRouter = (entries: Map<string, DispatchEntry>): Router => {
+    const dispatchRouter = Router();
+    for (const { pluginId, route, execLoader } of entries.values()) {
+      registerPluginRoute(dispatchRouter, pluginId, route, execLoader);
+    }
+    return dispatchRouter;
+  };
+
+  const registerPluginRoute = (
+    targetRouter: Router,
+    pluginId: string,
+    route: import("@fusion/core").PluginRouteDefinition,
+    execLoader: PluginLoader,
+  ): void => {
     const fullPath = `/${pluginId}${route.path.startsWith("/") ? route.path : `/${route.path}`}`;
 
     const handler = catchHandler(async (req: Request, res: Response) => {
       // Get the plugin context
-      const plugin = pluginLoader.getPlugin(pluginId);
+      const plugin = execLoader.getPlugin(pluginId);
       if (!plugin) {
         throw notFound(`Plugin "${pluginId}" not loaded`);
       }
@@ -759,7 +802,7 @@ export function createPluginRouter(
         }
       }
 
-      const ctx: PluginContext = await pluginLoader.createRouteContext(pluginId, {
+      const ctx: PluginContext = await execLoader.createRouteContext(pluginId, {
         taskStore,
         settings,
         resolveProjectTaskStore: getOrCreateProjectStore,
@@ -808,22 +851,51 @@ export function createPluginRouter(
 
     switch (route.method) {
       case "GET":
-        router.get(fullPath, handler);
+        targetRouter.get(fullPath, handler);
         break;
       case "POST":
-        router.post(fullPath, handler);
+        targetRouter.post(fullPath, handler);
         break;
       case "PUT":
-        router.put(fullPath, handler);
+        targetRouter.put(fullPath, handler);
         break;
       case "PATCH":
-        router.patch(fullPath, handler);
+        targetRouter.patch(fullPath, handler);
         break;
       case "DELETE":
-        router.delete(fullPath, handler);
+        targetRouter.delete(fullPath, handler);
         break;
     }
-  }
+  };
+
+  // Cache the compiled dispatch router per resolved loader; the signature encodes
+  // route identity AND owning loader so enabling a plugin later (route set grows)
+  // or a plugin migrating from host to project loader both trigger a rebuild.
+  const dispatchRouterCache = new WeakMap<PluginLoader, { signature: string; router: Router }>();
+  const dispatchSignature = (entries: Map<string, DispatchEntry>, resolvedLoader?: PluginLoader): string =>
+    [...entries.entries()]
+      .map(([key, entry]) => `${key}\0${entry.execLoader === resolvedLoader ? "p" : "h"}`)
+      .sort()
+      .join("\n");
+
+  router.use((req: Request, res: Response, next: import("express").NextFunction) => {
+    void (async () => {
+      const resolvedLoader = resolveProjectPluginLoader ? await resolveProjectPluginLoader(req) : undefined;
+      const entries = collectDispatchEntries(resolvedLoader);
+      if (entries.size === 0) {
+        next();
+        return;
+      }
+      const signature = dispatchSignature(entries, resolvedLoader);
+      const cacheKey = resolvedLoader ?? pluginLoader;
+      let cached = dispatchRouterCache.get(cacheKey);
+      if (!cached || cached.signature !== signature) {
+        cached = { signature, router: buildDispatchRouter(entries) };
+        dispatchRouterCache.set(cacheKey, cached);
+      }
+      cached.router(req, res, next);
+    })().catch(next);
+  });
 
   return router;
 }

packages/dashboard/src/routes.ts

@@ -885,6 +885,7 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
     getProjectIdFromRequest,
     getScopedStore,
     getProjectContext,
+    getProjectPluginLoader,
     emitRemoteRouteDiagnostic,
     emitAuthSyncAuditLog,
     parseScopeParam,
@@ -909,6 +910,7 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
     getProjectIdFromRequest,
     getScopedStore,
     getProjectContext,
+    getProjectPluginLoader,
     emitRemoteRouteDiagnostic,
     emitAuthSyncAuditLog,
     parseScopeParam,
@@ -2002,6 +2004,17 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
         options.pluginLoader,
         pluginRunner,
         store,
+        /*
+        FNXC:PluginRoutes 2026-07-22-20:30:
+        Per-request project-scoped loader resolution for plugin-defined routes — the
+        same getProjectPluginLoader cache the plugin management registrar uses — so a
+        plugin enabled after boot, or enabled only in a non-launch project, serves its
+        API routes the moment its dashboard view appears.
+        */
+        async (req) => {
+          const { store: scopedStore, engine } = await routeContext.getProjectContext(req);
+          return routeContext.getProjectPluginLoader(scopedStore, engine);
+        },
       ),
     );
   }

packages/dashboard/src/routes/context.ts

@@ -284,6 +284,63 @@ export function createApiRoutesContext(store: TaskStore, options?: ServerOptions
   }
 
   const resolveScopedStore = (req: Request): Promise<TaskStore> => getScopedStore(req, store, options);
+
+  /*
+  FNXC:PluginEnablementScope 2026-07-21-12:00:
+  Plugin installation metadata is global, but every enabled/state decision belongs to the
+  TaskStore selected for the request's project. A dashboard launched from project A must not
+  use A's host loader after mutating project B: that loader reads A's project_plugin_states row
+  and can immediately report B's newly enabled plugin as disabled. Prefer B's running engine
+  loader; only reuse the host loader when it owns the same PluginStore, otherwise bind a loader
+  directly to B's TaskStore.
+
+  FNXC:PluginEnablementScope 2026-07-21-15:30:
+  A project without a live engine still needs one loader for its dashboard lifetime.
+  Creating one per request starts a plugin in enable(), then loses that instance before
+  disable(), UI-slot, contribution, and runtime reads. Cache by the resolved TaskStore so
+  all fallback readers share the same project_plugin_states key and loaded plugin instance.
+
+  FNXC:PluginEnablementScope 2026-07-22-20:30:
+  Moved here from register-plugins-automation.ts so plugin-defined HTTP route dispatch
+  (plugin-routes.ts) resolves through the SAME loader cache as dashboard-views/ui-slots/
+  enable/disable. When these used separate loader instances, a plugin enabled after boot or
+  enabled only in a non-launch project rendered its dashboard view while every one of its
+  API routes 404'd (Compound Engineering "Failed to load sessions: Not found").
+  */
+  const fallbackProjectLoaders = new WeakMap<TaskStore, {
+    loader: PluginLoader;
+    initialized: Promise<void>;
+  }>();
+
+  const getProjectPluginLoader = async (
+    scopedStore: TaskStore,
+    engine?: { getPluginRunner?: () => { getLoader?: () => PluginLoader } | undefined },
+  ): Promise<PluginLoader | undefined> => {
+    const engineLoader = engine?.getPluginRunner?.()?.getLoader?.();
+    if (engineLoader) return engineLoader;
+
+    const scopedPluginStore = scopedStore.getPluginStore();
+    if (scopedPluginStore === options?.pluginStore) return options?.pluginLoader;
+
+    let fallback = fallbackProjectLoaders.get(scopedStore);
+    if (!fallback) {
+      const loader = new PluginLoader({ pluginStore: scopedPluginStore as PluginStore, taskStore: scopedStore });
+      /*
+      FNXC:PluginEnablementScope 2026-07-21-20:15:
+      Dashboard-only projects lack an engine startup pass, so initialize their persistent scoped
+      loader once before introspection. Reusing this promise prevents ui-slots, contributions,
+      runtimes, and views from observing an empty loader after a dashboard restart.
+      */
+      fallback = {
+        loader,
+        initialized: loader.loadAllPlugins().then(() => undefined),
+      };
+      fallbackProjectLoaders.set(scopedStore, fallback);
+    }
+    await fallback.initialized;
+    return fallback.loader;
+  };
+
   const fallbackMcpLoaders = new WeakMap<TaskStore, { loader: PluginLoader; initialized: Promise<void> }>();
   const projectMcpProviders = new WeakMap<PluginLoader, ReturnType<typeof createProjectScopedPluginMcpProvider>>();
 
@@ -486,6 +543,7 @@ export function createApiRoutesContext(store: TaskStore, options?: ServerOptions
     getProjectIdFromRequest,
     getScopedStore: resolveScopedStore,
     getProjectContext: resolveProjectContext,
+    getProjectPluginLoader,
     emitRemoteRouteDiagnostic: (input) => emitRemoteRouteDiagnostic(runtimeLogger, input),
     emitAuthSyncAuditLog,
     parseScopeParam,

packages/dashboard/src/routes/register-plugins-automation.ts

@@ -1,5 +1,5 @@
 import type { NextFunction, Request, Response } from "express";
-import { AutomationStore, PluginLoader, RoutineStore, isWebhookTrigger, resolvePluginEntryPath, type RoutineTriggerType, type ScheduleType } from "@fusion/core";
+import { AutomationStore, RoutineStore, isWebhookTrigger, resolvePluginEntryPath, type RoutineTriggerType, type ScheduleType } from "@fusion/core";
 import { ApiError, badRequest, conflict, internalError, notFound } from "../api-error.js";
 import { verifyWebhookSignature } from "../github-webhooks.js";
 import { resolvePluginManifest } from "../plugin-routes.js";
@@ -21,58 +21,16 @@ FNXC:PluginsAutomationRoutes 2026-07-19-12:00:
 Automation, routine, and plugin-management endpoints live in this registrar so routes.ts remains an orchestrator. Preserve registration order: Express parameter matching makes operation paths and the registry pass-through precedence-sensitive.
 */
 export function registerPluginsAutomationRoutes(ctx: ApiRoutesContext, deps: PluginsAutomationRouteDependencies): void {
-  const { router, options, parseScopeParam, resolveAutomationStore, resolveRoutineStore, resolveRoutineRunner, getScopedStore, getProjectContext, rethrowAsApiError, runtimeLogger } = ctx;
+  const { router, options, parseScopeParam, resolveAutomationStore, resolveRoutineStore, resolveRoutineRunner, getScopedStore, getProjectContext, getProjectPluginLoader, rethrowAsApiError, runtimeLogger } = ctx;
   const makeRunStreamHandler = createAutomationRunStreamHandlerFactory({ parseScopeParam, rethrowAsApiError, ...deps });
 
   /*
-  FNXC:PluginEnablementScope 2026-07-21-12:00:
-  Plugin installation metadata is global, but every enabled/state decision belongs to the
-  TaskStore selected for the request's project. A dashboard launched from project A must not
-  use A's host loader after mutating project B: that loader reads A's project_plugin_states row
-  and can immediately report B's newly enabled plugin as disabled. Prefer B's running engine
-  loader; only reuse the host loader when it owns the same PluginStore, otherwise bind a loader
-  directly to B's TaskStore.
+  FNXC:PluginEnablementScope 2026-07-22-20:30:
+  getProjectPluginLoader moved to routes/context.ts so plugin-defined HTTP route dispatch
+  (plugin-routes.ts) shares the same project-scoped loader cache as the management and
+  introspection routes below. Do not re-introduce a registrar-local loader cache: split
+  caches are how dashboard-views could show a plugin whose API routes 404'd.
   */
-  /*
-  FNXC:PluginEnablementScope 2026-07-21-15:30:
-  A project without a live engine still needs one loader for its dashboard lifetime.
-  Creating one per request starts a plugin in enable(), then loses that instance before
-  disable(), UI-slot, contribution, and runtime reads. Cache by the resolved TaskStore so
-  all fallback readers share the same project_plugin_states key and loaded plugin instance.
-  */
-  const fallbackProjectLoaders = new WeakMap<import("@fusion/core").TaskStore, {
-    loader: PluginLoader;
-    initialized: Promise<void>;
-  }>();
-
-  const getProjectPluginLoader = async (
-    scopedStore: import("@fusion/core").TaskStore,
-    engine?: { getPluginRunner?: () => { getLoader?: () => PluginLoader } | undefined },
-  ): Promise<PluginLoader | undefined> => {
-    const engineLoader = engine?.getPluginRunner?.()?.getLoader?.();
-    if (engineLoader) return engineLoader;
-
-    const scopedPluginStore = scopedStore.getPluginStore();
-    if (scopedPluginStore === options?.pluginStore) return options?.pluginLoader;
-
-    let fallback = fallbackProjectLoaders.get(scopedStore);
-    if (!fallback) {
-      const loader = new PluginLoader({ pluginStore: scopedPluginStore, taskStore: scopedStore });
-      /*
-      FNXC:PluginEnablementScope 2026-07-21-20:15:
-      Dashboard-only projects lack an engine startup pass, so initialize their persistent scoped
-      loader once before introspection. Reusing this promise prevents ui-slots, contributions,
-      runtimes, and views from observing an empty loader after a dashboard restart.
-      */
-      fallback = {
-        loader,
-        initialized: loader.loadAllPlugins().then(() => undefined),
-      };
-      fallbackProjectLoaders.set(scopedStore, fallback);
-    }
-    await fallback.initialized;
-    return fallback.loader;
-  };
 
   // ── Automation / Scheduled Task Routes ────────────────────────────
   //

packages/dashboard/src/routes/types.ts

@@ -1,5 +1,5 @@
 import type { Request, RequestHandler, Router } from "express";
-import type { AutomationStore, RoutineStore, TaskStore } from "@fusion/core";
+import type { AutomationStore, PluginLoader, RoutineStore, TaskStore } from "@fusion/core";
 import type { ServerOptions } from "../server.js";
 import type { RuntimeLogger } from "../runtime-logger.js";
 
@@ -51,6 +51,16 @@ export interface ApiRoutesContext {
   getProjectIdFromRequest(req: Request): string | undefined;
   getScopedStore(req: Request): Promise<TaskStore>;
   getProjectContext(req: Request): Promise<ProjectContext>;
+  /*
+  FNXC:PluginEnablementScope 2026-07-22-20:30:
+  Single per-request plugin-loader resolution shared by plugin management/introspection
+  routes AND plugin-defined HTTP route dispatch, so navigation (dashboard-views) and the
+  routes it calls can never disagree about which plugins exist for a project.
+  */
+  getProjectPluginLoader(
+    scopedStore: TaskStore,
+    engine?: { getPluginRunner?: () => { getLoader?: () => PluginLoader } | undefined },
+  ): Promise<PluginLoader | undefined>;
   prioritizeProjectsForCurrentDirectory<T extends { path: string }>(projects: T[]): T[];
   emitRemoteRouteDiagnostic(input: RemoteRouteDiagnosticInput): void;
   emitAuthSyncAuditLog(input: AuthSyncAuditLogInput): void;