diff --git a/packages/app/src/utils/host-routes.test.ts b/packages/app/src/utils/host-routes.test.ts
index 830192816..cc20ecf3e 100644
--- a/packages/app/src/utils/host-routes.test.ts
+++ b/packages/app/src/utils/host-routes.test.ts
@@ -216,6 +216,14 @@ describe("projects settings routes", () => {
     expect(decodeURIComponent(segment)).toBe(projectKey);
   });
 
+  it("preserves whitespace in opaque project keys", () => {
+    const projectKey = "host:6:host-a:project:10:/repo/foo ";
+    const route = buildProjectSettingsRoute(projectKey);
+    const segment = route.slice("/settings/projects/".length);
+
+    expect(decodeURIComponent(segment)).toBe(projectKey);
+  });
+
   it("keeps an already-decoded opaque project key unchanged", () => {
     const projectKey = "remote:github.com/acme/app#subdir:packages/my%20app";
     expect(normalizeProjectSettingsRouteKey(projectKey)).toBe(projectKey);
diff --git a/packages/app/src/utils/host-routes.ts b/packages/app/src/utils/host-routes.ts
index c05d3c283..39e159f63 100644
--- a/packages/app/src/utils/host-routes.ts
+++ b/packages/app/src/utils/host-routes.ts
@@ -567,11 +567,10 @@ export function buildProjectsSettingsRoute() {
 }
 
 export function buildProjectSettingsRoute(projectKey: string) {
-  const normalized = trimNonEmpty(projectKey);
-  if (!normalized) {
+  if (!projectKey.trim()) {
     throw new Error("buildProjectSettingsRoute requires a non-empty projectKey");
   }
-  return `/settings/projects/${encodeSegment(normalized)}` as const;
+  return `/settings/projects/${encodeSegment(projectKey)}` as const;
 }
 
 export function normalizeProjectSettingsRouteKey(value: string | string[] | undefined): string {
diff --git a/packages/server/src/server/session.test.ts b/packages/server/src/server/session.test.ts
index 29cb619b0..d86cf4d29 100644
--- a/packages/server/src/server/session.test.ts
+++ b/packages/server/src/server/session.test.ts
@@ -3417,7 +3417,7 @@ describe("session workspace descriptors", () => {
     const messages: unknown[] = [];
     const workspace = {
       workspaceId: "ws-gh",
-      projectId: "remote:github.com/acme/app",
+      projectId: "prj_app",
       cwd: "/repo/app",
       kind: "local_checkout" as const,
       displayName: "app",
@@ -3425,7 +3425,8 @@ describe("session workspace descriptors", () => {
       archivedAt: null,
     };
     const project = {
-      projectId: "remote:github.com/acme/app",
+      projectId: "prj_app",
+      projectKey: "remote:github.com/acme/app",
       rootPath: "/repo/app",
       kind: "git" as const,
       displayName: "acme/app",
@@ -3436,7 +3437,10 @@ describe("session workspace descriptors", () => {
     const session = createSessionForTest({
       messages,
       workspaceRegistry: { get: vi.fn(), list: vi.fn().mockResolvedValue([workspace]) },
-      projectRegistry: { list: vi.fn().mockResolvedValue([project]), get: vi.fn() },
+      projectRegistry: {
+        list: vi.fn().mockResolvedValue([project]),
+        get: vi.fn().mockResolvedValue(project),
+      },
       workspaceGitService: {
         getSnapshot: vi.fn(),
         peekSnapshot: vi.fn(() =>
@@ -3465,8 +3469,10 @@ describe("session workspace descriptors", () => {
         entries: [
           expect.objectContaining({
             id: "ws-gh",
+            projectId: "prj_app",
+            projectKey: "remote:github.com/acme/app",
             project: expect.objectContaining({
-              projectKey: "remote:github.com/acme/app",
+              projectKey: "prj_app",
               projectName: "acme/app",
               workspaceName: "app",
               checkout: expect.objectContaining({
diff --git a/packages/server/src/server/session.ts b/packages/server/src/server/session.ts
index 8533e7d83..b2dc3612b 100644
--- a/packages/server/src/server/session.ts
+++ b/packages/server/src/server/session.ts
@@ -1691,7 +1691,7 @@ export class Session {
       fallbackWorktreeRoot: snapshot?.git.repoRoot,
     });
     return {
-      projectKey: project.projectKey ?? project.projectId,
+      projectKey: project.projectId,
       projectName: resolveProjectDisplayName(project),
       workspaceName: resolveWorkspaceDisplayName(workspace),
       checkout,
@@ -4206,6 +4206,9 @@ export class Session {
     return {
       id: workspace.workspaceId,
       projectId: workspace.projectId,
+      ...(resolvedProjectRecord?.projectKey
+        ? { projectKey: resolvedProjectRecord.projectKey }
+        : {}),
       projectDisplayName: resolvedProjectRecord
         ? resolveProjectDisplayName(resolvedProjectRecord)
         : workspace.projectId,