Rewrite Next.js local BFF routes and mock catalog.

Projects, report, and graph JSON handlers overlay from periscope/src. Clerk proxy stays the inherited open-core seam.

periscope/src/frontend/src/app/(app)/api/_project-json.ts

@@ -0,0 +1,30 @@
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+import { NextResponse } from "next/server";
+
+const SIBLING_ROOT = path.resolve(process.cwd(), "..");
+
+function safeSegment(id: string): string | null {
+  if (!id || id.includes("/") || id.includes("\\") || id === "." || id === "..") {
+    return null;
+  }
+  return id;
+}
+
+export async function jsonFromProjectFile(
+  id: string,
+  filename: string,
+  missing: string,
+): Promise<NextResponse> {
+  const projectId = safeSegment(id);
+  if (!projectId) {
+    return NextResponse.json({ error: missing }, { status: 404 });
+  }
+  const filePath = path.join(SIBLING_ROOT, projectId, filename);
+  try {
+    const raw = await readFile(filePath, "utf-8");
+    return NextResponse.json(JSON.parse(raw) as unknown);
+  } catch {
+    return NextResponse.json({ error: missing }, { status: 404 });
+  }
+}

periscope/src/frontend/src/app/(app)/api/graph/[id]/route.ts

@@ -0,0 +1,9 @@
+import { jsonFromProjectFile } from "../../_project-json";
+
+export async function GET(
+  _req: Request,
+  { params }: { params: Promise<{ id: string }> },
+) {
+  const { id } = await params;
+  return jsonFromProjectFile(id, "design_graph.json", "Graph not found");
+}

periscope/src/frontend/src/app/(app)/api/projects/route.ts

@@ -0,0 +1,6 @@
+import { NextResponse } from "next/server";
+import { PROJECTS } from "@/lib/mock-data";
+
+export async function GET() {
+  return NextResponse.json(PROJECTS);
+}

periscope/src/frontend/src/app/(app)/api/report/[id]/route.ts

@@ -0,0 +1,9 @@
+import { jsonFromProjectFile } from "../../_project-json";
+
+export async function GET(
+  _req: Request,
+  { params }: { params: Promise<{ id: string }> },
+) {
+  const { id } = await params;
+  return jsonFromProjectFile(id, "report.json", "Report not found");
+}

periscope/src/frontend/src/lib/mock-data.ts

@@ -0,0 +1,47 @@
+import type { PipelineStep, Project } from "./types";
+
+/** Demo row for the local Next BFF when the FastAPI catalog is not in front. */
+export const PROJECTS: Project[] = [
+  {
+    id: "simple_project",
+    name: "TI MSP Tutorial Board",
+    created: "2026-04-09T00:00:00Z",
+    status: "complete",
+    summary: { total: 8, ERROR: 2, WARNING: 4, INFO: 2 },
+    hasNetlist: true,
+    hasBom: true,
+    datasheetCount: 3,
+  },
+];
+
+function pending(title: string, description: string, substeps: PipelineStep["substeps"]): PipelineStep {
+  return { title, description, status: "pending", substeps };
+}
+
+function pendingItem(key: string, label: string) {
+  return { key, label, status: "pending" as const };
+}
+
+export function createPipelineSteps(): PipelineStep[] {
+  return [
+    pending("IC Datasheet Extraction", "Parse component datasheets and extract constraints", [
+      pendingItem("SPX3819M5-L-3-3/TR", "SPX3819M5-L-3-3/TR (U1)"),
+      pendingItem("CH340E", "CH340E (U2)"),
+      pendingItem("MSPM0G3507SPTR", "MSPM0G3507SPTR (U3)"),
+    ]),
+    pending("Passive Pattern Extraction", "Resolve passive component values from MPN patterns", [
+      pendingItem("samsung", "Samsung capacitors"),
+      pendingItem("uniroyal", "Uniroyal resistors"),
+    ]),
+    pending("Build Design Graph", "Parse BOM and netlist into structured graph", [
+      pendingItem("parse-bom", "Parse BOM (17 components)"),
+      pendingItem("parse-netlist", "Parse netlist (36 nets)"),
+      pendingItem("enrich", "Enrich with datasheet data"),
+    ]),
+    pending("Review Design", "Review each IC against its datasheet", [
+      pendingItem("U1", "Review U1 — LDO"),
+      pendingItem("U2", "Review U2 — USB Bridge"),
+      pendingItem("U3", "Review U3 — MCU"),
+    ]),
+  ];
+}

tests/test_periscope_frontend_bff_rewrite.py

@@ -0,0 +1,58 @@
+"""Next.js BFF routes for local JSON live under periscope/src."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+SRC = ROOT / "periscope" / "src" / "frontend" / "src"
+
+
+def _text(rel: str) -> str:
+    path = SRC / rel
+    assert path.is_file(), rel
+    return path.read_text(encoding="utf-8")
+
+
+def test_bff_routes_are_src():
+    for rel in (
+        "lib/mock-data.ts",
+        "app/(app)/api/_project-json.ts",
+        "app/(app)/api/projects/route.ts",
+        "app/(app)/api/report/[id]/route.ts",
+        "app/(app)/api/graph/[id]/route.ts",
+    ):
+        head = _text(rel)[:400]
+        assert "Native Periscope overlay" not in head
+
+
+def test_projects_route_serves_mock_catalog():
+    route = _text("app/(app)/api/projects/route.ts")
+    assert "export async function GET" in route
+    assert "PROJECTS" in route
+    mock = _text("lib/mock-data.ts")
+    assert "export const PROJECTS" in mock
+    assert "simple_project" in mock
+    assert "export function createPipelineSteps" in mock
+
+
+def test_report_and_graph_read_sibling_json():
+    report = _text("app/(app)/api/report/[id]/route.ts")
+    graph = _text("app/(app)/api/graph/[id]/route.ts")
+    helper = _text("app/(app)/api/_project-json.ts")
+    assert "report.json" in report
+    assert "Report not found" in report
+    assert "design_graph.json" in graph
+    assert "Graph not found" in graph
+    assert "jsonFromProjectFile" in helper
+    assert "params: Promise<{ id: string }>" in report
+    assert "params: Promise<{ id: string }>" in graph
+
+
+def test_proxy_stays_clerk_seam_in_dependency():
+    src_proxy = ROOT / "periscope" / "src" / "frontend" / "src" / "proxy.ts"
+    dep_proxy = ROOT / "periscope" / "dependency" / "frontend" / "src" / "proxy.ts"
+    assert not src_proxy.exists()
+    text = dep_proxy.read_text(encoding="utf-8")
+    assert "Open-core seam" in text
+    assert "export function proxy" in text