diff --git a/backend/app/main.py b/backend/app/main.py
index bd5b324..f1f76a2 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -11,6 +11,8 @@ from app.modules.project.application.services import ProjectService
 from app.modules.project.interfaces.http.router import router as project_router, init_router as init_project_router
 from app.modules.scanner.application.services import ScanService
 from app.modules.scanner.interfaces.http.router import router as scanner_router, init_router as init_scanner_router
+from app.modules.graph.application.services import GraphService
+from app.modules.graph.interfaces.http.router import router as graph_router, init_router as init_graph_router
 
 
 def create_app() -> FastAPI:
@@ -28,9 +30,14 @@ def create_app() -> FastAPI:
     scan_service = ScanService()
     init_scanner_router(project_service, scan_service)
 
+    # Wire Graph module
+    graph_service = GraphService()
+    init_graph_router(project_service, scan_service, graph_service)
+
     # Register routers
     app.include_router(project_router, prefix="/api")
     app.include_router(scanner_router, prefix="/api")
+    app.include_router(graph_router, prefix="/api")
 
     # Health check
     @app.get("/api/health")
diff --git a/backend/app/modules/graph/interfaces/http/router.py b/backend/app/modules/graph/interfaces/http/router.py
index e69de29..400e8bb 100644
--- a/backend/app/modules/graph/interfaces/http/router.py
+++ b/backend/app/modules/graph/interfaces/http/router.py
@@ -0,0 +1,56 @@
+"""Graph HTTP router — panorama and neighbor query endpoints."""
+
+from __future__ import annotations
+
+from dataclasses import asdict
+
+from fastapi import APIRouter
+
+from app.modules.project.application.services import ProjectService
+from app.modules.scanner.application.services import ScanService
+from app.modules.graph.application.services import GraphService
+
+router = APIRouter(prefix="/projects/{project_id}/graph", tags=["graph"])
+
+_project_service: ProjectService | None = None
+_scan_service: ScanService | None = None
+_graph_service: GraphService | None = None
+
+
+def init_router(
+    project_service: ProjectService,
+    scan_service: ScanService,
+    graph_service: GraphService,
+) -> None:
+    global _project_service, _scan_service, _graph_service
+    _project_service = project_service
+    _scan_service = scan_service
+    _graph_service = graph_service
+
+
+def _get_or_trigger_scan(project_id: str):
+    """Get cached scan or trigger a new one."""
+    result = _scan_service.get_latest_scan(project_id)
+    if result is None:
+        project = _project_service.get_project(project_id)
+        result = _scan_service.scan(project)
+    return result
+
+
+@router.get("")
+def get_graph(project_id: str):
+    """Build and return the full panorama graph for a project."""
+    _project_service.get_project(project_id)  # Ensure project exists (raises 404)
+    scan_result = _get_or_trigger_scan(project_id)
+    view = _graph_service.build_panorama(scan_result)
+    return asdict(view)
+
+
+@router.get("/nodes/{node_id}/neighbors")
+def get_neighbors(project_id: str, node_id: str):
+    """Return the subgraph of neighbors for a given node."""
+    _project_service.get_project(project_id)  # Ensure project exists (raises 404)
+    scan_result = _get_or_trigger_scan(project_id)
+    view = _graph_service.build_panorama(scan_result)
+    neighbors = _graph_service.get_neighbors(view, node_id)
+    return asdict(neighbors)
diff --git a/backend/tests/test_api_graph.py b/backend/tests/test_api_graph.py
new file mode 100644
index 0000000..431fc2e
--- /dev/null
+++ b/backend/tests/test_api_graph.py
@@ -0,0 +1,44 @@
+import pytest
+
+DESIGN_DIR = "/workspace/arch-design-agent-skill-dashboard/design"
+
+
+@pytest.fixture
+def project_id(client):
+    r = client.post("/api/projects", json={"name": "test", "design_dir": DESIGN_DIR})
+    return r.json()["id"]
+
+
+def test_get_graph(client, project_id):
+    r = client.get(f"/api/projects/{project_id}/graph")
+    assert r.status_code == 200
+    data = r.json()
+    assert "nodes" in data
+    assert "edges" in data
+    assert "groups" in data
+    assert len(data["nodes"]) > 0
+    assert len(data["groups"]) == 5
+
+
+def test_get_graph_auto_scans(client, project_id):
+    """Graph endpoint should auto-scan if no cached scan exists."""
+    r = client.get(f"/api/projects/{project_id}/graph")
+    assert r.status_code == 200
+
+
+def test_get_neighbors(client, project_id):
+    # First trigger a scan via graph endpoint
+    client.get(f"/api/projects/{project_id}/graph")
+    r = client.get(f"/api/projects/{project_id}/graph/nodes/CAP-PROJ-REG/neighbors")
+    assert r.status_code == 200
+    data = r.json()
+    assert "nodes" in data
+    assert len(data["nodes"]) > 0
+
+
+def test_get_neighbors_unknown_node(client, project_id):
+    client.get(f"/api/projects/{project_id}/graph")
+    r = client.get(f"/api/projects/{project_id}/graph/nodes/NONEXISTENT/neighbors")
+    assert r.status_code == 200
+    data = r.json()
+    assert len(data["nodes"]) == 0