diff --git a/tests/backend/http_api_contract_helpers.py b/tests/backend/http_api_contract_helpers.py
new file mode 100644
index 0000000..8285af7
--- /dev/null
+++ b/tests/backend/http_api_contract_helpers.py
@@ -0,0 +1,70 @@
+"""Helpers for HTTP API route contract checks (meshchat.py vs frontend)."""
+
+from __future__ import annotations
+
+import json
+import re
+from pathlib import Path
+
+_ROUTE_DECORATOR = re.compile(
+    r'@routes\.(get|post|patch|delete|put)\(\s*(?:\n\s*)?["\']([^"\']+)["\']',
+    re.MULTILINE,
+)
+
+
+def extract_meshchat_http_routes(meshchat_py: Path) -> list[dict[str, str]]:
+    text = meshchat_py.read_text(encoding="utf-8")
+    rows: list[dict[str, str]] = []
+    for m in _ROUTE_DECORATOR.finditer(text):
+        rows.append({"method": m.group(1).upper(), "path": m.group(2)})
+    rows.sort(key=lambda x: (x["path"], x["method"]))
+    return rows
+
+
+def path_matches_aiohttp_route(route: str, path: str) -> bool:
+    pattern = ""
+    i = 0
+    while i < len(route):
+        if route[i] == "{":
+            j = route.find("}", i)
+            if j == -1:
+                return False
+            pattern += "[^/]+"
+            i = j + 1
+        else:
+            pattern += re.escape(route[i])
+            i += 1
+    return re.fullmatch(pattern, path) is not None
+
+
+def extract_frontend_api_paths(frontend_root: Path) -> set[str]:
+    out: set[str] = set()
+    for path in list(frontend_root.rglob("*.vue")) + list(frontend_root.rglob("*.js")):
+        if "node_modules" in path.parts:
+            continue
+        text = path.read_text(encoding="utf-8")
+        for m in re.finditer(r"`(/api/v1[^`]+)`", text):
+            s = m.group(1).split("?")[0]
+            s = re.sub(r"\$\{[^}]+\}", "a", s)
+            out.add(s)
+        for m in re.finditer(r'["\'](/api/v1[^"\']+)["\']', text):
+            s = m.group(1).split("?")[0]
+            if "${" in s:
+                continue
+            out.add(s)
+    return out
+
+
+def load_route_fixture(fixture_path: Path) -> list[dict[str, str]]:
+    data = json.loads(fixture_path.read_text(encoding="utf-8"))
+    routes = data["routes"]
+    routes.sort(key=lambda x: (x["path"], x["method"]))
+    return routes
+
+
+def write_route_fixture(fixture_path: Path, routes: list[dict[str, str]]) -> None:
+    fixture_path.parent.mkdir(parents=True, exist_ok=True)
+    fixture_path.write_text(
+        json.dumps({"routes": routes}, indent=2) + "\n",
+        encoding="utf-8",
+    )
diff --git a/tests/backend/test_http_api_contract.py b/tests/backend/test_http_api_contract.py
new file mode 100644
index 0000000..29a7434
--- /dev/null
+++ b/tests/backend/test_http_api_contract.py
@@ -0,0 +1,42 @@
+"""Contract tests: aiohttp routes in meshchat.py vs checked-in manifest; frontend /api/v1 usage."""
+
+import os
+from pathlib import Path
+
+import pytest
+
+from tests.backend.http_api_contract_helpers import (
+    extract_frontend_api_paths,
+    extract_meshchat_http_routes,
+    load_route_fixture,
+    path_matches_aiohttp_route,
+    write_route_fixture,
+)
+
+_REPO_ROOT = Path(__file__).resolve().parents[2]
+_MESHCHAT_PY = _REPO_ROOT / "meshchatx" / "meshchat.py"
+_FRONTEND_ROOT = _REPO_ROOT / "meshchatx" / "src" / "frontend"
+_FIXTURE = Path(__file__).resolve().parent / "fixtures" / "http_api_routes.json"
+
+
+def test_meshchat_http_routes_match_fixture():
+    live = extract_meshchat_http_routes(_MESHCHAT_PY)
+    if os.environ.get("UPDATE_HTTP_API_ROUTES") == "1":
+        write_route_fixture(_FIXTURE, live)
+        pytest.skip("UPDATE_HTTP_API_ROUTES=1: fixture updated; re-run without the env var")
+    expected = load_route_fixture(_FIXTURE)
+    assert live == expected, (
+        "HTTP route list drifted. If you added or renamed routes, run: "
+        "UPDATE_HTTP_API_ROUTES=1 poetry run pytest tests/backend/test_http_api_contract.py -k "
+        "meshchat_http_routes_match_fixture"
+    )
+
+
+def test_frontend_api_paths_exist_on_backend():
+    backend_paths = [r["path"] for r in extract_meshchat_http_routes(_MESHCHAT_PY)]
+    frontend_paths = extract_frontend_api_paths(_FRONTEND_ROOT)
+    missing = []
+    for fp in sorted(frontend_paths):
+        if not any(path_matches_aiohttp_route(br, fp) for br in backend_paths):
+            missing.append(fp)
+    assert not missing, f"Frontend references unknown HTTP paths: {missing}"
diff --git a/tests/backend/test_reticulum_live_network.py b/tests/backend/test_reticulum_live_network.py
new file mode 100644
index 0000000..c952fc5
--- /dev/null
+++ b/tests/backend/test_reticulum_live_network.py
@@ -0,0 +1,42 @@
+"""
+Optional live Reticulum smoke test.
+
+Reticulum is a process-wide singleton; this test runs a short script in a
+subprocess so it does not interfere with other tests.
+
+Enable with: MESHCHAT_LIVE_RETICULUM=1
+
+This does not replace multi-node mesh interoperability testing; it only
+verifies that a default-config Reticulum instance can start and exit cleanly
+in an isolated config directory (useful after RNS upgrades or OS changes).
+"""
+
+import os
+import subprocess
+import sys
+
+import pytest
+
+_RUN = os.environ.get("MESHCHAT_LIVE_RETICULUM") == "1"
+
+
+@pytest.mark.integration
+@pytest.mark.skipif(not _RUN, reason="Set MESHCHAT_LIVE_RETICULUM=1 to run live Reticulum subprocess smoke test")
+def test_reticulum_subprocess_start_and_exit():
+    script = r"""
+import tempfile
+import RNS
+
+tmpdir = tempfile.mkdtemp(prefix="meshchat_rns_live_")
+try:
+    RNS.Reticulum(configdir=tmpdir, loglevel=RNS.LOG_ERROR)
+finally:
+    RNS.exit(0)
+"""
+    result = subprocess.run(
+        [sys.executable, "-c", script],
+        capture_output=True,
+        text=True,
+        timeout=120,
+    )
+    assert result.returncode == 0, result.stderr + result.stdout