# SDD Design: Service Credential Tester

**Change:** `service-credential-tester`
**Phase:** design
**Date:** 2026-07-09

## 0. Source findings (read before anything else)

The proposal and spec were written against a mental model. Reading actual source surfaced deviations the design must account for. Trust source, not assumptions.

| Spec/proposal claim | Actual source reality | Design impact |
|---|---|---|
| Spec CT-115: "the edit dialog on `ServicePage.tsx`" | **`ServicePage.tsx` has no edit dialog.** It's a read-only tabbed view (Overview + content tabs + Widgets). Service editing lives in `Settings.tsx` as `ServiceConfigEditor` (a master-detail panel, lines ~1435–1596). The "Save" button calls `saveService.mutateAsync(buildInput())` directly (no try/catch — a latent error-swallow like the pre-#1-fix create dialog). | The Test button is added to **two** edit surfaces: `CreateServiceDialog` (ServicesPage.tsx) and `ServiceConfigEditor` (Settings.tsx). NOT ServicePage.tsx. Spec CT-115 should note this textual drift. |
| Proposal §5.1.3: "the edit dialog on `ServicePage.tsx`" | Same as above. | Same fix — target is `Settings.tsx::ServiceConfigEditor`. |
| Spec CT-109: "ssh_tasks test reuses the `test_machine_ssh` connect flow" | `test_machine_ssh` (settings.py:122–180) is a **router endpoint**, not a reusable function. Its logic (build client → connect → translate errors) is inlined. However, `build_ssh_client` in `task_runner.py` already builds an `RemoteSSHClient` from a `ServiceRecord` — the exact pattern needed. | The ssh_tasks test routine constructs an `RemoteSSHClient` via `build_ssh_client(store, service_record)` and calls `.connect()`, then translates errors using the same message patterns as `test_machine_ssh` (protocol banner / auth failed). It needs a `SettingsStore` (for SSH key resolution) — see §3.6 for how test_callables get store access. |
| Proposal: "construct a `QbittorrentClient` from the config + decrypted secrets" | `QbittorrentClient.__init__(base_url, username, password, timeout)` takes **positional strings**, not a `config` dict. The `qbittorrent` config has `base_url` + `timeout_seconds`; secrets have `username` + `password`. | The test routine extracts fields from `config`/`secrets` dicts explicitly: `QbittorrentClient(config["base_url"], secrets["username"], secrets["password"], config.get("timeout_seconds", 10))`. |
| Proposal: "Alertmanager test probes `/api/v2/alerts`" | `AlertmanagerWidgetSource.fetch` (sources.py) already hits `/api/v2/alerts` with optional bearer auth. The exact URL pattern + auth-header logic is reusable. | The test routine mirrors the widget source's request shape (GET `{base_url}/api/v2/alerts`, optional `Authorization: Bearer {api_key}`). |
| Proposal: "Authentik test probes its directory endpoint" | `routers/authentik_users.py::_build_client` builds an `AuthentikClient(base_url, api_token, timeout)`. The client has a `.users()` method that hits the directory endpoint. | The test routine constructs an `AuthentikClient` and calls `.users(page=1, page_size=1)` — the lightest possible probe. |
| Proposal: "Nextcloud test probes `/status.php`" | `NextcloudConfig` has `base_url` + `username` (not a ServiceBaseUrl). Secret is `app_password`. `/status.php` is unauthenticated. | The test routine does a simple `GET {base_url}/status.php` (no auth headers); extracts `version` from the JSON response. |
| Proposal: "test_callable field on `ServiceDefinition`" | `ServiceDefinition` is a `@dataclass(frozen=True)` with fields: `service_type, name, description, config_model, secret_fields, widget_kinds`. Adding `test_callable` after `widget_kinds` works (dataclass field ordering — it has a default). | New field `test_callable: TestCallable | None = None` placed last. The type alias `TestCallable = Callable[[dict[str, Any], dict[str, str], SettingsStore], TestResult]` includes the store for SSH key resolution. |

No proposal/spec scope change is required — the *intent* (per-type credential tester) still holds. The findings above refine implementation details and correct the edit-surface target.

---

## 1. Architecture overview

A new `POST /api/services/test` endpoint validates the input (reusing `_validate_input`), resolves the service definition's `test_callable`, and runs it. Each integration declares its own `test_connection` routine alongside its `DEFINITION`. A shared error-translation helper maps common exception types to human-friendly strings. The frontend gains a Test button + result pill + gating in both the create dialog and the settings edit panel.

```
 POST /api/services/test
   └► _validate_input(body)              → 422 on malformed config (CT-102)
   └► definition = get_service_definition(body.service_type)
   └► if definition.test_callable is None → {ok: true, detail: "No test..."} (CT-103/111)
   └► result = test_callable(config, secrets, store)
        └► per-type routine:
             qbittorrent → QbittorrentClient.maindata()
             prometheus  → POST {grafana_url}/api/ds/query (expr "up")
             alertmanager → GET {base_url}/api/v2/alerts
             jellyfin    → JellyfinClient.users()
             authentik   → AuthentikClient.users(page=1, page_size=1)
             ssh_tasks   → RemoteSSHClient.connect() via build_ssh_client
             nextcloud   → GET {base_url}/status.php
        └► translate_connection_error(exc) → TestResult(ok=False, detail=...)
   └► return {ok, detail, evidence}      → HTTP 200 (CT-101)
```

No persistence. No secrets in logs. Auth-gated identically to every other `/api/services/*` endpoint.

---

## 2. Core data structures

### 2.1 TestResult dataclass (CT-101)

**File:** `backend/src/media_library_viewer_api/integrations/base.py`

```python
@dataclass(frozen=True)
class TestResult:
    """Outcome of a credential/connectivity test for a service instance."""
    ok: bool
    detail: str
    evidence: str | None = None
```

### 2.2 TestCallable type alias + test_callable field on ServiceDefinition

**File:** `backend/src/media_library_viewer_api/integrations/base.py`

```python
from typing import Callable

# A test routine receives (config, secrets, store). The store is needed for
# ssh_tasks (SSH-key resolution via store.get_ssh_key). Other types ignore it.
TestCallable = Callable[["dict[str, Any]", "dict[str, str]", "SettingsStore"], TestResult]
```

`ServiceDefinition` gains (placed last, after `widget_kinds`, with a default):

```python
@dataclass(frozen=True)
class ServiceDefinition:
    service_type: str
    name: str
    description: str
    config_model: type[ServiceConfigBase]
    secret_fields: list[SecretField]
    widget_kinds: list[WidgetKind]
    test_callable: TestCallable | None = None  # NEW — placed last
```

**Why `SettingsStore` in the signature:** `ssh_tasks` needs `store.get_ssh_key(ssh_key_id)` to resolve the private key material. Every other type ignores it. Making it a uniform parameter avoids a special-case dispatch for one type.

### 2.3 Shared error-translation helper

**File:** `backend/src/media_library_viewer_api/integrations/base.py` (or a new `integrations/test_helpers.py` if base.py gets too large — design recommends base.py for discoverability)

```python
def translate_connection_error(exc: Exception, *, context: str = "") -> TestResult:
    """Map a common connection/auth exception to a human-friendly TestResult.

    Handles the patterns extracted from ``test_machine_ssh`` (settings.py) plus
    the HTTP-client patterns from the widget sources.
    """
    message = str(exc)
    lowered = message.lower()

    # Auth failures (HTTP 401/403 or auth-specific strings)
    if isinstance(exc, requests.HTTPError):
        status_code = exc.response.status_code if exc.response is not None else 0
        if status_code in (401, 403):
            return TestResult(ok=False, detail=f"Authentication failed — the service rejected the credentials ({status_code}).")
    if "authentication failed" in lowered or "no authentication methods available" in lowered:
        return TestResult(ok=False, detail="Authentication failed — check the credentials, API key, or SSH key.")

    # Connection refused / DNS / unreachable
    if isinstance(exc, (requests.ConnectionError, ConnectionRefusedError, OSError)):
        if "name or service not known" in lowered or "nodename nor servname" in lowered or "getaddrinfo failed" in lowered:
            return TestResult(ok=False, detail="Host not found — check the URL/hostname for typos.")
        return TestResult(ok=False, detail="Connection refused — the service is not reachable at the configured address.")

    # SSL / certificate errors
    if "ssl" in lowered or "certificate" in lowered:
        return TestResult(ok=False, detail="SSL/TLS error — the service's certificate is invalid or untrusted.")

    # Timeout
    if isinstance(exc, (requests.Timeout, TimeoutError, asyncio.TimeoutError)):
        return TestResult(ok=False, detail="Connection timed out — the service did not respond in time.")

    # SSH banner (from test_machine_ssh pattern)
    if "protocol banner" in lowered:
        return TestResult(ok=False, detail="SSH banner not received — confirm the SSH service is running and the port is correct.")

    # Fallback
    prefix = f"{context}: " if context else ""
    return TestResult(ok=False, detail=f"{prefix}{message[:200]}")
```

Each per-type routine wraps its probe in `try/except` and calls `translate_connection_error` for unexpected exceptions, but handles its **type-specific** auth failures directly (e.g., qBit `"Fails."` response).

---

## 3. Per-type test routines

Each routine lives alongside its integration's `DEFINITION`. The signature is `(config: dict, secrets: dict, store: SettingsStore) -> TestResult`. All use `requests` (synchronous) wrapped in a short timeout — no asyncio needed (the endpoint handler calls the callable synchronously).

### 3.1 qbittorrent (CT-104)

**File:** `backend/src/media_library_viewer_api/integrations/qbittorrent.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """Login + probe maindata; surface auth failures specifically."""
    try:
        base_url = str(config.get("base_url") or "")
        username = str(secrets.get("username") or "")
        password = str(secrets.get("password") or "")
        timeout = int(config.get("timeout_seconds") or 10)
        client = QbittorrentClient(base_url, username, password, timeout=timeout)
        data = client.maindata()
        version = str(data.get("server_state", {}).get("qbittorrent_version", "") or "connected")
        return TestResult(ok=True, detail="Connected to qBittorrent.", evidence=version)
    except RuntimeError as exc:
        # QbittorrentClient._login raises RuntimeError("qBittorrent login failed: Fails.")
        lowered = str(exc).lower()
        if "login failed" in lowered:
            return TestResult(ok=False, detail="Authentication failed — qBittorrent rejected the credentials.")
        return translate_connection_error(exc, context="qBittorrent")
    except Exception as exc:
        return translate_connection_error(exc, context="qBittorrent")
```

**Evidence:** qBittorrent version from `server_state` (fallback `"connected"`).

### 3.2 prometheus (CT-105)

**File:** `backend/src/media_library_viewer_api/integrations/prometheus.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """POST {grafana_url}/api/ds/query with expr 'up' via the Grafana gateway."""
    try:
        grafana_url = str(config.get("grafana_url") or "").rstrip("/")
        api_key = str(secrets.get("grafana_api_key") or "")
        datasource_uid = str(config.get("datasource_uid") or "prometheus")
        timeout = int(config.get("timeout_seconds") or 10)
        if not grafana_url:
            return TestResult(ok=False, detail="Grafana gateway URL is required.")
        if not api_key:
            return TestResult(ok=False, detail="Grafana API key is required.")
        body = {
            "queries": [{"datasource": {"uid": datasource_uid, "type": "prometheus"},
                          "expr": "up", "format": "time_series",
                          "intervalMs": 15000, "maxDataPoints": 1, "refId": "A"}],
            "from": "now-1m", "to": "now",
        }
        resp = requests.post(
            f"{grafana_url}/api/ds/query", json=body, timeout=timeout,
            headers={"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"},
        )
        resp.raise_for_status()
        return TestResult(ok=True, detail="Grafana gateway reachable.", evidence="Gateway reachable; datasource responded.")
    except requests.HTTPError as exc:
        return translate_connection_error(exc, context="Prometheus via Grafana")
    except Exception as exc:
        return translate_connection_error(exc, context="Prometheus via Grafana")
```

**Evidence:** `"Gateway reachable; datasource responded."` — validates the full path (Grafana up + datasource reachable + Prom responding).

### 3.3 alertmanager (CT-106)

**File:** `backend/src/media_library_viewer_api/integrations/alertmanager.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """GET /api/v2/alerts (or /api/v2/status) with optional bearer auth."""
    try:
        base_url = str(config.get("base_url") or "").rstrip("/")
        timeout = int(config.get("timeout_seconds") or 5)
        headers = {}
        api_key = str(secrets.get("api_key") or "")
        if api_key:
            headers["Authorization"] = f"Bearer {api_key}"
        resp = requests.get(f"{base_url}/api/v2/status", headers=headers, timeout=timeout)
        resp.raise_for_status()
        payload = resp.json()
        version = str(payload.get("versionInfo", {}).get("version", "") or "connected")
        return TestResult(ok=True, detail="Connected to Alertmanager.", evidence=version)
    except Exception as exc:
        return translate_connection_error(exc, context="Alertmanager")
```

**Evidence:** Alertmanager cluster version from `/api/v2/status`.

### 3.4 jellyfin (CT-107)

**File:** `backend/src/media_library_viewer_api/integrations/jellyfin.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """Call JellyfinClient.users() — the lightest authenticated probe."""
    try:
        base_url = str(config.get("base_url") or "")
        api_key = str(secrets.get("api_key") or "")
        timeout = int(config.get("timeout_seconds") or 10)
        client = JellyfinClient(base_url, api_key, timeout=timeout)
        users = client.users()
        return TestResult(ok=True, detail="Connected to Jellyfin.", evidence=f"{len(users)} users")
    except Exception as exc:
        return translate_connection_error(exc, context="Jellyfin")
```

**Evidence:** `"<N> users"`.

### 3.5 authentik (CT-108)

**File:** `backend/src/media_library_viewer_api/integrations/authentik.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """Probe AuthentikClient.users(page=1, page_size=1) — lightest directory call."""
    try:
        base_url = str(config.get("base_url") or "").rstrip("/")
        api_token = str(secrets.get("api_token") or "")
        timeout = float(config.get("timeout_seconds") or 10)
        client = AuthentikClient(base_url=base_url, api_token=api_token, timeout=timeout)
        result = client.users(page=1, page_size=1)
        return TestResult(ok=True, detail="Connected to Authentik.", evidence=f"{result.get('total', 0)} users")
    except Exception as exc:
        return translate_connection_error(exc, context="Authentik")
```

**Evidence:** `"<N> users"` from the directory total.

### 3.6 ssh_tasks (CT-109)

**File:** `backend/src/media_library_viewer_api/integrations/ssh_tasks.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """Build an SSH client via build_ssh_client and attempt .connect().

    Reuses the same error-translation patterns as test_machine_ssh (banner,
    auth failed). Known-host recording is preserved (first successful connect
    records the host key, same as test_machine_ssh).
    """
    from media_library_viewer_api.services.task_runner import build_ssh_client
    from media_library_viewer_api.widgets.sources import ServiceRecord

    host = str(config.get("host") or "").strip()
    port = int(config.get("port") or 22)
    try:
        service = ServiceRecord(id="", service_type="ssh_tasks", name="test",
                                config=config, secrets=secrets, enabled=True)
        client = build_ssh_client(store, service)
        try:
            client.connect()
        except Exception as exc:
            lowered = str(exc).lower()
            if "protocol banner" in lowered:
                return TestResult(ok=False, detail=f"SSH banner not received from {host}:{port}; confirm the SSH service is running.")
            if "no authentication methods available" in lowered or "authentication failed" in lowered:
                return TestResult(ok=False, detail=f"SSH authentication failed for {host}:{port}; check the SSH key, passphrase, or username.")
            return translate_connection_error(exc, context=f"SSH {host}:{port}")
        finally:
            client.close()
        return TestResult(ok=True, detail=f"SSH connection succeeded for {host}:{port}.", evidence=f"Connected to {host}:{port}")
    except ValueError as exc:
        return TestResult(ok=False, detail=str(exc))
    except Exception as exc:
        return translate_connection_error(exc, context=f"SSH {host}:{port}")
```

**Evidence:** `"Connected to <host>:<port>"`. **Known-host recording:** preserved — `RemoteSSHClient.connect()` records the host key on first successful connect (same as `test_machine_ssh`).

### 3.7 nextcloud (CT-110)

**File:** `backend/src/media_library_viewer_api/integrations/nextcloud.py`

```python
def test_connection(config: dict[str, Any], secrets: dict[str, str], store: SettingsStore) -> TestResult:
    """GET {base_url}/status.php (unauthenticated server probe)."""
    try:
        base_url = str(config.get("base_url") or "").rstrip("/")
        resp = requests.get(f"{base_url}/status.php", timeout=10)
        resp.raise_for_status()
        payload = resp.json()
        version = str(payload.get("version", "") or "connected")
        return TestResult(ok=True, detail="Connected to Nextcloud.", evidence=version)
    except Exception as exc:
        return translate_connection_error(exc, context="Nextcloud")
```

**Evidence:** Nextcloud version from `/status.php`.

### 3.8 backups (CT-111)

**File:** `backend/src/media_library_viewer_api/integrations/backups.py`

```python
# No test_connection function. The DEFINITION's test_callable stays None (default).
# The endpoint returns {ok: true, detail: "No connection test for this service type"}.
```

---

## 4. Backend endpoint design

### 4.1 POST /api/services/test (CT-101, CT-102, CT-103, CT-112, CT-113)

**File:** `backend/src/media_library_viewer_api/routers/services.py`

```python
from media_library_viewer_api.integrations.base import TestResult

@router.post("/test")
def test_instance(
    body: ServiceInstanceInput,
    store: SettingsStore = Depends(get_settings_store),
) -> dict[str, Any]:
    """Test connectivity + credentials for unsaved service input.

    Validates first (422 on malformed config), dispatches to the per-type
    test_callable, and returns {ok, detail, evidence}. Does NOT persist.
    """
    _validate_input(body)  # raises HTTPException(422) on bad config/type/secrets
    definition = require_service_definition(body.service_type)

    if definition.test_callable is None:
        logger.info("test requested type=%s ok=true (no test_callable)", body.service_type)
        return {"ok": True, "detail": "No connection test for this service type", "evidence": None}

    try:
        result: TestResult = definition.test_callable(body.config, body.secrets, store)
    except Exception as exc:
        # A routine should never raise (it catches internally), but defend.
        logger.exception("test_callable raised for type=%s", body.service_type)
        result = TestResult(ok=False, detail=f"Test failed unexpectedly: {exc}")

    logger.info("test requested type=%s ok=%s", body.service_type, result.ok)
    return {"ok": result.ok, "detail": result.detail, "evidence": result.evidence}
```

**Key properties:**

- **Validation-first** (CT-102): `_validate_input` runs before any network call. Malformed config → 422 with the same detail format as create.
- **No persistence** (CT-112): no `store.upsert_service`, no `store.update_setting`. The body is consumed and discarded.
- **No secret logging** (CT-113): only `test requested type=%s ok=%s` at INFO. No body/config/secrets in any log line.
- **Dispatch** (CT-103): keys off `definition.test_callable` (None → default ok response).

### 4.2 DEFINITION updates — wiring test_callable

Each integration's `DEFINITION` gains `test_callable=test_connection`:

```python
# integrations/qbittorrent.py
DEFINITION = ServiceDefinition(
    ...,
    test_callable=test_connection,
)

# integrations/backups.py
DEFINITION = ServiceDefinition(
    ...,  # test_callable stays None (default)
)
```

Every integration module that has a `test_connection` function imports `TestResult` + `translate_connection_error` from `base.py` and `requests` as needed.

---

## 5. Frontend design

### 5.1 TestResult type (CT-114)

**File:** `frontend/src/types/index.ts`

```typescript
export interface ServiceTestResult {
  ok: boolean;
  detail: string;
  evidence: string | null;
}
```

### 5.2 API client function (CT-114)

**File:** `frontend/src/api/services.ts`

```typescript
import type { ServiceTestResult } from "../types";

export async function testServiceInstance(
  input: ServiceInstanceInput,
): Promise<ServiceTestResult> {
  return post<ServiceTestResult>("/api/services/test", input);
}
```

### 5.3 useTestServiceInstance hook (CT-114)

**File:** `frontend/src/hooks/useServices.ts`

```typescript
import { testServiceInstance } from "../api/services";

export function useTestServiceInstance() {
  return useMutation({
    mutationFn: (input: ServiceInstanceInput) => testServiceInstance(input),
  });
}
```

No cache invalidation needed — the test is a one-shot mutation with no query to refresh.

### 5.4 Shared ServiceTestPanel component

**File:** `frontend/src/components/ServiceTestPanel.tsx` (NEW — shared by both surfaces)

Both `CreateServiceDialog` and `ServiceConfigEditor` need the same UI: a Test button, a result pill, testPassed state, and Save-anyway toggle. Extracting it avoids duplication.

```tsx
interface Props {
  input: ServiceInstanceInput | null;  // null = no draft yet
  onTestPassed: (passed: boolean) => void;
}

export function ServiceTestPanel({ input, onTestPassed }: Props) {
  const testService = useTestServiceInstance();
  const [result, setResult] = useState<ServiceTestResult | null>(null);
  const [saveAnyway, setSaveAnyway] = useState(false);

  // Clear result when input changes (CT-118)
  useEffect(() => {
    setResult(null);
    onTestPassed(false);
  }, [input]);  // input is a new object on every field edit → re-test required

  async function handleTest() {
    if (!input) return;
    setResult(null);
    try {
      const res = await testService.mutateAsync(input);
      setResult(res);
      onTestPassed(res.ok);
    } catch (err) {
      setResult({ ok: false, detail: err instanceof Error ? err.message : String(err), evidence: null });
      onTestPassed(false);
    }
  }

  const testPassed = result?.ok === true;
  const canSave = testPassed || saveAnyway;

  return (
    <div className="flex flex-col gap-2">
      <Button variant="outline" size="sm" onClick={handleTest} disabled={testService.isPending || !input}>
        {testService.isPending ? "Testing…" : "Test credentials"}
      </Button>
      {result ? (
        <Alert variant={result.ok ? "default" : "destructive"}>
          <AlertDescription>
            {result.ok ? `✓ Connected${result.evidence ? ` — ${result.evidence}` : ""}` : `✗ ${result.detail}`}
          </AlertDescription>
        </Alert>
      ) : null}
      <label className="flex items-center gap-2 text-xs text-muted-foreground">
        <input type="checkbox" checked={saveAnyway} onChange={(e) => { setSaveAnyway(e.target.checked); onTestPassed(e.target.checked || testPassed); }} />
        Save anyway (skip test)
      </label>
      {/* Hidden signal: parent reads canSave via onTestPassed callback */}
    </div>
  );
}
```

**CT-118 (field-edit clears result):** the `useEffect([input])` triggers on every render where `input` is a new object reference (React state updates create new objects). Since `setDraft({...draft, config})` creates a new object, any field edit resets the result.

**CT-117 (Save gating):** the parent passes `onTestPassed` to track the gating state. The parent's confirm button is disabled unless `testPassed || saveAnyway`.

### 5.5 Integration into CreateServiceDialog (CT-115, CT-117)

**File:** `frontend/src/pages/ServicesPage.tsx`

```tsx
function CreateServiceDialog({ open, onClose }) {
  // ... existing state ...
  const [testPassed, setTestPassed] = useState(false);

  function reset() {
    setDraft(null);
    setSubmitError(null);
    setTestPassed(false);
  }

  // Build the input object from the draft (for the test panel)
  const testInput: ServiceInstanceInput | null = draft ? {
    service_type: draft.serviceType,
    name: draft.name.trim(),
    config: draft.config,
    secrets: draft.secrets,
    enabled: draft.enabled,
  } : null;

  return (
    <Dialog ...>
      <DialogContent>
        {/* ... existing fields ... */}
        {draft ? (
          <ServiceTestPanel input={testInput} onTestPassed={setTestPassed} />
        ) : null}
        {submitError ? <Alert variant="destructive">...</Alert> : null}
        {draft ? (
          <DialogFooter
            onCancel={reset}
            onConfirm={save}
            confirmLabel="Create service"
            confirmDisabled={!draft.name.trim() || saveService.isPending || !testPassed}
          />
        ) : null}
      </DialogContent>
    </Dialog>
  );
}
```

### 5.6 Integration into ServiceConfigEditor (CT-115, CT-117)

**File:** `frontend/src/pages/Settings.tsx`

```tsx
function ServiceConfigEditor({ instance, typeInfo }) {
  // ... existing state ...
  const [testPassed, setTestPassed] = useState(false);

  const testInput: ServiceInstanceInput = {
    id: instance.id,
    service_type: instance.service_type,
    name,
    config: draftConfig,
    secrets: Object.fromEntries(Object.entries(draftSecrets).filter(([, v]) => v !== "")),
    enabled,
  };

  return (
    <>
      <div className="rounded-lg border p-4">
        {/* ... existing fields ... */}
        <ServiceTestPanel input={testInput} onTestPassed={setTestPassed} />
        <div className="flex justify-between">
          <Button onClick={handleSave} disabled={saveService.isPending || !testPassed}>Save</Button>
          {/* ... delete button ... */}
        </div>
      </div>
    </>
  );
}
```

---

## 6. Slice plan

### Slice 1: Backend (~300–380 lines)

**Goal:** endpoint + test_callable + shared helper + 7 per-type routines + tests.

| Task | File(s) | Lines |
|---|---|---|
| `TestResult` dataclass + `TestCallable` type + `translate_connection_error` helper | `integrations/base.py` | ~60 |
| `test_callable` field on `ServiceDefinition` | `integrations/base.py` | ~3 |
| 7 per-type `test_connection` routines + wire into DEFINITIONs | `integrations/{qbittorrent,prometheus,alertmanager,jellyfin,authentik,ssh_tasks,nextcloud}.py` | ~180 |
| `POST /api/services/test` endpoint | `routers/services.py` | ~30 |
| Backend tests: per-type mocked routines, endpoint dispatch, validation-first, no-persistence | `tests/test_services.py` + `tests/test_api.py` | ~120 |

**Exit gate:** `pytest` + `ruff` green.

### Slice 2: Frontend (~250–320 lines)

**Goal:** API client + hook + shared Test panel + wire into both surfaces + tests.

| Task | File(s) | Lines |
|---|---|---|
| `ServiceTestResult` type | `types/index.ts` | ~5 |
| `testServiceInstance` API function | `api/services.ts` | ~5 |
| `useTestServiceInstance` hook | `hooks/useServices.ts` | ~8 |
| `ServiceTestPanel` component | `components/ServiceTestPanel.tsx` | ~70 |
| Wire into `CreateServiceDialog` | `pages/ServicesPage.tsx` | ~20 |
| Wire into `ServiceConfigEditor` | `pages/Settings.tsx` | ~15 |
| Frontend tests: panel renders both states, button fires mutation, gating, field-clear | `components/__tests__/ServiceTestPanel.test.tsx` + existing page tests | ~130 |

**Exit gate:** `npm run build` + `npm run lint` + `npm run test` green.

---

## 7. Test strategy

### 7.1 Backend tests (CT-119)

- **Per-type test_connection** (mocked): each routine gets a success case (mocked client returns data → `{ok: true, evidence: ...}`) and at least one failure case (mocked client raises → `{ok: false, detail: ...}`). qBit gets a specific `"Fails."` auth-failure test.
- **Endpoint dispatch**: `POST /api/services/test` with each service type dispatches correctly; backups returns the default ok-no-test.
- **Validation-first**: schema-less URL → 422, no network call mocked.
- **No-persistence**: call `/test`, assert store count unchanged.

### 7.2 Frontend tests (CT-120)

- **ServiceTestPanel**: renders Test button; click fires mocked mutation; success → green pill with evidence; failure → red pill with detail; Save-anyway checkbox toggles gating.
- **CreateServiceDialog**: confirm disabled until test passes; Save anyway re-enables; editing a field clears the result.
- **ServiceConfigEditor**: same gating behavior.

---

## 8. Security considerations

- **No persistence** (CT-112): the endpoint never calls any `store.*` method except read-only `get_ssh_key` (for SSH key resolution in ssh_tasks). No `upsert_service`, no `update_setting`.
- **No secret logging** (CT-113): only `test requested type=%s ok=%s` at INFO. No request body in logs. The `sanitize_log_extra` helper is available if structured logging is added later.
- **Auth gating**: identical to every other `/api/services/*` endpoint (JWT/API-key via the app-level middleware).
- **Secrets in transit**: plaintext in the request body over TLS — identical to the existing `POST /api/services/instances` create endpoint. No new attack surface.
- **Timeout**: each routine uses a short timeout (≤10s) from the service config. No long-running probes.

---

## 9. Key design decisions summary

1. **`TestResult` is a frozen dataclass** in `integrations/base.py` — immutable, serializable, co-located with the `ServiceDefinition` it augments.
2. **`test_callable` signature includes `SettingsStore`** — needed for ssh_tasks SSH-key resolution; other types ignore it. Uniform signature avoids per-type dispatch special-cases.
3. **`translate_connection_error` is shared** — extracts the `test_machine_ssh` message-translation pattern into a reusable helper covering HTTP errors, connection errors, SSL, timeout, SSH banner. Type-specific auth failures (qBit `"Fails."`) are handled in-routine.
4. **`POST /api/services/test` validation-first** — reuses `_validate_input` so malformed configs get the same 422 as create. The #1 validation-surfacing fix covers this endpoint too.
5. **Shared `ServiceTestPanel` component** — extracted to avoid duplicating the Test button + pill + gating between `CreateServiceDialog` and `ServiceConfigEditor`.
6. **Field-edit-clears-result via `useEffect([input])`** — React state updates create new object references on every edit, naturally clearing the result without explicit field-tracking.
7. **Prometheus test queries via Grafana gateway** — mirrors `MetricSource._gateway_query` exactly (`POST /api/ds/query` with `expr: "up"`). No direct Prom.
8. **ssh_tasks test reuses `build_ssh_client`** — the same `task_runner.build_ssh_client(store, ServiceRecord)` that powers task execution, wrapped with the `test_machine_ssh` error-translation patterns.