diff --git a/.env.example b/.env.example
index 2b1feca7..3875ece0 100644
--- a/.env.example
+++ b/.env.example
@@ -12,6 +12,11 @@ ORTHOPHOTO_RESOLUTION_M=1.0
 ORTHOPHOTO_MIN_SIDE_M=128
 ORTHOPHOTO_MAX_SIDE_M=1024
 ORTHOPHOTO_CACHE_TTL_HOURS=24
+SOURCE_CATALOG_PROBE_ENABLED=true
+SOURCE_CATALOG_GRB_WFS_URL=https://geo.api.vlaanderen.be/GRB/wfs
+SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS=10
+SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB=2
+SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS=900
 DHMV_ENABLED=true
 DHMV_WCS_URL=https://geo.api.vlaanderen.be/DHMV/wcs
 DHMV_RESOLUTION_M=5.0
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 19d8330b..e623c765 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,18 @@
 
 # Changelog
 
+## Sprint 222 Official source edition probes (2026-07-16)
+
+- Added explicit, read-only GRB and most-recent orthophoto catalog probes using
+  official WFS/WMS capabilities and linked ISO 19139 CSW metadata records.
+- Added bounded response sizes, timeouts, provider-isolated failures, a short
+  cache and strict metadata-host/path validation. No provider features, raster
+  pixels or application data are fetched or modified.
+- Added canonical API, compact opt-in Status UI and operator CLI support. The
+  local source-freshness audit remains automatic and provider-free.
+- Added deterministic XML/network-boundary tests and editable Compose/Unraid
+  controls without changing migrations or persistence contracts.
+
 ## Sprint 221 Governed source freshness audit (2026-07-16)
 
 - Added a project-wide read-only source report derived from Dataset,
diff --git a/backend/README.md b/backend/README.md
index 8ce811bc..af97d7d3 100644
--- a/backend/README.md
+++ b/backend/README.md
@@ -1443,3 +1443,29 @@ docker exec geointel python /app/scripts/audit_source_freshness.py \
 
 Use `--fail-on due` to make a planned review date fail automation, or
 `--fail-on never` for reporting only. The command never starts a refresh.
+
+An operator can explicitly add the official GRB and orthophoto edition check:
+
+```bash
+docker exec geointel python /app/scripts/audit_source_freshness.py \
+  --project-id 82a85913-c522-45d7-84a1-02b393d89e55 \
+  --api-url http://127.0.0.1/api/v1 \
+  --probe-catalogs \
+  --output /app/storage/operator-evidence/source-freshness/with-catalogs.json
+```
+
+Use `--refresh-catalogs` to bypass the 15-minute in-memory cache and
+`--fail-on-catalog` only when temporary official-provider unavailability must
+fail an operator job. This path reads bounded WFS/WMS capabilities and their
+fixed ISO 19139 metadata records. It confirms GRB `GBG`, `WBN`, `WGO`, `ADP`
+and orthophoto `Ortho`, `Vliegdagcontour`; it never requests feature or raster
+content. The public Datavindplaats API requires an access token, so release
+evidence comes from the public metadata links published by the official OGC
+services rather than HTML scraping.
+
+Runtime controls are `SOURCE_CATALOG_PROBE_ENABLED`,
+`SOURCE_CATALOG_GRB_WFS_URL`, `SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS`,
+`SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB` and
+`SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS`. Metadata links remain restricted to
+the official HTTPS CSW path on `metadata.vlaanderen.be` even when an operator
+overrides the capabilities endpoint.
diff --git a/backend/app/api/routes/datasets.py b/backend/app/api/routes/datasets.py
index a6c31b40..212c4cff 100644
--- a/backend/app/api/routes/datasets.py
+++ b/backend/app/api/routes/datasets.py
@@ -45,6 +45,7 @@ from app.services.vector_operations_service import VectorOperationsService
 from app.services.vector_feature_service import VectorFeatureService
 from app.services.dataset_service import DatasetService
 from app.services.source_freshness_service import SourceFreshnessService
+from app.services.source_catalog_probe_service import SourceCatalogProbeService
 from app.services.orthophoto_acquisition_service import OrthophotoAcquisitionService
 from app.services.dhmv_acquisition_service import DhmvAcquisitionService
 from app.services.terrain_analysis_service import TerrainAnalysisService
@@ -255,6 +256,16 @@ def audit_dataset_source_freshness(
     return envelope(report.model_dump())
 
 
+@router.get("/datasets/source-catalog-probes", response_model=dict)
+def probe_dataset_source_catalogs(
+    project_id: UUID,
+    refresh: bool = Query(default=False),
+    db: Session = Depends(get_db),
+):
+    report = SourceCatalogProbeService.audit_project(db, project_id, force=refresh)
+    return envelope(report.model_dump())
+
+
 @router.get("/datasets/{dataset_id}", response_model=dict)
 def get_dataset(
     project_id: UUID,
diff --git a/backend/app/core/config.py b/backend/app/core/config.py
index 83af58c3..ca22b1fd 100644
--- a/backend/app/core/config.py
+++ b/backend/app/core/config.py
@@ -31,6 +31,29 @@ class Settings(BaseSettings):
     orthophoto_timeout_seconds: int = Field(default=120, ge=1, validation_alias="ORTHOPHOTO_TIMEOUT_SECONDS")
     orthophoto_max_response_mb: int = Field(default=32, ge=1, validation_alias="ORTHOPHOTO_MAX_RESPONSE_MB")
     orthophoto_cache_ttl_hours: int = Field(default=24, ge=0, validation_alias="ORTHOPHOTO_CACHE_TTL_HOURS")
+    source_catalog_probe_enabled: bool = Field(default=True, validation_alias="SOURCE_CATALOG_PROBE_ENABLED")
+    source_catalog_grb_wfs_url: str = Field(
+        default="https://geo.api.vlaanderen.be/GRB/wfs",
+        validation_alias="SOURCE_CATALOG_GRB_WFS_URL",
+    )
+    source_catalog_probe_timeout_seconds: int = Field(
+        default=10,
+        ge=1,
+        le=60,
+        validation_alias="SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS",
+    )
+    source_catalog_probe_max_response_mb: int = Field(
+        default=2,
+        ge=1,
+        le=10,
+        validation_alias="SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB",
+    )
+    source_catalog_probe_cache_ttl_seconds: int = Field(
+        default=900,
+        ge=0,
+        le=86_400,
+        validation_alias="SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS",
+    )
     dhmv_enabled: bool = Field(default=True, validation_alias="DHMV_ENABLED")
     dhmv_wcs_url: str = Field(
         default="https://geo.api.vlaanderen.be/DHMV/wcs",
diff --git a/backend/app/schemas/__init__.py b/backend/app/schemas/__init__.py
index 610db024..9bc80ab4 100644
--- a/backend/app/schemas/__init__.py
+++ b/backend/app/schemas/__init__.py
@@ -11,6 +11,11 @@ from .source_freshness import (
     SourceFreshnessSummary,
     SourceIntegritySummary,
 )
+from .source_catalog import (
+    SourceCatalogProbeItem,
+    SourceCatalogProbeReport,
+    SourceCatalogProbeSummary,
+)
 from .detection import (
     DetectionListResponse,
     DetectionModelCapability,
@@ -141,6 +146,9 @@ __all__ = [
     "SourceFreshnessReport",
     "SourceFreshnessSummary",
     "SourceIntegritySummary",
+    "SourceCatalogProbeItem",
+    "SourceCatalogProbeReport",
+    "SourceCatalogProbeSummary",
     "DetectionListResponse",
     "DetectionModelCapability",
     "DetectionModelsResponse",
diff --git a/backend/app/schemas/source_catalog.py b/backend/app/schemas/source_catalog.py
new file mode 100644
index 00000000..664b5baa
--- /dev/null
+++ b/backend/app/schemas/source_catalog.py
@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Literal
+from uuid import UUID
+
+from pydantic import BaseModel
+
+
+SourceCatalogProbeStatus = Literal["available", "degraded", "unavailable", "disabled"]
+SourceCatalogComparisonStatus = Literal["same", "different", "not_comparable", "no_local_data", "unavailable"]
+
+
+class SourceCatalogProbeItem(BaseModel):
+    source_name: str
+    display_name: str
+    service_type: Literal["WFS", "WMS"]
+    endpoint_url: str
+    status: SourceCatalogProbeStatus
+    reachable: bool
+    checked_at: datetime
+    cached: bool = False
+    expected_layers: list[str]
+    matched_layers: list[str]
+    missing_layers: list[str]
+    advertised_layer_count: int
+    metadata_url: str | None = None
+    metadata_identifier: str | None = None
+    remote_title: str | None = None
+    remote_version: str | None = None
+    remote_modified_at: datetime | None = None
+    remote_published_at: datetime | None = None
+    local_source_version: str | None = None
+    comparison_status: SourceCatalogComparisonStatus
+    capabilities_sha256: str | None = None
+    capabilities_etag: str | None = None
+    capabilities_last_modified_at: datetime | None = None
+    message: str
+    error_code: str | None = None
+
+
+class SourceCatalogProbeSummary(BaseModel):
+    provider_count: int
+    available_count: int
+    degraded_count: int
+    unavailable_count: int
+    disabled_count: int
+    different_version_count: int
+
+
+class SourceCatalogProbeReport(BaseModel):
+    project_id: UUID
+    generated_at: datetime
+    summary: SourceCatalogProbeSummary
+    items: list[SourceCatalogProbeItem]
+    limitations: list[str]
diff --git a/backend/app/services/source_catalog_probe_service.py b/backend/app/services/source_catalog_probe_service.py
new file mode 100644
index 00000000..fae36671
--- /dev/null
+++ b/backend/app/services/source_catalog_probe_service.py
@@ -0,0 +1,545 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, replace
+from datetime import datetime, timedelta, timezone
+from email.utils import parsedate_to_datetime
+from hashlib import sha256
+import re
+from threading import Lock
+from typing import Any, Callable
+from urllib.error import HTTPError, URLError
+from urllib.parse import parse_qsl, urlencode, urlsplit, urlunsplit
+from urllib.request import Request, urlopen
+from uuid import UUID
+from xml.etree import ElementTree
+
+from sqlalchemy.orm import Session
+
+from app.core.config import Settings, get_settings
+from app.core.errors import AppError
+from app.models import Dataset, Project
+from app.schemas.source_catalog import (
+    SourceCatalogProbeItem,
+    SourceCatalogProbeReport,
+    SourceCatalogProbeSummary,
+)
+
+
+_GMD = "http://www.isotc211.org/2005/gmd"
+_GCO = "http://www.isotc211.org/2005/gco"
+_WFS = "http://www.opengis.net/wfs/2.0"
+_XLINK = "http://www.w3.org/1999/xlink"
+_METADATA_HOST = "metadata.vlaanderen.be"
+_VERSION_DATE = re.compile(r"^(?:toestand\s+)?(\d{4}-\d{2}-\d{2})$", re.IGNORECASE)
+_ORTHOPHOTO_EDITION = re.compile(r"^\d{4}\.\d{2}$")
+
+
+class CatalogProbeFailure(RuntimeError):
+    def __init__(self, code: str, message: str) -> None:
+        super().__init__(message)
+        self.code = code
+        self.message = message
+
+
+@dataclass(frozen=True)
+class ProbeContract:
+    source_name: str
+    display_name: str
+    service_type: str
+    endpoint_url: str
+    expected_layers: tuple[str, ...]
+
+
+@dataclass(frozen=True)
+class FetchResult:
+    content: bytes
+    content_type: str
+    etag: str | None
+    last_modified_at: datetime | None
+    final_url: str
+
+
+@dataclass(frozen=True)
+class RemoteProbe:
+    status: str
+    reachable: bool
+    checked_at: datetime
+    expected_layers: tuple[str, ...]
+    matched_layers: tuple[str, ...] = ()
+    missing_layers: tuple[str, ...] = ()
+    advertised_layer_count: int = 0
+    metadata_url: str | None = None
+    metadata_identifier: str | None = None
+    remote_title: str | None = None
+    remote_version: str | None = None
+    remote_modified_at: datetime | None = None
+    remote_published_at: datetime | None = None
+    capabilities_sha256: str | None = None
+    capabilities_etag: str | None = None
+    capabilities_last_modified_at: datetime | None = None
+    message: str = ""
+    error_code: str | None = None
+    cached: bool = False
+
+
+@dataclass(frozen=True)
+class CacheEntry:
+    expires_at: datetime
+    probe: RemoteProbe
+
+
+_REMOTE_CACHE: dict[str, CacheEntry] = {}
+_CACHE_LOCK = Lock()
+
+
+def _utc(value: datetime | None = None) -> datetime:
+    current = value or datetime.now(timezone.utc)
+    if current.tzinfo is None:
+        return current.replace(tzinfo=timezone.utc)
+    return current.astimezone(timezone.utc)
+
+
+def _header(headers: Any, name: str) -> str | None:
+    value = headers.get(name) if headers is not None else None
+    return str(value).strip() if value is not None and str(value).strip() else None
+
+
+def _http_date(value: str | None) -> datetime | None:
+    if not value:
+        return None
+    try:
+        return _utc(parsedate_to_datetime(value))
+    except (TypeError, ValueError, OverflowError):
+        return None
+
+
+def _with_capabilities_query(base_url: str, service_type: str) -> str:
+    parsed = urlsplit(base_url)
+    retained = [(key, value) for key, value in parse_qsl(parsed.query) if key.lower() not in {"service", "request", "version"}]
+    version = "2.0.0" if service_type == "WFS" else "1.3.0"
+    query = urlencode([*retained, ("SERVICE", service_type), ("VERSION", version), ("REQUEST", "GetCapabilities")])
+    return urlunsplit((parsed.scheme, parsed.netloc, parsed.path, query, ""))
+
+
+def _bounded_fetch(url: str, settings: Settings, opener: Callable[..., Any] | None = None) -> FetchResult:
+    request = Request(
+        url,
+        headers={"Accept": "application/xml,text/xml,application/json", "User-Agent": "GeoIntel/0.1 source-catalog-probe"},
+    )
+    max_bytes = settings.source_catalog_probe_max_response_mb * 1024 * 1024
+    try:
+        with (opener or urlopen)(request, timeout=settings.source_catalog_probe_timeout_seconds) as response:
+            content_length = _header(response.headers, "Content-Length")
+            if content_length:
+                try:
+                    if int(content_length) > max_bytes:
+                        raise CatalogProbeFailure("CATALOG_RESPONSE_TOO_LARGE", "De officiële metadatarespons overschrijdt de ingestelde limiet.")
+                except ValueError as exc:
+                    raise CatalogProbeFailure("CATALOG_INVALID_RESPONSE", "De officiële metadatarespons bevat een ongeldige Content-Length.") from exc
+            content = response.read(max_bytes + 1)
+            result = FetchResult(
+                content=content,
+                content_type=_header(response.headers, "Content-Type") or "",
+                etag=_header(response.headers, "ETag"),
+                last_modified_at=_http_date(_header(response.headers, "Last-Modified")),
+                final_url=str(response.geturl()) if hasattr(response, "geturl") else url,
+            )
+    except CatalogProbeFailure:
+        raise
+    except (HTTPError, URLError, TimeoutError, OSError) as exc:
+        raise CatalogProbeFailure("CATALOG_PROVIDER_UNAVAILABLE", "De officiële catalogus kon niet tijdig worden gelezen.") from exc
+    if len(result.content) > max_bytes:
+        raise CatalogProbeFailure("CATALOG_RESPONSE_TOO_LARGE", "De officiële metadatarespons overschrijdt de ingestelde limiet.")
+    return result
+
+
+def _local_name(tag: str) -> str:
+    return tag.rsplit("}", 1)[-1]
+
+
+def _direct_text(parent: ElementTree.Element, name: str) -> str | None:
+    for child in parent:
+        if _local_name(child.tag) == name and child.text and child.text.strip():
+            return child.text.strip()
+    return None
+
+
+def _metadata_urls(parent: ElementTree.Element) -> list[str]:
+    urls: list[str] = []
+    for node in parent.iter():
+        if _local_name(node.tag) not in {"MetadataURL", "MetadataUrl"}:
+            continue
+        href = node.attrib.get(f"{{{_XLINK}}}href")
+        if href:
+            urls.append(href.strip())
+        for child in node.iter():
+            if _local_name(child.tag) in {"URL", "OnlineResource"}:
+                nested = child.attrib.get(f"{{{_XLINK}}}href") or (child.text or "").strip()
+                if nested:
+                    urls.append(nested)
+    return urls
+
+
+def _parse_capabilities(content: bytes, contract: ProbeContract) -> tuple[list[str], str | None]:
+    try:
+        root = ElementTree.fromstring(content)
+    except ElementTree.ParseError as exc:
+        raise CatalogProbeFailure("CATALOG_INVALID_XML", "De capabilities-respons is geen geldige XML.") from exc
+
+    layers: list[str] = []
+    metadata_urls: list[str] = []
+    node_name = "FeatureType" if contract.service_type == "WFS" else "Layer"
+    for node in root.iter():
+        if _local_name(node.tag) != node_name:
+            continue
+        raw_name = _direct_text(node, "Name")
+        if not raw_name:
+            continue
+        name = raw_name.rsplit(":", 1)[-1]
+        layers.append(name)
+        if name in contract.expected_layers:
+            metadata_urls.extend(_metadata_urls(node))
+
+    expected = set(contract.expected_layers)
+    if not expected.intersection(layers):
+        raise CatalogProbeFailure("CATALOG_EXPECTED_LAYERS_MISSING", "De officiële service bevat geen van de verwachte lagen.")
+    xml_metadata = next((url for url in metadata_urls if "GetRecordById" in url and "OUTPUTSCHEMA" in url.upper()), None)
+    return sorted(set(layers)), xml_metadata
+
+
+def _validate_metadata_url(url: str) -> str:
+    parsed = urlsplit(url)
+    if parsed.scheme != "https" or parsed.hostname != _METADATA_HOST or parsed.username or parsed.password:
+        raise CatalogProbeFailure("CATALOG_METADATA_URL_REJECTED", "De capabilities verwijzen niet naar de toegestane officiële metadatahost.")
+    if not parsed.path.startswith("/srv/dut/csw"):
+        raise CatalogProbeFailure("CATALOG_METADATA_URL_REJECTED", "De capabilities verwijzen niet naar het toegestane CSW-pad.")
+    query = {key.lower(): value for key, value in parse_qsl(parsed.query)}
+    if query.get("request", "").lower() != "getrecordbyid" or not query.get("id"):
+        raise CatalogProbeFailure("CATALOG_METADATA_URL_REJECTED", "De capabilities bevatten geen begrensde GetRecordById-verwijzing.")
+    return url
+
+
+def _validate_capabilities_url(url: str) -> str:
+    parsed = urlsplit(url)
+    if parsed.scheme not in {"http", "https"} or not parsed.hostname or parsed.username or parsed.password:
+        raise CatalogProbeFailure("CATALOG_ENDPOINT_REJECTED", "De ingestelde capabilities-URL moet een geldige HTTP(S)-URL zonder credentials zijn.")
+    return url
+
+
+def _node_text(node: ElementTree.Element | None) -> str | None:
+    if node is None:
+        return None
+    for descendant in node.iter():
+        if descendant is not node and descendant.text and descendant.text.strip():
+            return descendant.text.strip()
+    return node.text.strip() if node.text and node.text.strip() else None
+
+
+def _parse_iso_datetime(value: str | None) -> datetime | None:
+    if not value:
+        return None
+    normalized = value.strip().replace("Z", "+00:00")
+    try:
+        return _utc(datetime.fromisoformat(normalized))
+    except ValueError:
+        try:
+            return datetime.strptime(normalized, "%Y-%m-%d").replace(tzinfo=timezone.utc)
+        except ValueError:
+            return None
+
+
+def _parse_metadata(content: bytes) -> dict[str, Any]:
+    try:
+        root = ElementTree.fromstring(content)
+    except ElementTree.ParseError as exc:
+        raise CatalogProbeFailure("CATALOG_INVALID_METADATA_XML", "Het officiële metadatarecord is geen geldige XML.") from exc
+    namespaces = {"gmd": _GMD, "gco": _GCO}
+    metadata = root.find(".//gmd:MD_Metadata", namespaces)
+    if metadata is None and _local_name(root.tag) == "MD_Metadata":
+        metadata = root
+    if metadata is None:
+        raise CatalogProbeFailure("CATALOG_METADATA_MISSING", "Het CSW-antwoord bevat geen ISO 19139 metadatarecord.")
+    citation = metadata.find(".//gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation", namespaces)
+    title = _node_text(citation.find("gmd:title", namespaces) if citation is not None else None)
+    edition = _node_text(citation.find("gmd:edition", namespaces) if citation is not None else None)
+    identifier = _node_text(metadata.find("gmd:fileIdentifier", namespaces))
+    modified = _parse_iso_datetime(_node_text(metadata.find("gmd:dateStamp", namespaces)))
+    published = None
+    if citation is not None:
+        for date_node in citation.findall("gmd:date/gmd:CI_Date", namespaces):
+            date_type = date_node.find("gmd:dateType/gmd:CI_DateTypeCode", namespaces)
+            if date_type is not None and date_type.attrib.get("codeListValue") == "publication":
+                published = _parse_iso_datetime(_node_text(date_node.find("gmd:date", namespaces)))
+                break
+    if not title or not edition:
+        raise CatalogProbeFailure("CATALOG_VERSION_MISSING", "Het officiële metadatarecord bevat geen herkenbare titel en editie.")
+    return {
+        "identifier": identifier,
+        "title": title,
+        "version": edition,
+        "modified_at": modified,
+        "published_at": published,
+    }
+
+
+def _probe_remote(
+    contract: ProbeContract,
+    settings: Settings,
+    *,
+    opener: Callable[..., Any] | None,
+    now: datetime,
+) -> RemoteProbe:
+    try:
+        capabilities = _bounded_fetch(_validate_capabilities_url(contract.endpoint_url), settings, opener)
+        _validate_capabilities_url(capabilities.final_url)
+        content_type = capabilities.content_type.lower()
+        if content_type and "xml" not in content_type and "text" not in content_type:
+            raise CatalogProbeFailure("CATALOG_INVALID_CONTENT_TYPE", "De officiële capabilities-respons is geen XML.")
+        layers, metadata_url = _parse_capabilities(capabilities.content, contract)
+        matched = tuple(layer for layer in contract.expected_layers if layer in layers)
+        missing = tuple(layer for layer in contract.expected_layers if layer not in layers)
+        digest = sha256(capabilities.content).hexdigest()
+        if not metadata_url:
+            return RemoteProbe(
+                status="degraded",
+                reachable=True,
+                checked_at=now,
+                expected_layers=contract.expected_layers,
+                matched_layers=matched,
+                missing_layers=missing,
+                advertised_layer_count=len(layers),
+                capabilities_sha256=digest,
+                capabilities_etag=capabilities.etag,
+                capabilities_last_modified_at=capabilities.last_modified_at,
+                message="De service is bereikbaar, maar publiceert geen machineleesbare ISO-metadata voor de verwachte lagen.",
+                error_code="CATALOG_METADATA_LINK_MISSING",
+            )
+        metadata_url = _validate_metadata_url(metadata_url)
+        metadata_response = _bounded_fetch(metadata_url, settings, opener)
+        _validate_metadata_url(metadata_response.final_url)
+        metadata = _parse_metadata(metadata_response.content)
+        status = "degraded" if missing else "available"
+        message = (
+            f"De officiële catalogus is bereikbaar en publiceert editie {metadata['version']}."
+            if not missing
+            else f"Editie {metadata['version']} is gevonden, maar niet alle verwachte lagen worden aangeboden."
+        )
+        return RemoteProbe(
+            status=status,
+            reachable=True,
+            checked_at=now,
+            expected_layers=contract.expected_layers,
+            matched_layers=matched,
+            missing_layers=missing,
+            advertised_layer_count=len(layers),
+            metadata_url=metadata_url,
+            metadata_identifier=metadata["identifier"],
+            remote_title=metadata["title"],
+            remote_version=metadata["version"],
+            remote_modified_at=metadata["modified_at"],
+            remote_published_at=metadata["published_at"],
+            capabilities_sha256=digest,
+            capabilities_etag=capabilities.etag,
+            capabilities_last_modified_at=capabilities.last_modified_at,
+            message=message,
+            error_code="CATALOG_EXPECTED_LAYERS_INCOMPLETE" if missing else None,
+        )
+    except CatalogProbeFailure as exc:
+        return RemoteProbe(
+            status="unavailable",
+            reachable=False,
+            checked_at=now,
+            expected_layers=contract.expected_layers,
+            missing_layers=contract.expected_layers,
+            message=exc.message,
+            error_code=exc.code,
+        )
+
+
+def _remote_with_cache(
+    contract: ProbeContract,
+    settings: Settings,
+    *,
+    force: bool,
+    opener: Callable[..., Any] | None,
+    now: datetime,
+) -> RemoteProbe:
+    cache_key = f"{contract.source_name}|{contract.endpoint_url}|{','.join(contract.expected_layers)}"
+    if not force and settings.source_catalog_probe_cache_ttl_seconds > 0:
+        with _CACHE_LOCK:
+            entry = _REMOTE_CACHE.get(cache_key)
+            if entry and entry.expires_at > now:
+                return replace(entry.probe, cached=True)
+    probe = _probe_remote(contract, settings, opener=opener, now=now)
+    if settings.source_catalog_probe_cache_ttl_seconds > 0:
+        with _CACHE_LOCK:
+            _REMOTE_CACHE[cache_key] = CacheEntry(
+                expires_at=now + timedelta(seconds=settings.source_catalog_probe_cache_ttl_seconds),
+                probe=probe,
+            )
+    return probe
+
+
+def _dataset_source_name(dataset: Dataset) -> str:
+    return (dataset.source_name or dataset.source or "").strip().lower()
+
+
+def _latest_local_version(source_name: str, datasets: list[Dataset]) -> str | None:
+    candidates = [item for item in datasets if _dataset_source_name(item) == source_name and item.source_version]
+    if source_name == "digitaal_vlaanderen_orthophoto":
+        explicit_current = [
+            item
+            for item in candidates
+            if any(token in (item.source_version or "").lower() for token in ("most_recent", "latest", "current"))
+        ]
+        if explicit_current:
+            candidates = explicit_current
+    if not candidates:
+        return None
+    latest = max(
+        candidates,
+        key=lambda item: (
+            _utc(item.imported_at) if item.imported_at else datetime.min.replace(tzinfo=timezone.utc),
+            _utc(item.observed_at) if item.observed_at else datetime.min.replace(tzinfo=timezone.utc),
+            str(item.id),
+        ),
+    )
+    return latest.source_version
+
+
+def _normalized_version(source_name: str, version: str | None) -> str | None:
+    if not version:
+        return None
+    value = version.strip()
+    if source_name == "grb":
+        match = _VERSION_DATE.fullmatch(value)
+        return match.group(1) if match else None
+    if source_name == "digitaal_vlaanderen_orthophoto" and _ORTHOPHOTO_EDITION.fullmatch(value):
+        return value
+    return None
+
+
+def _comparison(source_name: str, local: str | None, remote: str | None, remote_status: str) -> str:
+    if remote_status in {"unavailable", "disabled"}:
+        return "unavailable"
+    if not local:
+        return "no_local_data"
+    normalized_local = _normalized_version(source_name, local)
+    normalized_remote = _normalized_version(source_name, remote)
+    if normalized_local is None or normalized_remote is None:
+        return "not_comparable"
+    return "same" if normalized_local == normalized_remote else "different"
+
+
+class SourceCatalogProbeService:
+    @staticmethod
+    def clear_cache() -> None:
+        with _CACHE_LOCK:
+            _REMOTE_CACHE.clear()
+
+    @staticmethod
+    def audit_project(
+        db: Session,
+        project_id: UUID,
+        *,
+        force: bool = False,
+        opener: Callable[..., Any] | None = None,
+        now: datetime | None = None,
+        settings: Settings | None = None,
+    ) -> SourceCatalogProbeReport:
+        if not db.get(Project, project_id):
+            raise AppError(code="PROJECT_NOT_FOUND", message="Project not found", status_code=404)
+        active_settings = settings or get_settings()
+        generated_at = _utc(now)
+        datasets = db.query(Dataset).filter(Dataset.project_id == project_id).all()
+        contracts = (
+            ProbeContract(
+                source_name="grb",
+                display_name="Basiskaart Vlaanderen (GRB)",
+                service_type="WFS",
+                endpoint_url=_with_capabilities_query(active_settings.source_catalog_grb_wfs_url, "WFS"),
+                expected_layers=("GBG", "WBN", "WGO", "ADP"),
+            ),
+            ProbeContract(
+                source_name="digitaal_vlaanderen_orthophoto",
+                display_name="Orthofoto Vlaanderen",
+                service_type="WMS",
+                endpoint_url=_with_capabilities_query(active_settings.orthophoto_wms_url, "WMS"),
+                expected_layers=(active_settings.orthophoto_wms_layer, "Vliegdagcontour"),
+            ),
+        )
+        items: list[SourceCatalogProbeItem] = []
+        for contract in contracts:
+            local_version = _latest_local_version(contract.source_name, datasets)
+            if active_settings.source_catalog_probe_enabled:
+                remote = _remote_with_cache(
+                    contract,
+                    active_settings,
+                    force=force,
+                    opener=opener,
+                    now=generated_at,
+                )
+            else:
+                remote = RemoteProbe(
+                    status="disabled",
+                    reachable=False,
+                    checked_at=generated_at,
+                    expected_layers=contract.expected_layers,
+                    missing_layers=contract.expected_layers,
+                    message="Officiële catalogusprobes zijn uitgeschakeld in de runtimeconfiguratie.",
+                    error_code="CATALOG_PROBE_DISABLED",
+                )
+            comparison = _comparison(contract.source_name, local_version, remote.remote_version, remote.status)
+            message = remote.message
+            if comparison == "different":
+                message += " De officiële editie verschilt van de lokaal vastgelegde bronversie; controleer dit handmatig vóór een begrensde verversing."
+            elif comparison == "not_comparable" and local_version:
+                message += " De lokale waarde is een opname- of importmarkering en kan niet eerlijk als officiële cataloguseditie worden vergeleken."
+            items.append(
+                SourceCatalogProbeItem(
+                    source_name=contract.source_name,
+                    display_name=contract.display_name,
+                    service_type=contract.service_type,
+                    endpoint_url=contract.endpoint_url,
+                    status=remote.status,
+                    reachable=remote.reachable,
+                    checked_at=remote.checked_at,
+                    cached=remote.cached,
+                    expected_layers=list(remote.expected_layers),
+                    matched_layers=list(remote.matched_layers),
+                    missing_layers=list(remote.missing_layers),
+                    advertised_layer_count=remote.advertised_layer_count,
+                    metadata_url=remote.metadata_url,
+                    metadata_identifier=remote.metadata_identifier,
+                    remote_title=remote.remote_title,
+                    remote_version=remote.remote_version,
+                    remote_modified_at=remote.remote_modified_at,
+                    remote_published_at=remote.remote_published_at,
+                    local_source_version=local_version,
+                    comparison_status=comparison,
+                    capabilities_sha256=remote.capabilities_sha256,
+                    capabilities_etag=remote.capabilities_etag,
+                    capabilities_last_modified_at=remote.capabilities_last_modified_at,
+                    message=message,
+                    error_code=remote.error_code,
+                )
+            )
+        summary = SourceCatalogProbeSummary(
+            provider_count=len(items),
+            available_count=sum(item.status == "available" for item in items),
+            degraded_count=sum(item.status == "degraded" for item in items),
+            unavailable_count=sum(item.status == "unavailable" for item in items),
+            disabled_count=sum(item.status == "disabled" for item in items),
+            different_version_count=sum(item.comparison_status == "different" for item in items),
+        )
+        return SourceCatalogProbeReport(
+            project_id=project_id,
+            generated_at=generated_at,
+            summary=summary,
+            items=items,
+            limitations=[
+                "Deze expliciete controle leest alleen allowlisted WFS/WMS-capabilities en gekoppelde ISO 19139 metadata.",
+                "Er worden geen features, rasters of modelbestanden opgehaald en geen datasets aangemaakt of overschreven.",
+                "Een versieverschil is controlesignaal, geen bewijs dat een lokale dataset onbruikbaar is en geen automatische importopdracht.",
+            ],
+        )
diff --git a/backend/tests/test_sprint222_source_catalog_probes.py b/backend/tests/test_sprint222_source_catalog_probes.py
new file mode 100644
index 00000000..23451d95
--- /dev/null
+++ b/backend/tests/test_sprint222_source_catalog_probes.py
@@ -0,0 +1,332 @@
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from email.message import Message
+from pathlib import Path
+from types import SimpleNamespace
+from urllib.error import URLError
+import uuid
+
+from app.core.config import Settings
+from app.models import Dataset
+from app.services.source_catalog_probe_service import SourceCatalogProbeService
+
+
+NOW = datetime(2026, 7, 16, 15, 0, tzinfo=timezone.utc)
+GRB_METADATA_URL = (
+    "https://metadata.vlaanderen.be/srv/dut/csw?request=GetRecordById&service=CSW&"
+    "id=7C823055-7BBF-4D62-B55E-F85C30D53162&OUTPUTSCHEMA=http://www.isotc211.org/2005/gmd"
+)
+ORTHO_METADATA_URL = (
+    "https://metadata.vlaanderen.be/srv/dut/csw?request=GetRecordById&service=CSW&"
+    "id=f5304d6d-0dd4-43fd-a726-427af31e8d61&OUTPUTSCHEMA=http://www.isotc211.org/2005/gmd"
+)
+
+
+def _wfs_capabilities(metadata_url: str = GRB_METADATA_URL) -> bytes:
+    layers = "".join(
+        f"""
+        <wfs:FeatureType>
+          <wfs:Name>GRB:{name}</wfs:Name>
+          <wfs:MetadataURL xlink:href="{metadata_url.replace('&', '&amp;')}" />
+        </wfs:FeatureType>
+        """
+        for name in ("GBG", "WBN", "WGO", "ADP", "WTZ")
+    )
+    return f"""
+    <wfs:WFS_Capabilities xmlns:wfs="http://www.opengis.net/wfs/2.0"
+      xmlns:xlink="http://www.w3.org/1999/xlink">
+      <wfs:FeatureTypeList>{layers}</wfs:FeatureTypeList>
+    </wfs:WFS_Capabilities>
+    """.encode()
+
+
+def _wms_capabilities(metadata_url: str = ORTHO_METADATA_URL) -> bytes:
+    return f"""
+    <WMS_Capabilities xmlns="http://www.opengis.net/wms"
+      xmlns:xlink="http://www.w3.org/1999/xlink">
+      <Capability><Layer><Title>Orthofoto</Title>
+        <Layer><Name>Ortho</Name><MetadataURL><Format>text/xml</Format>
+          <OnlineResource xlink:href="{metadata_url.replace('&', '&amp;')}" />
+        </MetadataURL></Layer>
+        <Layer><Name>Vliegdagcontour</Name><MetadataURL><Format>text/xml</Format>
+          <OnlineResource xlink:href="{metadata_url.replace('&', '&amp;')}" />
+        </MetadataURL></Layer>
+      </Layer></Capability>
+    </WMS_Capabilities>
+    """.encode()
+
+
+def _metadata(identifier: str, title: str, edition: str, modified: str, published: str) -> bytes:
+    return f"""
+    <csw:GetRecordByIdResponse xmlns:csw="http://www.opengis.net/cat/csw/2.0.2"
+      xmlns:gmd="http://www.isotc211.org/2005/gmd"
+      xmlns:gco="http://www.isotc211.org/2005/gco">
+      <gmd:MD_Metadata>
+        <gmd:fileIdentifier><gco:CharacterString>{identifier}</gco:CharacterString></gmd:fileIdentifier>
+        <gmd:dateStamp><gco:Date>{modified}</gco:Date></gmd:dateStamp>
+        <gmd:identificationInfo><gmd:MD_DataIdentification><gmd:citation><gmd:CI_Citation>
+          <gmd:title><gco:CharacterString>{title}</gco:CharacterString></gmd:title>
+          <gmd:edition><gco:CharacterString>{edition}</gco:CharacterString></gmd:edition>
+          <gmd:date><gmd:CI_Date><gmd:date><gco:Date>{published}</gco:Date></gmd:date>
+            <gmd:dateType><gmd:CI_DateTypeCode codeListValue="publication">publication</gmd:CI_DateTypeCode></gmd:dateType>
+          </gmd:CI_Date></gmd:date>
+        </gmd:CI_Citation></gmd:citation></gmd:MD_DataIdentification></gmd:identificationInfo>
+      </gmd:MD_Metadata>
+    </csw:GetRecordByIdResponse>
+    """.encode()
+
+
+class _Response:
+    def __init__(self, content: bytes, content_type: str = "text/xml", *, content_length: int | None = None) -> None:
+        self.content = content
+        self.headers = Message()
+        self.headers["Content-Type"] = content_type
+        self.headers["Content-Length"] = str(content_length if content_length is not None else len(content))
+        self.headers["ETag"] = '"catalog-test"'
+        self.headers["Last-Modified"] = "Wed, 15 Jul 2026 10:00:00 GMT"
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *_args):
+        return False
+
+    def read(self, size: int = -1) -> bytes:
+        return self.content if size < 0 else self.content[:size]
+
+
+class _RedirectedResponse(_Response):
+    def __init__(self, content: bytes, final_url: str) -> None:
+        super().__init__(content)
+        self.final_url = final_url
+
+    def geturl(self) -> str:
+        return self.final_url
+
+class _Query:
+    def __init__(self, datasets: list[Dataset]) -> None:
+        self.datasets = datasets
+
+    def filter(self, *_args):
+        return self
+
+    def all(self) -> list[Dataset]:
+        return self.datasets
+
+
+class _Db:
+    def __init__(self, datasets: list[Dataset]) -> None:
+        self.datasets = datasets
+
+    def get(self, _model, _identifier):
+        return SimpleNamespace(id=_identifier)
+
+    def query(self, _model):
+        return _Query(self.datasets)
+
+
+def _dataset(source_name: str, version: str) -> Dataset:
+    return Dataset(
+        id=uuid.uuid4(),
+        project_id=uuid.uuid4(),
+        name=f"{source_name} source",
+        dataset_type="vector" if source_name == "grb" else "raster",
+        source=source_name,
+        source_name=source_name,
+        source_version=version,
+        imported_at=NOW,
+        status="ready",
+    )
+
+
+def _settings(**overrides) -> Settings:
+    values = {
+        "SOURCE_CATALOG_PROBE_ENABLED": True,
+        "SOURCE_CATALOG_GRB_WFS_URL": "https://geo.api.vlaanderen.be/GRB/wfs",
+        "SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS": 3,
+        "SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB": 1,
+        "SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS": 0,
+        "ORTHOPHOTO_WMS_URL": "https://geo.api.vlaanderen.be/OMWRGBMRVL/wms",
+        "ORTHOPHOTO_WMS_LAYER": "Ortho",
+    }
+    values.update(overrides)
+    return Settings(**values)
+
+
+def _opener(request, timeout):
+    assert timeout == 3
+    url = request.full_url
+    if "metadata.vlaanderen.be" in url:
+        if "f5304d6d" in url:
+            return _Response(_metadata("f5304d6d", "Orthofoto meest recent, 2025.04", "2025.04", "2026-04-27", "2025-12-11"))
+        return _Response(_metadata("7C823055", "GRBgis", "Toestand 2026-07-15", "2026-07-15", "2026-07-15"))
+    if "/GRB/" in url:
+        return _Response(_wfs_capabilities())
+    return _Response(_wms_capabilities())
+
+
+def test_catalog_probe_reads_real_editions_and_compares_only_compatible_versions() -> None:
+    SourceCatalogProbeService.clear_cache()
+    project_id = uuid.uuid4()
+    report = SourceCatalogProbeService.audit_project(
+        _Db([_dataset("grb", "2026-07-14"), _dataset("digitaal_vlaanderen_orthophoto", "most_recent_at_2026-07-14")]),
+        project_id,
+        settings=_settings(),
+        opener=_opener,
+        now=NOW,
+    )
+    by_source = {item.source_name: item for item in report.items}
+
+    assert report.summary.available_count == 2
+    assert report.summary.different_version_count == 1
+    assert by_source["grb"].remote_version == "Toestand 2026-07-15"
+    assert by_source["grb"].comparison_status == "different"
+    assert by_source["grb"].matched_layers == ["GBG", "WBN", "WGO", "ADP"]
+    assert by_source["grb"].advertised_layer_count == 5
+    assert by_source["digitaal_vlaanderen_orthophoto"].remote_version == "2025.04"
+    assert by_source["digitaal_vlaanderen_orthophoto"].comparison_status == "not_comparable"
+    assert by_source["digitaal_vlaanderen_orthophoto"].remote_published_at.year == 2025
+    assert all(item.capabilities_sha256 for item in report.items)
+
+
+def test_catalog_probe_isolates_provider_failure() -> None:
+    def partial_opener(request, timeout):
+        if "/GRB/" in request.full_url:
+            raise URLError("offline")
+        return _opener(request, timeout)
+
+    report = SourceCatalogProbeService.audit_project(
+        _Db([]), uuid.uuid4(), settings=_settings(), opener=partial_opener, now=NOW
+    )
+    by_source = {item.source_name: item for item in report.items}
+
+    assert by_source["grb"].status == "unavailable"
+    assert by_source["grb"].error_code == "CATALOG_PROVIDER_UNAVAILABLE"
+    assert by_source["digitaal_vlaanderen_orthophoto"].status == "available"
+    assert report.summary.unavailable_count == 1
+
+
+def test_catalog_probe_rejects_metadata_redirect_outside_allowlist() -> None:
+    def malicious_opener(request, timeout):
+        if "/GRB/" in request.full_url:
+            return _Response(
+                _wfs_capabilities(
+                    "https://example.com/csw?request=GetRecordById&id=evil&OUTPUTSCHEMA=http://www.isotc211.org/2005/gmd"
+                )
+            )
+        return _opener(request, timeout)
+
+    report = SourceCatalogProbeService.audit_project(
+        _Db([]), uuid.uuid4(), settings=_settings(), opener=malicious_opener, now=NOW
+    )
+    grb = next(item for item in report.items if item.source_name == "grb")
+
+    assert grb.status == "unavailable"
+    assert grb.error_code == "CATALOG_METADATA_URL_REJECTED"
+
+
+def test_catalog_probe_enforces_response_limit_without_reading_external_data() -> None:
+    def oversized_opener(request, timeout):
+        if "/GRB/" in request.full_url:
+            return _Response(b"<xml />", content_length=2 * 1024 * 1024)
+        return _opener(request, timeout)
+
+    report = SourceCatalogProbeService.audit_project(
+        _Db([]), uuid.uuid4(), settings=_settings(), opener=oversized_opener, now=NOW
+    )
+    grb = next(item for item in report.items if item.source_name == "grb")
+
+    assert grb.status == "unavailable"
+    assert grb.error_code == "CATALOG_RESPONSE_TOO_LARGE"
+
+
+def test_catalog_probe_revalidates_metadata_host_after_redirect() -> None:
+    def redirected_opener(request, timeout):
+        if "metadata.vlaanderen.be" in request.full_url and "7C823055" in request.full_url:
+            return _RedirectedResponse(
+                _metadata("7C823055", "GRBgis", "Toestand 2026-07-15", "2026-07-15", "2026-07-15"),
+                "https://example.com/redirected-metadata",
+            )
+        return _opener(request, timeout)
+
+    report = SourceCatalogProbeService.audit_project(
+        _Db([]), uuid.uuid4(), settings=_settings(), opener=redirected_opener, now=NOW
+    )
+    grb = next(item for item in report.items if item.source_name == "grb")
+
+    assert grb.status == "unavailable"
+    assert grb.error_code == "CATALOG_METADATA_URL_REJECTED"
+
+
+def test_catalog_probe_cache_is_explicitly_bypassable() -> None:
+    calls: list[str] = []
+
+    def counting_opener(request, timeout):
+        calls.append(request.full_url)
+        return _opener(request, timeout)
+
+    SourceCatalogProbeService.clear_cache()
+    settings = _settings(SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS=900)
+    db = _Db([])
+    project_id = uuid.uuid4()
+    first = SourceCatalogProbeService.audit_project(db, project_id, settings=settings, opener=counting_opener, now=NOW)
+    first_call_count = len(calls)
+    second = SourceCatalogProbeService.audit_project(db, project_id, settings=settings, opener=counting_opener, now=NOW)
+    SourceCatalogProbeService.audit_project(db, project_id, settings=settings, opener=counting_opener, now=NOW, force=True)
+
+    assert first_call_count == 4
+    assert all(item.cached is False for item in first.items)
+    assert all(item.cached is True for item in second.items)
+    assert len(calls) == 8
+
+
+def test_catalog_probe_can_be_disabled_without_network_access() -> None:
+    def forbidden_opener(*_args, **_kwargs):
+        raise AssertionError("network must not be called")
+
+    report = SourceCatalogProbeService.audit_project(
+        _Db([]),
+        uuid.uuid4(),
+        settings=_settings(SOURCE_CATALOG_PROBE_ENABLED=False),
+        opener=forbidden_opener,
+        now=NOW,
+    )
+
+    assert report.summary.disabled_count == 2
+    assert all(item.status == "disabled" for item in report.items)
+
+
+def test_catalog_probe_route_returns_canonical_envelope(monkeypatch) -> None:
+    from app.api.routes import datasets as dataset_routes
+
+    project_id = uuid.uuid4()
+    expected = SourceCatalogProbeService.audit_project(
+        _Db([]), project_id, settings=_settings(SOURCE_CATALOG_PROBE_ENABLED=False), now=NOW
+    )
+    monkeypatch.setattr(
+        dataset_routes.SourceCatalogProbeService,
+        "audit_project",
+        lambda db, selected_project_id, force=False: expected,
+    )
+
+    response = dataset_routes.probe_dataset_source_catalogs(
+        project_id=project_id, refresh=False, db=SimpleNamespace()
+    )
+
+    assert list(response) == ["data"]
+    assert response["data"]["project_id"] == project_id
+    assert response["data"]["summary"]["provider_count"] == 2
+
+
+def test_catalog_probe_remains_explicit_and_never_imports_provider_data() -> None:
+    root = Path(__file__).resolve().parents[2]
+    hook = (root / "frontend" / "src" / "hooks" / "useSourceFreshness.ts").read_text(encoding="utf-8")
+    service = (root / "backend" / "app" / "services" / "source_catalog_probe_service.py").read_text(encoding="utf-8")
+    operator = (root / "scripts" / "audit_source_freshness.py").read_text(encoding="utf-8")
+
+    assert "void probeCatalogs(" not in hook
+    assert "DatasetService" not in service
+    assert "VectorFeatureService" not in service
+    assert "--probe-catalogs" in operator
+    assert "/datasets/source-catalog-probes" in operator
diff --git a/deploy/unraid/geointel-unraid-template.xml b/deploy/unraid/geointel-unraid-template.xml
index fd577449..7f06fa13 100644
--- a/deploy/unraid/geointel-unraid-template.xml
+++ b/deploy/unraid/geointel-unraid-template.xml
@@ -34,6 +34,11 @@
   <Config Name="Orthophoto WMS URL" Target="ORTHOPHOTO_WMS_URL" Default="https://geo.api.vlaanderen.be/OMWRGBMRVL/wms" Mode="" Description="Official Digitaal Vlaanderen most-recent winter orthophoto WMS endpoint." Type="Variable" Display="advanced" Required="true" Mask="false">https://geo.api.vlaanderen.be/OMWRGBMRVL/wms</Config>
   <Config Name="Orthophoto Resolution (m)" Target="ORTHOPHOTO_RESOLUTION_M" Default="1.0" Mode="" Description="Requested analysis sampling in metres per pixel. Keep at 1.0 for the active building model profile." Type="Variable" Display="advanced" Required="true" Mask="false">1.0</Config>
   <Config Name="Orthophoto Maximum Side (m)" Target="ORTHOPHOTO_MAX_SIDE_M" Default="1024" Mode="" Description="Safety limit for each selected rectangle side before external acquisition and local inference." Type="Variable" Display="advanced" Required="true" Mask="false">1024</Config>
+  <Config Name="Official Catalog Edition Probe" Target="SOURCE_CATALOG_PROBE_ENABLED" Default="true" Mode="" Description="Allow explicit read-only GRB and orthophoto edition checks. This never imports provider data." Type="Variable" Display="advanced" Required="true" Mask="false">true</Config>
+  <Config Name="GRB Catalog WFS URL" Target="SOURCE_CATALOG_GRB_WFS_URL" Default="https://geo.api.vlaanderen.be/GRB/wfs" Mode="" Description="Official GRB WFS used only for capabilities and linked ISO metadata checks." Type="Variable" Display="advanced" Required="true" Mask="false">https://geo.api.vlaanderen.be/GRB/wfs</Config>
+  <Config Name="Catalog Probe Timeout (seconds)" Target="SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS" Default="10" Mode="" Description="Per-request timeout for explicit read-only official catalog checks." Type="Variable" Display="advanced" Required="true" Mask="false">10</Config>
+  <Config Name="Catalog Probe Maximum Response (MiB)" Target="SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB" Default="2" Mode="" Description="Maximum capabilities or ISO metadata response size accepted by a catalog probe." Type="Variable" Display="advanced" Required="true" Mask="false">2</Config>
+  <Config Name="Catalog Probe Cache (seconds)" Target="SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS" Default="900" Mode="" Description="Short in-memory cache for repeated official edition checks; use zero to disable." Type="Variable" Display="advanced" Required="true" Mask="false">900</Config>
   <Config Name="Official DHMV Acquisition" Target="DHMV_ENABLED" Default="true" Mode="" Description="Allow bounded official DHMV II terrain and surface raster acquisition." Type="Variable" Display="advanced" Required="true" Mask="false">true</Config>
   <Config Name="DHMV WCS URL" Target="DHMV_WCS_URL" Default="https://geo.api.vlaanderen.be/DHMV/wcs" Mode="" Description="Official Digitaal Vlaanderen DHMV WCS endpoint." Type="Variable" Display="advanced" Required="true" Mask="false">https://geo.api.vlaanderen.be/DHMV/wcs</Config>
   <Config Name="DHMV Analysis Resolution (m)" Target="DHMV_RESOLUTION_M" Default="5.0" Mode="" Description="Stored analysis grid resolution. Native source resolution remains recorded as 1 metre." Type="Variable" Display="advanced" Required="true" Mask="false">5.0</Config>
diff --git a/deploy/unraid/geointel.env.example b/deploy/unraid/geointel.env.example
index 1e01892d..50797d53 100644
--- a/deploy/unraid/geointel.env.example
+++ b/deploy/unraid/geointel.env.example
@@ -32,6 +32,14 @@ ORTHOPHOTO_RESOLUTION_M=1.0
 ORTHOPHOTO_MIN_SIDE_M=128
 ORTHOPHOTO_MAX_SIDE_M=1024
 ORTHOPHOTO_CACHE_TTL_HOURS=24
+
+# Explicit read-only edition checks for GRB and the most-recent orthophoto.
+# No feature or raster data is downloaded by these probes.
+SOURCE_CATALOG_PROBE_ENABLED=true
+SOURCE_CATALOG_GRB_WFS_URL=https://geo.api.vlaanderen.be/GRB/wfs
+SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS=10
+SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB=2
+SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS=900
 DHMV_ENABLED=true
 DHMV_WCS_URL=https://geo.api.vlaanderen.be/DHMV/wcs
 DHMV_RESOLUTION_M=5.0
diff --git a/deploy/unraid/run-dockerman-container.sh b/deploy/unraid/run-dockerman-container.sh
index fd241acd..2b762306 100644
--- a/deploy/unraid/run-dockerman-container.sh
+++ b/deploy/unraid/run-dockerman-container.sh
@@ -27,6 +27,11 @@ ORTHOPHOTO_RESOLUTION_M="${ORTHOPHOTO_RESOLUTION_M:-1.0}"
 ORTHOPHOTO_MIN_SIDE_M="${ORTHOPHOTO_MIN_SIDE_M:-128}"
 ORTHOPHOTO_MAX_SIDE_M="${ORTHOPHOTO_MAX_SIDE_M:-1024}"
 ORTHOPHOTO_CACHE_TTL_HOURS="${ORTHOPHOTO_CACHE_TTL_HOURS:-24}"
+SOURCE_CATALOG_PROBE_ENABLED="${SOURCE_CATALOG_PROBE_ENABLED:-true}"
+SOURCE_CATALOG_GRB_WFS_URL="${SOURCE_CATALOG_GRB_WFS_URL:-https://geo.api.vlaanderen.be/GRB/wfs}"
+SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS="${SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS:-10}"
+SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB="${SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB:-2}"
+SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS="${SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS:-900}"
 DHMV_ENABLED="${DHMV_ENABLED:-true}"
 DHMV_WCS_URL="${DHMV_WCS_URL:-https://geo.api.vlaanderen.be/DHMV/wcs}"
 DHMV_RESOLUTION_M="${DHMV_RESOLUTION_M:-5.0}"
@@ -126,6 +131,11 @@ docker run -d \
   -e ORTHOPHOTO_MIN_SIDE_M="$ORTHOPHOTO_MIN_SIDE_M" \
   -e ORTHOPHOTO_MAX_SIDE_M="$ORTHOPHOTO_MAX_SIDE_M" \
   -e ORTHOPHOTO_CACHE_TTL_HOURS="$ORTHOPHOTO_CACHE_TTL_HOURS" \
+  -e SOURCE_CATALOG_PROBE_ENABLED="$SOURCE_CATALOG_PROBE_ENABLED" \
+  -e SOURCE_CATALOG_GRB_WFS_URL="$SOURCE_CATALOG_GRB_WFS_URL" \
+  -e SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS="$SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS" \
+  -e SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB="$SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB" \
+  -e SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS="$SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS" \
   -e DHMV_ENABLED="$DHMV_ENABLED" \
   -e DHMV_WCS_URL="$DHMV_WCS_URL" \
   -e DHMV_RESOLUTION_M="$DHMV_RESOLUTION_M" \
diff --git a/docker-compose.unraid.yml b/docker-compose.unraid.yml
index e307df27..b68dc52a 100644
--- a/docker-compose.unraid.yml
+++ b/docker-compose.unraid.yml
@@ -25,6 +25,11 @@ services:
       ORTHOPHOTO_MIN_SIDE_M: ${ORTHOPHOTO_MIN_SIDE_M:-128}
       ORTHOPHOTO_MAX_SIDE_M: ${ORTHOPHOTO_MAX_SIDE_M:-1024}
       ORTHOPHOTO_CACHE_TTL_HOURS: ${ORTHOPHOTO_CACHE_TTL_HOURS:-24}
+      SOURCE_CATALOG_PROBE_ENABLED: ${SOURCE_CATALOG_PROBE_ENABLED:-true}
+      SOURCE_CATALOG_GRB_WFS_URL: ${SOURCE_CATALOG_GRB_WFS_URL:-https://geo.api.vlaanderen.be/GRB/wfs}
+      SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS: ${SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS:-10}
+      SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB: ${SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB:-2}
+      SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS: ${SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS:-900}
       DHMV_ENABLED: ${DHMV_ENABLED:-true}
       DHMV_WCS_URL: ${DHMV_WCS_URL:-https://geo.api.vlaanderen.be/DHMV/wcs}
       DHMV_RESOLUTION_M: ${DHMV_RESOLUTION_M:-5.0}
diff --git a/docker-compose.yml b/docker-compose.yml
index 1c253397..d2500ea5 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -30,6 +30,11 @@ services:
       ORTHOPHOTO_MIN_SIDE_M: ${ORTHOPHOTO_MIN_SIDE_M:-128}
       ORTHOPHOTO_MAX_SIDE_M: ${ORTHOPHOTO_MAX_SIDE_M:-1024}
       ORTHOPHOTO_CACHE_TTL_HOURS: ${ORTHOPHOTO_CACHE_TTL_HOURS:-24}
+      SOURCE_CATALOG_PROBE_ENABLED: ${SOURCE_CATALOG_PROBE_ENABLED:-true}
+      SOURCE_CATALOG_GRB_WFS_URL: ${SOURCE_CATALOG_GRB_WFS_URL:-https://geo.api.vlaanderen.be/GRB/wfs}
+      SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS: ${SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS:-10}
+      SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB: ${SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB:-2}
+      SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS: ${SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS:-900}
       DHMV_ENABLED: ${DHMV_ENABLED:-true}
       DHMV_WCS_URL: ${DHMV_WCS_URL:-https://geo.api.vlaanderen.be/DHMV/wcs}
       DHMV_RESOLUTION_M: ${DHMV_RESOLUTION_M:-5.0}
diff --git a/docs/API_CONTRACTS.md b/docs/API_CONTRACTS.md
index 921dae81..744c08dc 100644
--- a/docs/API_CONTRACTS.md
+++ b/docs/API_CONTRACTS.md
@@ -412,6 +412,26 @@ Dataset or silently refreshes a publication. Fixed editions and scenarios are
 not marked stale merely because their source date is old. Unknown sources are
 `review_required` until an explicit publication policy is defined.
 
+### GET `/api/v1/projects/{project_id}/datasets/source-catalog-probes`
+
+Performs an explicit, read-only release probe for the allowlisted GRB WFS and
+most-recent orthophoto WMS. The endpoint reads bounded `GetCapabilities`
+responses, confirms the expected layers and follows only HTTPS ISO 19139
+`GetRecordById` links on `metadata.vlaanderen.be`. Query parameter
+`refresh=true` bypasses the short in-memory response cache.
+
+Each provider item returns service reachability, matched/missing layers, the
+official metadata identifier, title, edition, publication/metadata dates,
+local `source_version` and one comparison status: `same`, `different`,
+`not_comparable`, `no_local_data` or `unavailable`. Provider status is
+`available`, `degraded`, `unavailable` or `disabled`. A difference means only
+that an operator should review provenance; it is not an update instruction.
+
+The endpoint accepts no arbitrary URL, feature query, area or layer. It does
+not fetch vector features, raster pixels or models, create jobs/datasets, write
+to PostGIS or trigger an import. The normal `source-freshness` endpoint remains
+local-only and never invokes this probe implicitly.
+
 ### GET `/api/v1/projects/{project_id}/datasets/{dataset_id}`
 
 Return metadata.
diff --git a/docs/CODEX_EXECUTION_LOG.md b/docs/CODEX_EXECUTION_LOG.md
index 915e7338..3696182c 100644
--- a/docs/CODEX_EXECUTION_LOG.md
+++ b/docs/CODEX_EXECUTION_LOG.md
@@ -9302,3 +9302,40 @@ Next:
 - Add machine-readable catalogue release probes only for providers with stable
   official version endpoints, keeping every acquisition an explicit bounded
   operator action.
+
+## Sprint 222 - Official source edition probes (2026-07-16)
+
+Implemented:
+- Verified the public machine-readable contracts published by Digitaal
+  Vlaanderen. GRB WFS and OMWRGBMRVL WMS capabilities expose stable ISO 19139
+  CSW records containing real source editions and metadata dates.
+- Added a canonical project endpoint that reads only allowlisted capabilities
+  and linked `metadata.vlaanderen.be` `GetRecordById` responses. It confirms
+  GRB `GBG/WBN/WGO/ADP` and orthophoto `Ortho/Vliegdagcontour` availability,
+  then reports the official edition beside local `source_version` evidence.
+- Added strict HTTP(S)/metadata allowlists, timeout and byte limits,
+  post-redirect validation, SHA-256 capabilities evidence, provider-isolated
+  degraded/unavailable states and a short in-memory cache.
+- Added an explicit Status action and operator CLI flags. Neither path runs on
+  page load, starts a job, downloads source data or changes a Dataset.
+- Added Compose, all-in-one Unraid and DockerMan controls for the bounded probe.
+
+Validation:
+- Deterministic tests cover official XML parsing, edition comparison,
+  provider failure isolation, metadata URL rejection, size limits, caching,
+  disabled mode and canonical envelopes.
+- Frontend typecheck/build and targeted backend tests pass before the full
+  release and Tower validation recorded in the delivery result.
+
+Boundaries:
+- The general Datavindplaats API requires authentication and is not scraped or
+  silently bypassed. GeoIntel uses only public metadata records advertised by
+  the official OGC services.
+- A version difference remains a manual provenance-review signal. No automatic
+  import, refresh scheduler, GRB feature fetch or orthophoto pixel request was
+  added.
+
+Next:
+- Extend the same probe pattern only where another official source publishes a
+  stable machine-readable edition. Do not infer release versions from service
+  protocol versions, ETags or HTTP modification dates.
diff --git a/docs/ENVIRONMENT_SPEC.md b/docs/ENVIRONMENT_SPEC.md
index bda34307..ea6d6087 100644
--- a/docs/ENVIRONMENT_SPEC.md
+++ b/docs/ENVIRONMENT_SPEC.md
@@ -25,6 +25,13 @@ YOLO_MAX_DETECTIONS=1000
 YOLO_DUPLICATE_IOU_THRESHOLD=0.5
 ENABLE_GRB_WFS=false
 GRB_WFS_URL=
+
+# Explicit read-only source-edition probes (no provider import).
+SOURCE_CATALOG_PROBE_ENABLED=true
+SOURCE_CATALOG_GRB_WFS_URL=https://geo.api.vlaanderen.be/GRB/wfs
+SOURCE_CATALOG_PROBE_TIMEOUT_SECONDS=10
+SOURCE_CATALOG_PROBE_MAX_RESPONSE_MB=2
+SOURCE_CATALOG_PROBE_CACHE_TTL_SECONDS=900
 OSM_OVERPASS_URL=https://overpass-api.de/api/interpreter
 ```
 
diff --git a/docs/TODO.md b/docs/TODO.md
index 20479f04..08d26d53 100644
--- a/docs/TODO.md
+++ b/docs/TODO.md
@@ -39,7 +39,8 @@
 - [x] Execute and audit the complete 336-product VMM and 56-product DHMV regional runtime matrices.
 - [x] Present municipal DHMV/VMM partitions as logical regional layers and analyse cross-boundary rectangles without a municipality prerequisite.
 - [x] Add a read-only source freshness/version audit with explicit publication policies, local integrity checks, operator CLI and compact Status workspace surface.
-- [ ] Add external catalogue release probes only after each official provider exposes a stable machine-readable version contract; keep every refresh explicit and bounded.
+- [x] Add explicit bounded GRB/orthophoto catalogue release probes using official capabilities and ISO metadata; keep every acquisition separate and operator-controlled.
+- [ ] Extend catalogue probes only to additional sources that publish a stable machine-readable edition contract; do not add background polling or infer releases from HTTP dates alone.
 
 ## Governed source expansion backlog
 
diff --git a/frontend/README.md b/frontend/README.md
index b0c53a34..0eb91901 100644
--- a/frontend/README.md
+++ b/frontend/README.md
@@ -9,7 +9,10 @@ surface. It separates sources that are current, due for a catalogue review,
 require local integrity review or are local artifacts. Only attention items are
 expanded by default; all source detail remains available through disclosure.
 The refresh button reruns the local read-only audit and never downloads or
-replaces source data.
+replaces source data. A separate `Officiële edities controleren` action is the
+only trigger for bounded GRB/orthophoto catalog reads. It presents official and
+local editions, layer-contract coverage and honest non-comparable version
+markers without starting an import or background poll.
 
 The user-facing shell is task based: `Kaart`, `Bronnen`, `Kwaliteit`, `Beeldanalyse`, `Downloads`, `Status` and `Beheer`. Internal benchmark projects, raw dataset metadata, provider capabilities, model registry details and QA evidence remain accessible through labelled advanced disclosures instead of competing with the normal workflow.
 
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 72d4b885..9d01c1a9 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -860,6 +860,10 @@ function App(): JSX.Element {
                 loading={sourceFreshness.loading}
                 error={sourceFreshness.error}
                 onRefresh={() => { void sourceFreshness.refresh() }}
+                catalogReport={sourceFreshness.catalogReport}
+                catalogLoading={sourceFreshness.catalogLoading}
+                catalogError={sourceFreshness.catalogError}
+                onProbeCatalogs={(force) => { void sourceFreshness.probeCatalogs(force) }}
               />
               <details className="status-details-disclosure">
                 <summary>
diff --git a/frontend/src/components/status/SourceFreshnessPanel.tsx b/frontend/src/components/status/SourceFreshnessPanel.tsx
index 8fec2012..2e089ded 100644
--- a/frontend/src/components/status/SourceFreshnessPanel.tsx
+++ b/frontend/src/components/status/SourceFreshnessPanel.tsx
@@ -1,10 +1,22 @@
-import type { SourceFreshnessItem, SourceFreshnessReport, SourceFreshnessStatus } from '../../types'
+import type {
+  SourceCatalogComparisonStatus,
+  SourceCatalogProbeItem,
+  SourceCatalogProbeReport,
+  SourceCatalogProbeStatus,
+  SourceFreshnessItem,
+  SourceFreshnessReport,
+  SourceFreshnessStatus,
+} from '../../types'
 
 interface SourceFreshnessPanelProps {
   report: SourceFreshnessReport | null
   loading: boolean
   error: string | null
   onRefresh: () => void
+  catalogReport: SourceCatalogProbeReport | null
+  catalogLoading: boolean
+  catalogError: string | null
+  onProbeCatalogs: (force: boolean) => void
 }
 
 function statusLabel(status: SourceFreshnessStatus): string {
@@ -14,6 +26,21 @@ function statusLabel(status: SourceFreshnessStatus): string {
   return 'lokaal'
 }
 
+function catalogStatusLabel(status: SourceCatalogProbeStatus): string {
+  if (status === 'available') return 'bereikbaar'
+  if (status === 'degraded') return 'beperkt'
+  if (status === 'unavailable') return 'niet bereikbaar'
+  return 'uitgeschakeld'
+}
+
+function comparisonLabel(status: SourceCatalogComparisonStatus): string {
+  if (status === 'same') return 'zelfde editie'
+  if (status === 'different') return 'verschil controleren'
+  if (status === 'no_local_data') return 'nog niet lokaal ingeladen'
+  if (status === 'not_comparable') return 'andere versienotatie'
+  return 'niet vergelijkbaar'
+}
+
 function formatDate(value?: string | null): string {
   if (!value) return 'geen datum'
   return new Intl.DateTimeFormat('nl-BE', { dateStyle: 'medium' }).format(new Date(value))
@@ -23,6 +50,27 @@ function integrityIssueCount(item: SourceFreshnessItem): number {
   return Object.values(item.integrity).reduce((total, value) => total + value, 0)
 }
 
+function CatalogRow({ item }: { item: SourceCatalogProbeItem }): JSX.Element {
+  return (
+    <div className={`source-catalog-row source-catalog-row-${item.status}`}>
+      <div className="source-freshness-main">
+        <div>
+          <strong>{item.display_name}</strong>
+          <span>{catalogStatusLabel(item.status)} / {comparisonLabel(item.comparison_status)}</span>
+        </div>
+        <span className="source-freshness-status">{item.remote_version ?? 'geen editie'}</span>
+      </div>
+      <p>{item.message}</p>
+      <div className="source-freshness-meta">
+        <span>Lokaal: {item.local_source_version ?? 'niet aanwezig'}</span>
+        <span>Lagen: {item.matched_layers.length}/{item.expected_layers.length} bevestigd</span>
+        {item.remote_modified_at ? <span>Metadata: {formatDate(item.remote_modified_at)}</span> : null}
+        {item.cached ? <span>cache gebruikt</span> : null}
+      </div>
+    </div>
+  )
+}
+
 function SourceRow({ item }: { item: SourceFreshnessItem }): JSX.Element {
   const issueCount = integrityIssueCount(item)
   return (
@@ -30,7 +78,7 @@ function SourceRow({ item }: { item: SourceFreshnessItem }): JSX.Element {
       <div className="source-freshness-main">
         <div>
           <strong>{item.display_name}</strong>
-          <span>{item.dataset_count} datasets · {item.version_count} versies</span>
+          <span>{item.dataset_count} datasets / {item.version_count} versies</span>
         </div>
         <span className="source-freshness-status">{statusLabel(item.status)}</span>
       </div>
@@ -45,7 +93,16 @@ function SourceRow({ item }: { item: SourceFreshnessItem }): JSX.Element {
   )
 }
 
-export function SourceFreshnessPanel({ report, loading, error, onRefresh }: SourceFreshnessPanelProps): JSX.Element {
+export function SourceFreshnessPanel({
+  report,
+  loading,
+  error,
+  onRefresh,
+  catalogReport,
+  catalogLoading,
+  catalogError,
+  onProbeCatalogs,
+}: SourceFreshnessPanelProps): JSX.Element {
   const attentionItems = report?.items.filter((item) => item.status === 'due' || item.status === 'review_required') ?? []
   const summary = report?.summary
 
@@ -55,11 +112,21 @@ export function SourceFreshnessPanel({ report, loading, error, onRefresh }: Sour
         <div>
           <p className="eyebrow">Bronbeheer</p>
           <h2>Actualiteit en versiecontrole</h2>
-          <p>Controleert lokale publicaties, versies en bestanden zonder externe bronnen automatisch te wijzigen.</p>
+          <p>Controleert lokale publicaties en kan op aanvraag de officiële GRB- en orthofoto-editie uitlezen.</p>
+        </div>
+        <div className="source-freshness-actions">
+          <button className="secondary-action" type="button" onClick={onRefresh} disabled={loading}>
+            {loading ? 'Controleren...' : 'Lokale status vernieuwen'}
+          </button>
+          <button
+            className="primary-action"
+            type="button"
+            onClick={() => onProbeCatalogs(Boolean(catalogReport))}
+            disabled={catalogLoading}
+          >
+            {catalogLoading ? 'Officiële bronnen lezen...' : catalogReport ? 'Opnieuw bij bron controleren' : 'Officiële edities controleren'}
+          </button>
         </div>
-        <button className="secondary-action" type="button" onClick={onRefresh} disabled={loading}>
-          {loading ? 'Controleren...' : 'Opnieuw controleren'}
-        </button>
       </div>
 
       {error ? <p className="inline-error">{error}</p> : null}
@@ -89,6 +156,31 @@ export function SourceFreshnessPanel({ report, loading, error, onRefresh }: Sour
             </div>
             <p className="source-freshness-limitation">{report.limitations.join(' ')}</p>
           </details>
+          <div className="source-catalog-section" aria-live="polite">
+            <div className="source-catalog-heading">
+              <div>
+                <strong>Officiële catalogusedities</strong>
+                <span>Alleen na jouw expliciete controle; er wordt niets ingeladen of vervangen.</span>
+              </div>
+              {catalogReport ? (
+                <span>{catalogReport.summary.available_count}/{catalogReport.summary.provider_count} bereikbaar</span>
+              ) : null}
+            </div>
+            {catalogError ? <p className="inline-error">{catalogError}</p> : null}
+            {!catalogReport && !catalogError ? (
+              <p className="source-catalog-empty">Controleer GRB en orthofoto wanneer je een lokale bronversie met de officiële editie wilt vergelijken.</p>
+            ) : null}
+            {catalogReport ? (
+              <>
+                <div className="source-catalog-list">
+                  {catalogReport.items.map((item) => <CatalogRow item={item} key={item.source_name} />)}
+                </div>
+                <p className="source-freshness-limitation">
+                  Gecontroleerd {formatDate(catalogReport.generated_at)}. Een verschil vraagt menselijke beoordeling en start nooit automatisch een import.
+                </p>
+              </>
+            ) : null}
+          </div>
         </>
       ) : null}
     </section>
diff --git a/frontend/src/hooks/useSourceFreshness.ts b/frontend/src/hooks/useSourceFreshness.ts
index 4c1a2c9c..ec3549a1 100644
--- a/frontend/src/hooks/useSourceFreshness.ts
+++ b/frontend/src/hooks/useSourceFreshness.ts
@@ -1,13 +1,17 @@
 import { useCallback, useEffect, useRef, useState } from 'react'
 
 import { datasetsApi } from '../services/api'
-import type { SourceFreshnessReport } from '../types'
+import type { SourceCatalogProbeReport, SourceFreshnessReport } from '../types'
 
 export function useSourceFreshness(selectedProjectId: string | null) {
   const [report, setReport] = useState<SourceFreshnessReport | null>(null)
   const [loading, setLoading] = useState(false)
   const [error, setError] = useState<string | null>(null)
   const requestSequence = useRef(0)
+  const catalogRequestSequence = useRef(0)
+  const [catalogReport, setCatalogReport] = useState<SourceCatalogProbeReport | null>(null)
+  const [catalogLoading, setCatalogLoading] = useState(false)
+  const [catalogError, setCatalogError] = useState<string | null>(null)
 
   const refresh = useCallback(async () => {
     const requestId = ++requestSequence.current
@@ -35,6 +39,32 @@ export function useSourceFreshness(selectedProjectId: string | null) {
     }
   }, [selectedProjectId])
 
+  const probeCatalogs = useCallback(async (force = false) => {
+    const requestId = ++catalogRequestSequence.current
+    if (!selectedProjectId) {
+      setCatalogReport(null)
+      setCatalogError(null)
+      setCatalogLoading(false)
+      return
+    }
+    setCatalogLoading(true)
+    setCatalogError(null)
+    try {
+      const nextReport = await datasetsApi.sourceCatalogProbes(selectedProjectId, force)
+      if (catalogRequestSequence.current === requestId) {
+        setCatalogReport(nextReport)
+      }
+    } catch (caught) {
+      if (catalogRequestSequence.current === requestId) {
+        setCatalogError(caught instanceof Error ? caught.message : 'De officiële broncatalogi konden niet worden gecontroleerd.')
+      }
+    } finally {
+      if (catalogRequestSequence.current === requestId) {
+        setCatalogLoading(false)
+      }
+    }
+  }, [selectedProjectId])
+
   useEffect(() => {
     void refresh()
     return () => {
@@ -42,5 +72,21 @@ export function useSourceFreshness(selectedProjectId: string | null) {
     }
   }, [refresh])
 
-  return { report, loading, error, refresh }
+  useEffect(() => {
+    catalogRequestSequence.current += 1
+    setCatalogReport(null)
+    setCatalogError(null)
+    setCatalogLoading(false)
+  }, [selectedProjectId])
+
+  return {
+    report,
+    loading,
+    error,
+    refresh,
+    catalogReport,
+    catalogLoading,
+    catalogError,
+    probeCatalogs,
+  }
 }
diff --git a/frontend/src/services/api/datasets.ts b/frontend/src/services/api/datasets.ts
index 3bdb78b5..6c17eab1 100644
--- a/frontend/src/services/api/datasets.ts
+++ b/frontend/src/services/api/datasets.ts
@@ -28,6 +28,7 @@ import type {
   ThematicRasterProductRead,
   ThematicRasterSelectionResponse,
   SourceFreshnessReport,
+  SourceCatalogProbeReport,
 } from '../../types'
 
 const DATASET_PAGE_SIZE = 200
@@ -61,6 +62,10 @@ export const datasetsApi = {
   list: listProjectDatasets,
   sourceFreshness: (projectId: string): Promise<SourceFreshnessReport> =>
     apiGet<SourceFreshnessReport>(`/api/v1/projects/${projectId}/datasets/source-freshness`),
+  sourceCatalogProbes: (projectId: string, refresh = false): Promise<SourceCatalogProbeReport> =>
+    apiGet<SourceCatalogProbeReport>(
+      `/api/v1/projects/${projectId}/datasets/source-catalog-probes?refresh=${refresh ? 'true' : 'false'}`,
+    ),
   upload: (
     projectId: string,
     payload: {
diff --git a/frontend/src/styles/premium.css b/frontend/src/styles/premium.css
index 46d13a20..74d8080e 100644
--- a/frontend/src/styles/premium.css
+++ b/frontend/src/styles/premium.css
@@ -836,13 +836,20 @@ details.ai-lab-model-surface > summary strong {
   padding: 1rem 1.2rem;
 }
 
-.source-freshness-header .secondary-action {
+.source-freshness-header .secondary-action,
+.source-freshness-header .primary-action {
   flex: 0 0 auto;
   width: auto;
   min-width: 10rem;
   margin-top: 0;
 }
 
+.source-freshness-actions {
+  display: flex;
+  flex: 0 0 auto;
+  gap: 0.55rem;
+}
+
 .source-freshness-header h2 {
   margin: 0;
   font-size: 1.05rem;
@@ -959,6 +966,81 @@ details.ai-lab-model-surface > summary strong {
   border-top: 1px solid var(--line);
 }
 
+.source-catalog-section {
+  border-top: 1px solid var(--line);
+  background: #fbfcfd;
+}
+
+.source-catalog-heading {
+  display: flex;
+  gap: 1rem;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0.8rem 1rem;
+}
+
+.source-catalog-heading > div {
+  display: grid;
+  gap: 0.12rem;
+}
+
+.source-catalog-heading strong {
+  color: #23313b;
+  font-size: 0.84rem;
+}
+
+.source-catalog-heading span,
+.source-catalog-empty {
+  color: var(--muted);
+  font-size: 0.75rem;
+}
+
+.source-catalog-heading > span {
+  flex: 0 0 auto;
+  font-weight: 700;
+}
+
+.source-catalog-empty {
+  margin: 0;
+  padding: 0 1rem 0.85rem;
+}
+
+.source-catalog-list {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  border-top: 1px solid var(--line);
+}
+
+.source-catalog-row {
+  min-width: 0;
+  padding: 0.8rem 1rem;
+  border-right: 1px solid var(--line);
+  box-shadow: inset 0 3px 0 #8a98a3;
+}
+
+.source-catalog-row:last-child {
+  border-right: 0;
+}
+
+.source-catalog-row-available {
+  box-shadow: inset 0 3px 0 #2d9272;
+}
+
+.source-catalog-row-degraded {
+  box-shadow: inset 0 3px 0 #ca7a18;
+}
+
+.source-catalog-row-unavailable,
+.source-catalog-row-disabled {
+  box-shadow: inset 0 3px 0 #b84e4e;
+}
+
+.source-catalog-row p {
+  margin: 0.45rem 0;
+  color: var(--muted);
+  font-size: 0.75rem;
+}
+
 .source-freshness-details > summary {
   display: flex;
   cursor: pointer;
@@ -982,10 +1064,15 @@ details.ai-lab-model-surface > summary strong {
     flex-direction: column;
   }
 
-  .source-freshness-header .secondary-action {
+  .source-freshness-header .secondary-action,
+  .source-freshness-header .primary-action {
     width: 100%;
   }
 
+  .source-freshness-actions {
+    flex-direction: column;
+  }
+
   .source-freshness-summary {
     grid-template-columns: repeat(2, minmax(0, 1fr));
   }
@@ -997,6 +1084,19 @@ details.ai-lab-model-surface > summary strong {
   .source-freshness-summary span:nth-child(-n + 2) {
     border-bottom: 1px solid var(--line);
   }
+
+  .source-catalog-list {
+    grid-template-columns: 1fr;
+  }
+
+  .source-catalog-row {
+    border-right: 0;
+    border-bottom: 1px solid var(--line);
+  }
+
+  .source-catalog-row:last-child {
+    border-bottom: 0;
+  }
 }
 
 .workflow-guidance-panel {
diff --git a/frontend/src/types.ts b/frontend/src/types.ts
index 8bc93812..e8c4915e 100644
--- a/frontend/src/types.ts
+++ b/frontend/src/types.ts
@@ -709,6 +709,52 @@ export interface SourceFreshnessReport {
   limitations: string[]
 }
 
+export type SourceCatalogProbeStatus = 'available' | 'degraded' | 'unavailable' | 'disabled'
+export type SourceCatalogComparisonStatus = 'same' | 'different' | 'not_comparable' | 'no_local_data' | 'unavailable'
+
+export interface SourceCatalogProbeItem {
+  source_name: string
+  display_name: string
+  service_type: 'WFS' | 'WMS'
+  endpoint_url: string
+  status: SourceCatalogProbeStatus
+  reachable: boolean
+  checked_at: string
+  cached: boolean
+  expected_layers: string[]
+  matched_layers: string[]
+  missing_layers: string[]
+  advertised_layer_count: number
+  metadata_url?: string | null
+  metadata_identifier?: string | null
+  remote_title?: string | null
+  remote_version?: string | null
+  remote_modified_at?: string | null
+  remote_published_at?: string | null
+  local_source_version?: string | null
+  comparison_status: SourceCatalogComparisonStatus
+  capabilities_sha256?: string | null
+  capabilities_etag?: string | null
+  capabilities_last_modified_at?: string | null
+  message: string
+  error_code?: string | null
+}
+
+export interface SourceCatalogProbeReport {
+  project_id: string
+  generated_at: string
+  summary: {
+    provider_count: number
+    available_count: number
+    degraded_count: number
+    unavailable_count: number
+    disabled_count: number
+    different_version_count: number
+  }
+  items: SourceCatalogProbeItem[]
+  limitations: string[]
+}
+
 export interface GeojsonEnvelopeResponse {
   data: object
 }
diff --git a/scripts/README.md b/scripts/README.md
index e5ce9c4e..b8a30e13 100644
--- a/scripts/README.md
+++ b/scripts/README.md
@@ -1708,6 +1708,14 @@ uses one canonical `GET`, changes no application data and performs no source
 download. It can therefore be scheduled explicitly through Unraid cron without
 turning GeoIntel into a real-time monitoring system.
 
+Add `--probe-catalogs` to explicitly read the allowlisted official GRB and
+orthophoto capabilities plus linked ISO metadata. `--refresh-catalogs` bypasses
+the short server cache and implies the probe. `--fail-on-catalog` makes a
+degraded/unavailable official metadata service fail the command. With a probe,
+JSON output contains `source_freshness` and `catalog_probes`; without it, the
+original local report shape is unchanged. No flag downloads provider features
+or imagery and no flag writes a Dataset.
+
 ## Tower deployment
 
 Push the local branch to Gitea, then rebuild the Unraid/Tower Docker runtime:
diff --git a/scripts/audit_source_freshness.py b/scripts/audit_source_freshness.py
index c98bdd8e..40c2769a 100644
--- a/scripts/audit_source_freshness.py
+++ b/scripts/audit_source_freshness.py
@@ -26,6 +26,21 @@ def parse_args() -> argparse.Namespace:
         default="integrity",
         help="Non-zero exit policy for cron or release automation",
     )
+    parser.add_argument(
+        "--probe-catalogs",
+        action="store_true",
+        help="Explicitly query the allowlisted official GRB and orthophoto metadata catalogs",
+    )
+    parser.add_argument(
+        "--refresh-catalogs",
+        action="store_true",
+        help="Bypass the short server-side catalog cache (implies --probe-catalogs)",
+    )
+    parser.add_argument(
+        "--fail-on-catalog",
+        action="store_true",
+        help="Exit non-zero when an explicitly requested official catalog is degraded or unavailable",
+    )
     return parser.parse_args()
 
 
@@ -45,7 +60,24 @@ def fetch_report(api_url: str, project_id: str, timeout: float) -> dict:
     return payload["data"]
 
 
-def print_text(report: dict) -> None:
+def fetch_catalog_report(api_url: str, project_id: str, timeout: float, refresh: bool) -> dict:
+    query = "true" if refresh else "false"
+    endpoint = f"{api_url.rstrip('/')}/projects/{project_id}/datasets/source-catalog-probes?refresh={query}"
+    request = Request(endpoint, headers={"Accept": "application/json", "User-Agent": "GeoIntel-source-audit/1.0"})
+    try:
+        with urlopen(request, timeout=timeout) as response:
+            payload = json.load(response)
+    except HTTPError as exc:
+        body = exc.read().decode("utf-8", errors="replace")
+        raise RuntimeError(f"GeoIntel catalog probe returned HTTP {exc.code}: {body}") from exc
+    except URLError as exc:
+        raise RuntimeError(f"GeoIntel API is unreachable: {exc.reason}") from exc
+    if not isinstance(payload, dict) or not isinstance(payload.get("data"), dict):
+        raise RuntimeError("Catalog probe response is not a canonical GeoIntel data envelope")
+    return payload["data"]
+
+
+def print_text(report: dict, *, catalog_queried: bool = False) -> None:
     summary = report.get("summary", {})
     print(
         "GeoIntel source audit: "
@@ -59,7 +91,30 @@ def print_text(report: dict) -> None:
         status = item.get("status", "unknown")
         if status not in {"current", "local"} or item.get("integrity", {}).get("missing_version_count", 0):
             print(f"- {status:15} {item.get('display_name', item.get('source_name'))}: {item.get('reason', '')}")
-    print("No external catalog was queried and no dataset was modified.")
+    if catalog_queried:
+        print("The official catalog was queried read-only; no feature, raster or dataset was modified.")
+    else:
+        print("No external catalog was queried and no dataset was modified.")
+
+
+def print_catalog_text(report: dict) -> None:
+    summary = report.get("summary", {})
+    print(
+        "Official catalog probe: "
+        f"{summary.get('available_count', 0)}/{summary.get('provider_count', 0)} available, "
+        f"{summary.get('degraded_count', 0)} degraded, "
+        f"{summary.get('unavailable_count', 0)} unavailable, "
+        f"{summary.get('different_version_count', 0)} version differences"
+    )
+    for item in report.get("items", []):
+        remote = item.get("remote_version") or "no official edition"
+        local = item.get("local_source_version") or "not loaded locally"
+        print(
+            f"- {item.get('display_name', item.get('source_name'))}: "
+            f"{item.get('status')} / official={remote} / local={local} / "
+            f"comparison={item.get('comparison_status')}"
+        )
+        print(f"  {item.get('message', '')}")
 
 
 def should_fail(report: dict, fail_on: str) -> bool:
@@ -76,22 +131,42 @@ def should_fail(report: dict, fail_on: str) -> bool:
     return integrity > 0 or due > 0 or review > 0
 
 
+def catalog_should_fail(report: dict) -> bool:
+    summary = report.get("summary", {})
+    return int(summary.get("degraded_count", 0)) > 0 or int(summary.get("unavailable_count", 0)) > 0
+
+
 def main() -> int:
     args = parse_args()
     try:
         report = fetch_report(args.api_url, args.project_id, args.timeout)
+        catalog_report = (
+            fetch_catalog_report(args.api_url, args.project_id, args.timeout, args.refresh_catalogs)
+            if args.probe_catalogs or args.refresh_catalogs
+            else None
+        )
     except RuntimeError as exc:
         print(str(exc), file=sys.stderr)
         return 2
-    serialized = json.dumps(report, indent=2, sort_keys=True)
+    output_payload = (
+        {"source_freshness": report, "catalog_probes": catalog_report}
+        if catalog_report is not None
+        else report
+    )
+    serialized = json.dumps(output_payload, indent=2, sort_keys=True)
     if args.output:
         args.output.parent.mkdir(parents=True, exist_ok=True)
         args.output.write_text(serialized + "\n", encoding="utf-8")
     if args.json:
         print(serialized)
     else:
-        print_text(report)
-    return 1 if should_fail(report, args.fail_on) else 0
+        print_text(report, catalog_queried=catalog_report is not None)
+        if catalog_report is not None:
+            print_catalog_text(catalog_report)
+    failed = should_fail(report, args.fail_on)
+    if args.fail_on_catalog and catalog_report is not None:
+        failed = failed or catalog_should_fail(catalog_report)
+    return 1 if failed else 0
 
 
 if __name__ == "__main__":