diff --git a/docs/mcp.md b/docs/mcp.md
index eed0e3e..98a927e 100644
--- a/docs/mcp.md
+++ b/docs/mcp.md
@@ -59,3 +59,28 @@ compact aggregates unless `detail=true` is passed, and the list tools
 paginate (default `limit` of 20) and accept a `fields` list to return
 only the named keys per entry. Prefer `status`/`arch` filters, small
 limits and field projection when exploring large trees.
+
+## Querying a single lab
+
+To look at one lab (test runtime) rather than a whole tree, start from
+`list_labs`, which returns the labs reporting to KernelCI with their
+build, boot and test counts for the last N days. Those names are then
+usable as:
+
+- the `lab` filter of `list_builds`, `list_boots` and `list_tests`,
+  which narrows a commit's results to that lab;
+- the `data.runtime` filter of `list_nodes`, for example
+  `list_nodes(filters=["kind=job", "data.runtime=lava-collabora",
+  "data.platform__re=^qcom"])`. Maestro applies this filter server-side,
+  so it is the cheapest way to ask what one lab is doing with a family
+  of boards.
+
+For the status of a lab rather than its individual results, `get_summary`
+and `get_hardware_summary` both carry a per-lab breakdown of pass/fail
+counts under `summary.<section>.labs`, which answers "how is this tree or
+platform doing in lab X" in a single call.
+
+The dashboard has no server-side lab filter, so the `lab` option of the
+list tools is applied to the fetched page after the request. It shrinks
+the response, not the query: `total` counts entries before filtering and
+`matched` after.
diff --git a/kcidev/api.py b/kcidev/api.py
index d269b85..ccfd030 100644
--- a/kcidev/api.py
+++ b/kcidev/api.py
@@ -39,6 +39,7 @@
     dashboard_fetch_issue_list,
     dashboard_fetch_issue_tests,
     dashboard_fetch_issues_extra,
+    dashboard_fetch_metrics,
     dashboard_fetch_summary,
     dashboard_fetch_test,
     dashboard_fetch_tests,
@@ -735,6 +736,15 @@ def get_tree_list(self, origin, days=7):
             days,
         )
 
+    def get_metrics(self, start_days_ago=7, end_days_ago=0):
+        return self._dashboard_request(
+            "Dashboard metrics request failed",
+            dashboard_fetch_metrics,
+            True,
+            start_days_ago,
+            end_days_ago,
+        )
+
     def get_hardware_list(self, origin):
         return self._dashboard_request(
             "Dashboard hardware list request failed",
diff --git a/kcidev/libs/dashboard.py b/kcidev/libs/dashboard.py
index 054d92e..9114263 100644
--- a/kcidev/libs/dashboard.py
+++ b/kcidev/libs/dashboard.py
@@ -316,6 +316,18 @@ def dashboard_fetch_tree_list(origin, use_json, days=7):
     return dashboard_api_fetch("tree", params, use_json)
 
 
+def dashboard_fetch_metrics(use_json, start_days_ago=7, end_days_ago=0):
+    """Fetch global KernelCI metrics, including per-lab result counts."""
+    params = {
+        "start_days_ago": start_days_ago,
+        "end_days_ago": end_days_ago,
+    }
+    logging.info(
+        f"Fetching metrics for days {start_days_ago} to {end_days_ago} days ago"
+    )
+    return dashboard_api_fetch("metrics/", params, use_json)
+
+
 def dashboard_fetch_hardware_list(origin, use_json):
     # TODO: add date filter
     now = datetime.today()
diff --git a/kcidev/mcp/tools_dashboard.py b/kcidev/mcp/tools_dashboard.py
index 7f05426..26eb3c3 100644
--- a/kcidev/mcp/tools_dashboard.py
+++ b/kcidev/mcp/tools_dashboard.py
@@ -7,7 +7,12 @@
 from kcidev.api import KciDevError, KernelCIClient
 from kcidev.libs.filters import StatusFilter
 from kcidev.mcp.errors import tool_errors
-from kcidev.mcp.validation import check_page_args, check_page_bounds, checked_status
+from kcidev.mcp.validation import (
+    check_page_args,
+    check_page_bounds,
+    checked_days,
+    checked_status,
+)
 
 _active_client = ContextVar("dashboard_tool_client", default=None)
 
@@ -16,23 +21,43 @@ def _current_client():
     return _active_client.get() or KernelCIClient()
 
 
-def _page(data, key, status, limit, offset, fields=None):
+def _entry_labs(item):
+    """Return the lab/runtime names an entry reports, lowercased.
+
+    Boots and tests carry a top-level 'lab'; builds report the same
+    information as 'misc.lab' and 'misc.runtime'.
+    """
+    misc = item.get("misc") or {}
+    names = (item.get("lab"), misc.get("lab"), misc.get("runtime"))
+    return {name.lower() for name in names if isinstance(name, str)}
+
+
+def _page(data, key, status, limit, offset, fields=None, lab=None):
     check_page_bounds(limit, offset)
     items = data[key] if isinstance(data, dict) else data
     total = len(items)
+    candidates = items
     if status:
         status_filter = StatusFilter(checked_status(status))
         items = [item for item in items if status_filter.matches(item)]
+    if lab:
+        wanted = lab.lower()
+        items = [item for item in items if wanted in _entry_labs(item)]
     page = items[offset : offset + limit]
     if fields:
         page = [{k: item[k] for k in fields if k in item} for item in page]
-    return {
+    result = {
         key: page,
         "total": total,
         "matched": len(items),
         "limit": limit,
         "offset": offset,
     }
+    if lab and not items:
+        result["labs_present"] = sorted(
+            {name for item in candidates for name in _entry_labs(item)}
+        )
+    return result
 
 
 @tool_errors
@@ -46,7 +71,13 @@ def list_trees(origin: str = "maestro", days: int = 7):
     return _current_client().get_tree_list(origin, days)
 
 
-_COMPACT_SUMMARY_KEYS = ("status", "architectures", "issues", "failed_platforms")
+_COMPACT_SUMMARY_KEYS = (
+    "status",
+    "architectures",
+    "labs",
+    "issues",
+    "failed_platforms",
+)
 
 
 @tool_errors
@@ -137,24 +168,33 @@ def list_builds(
     start_date: str | None = None,
     end_date: str | None = None,
     status: str | None = None,
+    lab: str | None = None,
     limit: int = 20,
     offset: int = 0,
     fields: list[str] | None = None,
 ):
     """List kernel builds for one commit of a tree.
 
-    Optional filters: arch (e.g. 'arm64'), tree name, ISO date range, and
-    status ('pass', 'fail', 'inconclusive' or 'all'). Results are paginated with
-    limit/offset; the response carries 'total' (before status filtering)
-    and 'matched' counts so you know whether to fetch further pages;
-    fields projects each entry to only those keys.
+    Optional filters: arch (e.g. 'arm64'), tree name, ISO date range,
+    status ('pass', 'fail', 'inconclusive' or 'all'), and lab, the lab
+    or runtime that produced the build (builds report this as
+    'misc.lab' and 'misc.runtime'; 'misc.lab' is effectively the
+    origin, so the runtime cluster such as 'k8s-all' is the value that
+    discriminates); use list_labs to find valid names. Results are
+    paginated with limit/offset; the response carries 'total' (before
+    filtering) and 'matched' counts so you know whether to fetch
+    further pages, and a lab matching nothing returns 'labs_present',
+    every lab the entries report before any status filter, so a mistyped
+    name shows up without a second call and a real lab with no matching
+    status is still listed; fields projects each entry to only those
+    keys.
     Returns build entries with ids usable with get_build.
     """
     check_page_args(status, limit, offset)
     data = _current_client().get_builds(
         origin, giturl, branch, commit, arch, tree, start_date, end_date
     )
-    return _page(data, "builds", status, limit, offset, fields)
+    return _page(data, "builds", status, limit, offset, fields, lab)
 
 
 @tool_errors
@@ -169,24 +209,32 @@ def list_boots(
     end_date: str | None = None,
     boot_origin: str | None = None,
     status: str | None = None,
+    lab: str | None = None,
     limit: int = 20,
     offset: int = 0,
     fields: list[str] | None = None,
 ):
     """List boot test results for one commit of a tree.
 
-    Optional filters: arch, tree name, ISO date range, boot origin, and
-    status ('pass', 'fail', 'inconclusive' or 'all'). Results are paginated with
-    limit/offset; the response carries 'total' (before status filtering)
-    and 'matched' counts so you know whether to fetch further pages;
-    fields projects each entry to only those keys.
+    Optional filters: arch, tree name, ISO date range, boot origin,
+    status ('pass', 'fail', 'inconclusive' or 'all'), and lab, the lab
+    or runtime that ran the boot (for example 'lava-collabora'); use
+    list_labs to find valid names, or get_summary, whose per-section
+    'labs' counts show which labs ran this commit at all. Results are
+    paginated with limit/offset; the response carries 'total' (before
+    filtering) and 'matched' counts so you know whether to fetch
+    further pages, and a lab matching nothing returns 'labs_present',
+    every lab the entries report before any status filter, so a mistyped
+    name shows up without a second call and a real lab with no matching
+    status is still listed; fields projects each entry to only those
+    keys.
     Returns boot entries with ids usable with get_test.
     """
     check_page_args(status, limit, offset)
     data = _current_client().get_boots(
         origin, giturl, branch, commit, arch, tree, start_date, end_date, boot_origin
     )
-    return _page(data, "boots", status, limit, offset, fields)
+    return _page(data, "boots", status, limit, offset, fields, lab)
 
 
 @tool_errors
@@ -200,25 +248,32 @@ def list_tests(
     start_date: str | None = None,
     end_date: str | None = None,
     status: str | None = None,
+    lab: str | None = None,
     limit: int = 20,
     offset: int = 0,
     fields: list[str] | None = None,
 ):
     """List test results for one commit of a tree.
 
-    Optional filters: arch, tree name, ISO date range, and status ('pass',
-    'fail', 'inconclusive' or 'all'). A full commit can carry tens of thousands
-    of tests, so filter by status and paginate with limit/offset; the
-    response carries 'total' (before status filtering) and 'matched'
-    counts so you know whether to fetch further pages; fields projects
-    each entry to only those keys.
+    Optional filters: arch, tree name, ISO date range, status ('pass',
+    'fail', 'inconclusive' or 'all'), and lab, the lab or runtime that
+    ran the test (for example 'lava-collabora'); use list_labs to find
+    valid names, or get_summary, whose per-section 'labs' counts show
+    which labs ran this commit at all. A full commit can carry tens of
+    thousands of tests, so filter by lab and status and paginate with
+    limit/offset; the response carries 'total' (before filtering) and
+    'matched' counts so you know whether to fetch further pages, and a
+    lab matching nothing returns 'labs_present', every lab the entries
+    report before any status filter, so a mistyped name shows up without
+    a second call and a real lab with no matching status is still listed;
+    fields projects each entry to only those keys.
     Returns test entries with ids usable with get_test.
     """
     check_page_args(status, limit, offset)
     data = _current_client().get_tests(
         origin, giturl, branch, commit, arch, tree, start_date, end_date
     )
-    return _page(data, "tests", status, limit, offset, fields)
+    return _page(data, "tests", status, limit, offset, fields, lab)
 
 
 @tool_errors
@@ -285,6 +340,33 @@ def get_build_issues(build_id: str):
     return _current_client().get_build_issues(build_id)
 
 
+@tool_errors
+def list_labs(days: int = 7):
+    """List the labs (test runtimes) that ran boots or tests on KernelCI.
+
+    Returns each lab name with how many builds, boots and tests are
+    associated with it over the last N days, so you can pick a valid lab
+    name without scanning result listings. The names are usable as the
+    'lab' filter of list_boots and list_tests, and as the 'data.runtime'
+    filter of list_nodes.
+
+    The figures come from the dashboard's test metrics, so they are
+    test-derived: the 'builds' count is builds referenced by those tests,
+    not builds a lab produced, and a lab that only produces builds and
+    runs no tests may be absent. Treat this as boot/test lab discovery,
+    not a complete lab list for list_builds. Counts cover all origins and
+    trees; for the labs that ran one specific tree or platform, use the
+    per-section 'labs' counts of get_summary or get_hardware_summary. The
+    window is capped at 7 days; wider windows time out in the dashboard's
+    metrics aggregation.
+    """
+    data = _current_client().get_metrics(start_days_ago=checked_days(days))
+    labs = data.get("lab_maps") if isinstance(data, dict) else None
+    if not isinstance(labs, dict):
+        raise KciDevError("dashboard metrics response carried no lab data")
+    return {"labs": labs, "days": days}
+
+
 @tool_errors
 def list_hardware(origin: str = "maestro"):
     """List hardware platforms with results over the last 7 days.
@@ -299,6 +381,9 @@ def get_hardware_summary(name: str, origin: str = "maestro"):
     """Get the build/boot/test summary for one hardware platform.
 
     Covers the last 7 days. Use list_hardware to find platform names.
+    Each build/boot/test section carries a 'labs' breakdown of status
+    counts per lab, so this answers "how is this platform doing in lab
+    X" in one call, without listing and filtering individual results.
     """
     return _current_client().get_hardware_summary(name, origin)
 
@@ -381,6 +466,7 @@ def get_issue_tests(
     get_log,
     get_test_issues,
     get_build_issues,
+    list_labs,
     list_hardware,
     get_hardware_summary,
     list_issues,
diff --git a/kcidev/mcp/tools_maestro.py b/kcidev/mcp/tools_maestro.py
index d6f9185..9a8ae1c 100644
--- a/kcidev/mcp/tools_maestro.py
+++ b/kcidev/mcp/tools_maestro.py
@@ -36,14 +36,24 @@ def list_nodes(
             """List Maestro nodes, oldest first, optionally filtered.
 
             Filters are 'field=value' strings, for example 'name=checkout',
-            'state=done', 'result=fail' or 'treeid=<tree id>'. Matching is
-            exact; append '__re' to a field for a regex match, for example
-            'name__re=baseline' matches all baseline job variants. Results
-            are returned oldest first, so to reach recent nodes window the
-            query with a filter such as 'created__gt=2026-07-01' rather
-            than paginating from the start. Use limit and offset to
-            paginate within the window; full nodes are large, so use
-            fields to project each node to only those keys.
+            'state=done', 'result=fail' or 'treeid=<tree id>'. Nested node
+            fields are addressed with a dot, most usefully
+            'data.runtime=<lab>' to restrict results to one lab or runtime
+            (for example 'data.runtime=lava-collabora') and
+            'data.platform=<platform>' for one board; both are applied by
+            the server, so prefer them over listing everything and
+            filtering afterwards. Matching is exact; append '__re' to a
+            field for a regex match, for example 'name__re=baseline'
+            matches all baseline job variants and
+            'data.platform__re=sc7180' all sc7180 boards. Filters combine,
+            so 'data.runtime=lava-collabora' with
+            'data.platform__re=^qcom' answers "what is this lab doing with
+            qcom boards" in one query. Results are returned oldest first,
+            so to reach recent nodes window the query with a filter such as
+            'created__gt=2026-07-01' rather than paginating from the start.
+            Use limit and offset to paginate within the window; full nodes
+            are large, so use fields to project each node to only those
+            keys.
             """
             check_page_bounds(limit, offset)
             nodes = client.get_nodes(
diff --git a/kcidev/mcp/validation.py b/kcidev/mcp/validation.py
index 6c4d26a..afc6bd1 100644
--- a/kcidev/mcp/validation.py
+++ b/kcidev/mcp/validation.py
@@ -5,6 +5,8 @@
 
 STATUS_CHOICES = ("all", "pass", "fail", "inconclusive")
 
+MAX_LAB_DAYS = 7
+
 
 def checked_status(status):
     normalised = status.strip().lower()
@@ -43,3 +45,14 @@ def check_page_args(status, limit, offset):
     check_page_bounds(limit, offset)
     if status:
         checked_status(status)
+
+
+def checked_days(days, maximum=MAX_LAB_DAYS):
+    if days < 1:
+        raise KciDevError(f"Invalid days {days}: must be one or greater")
+    if days > maximum:
+        raise KciDevError(
+            f"Invalid days {days}: must be at most {maximum}. Wider windows "
+            "time out in the dashboard metrics aggregation"
+        )
+    return days
diff --git a/tests/test_mcp_tools_dashboard.py b/tests/test_mcp_tools_dashboard.py
index 87c9cd6..70b0c9c 100644
--- a/tests/test_mcp_tools_dashboard.py
+++ b/tests/test_mcp_tools_dashboard.py
@@ -196,6 +196,7 @@ def test_get_summary_compact_by_default(monkeypatch):
     assert result["summary"]["builds"] == {
         "status": {"PASS": 10, "FAIL": 1},
         "architectures": {"x86_64": {"PASS": 5}},
+        "labs": {"lab-1": {}},
         "issues": [],
     }
     assert result["summary"]["boots"] == {
@@ -356,3 +357,164 @@ def test_issue_tools_validate_before_any_request(monkeypatch):
     with pytest.raises(ToolExecutionError):
         tools_dashboard.get_issue_tests("maestro:i1", status="borked")
     get.assert_not_called()
+
+
+def test_list_labs_returns_lab_counts(monkeypatch):
+    get = _mock_get(
+        monkeypatch,
+        {
+            "n_builds": 100,
+            "lab_maps": {
+                "lava-collabora": {"builds": 161, "boots": 987, "tests": 100105},
+                "opentest-ti": {"builds": 4, "boots": 80, "tests": 0},
+            },
+        },
+    )
+    result = tools_dashboard.list_labs(days=3)
+    url = get.call_args[0][0]
+    assert "metrics/" in url
+    assert "start_days_ago=3" in url
+    assert result["days"] == 3
+    assert result["labs"]["opentest-ti"] == {"builds": 4, "boots": 80, "tests": 0}
+    assert "n_builds" not in result
+
+
+def test_list_labs_without_lab_data_errors(monkeypatch):
+    _mock_get(monkeypatch, {"n_builds": 100})
+    with pytest.raises(ToolExecutionError, match="lab data"):
+        tools_dashboard.list_labs()
+
+
+def test_list_boots_filters_by_lab(monkeypatch):
+    _mock_get(
+        monkeypatch,
+        {
+            "boots": [
+                {"id": "b1", "status": "PASS", "lab": "lava-collabora"},
+                {"id": "b2", "status": "FAIL", "lab": "opentest-ti"},
+                {"id": "b3", "status": "FAIL", "lab": "lava-collabora"},
+                {"id": "b4", "status": "PASS", "lab": None},
+            ]
+        },
+    )
+    result = tools_dashboard.list_boots(
+        giturl="https://git.example.org/linux.git",
+        branch="master",
+        commit="deadbeef",
+        lab="LAVA-Collabora",
+    )
+    assert result["total"] == 4
+    assert result["matched"] == 2
+    assert [b["id"] for b in result["boots"]] == ["b1", "b3"]
+
+
+def test_list_tests_combines_lab_and_status_filters(monkeypatch):
+    _mock_get(
+        monkeypatch,
+        {
+            "tests": [
+                {"id": "t1", "status": "FAIL", "lab": "lava-collabora"},
+                {"id": "t2", "status": "PASS", "lab": "lava-collabora"},
+                {"id": "t3", "status": "FAIL", "lab": "maestro"},
+            ]
+        },
+    )
+    result = tools_dashboard.list_tests(
+        giturl="https://git.example.org/linux.git",
+        branch="master",
+        commit="deadbeef",
+        status="fail",
+        lab="lava-collabora",
+    )
+    assert result["total"] == 3
+    assert result["matched"] == 1
+    assert [t["id"] for t in result["tests"]] == ["t1"]
+
+
+def test_list_builds_matches_lab_in_misc(monkeypatch):
+    _mock_get(
+        monkeypatch,
+        {
+            "builds": [
+                {"id": "b1", "status": "PASS", "misc": {"lab": "maestro"}},
+                {"id": "b2", "status": "PASS", "misc": {"runtime": "k8s-all"}},
+                {"id": "b3", "status": "PASS", "misc": None},
+                {"id": "b4", "status": "PASS"},
+            ]
+        },
+    )
+    result = tools_dashboard.list_builds(
+        giturl="https://git.example.org/linux.git",
+        branch="master",
+        commit="deadbeef",
+        lab="k8s-all",
+    )
+    assert result["matched"] == 1
+    assert [b["id"] for b in result["builds"]] == ["b2"]
+
+
+def test_get_summary_keeps_lab_breakdown(monkeypatch):
+    _mock_get(monkeypatch, SUMMARY_PAYLOAD)
+    result = tools_dashboard.get_summary(
+        giturl="https://git.example.org/linux.git", branch="master", commit="deadbeef"
+    )
+    assert result["summary"]["builds"]["labs"] == {"lab-1": {}}
+
+
+def test_list_labs_rejects_non_positive_days(monkeypatch):
+    get = _mock_get(monkeypatch, {"lab_maps": {}})
+    with pytest.raises(ToolExecutionError):
+        tools_dashboard.list_labs(days=0)
+    get.assert_not_called()
+
+
+def test_list_labs_rejects_days_above_cap(monkeypatch):
+    get = _mock_get(monkeypatch, {"lab_maps": {}})
+    with pytest.raises(ToolExecutionError) as excinfo:
+        tools_dashboard.list_labs(days=90)
+    assert "90" in str(excinfo.value)
+    get.assert_not_called()
+
+
+def test_unmatched_lab_reports_the_labs_that_are_present(monkeypatch):
+    _mock_get(
+        monkeypatch,
+        {
+            "tests": [
+                {"id": "t1", "status": "PASS", "lab": "lava-collabora"},
+                {"id": "t2", "status": "PASS", "lab": "lava-broonie"},
+            ]
+        },
+    )
+    result = tools_dashboard.list_tests(**_tree_args(lab="lava-colabora"))
+    assert result["matched"] == 0
+    assert result["labs_present"] == ["lava-broonie", "lava-collabora"]
+
+
+def test_matched_lab_omits_the_labs_present_hint(monkeypatch):
+    _mock_get(
+        monkeypatch,
+        {"tests": [{"id": "t1", "status": "PASS", "lab": "lava-collabora"}]},
+    )
+    result = tools_dashboard.list_tests(**_tree_args(lab="lava-collabora"))
+    assert result["matched"] == 1
+    assert "labs_present" not in result
+
+
+def test_labs_present_ignores_the_status_filter(monkeypatch):
+    _mock_get(
+        monkeypatch,
+        {
+            "tests": [
+                {"id": "p1", "status": "PASS", "lab": "lava-collabora"},
+                {"id": "f1", "status": "FAIL", "lab": "lava-broonie"},
+            ]
+        },
+    )
+
+    result = tools_dashboard.list_tests(
+        **_tree_args(status="fail", lab="lava-collabora")
+    )
+
+    assert result["matched"] == 0
+    assert "lava-collabora" in result["labs_present"]