diff --git a/deployments/api/src/stitch/api/db/og_field_resource_actions.py b/deployments/api/src/stitch/api/db/og_field_resource_actions.py
index 94c5d157..d5960d1f 100644
--- a/deployments/api/src/stitch/api/db/og_field_resource_actions.py
+++ b/deployments/api/src/stitch/api/db/og_field_resource_actions.py
@@ -22,7 +22,11 @@
     attach_sources_to_resource,
     get_or_create_sources,
 )
-from stitch.ogsi.model import OGFieldListItemView, OGFieldResource
+from stitch.ogsi.model import (
+    OGFieldListItemView,
+    OGFieldResource,
+    OGFieldSourceValueView,
+)
 from stitch.ogsi.model.types import OGSISrcKey
 
 from .model import (
@@ -30,7 +34,7 @@
     MembershipStatus,
     ResourceModel,
 )
-from .model.oil_gas_field_source_value import value_attr_for
+from .model.oil_gas_field_source_value import ATTRIBUTE_NAMES, value_attr_for
 from .queries import base_resource_query, construct_base_query_statement, add_ranking
 from .utils import (
     coalesce_resources,
@@ -127,6 +131,45 @@ async def get(
     )
 
 
+async def field_source_values(
+    session: AsyncSession,
+    id: int,
+    field: str,
+    licensed_sources: Collection[OGSISrcKey] | None = None,
+) -> list[OGFieldSourceValueView]:
+    """Every source's value for one field of a resource, best-priority first.
+
+    Returns only sources that carry a value for ``field`` (empty/null omitted),
+    each with its effective per-resource priority. The first entry is the
+    coalesced winner. Licensing is applied. Priority is source-scoped today; the
+    contract is unchanged when it becomes resource/field-scoped.
+    """
+    if field not in ATTRIBUTE_NAMES:
+        raise HTTPException(
+            status_code=422,
+            detail=f"field={field} is not a known resource field.",
+        )
+    if await session.get(ResourceModel, id) is None:
+        raise HTTPException(
+            status_code=HTTP_404_NOT_FOUND, detail=f"No Resource with id `{id}` found."
+        )
+
+    by_id = await ResourceModel.source_data_by_resource_id(
+        session, [id], licensed_sources
+    )
+    values = [
+        OGFieldSourceValueView(
+            source=src.source, id=src.id, value=value, priority=priority
+        )
+        for src, priority in by_id.get(id, [])
+        if src.id is not None
+        and (value := getattr(src, field)) is not None
+        and value != ""
+    ]
+    values.sort(key=lambda v: (v.priority, v.id))
+    return values
+
+
 async def create(
     session: AsyncSession, user: CurrentUser, resource: OGFieldResource
 ) -> OGFieldResource:
diff --git a/deployments/api/src/stitch/api/routers/oil_gas_fields.py b/deployments/api/src/stitch/api/routers/oil_gas_fields.py
index b38c1f00..75c7b620 100644
--- a/deployments/api/src/stitch/api/routers/oil_gas_fields.py
+++ b/deployments/api/src/stitch/api/routers/oil_gas_fields.py
@@ -41,6 +41,7 @@
     OGFieldListItemView,
     OGFieldResource,
     OGFieldResourceView,
+    OGFieldSourceValueView,
     OGFieldView,
 )
 
@@ -284,6 +285,27 @@ async def get_resource_detail(
     return resource_to_detail_view(resource=res)
 
 
+@router.get(
+    "/{id}/fields/{field}/sources",
+    response_model=list[OGFieldSourceValueView],
+    dependencies=[Depends(require_permissions(RESOURCE_READ))],
+)
+async def get_field_source_values(
+    *,
+    uow: UnitOfWorkDep,
+    user: CurrentUser,
+    claims: Claims,
+    id: int,
+    field: str,
+) -> list[OGFieldSourceValueView]:
+    return await resource_actions.field_source_values(
+        session=uow.session,
+        id=id,
+        field=field,
+        licensed_sources=licensed_sources(claims),
+    )
+
+
 @router.post(
     "/",
     response_model=OGFieldResourceView,
diff --git a/deployments/api/tests/db/test_resource_actions.py b/deployments/api/tests/db/test_resource_actions.py
index edac7208..e7eea148 100644
--- a/deployments/api/tests/db/test_resource_actions.py
+++ b/deployments/api/tests/db/test_resource_actions.py
@@ -1092,6 +1092,115 @@ async def test_override_is_scoped_to_its_resource(
         assert (await resource_actions.get(session, untouched)).view.name == "GEM Name"
 
 
+class TestFieldSourceValues:
+    """Per-field source-value listing, best-priority first."""
+
+    async def _seed(self, session, user) -> int:
+        # gem(2) outranks wm(3) by default; llm has no state_province.
+        return await _create_resource_with_sources(
+            session,
+            user,
+            {"source": "gem", "name": "GEM Name", "country": "USA", "basin": "Alpha"},
+            {"source": "wm", "name": "WM Name", "country": "CAN", "basin": "Beta"},
+            {"source": "llm", "name": "LLM Name", "country": "GBR"},
+        )
+
+    @pytest.mark.anyio
+    async def test_lists_values_sorted_by_priority_with_winner_first(
+        self,
+        seeded_integration_session: AsyncSession,
+        test_user: User,
+    ):
+        session = seeded_integration_session
+        rid = await self._seed(session, test_user)
+
+        rows = await resource_actions.field_source_values(session, rid, "name")
+
+        # gem(2) < wm(3) < llm(4): winner (gem) first, then in priority order.
+        assert [(r.source, r.value) for r in rows] == [
+            ("gem", "GEM Name"),
+            ("wm", "WM Name"),
+            ("llm", "LLM Name"),
+        ]
+        assert [r.priority for r in rows] == sorted(r.priority for r in rows)
+
+    @pytest.mark.anyio
+    async def test_override_reorders_field_values(
+        self,
+        seeded_integration_session: AsyncSession,
+        test_user: User,
+    ):
+        session = seeded_integration_session
+        rid = await self._seed(session, test_user)
+        session.add(
+            OGFieldResourceSourcePriority(resource_id=rid, source="wm", priority=1)
+        )
+        await session.flush()
+
+        rows = await resource_actions.field_source_values(session, rid, "basin")
+
+        # wm promoted above gem; llm has no basin so it is omitted.
+        assert [(r.source, r.value) for r in rows] == [
+            ("wm", "Beta"),
+            ("gem", "Alpha"),
+        ]
+
+    @pytest.mark.anyio
+    async def test_omits_sources_without_a_value(
+        self,
+        seeded_integration_session: AsyncSession,
+        test_user: User,
+    ):
+        session = seeded_integration_session
+        rid = await self._seed(session, test_user)
+
+        rows = await resource_actions.field_source_values(
+            session, rid, "state_province"
+        )
+
+        assert rows == []
+
+    @pytest.mark.anyio
+    async def test_unlicensed_sources_are_excluded(
+        self,
+        seeded_integration_session: AsyncSession,
+        test_user: User,
+    ):
+        session = seeded_integration_session
+        rid = await self._seed(session, test_user)
+
+        rows = await resource_actions.field_source_values(
+            session, rid, "name", licensed_sources=["gem"]
+        )
+
+        assert [r.source for r in rows] == ["gem"]
+
+    @pytest.mark.anyio
+    async def test_unknown_field_is_rejected(
+        self,
+        seeded_integration_session: AsyncSession,
+        test_user: User,
+    ):
+        session = seeded_integration_session
+        rid = await self._seed(session, test_user)
+
+        with pytest.raises(HTTPException) as exc:
+            await resource_actions.field_source_values(session, rid, "not_a_field")
+        assert exc.value.status_code == 422
+
+    @pytest.mark.anyio
+    async def test_missing_resource_is_404(
+        self,
+        seeded_integration_session: AsyncSession,
+        test_user: User,
+    ):
+        with pytest.raises(HTTPException) as exc:
+            await resource_actions.field_source_values(
+                seeded_integration_session, 9_999_999, "name"
+            )
+        assert exc.value.status_code == 404
+
+
 class TestResourceDetailCoalescing:
     """Detail-path (``resource_actions.get``) coalescing behavior.
 
diff --git a/deployments/seed/data/006-source-values-demo.json b/deployments/seed/data/006-source-values-demo.json
new file mode 100644
index 00000000..8ad7e9cf
--- /dev/null
+++ b/deployments/seed/data/006-source-values-demo.json
@@ -0,0 +1,56 @@
+[
+  {
+    "id": 0,
+    "source_data": [
+      {
+        "source": "rmi",
+        "name": "Coalescing Demo Field",
+        "country": "USA",
+        "location_type": "Onshore",
+        "discovery_year": 1969
+      },
+      {
+        "source": "gem",
+        "name": "Coalescing Demo (GEM A)",
+        "country": "USA",
+        "basin": "Permian Basin",
+        "latitude": 31.9,
+        "longitude": -102.1,
+        "production_conventionality": "Unconventional",
+        "discovery_year": 1970,
+        "production_start_year": 1975
+      },
+      {
+        "source": "gem",
+        "name": "Coalescing Demo (GEM B)",
+        "country": "CAN",
+        "basin": "Williston Basin",
+        "production_conventionality": "Conventional",
+        "discovery_year": 1971
+      },
+      {
+        "source": "wm",
+        "name": "Coalescing Demo (WM)",
+        "country": "GBR",
+        "basin": "North Sea",
+        "state_province": "Texas",
+        "latitude": 31.85,
+        "longitude": -102.2,
+        "location_type": "Offshore",
+        "primary_hydrocarbon_group": "Light Oil",
+        "discovery_year": 1968,
+        "production_start_year": 1974,
+        "field_status": "Producing"
+      },
+      {
+        "source": "llm",
+        "name": "Coalescing Demo (LLM)",
+        "country": null,
+        "basin": "Ghawar (guess)",
+        "primary_hydrocarbon_group": "Medium Oil",
+        "field_status": "Non-Producing"
+      }
+    ],
+    "constituents": []
+  }
+]
diff --git a/deployments/stitch-frontend/src/components/FieldCard.jsx b/deployments/stitch-frontend/src/components/FieldCard.jsx
index 0b7f023c..de174bed 100644
--- a/deployments/stitch-frontend/src/components/FieldCard.jsx
+++ b/deployments/stitch-frontend/src/components/FieldCard.jsx
@@ -1,3 +1,4 @@
+import { useId } from "react";
 import {
   SOURCE_COLORS,
   SOURCE_LABELS,
@@ -7,7 +8,19 @@ import {
 
 // Used to display a single field value in a card, as seen in the ResourceDetailPage.
 // Pass `source` (one of "gem" | "wm" | "rmi" | "llm") to tint the left border by data source.
-export function FieldCard({ label, value, source }) {
+// Pass `expandable` + `isOpen` + `onToggle` to make the value a toggle button; `children`
+// (e.g. an "All sources" panel) render below the box while open. The card is presentational:
+// the parent owns open state and any data fetching.
+export function FieldCard({
+  label,
+  value,
+  source,
+  expandable = false,
+  isOpen = false,
+  onToggle,
+  children,
+}) {
+  const panelId = useId();
   const display =
     value === null || value === undefined || value === ""
       ? null
@@ -18,30 +31,61 @@ export function FieldCard({ label, value, source }) {
     ? (SOURCE_LABELS[source] ?? UNKNOWN_SOURCE_LABEL)
     : null;
 
+  const boxContent = (
+    <>
+      <div className="flex items-start gap-2">
+        <div className="min-w-0 flex-1 break-words">
+          {display ?? <span className="text-ink-muted">—</span>}
+        </div>
+        {expandable && (
+          <span aria-hidden="true" className="shrink-0 text-xs text-ink-muted">
+            {isOpen ? "▾" : "▸"}
+          </span>
+        )}
+      </div>
+      {sourceLabel && (
+        <div className="mt-1 flex items-center gap-1.5 text-xs font-medium leading-4 text-ink-muted">
+          <span
+            className="h-2 w-2 shrink-0 rounded-sm ring-1 ring-ink/10"
+            style={{ backgroundColor: borderColor }}
+            aria-hidden="true"
+          />
+          Source: {sourceLabel}
+        </div>
+      )}
+    </>
+  );
+
+  const boxClasses =
+    "min-h-[2.5rem] w-full rounded-md border border-line bg-panel px-3 py-2 text-left text-sm text-ink";
+
   return (
     <div className="min-w-0">
       <p className="mb-1 text-left text-xs font-semibold uppercase tracking-wide text-ink-muted">
         {label}
       </p>
-      <div
-        className="min-h-[2.5rem] rounded-md border border-line bg-panel px-3 py-2 text-sm text-ink"
-        style={{ borderLeftColor: borderColor }}
-        title={sourceLabel ? `Source: ${sourceLabel}` : undefined}
-      >
-        <div className="break-words">
-          {display ?? <span className="text-ink-muted">—</span>}
+      {expandable ? (
+        <button
+          type="button"
+          aria-expanded={isOpen}
+          // Only reference the panel while it is mounted (rendered on open).
+          aria-controls={isOpen ? panelId : undefined}
+          onClick={onToggle}
+          className={`${boxClasses} transition-colors hover:bg-surface focus:outline-none focus-visible:ring-2 focus-visible:ring-primary/30 focus-visible:ring-offset-1`}
+          style={{ borderLeftColor: borderColor }}
+        >
+          {boxContent}
+        </button>
+      ) : (
+        <div
+          className={boxClasses}
+          style={{ borderLeftColor: borderColor }}
+          title={sourceLabel ? `Source: ${sourceLabel}` : undefined}
+        >
+          {boxContent}
         </div>
-        {sourceLabel && (
-          <div className="mt-1 flex items-center gap-1.5 text-xs font-medium leading-4 text-ink-muted">
-            <span
-              className="h-2 w-2 shrink-0 rounded-sm ring-1 ring-ink/10"
-              style={{ backgroundColor: borderColor }}
-              aria-hidden="true"
-            />
-            Source: {sourceLabel}
-          </div>
-        )}
-      </div>
+      )}
+      {expandable && isOpen && <div id={panelId}>{children}</div>}
     </div>
   );
 }
diff --git a/deployments/stitch-frontend/src/components/FieldCard.test.jsx b/deployments/stitch-frontend/src/components/FieldCard.test.jsx
index 1a825509..d064ea91 100644
--- a/deployments/stitch-frontend/src/components/FieldCard.test.jsx
+++ b/deployments/stitch-frontend/src/components/FieldCard.test.jsx
@@ -1,5 +1,6 @@
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, vi } from "vitest";
 import { render, screen } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
 import { FieldCard, FieldGrid } from "./FieldCard";
 import {
   SOURCE_COLORS,
@@ -82,6 +83,55 @@ describe("FieldCard", () => {
   });
 });
 
+describe("FieldCard expandable behavior", () => {
+  it("renders a plain box (no button) when not expandable", () => {
+    render(<FieldCard label="Basin" value="Foo Basin" source="wm" />);
+    expect(screen.queryByRole("button")).not.toBeInTheDocument();
+  });
+
+  it("renders a toggle button reflecting isOpen when expandable", () => {
+    const { rerender } = render(
+      <FieldCard label="Basin" value="Foo Basin" expandable isOpen={false} />,
+    );
+    const toggle = screen.getByRole("button");
+    expect(toggle).toHaveAttribute("aria-expanded", "false");
+
+    rerender(<FieldCard label="Basin" value="Foo Basin" expandable isOpen />);
+    expect(screen.getByRole("button")).toHaveAttribute("aria-expanded", "true");
+  });
+
+  it("calls onToggle when the value button is clicked", async () => {
+    const user = userEvent.setup();
+    const onToggle = vi.fn();
+    render(
+      <FieldCard
+        label="Basin"
+        value="Foo Basin"
+        expandable
+        onToggle={onToggle}
+      />,
+    );
+    await user.click(screen.getByRole("button"));
+    expect(onToggle).toHaveBeenCalledTimes(1);
+  });
+
+  it("renders children only when expandable and open", () => {
+    const { rerender } = render(
+      <FieldCard label="Basin" value="Foo Basin" expandable isOpen={false}>
+        <div>panel body</div>
+      </FieldCard>,
+    );
+    expect(screen.queryByText("panel body")).not.toBeInTheDocument();
+
+    rerender(
+      <FieldCard label="Basin" value="Foo Basin" expandable isOpen>
+        <div>panel body</div>
+      </FieldCard>,
+    );
+    expect(screen.getByText("panel body")).toBeInTheDocument();
+  });
+});
+
 describe("FieldGrid", () => {
   it("renders its children", () => {
     render(
diff --git a/deployments/stitch-frontend/src/components/ResourceFieldCard.jsx b/deployments/stitch-frontend/src/components/ResourceFieldCard.jsx
new file mode 100644
index 00000000..4770fa9f
--- /dev/null
+++ b/deployments/stitch-frontend/src/components/ResourceFieldCard.jsx
@@ -0,0 +1,101 @@
+import { useState } from "react";
+import { FieldCard } from "./FieldCard";
+import { useFieldSourceValues } from "../hooks/useResources";
+import {
+  SOURCE_COLORS,
+  SOURCE_LABELS,
+  UNKNOWN_SOURCE_LABEL,
+  DEFAULT_FIELD_COLOR,
+} from "../constants/sourceMeta";
+
+function SourceValueRow({ source, value, id, isWinner }) {
+  const barColor = SOURCE_COLORS[source] ?? DEFAULT_FIELD_COLOR;
+  const sourceLabel = SOURCE_LABELS[source] ?? UNKNOWN_SOURCE_LABEL;
+  const meta =
+    id !== null && id !== undefined ? `${sourceLabel} · #${id}` : sourceLabel;
+  // Quote strings to set text values apart; render numbers/booleans bare.
+  const display = typeof value === "string" ? `"${value}"` : String(value);
+
+  return (
+    <div
+      className={`rounded-md border border-line border-l-4 px-2.5 py-1.5 ${
+        isWinner ? "bg-surface" : "bg-panel"
+      }`}
+      style={{ borderLeftColor: barColor }}
+    >
+      <div className="break-words text-sm text-ink">{display}</div>
+      <div className="mt-0.5 text-xs text-ink-muted">{meta}</div>
+    </div>
+  );
+}
+
+function FieldSourcesPanel({ isLoading, isError, sources }) {
+  return (
+    <div className="mt-2 space-y-2 rounded-md border border-line bg-panel p-3">
+      {/* Reserved header — future controls will live alongside this label. */}
+      <p className="text-xs font-semibold uppercase tracking-wide text-ink-muted">
+        All sources
+      </p>
+      {isLoading && <p className="text-sm text-ink-muted">Loading sources…</p>}
+      {isError && (
+        <p className="text-sm text-danger">Failed to load source values.</p>
+      )}
+      {!isLoading && !isError && sources.length === 0 && (
+        <p className="text-sm text-ink-muted">
+          No source values for this field.
+        </p>
+      )}
+      {!isLoading && !isError && sources.length > 0 && (
+        <div className="space-y-1.5">
+          {/* The endpoint returns best-priority first, so index 0 is the winner. */}
+          {sources.map((row, idx) => (
+            <SourceValueRow
+              key={`${row.source}-${row.id}`}
+              source={row.source}
+              value={row.value}
+              id={row.id}
+              isWinner={idx === 0}
+            />
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
+// A FieldCard for the resource detail page: clicking a populated value lazily
+// fetches every source's value for that field and shows them in priority order.
+export default function ResourceFieldCard({
+  endpoint,
+  resourceId,
+  fieldKey,
+  label,
+  value,
+  source,
+}) {
+  const [isOpen, setIsOpen] = useState(false);
+  const expandable = value !== null && value !== undefined && value !== "";
+  const { data, isLoading, isError } = useFieldSourceValues(
+    endpoint,
+    resourceId,
+    fieldKey,
+    isOpen && expandable,
+  );
+
+  return (
+    <FieldCard
+      label={label}
+      value={value}
+      source={source}
+      expandable={expandable}
+      isOpen={isOpen}
+      onToggle={() => setIsOpen((current) => !current)}
+    >
+      <FieldSourcesPanel
+        isLoading={isLoading}
+        isError={isError}
+        sources={data ?? []}
+      />
+    </FieldCard>
+  );
+}
diff --git a/deployments/stitch-frontend/src/components/ResourceFieldCard.test.jsx b/deployments/stitch-frontend/src/components/ResourceFieldCard.test.jsx
new file mode 100644
index 00000000..f28b7010
--- /dev/null
+++ b/deployments/stitch-frontend/src/components/ResourceFieldCard.test.jsx
@@ -0,0 +1,124 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import ResourceFieldCard from "./ResourceFieldCard";
+import { useFieldSourceValues } from "../hooks/useResources";
+import { SOURCE_LABELS } from "../constants/sourceMeta";
+
+vi.mock("../hooks/useResources", () => ({
+  useFieldSourceValues: vi.fn(),
+}));
+
+function renderCard(props = {}) {
+  return render(
+    <ResourceFieldCard
+      endpoint="oil-gas-fields"
+      resourceId={42}
+      fieldKey="basin"
+      label="Basin"
+      value="Foo Basin"
+      source="wm"
+      {...props}
+    />,
+  );
+}
+
+describe("ResourceFieldCard", () => {
+  beforeEach(() => {
+    useFieldSourceValues.mockReset();
+    useFieldSourceValues.mockReturnValue({
+      data: undefined,
+      isLoading: false,
+      isError: false,
+    });
+  });
+
+  it("is not expandable when the value is empty", () => {
+    renderCard({ value: null });
+    expect(screen.queryByRole("button")).not.toBeInTheDocument();
+  });
+
+  it("does not enable the query until the panel is opened", () => {
+    renderCard();
+    // Closed on first render → query disabled.
+    expect(useFieldSourceValues).toHaveBeenLastCalledWith(
+      "oil-gas-fields",
+      42,
+      "basin",
+      false,
+    );
+  });
+
+  it("enables the query and shows the panel when opened", async () => {
+    const user = userEvent.setup();
+    useFieldSourceValues.mockReturnValue({
+      data: [
+        { source: "wm", id: 20, value: "Foo Basin", priority: 1 },
+        { source: "gem", id: 10, value: "Bar Basin", priority: 2 },
+      ],
+      isLoading: false,
+      isError: false,
+    });
+    renderCard();
+
+    await user.click(screen.getByRole("button"));
+
+    expect(useFieldSourceValues).toHaveBeenLastCalledWith(
+      "oil-gas-fields",
+      42,
+      "basin",
+      true,
+    );
+    expect(screen.getByText("All sources")).toBeInTheDocument();
+    expect(screen.getByText('"Foo Basin"')).toBeInTheDocument();
+    expect(screen.getByText('"Bar Basin"')).toBeInTheDocument();
+    expect(screen.getByText(`${SOURCE_LABELS.wm} · #20`)).toBeInTheDocument();
+  });
+
+  it("highlights the first (winning) row and diminishes the rest", async () => {
+    const user = userEvent.setup();
+    useFieldSourceValues.mockReturnValue({
+      data: [
+        { source: "wm", id: 20, value: "Foo Basin", priority: 1 },
+        { source: "gem", id: 10, value: "Bar Basin", priority: 2 },
+      ],
+      isLoading: false,
+      isError: false,
+    });
+    renderCard();
+    await user.click(screen.getByRole("button"));
+
+    expect(screen.getByText('"Foo Basin"').closest(".border-l-4")).toHaveClass(
+      "bg-surface",
+    );
+    expect(screen.getByText('"Bar Basin"').closest(".border-l-4")).toHaveClass(
+      "bg-panel",
+    );
+  });
+
+  it("shows a loading state while fetching", async () => {
+    const user = userEvent.setup();
+    useFieldSourceValues.mockReturnValue({
+      data: undefined,
+      isLoading: true,
+      isError: false,
+    });
+    renderCard();
+    await user.click(screen.getByRole("button"));
+    expect(screen.getByText("Loading sources…")).toBeInTheDocument();
+  });
+
+  it("shows an error state when the fetch fails", async () => {
+    const user = userEvent.setup();
+    useFieldSourceValues.mockReturnValue({
+      data: undefined,
+      isLoading: false,
+      isError: true,
+    });
+    renderCard();
+    await user.click(screen.getByRole("button"));
+    expect(
+      screen.getByText("Failed to load source values."),
+    ).toBeInTheDocument();
+  });
+});
diff --git a/deployments/stitch-frontend/src/hooks/useResources.js b/deployments/stitch-frontend/src/hooks/useResources.js
index 1b4de26d..a990b884 100644
--- a/deployments/stitch-frontend/src/hooks/useResources.js
+++ b/deployments/stitch-frontend/src/hooks/useResources.js
@@ -87,6 +87,19 @@ function useSourceDetailReal(
   });
 }
 
+function useFieldSourceValuesReal(
+  endpoint = "oil-gas-fields",
+  id,
+  field,
+  enabled = false,
+) {
+  const config = useConfig();
+  return useAuthenticatedQuery({
+    ...resourceQueries.fieldSources(config, endpoint, id, field),
+    enabled: enabled && Boolean(field) && Number.isFinite(id),
+  });
+}
+
 function useMergeCandidatesReal(endpoint = "oil-gas-fields", enabled = false) {
   const config = useConfig();
   return useAuthenticatedQuery({
@@ -287,6 +300,22 @@ function useSourceDetailMock(
   });
 }
 
+function useFieldSourceValuesMock(
+  endpoint = "oil-gas-fields",
+  id,
+  field,
+  enabled = false,
+) {
+  // Mock mode has no backend; the panel degrades to an empty state, matching
+  // useSourceDetailMock. Real behavior is exercised against the API. Guard `id`
+  // the same way the real hook does so the query key stays stable.
+  return useQuery({
+    queryKey: resourceKeys.fieldSources(endpoint, id, field),
+    queryFn: () => Promise.resolve([]),
+    enabled: enabled && Boolean(field) && Number.isFinite(id),
+  });
+}
+
 function useMergeCandidatesMock(endpoint = "oil-gas-fields", enabled = false) {
   return useQuery({
     queryKey: resourceKeys.mergeCandidates(endpoint),
@@ -343,6 +372,9 @@ export const useResourceDetail = USE_MOCK_DATA
 export const useSourceDetail = USE_MOCK_DATA
   ? useSourceDetailMock
   : useSourceDetailReal;
+export const useFieldSourceValues = USE_MOCK_DATA
+  ? useFieldSourceValuesMock
+  : useFieldSourceValuesReal;
 export const useMergeCandidates = USE_MOCK_DATA
   ? useMergeCandidatesMock
   : useMergeCandidatesReal;
diff --git a/deployments/stitch-frontend/src/pages/ResourceDetailPage.jsx b/deployments/stitch-frontend/src/pages/ResourceDetailPage.jsx
index 6354c680..01d67100 100644
--- a/deployments/stitch-frontend/src/pages/ResourceDetailPage.jsx
+++ b/deployments/stitch-frontend/src/pages/ResourceDetailPage.jsx
@@ -12,6 +12,7 @@ import {
 import SourceMixBar from "../components/SourceMixBar";
 import SectionHeader from "../components/SectionHeader";
 import { FieldCard, FieldGrid } from "../components/FieldCard";
+import ResourceFieldCard from "../components/ResourceFieldCard";
 import { SOURCE_LABELS } from "../constants/sourceMeta";
 import Button from "../components/Button";
 import {
@@ -578,8 +579,11 @@ export default function ResourceDetailPage() {
             <SectionHeader title="Identity and location" />
             <FieldGrid>
               {IDENTITY_FIELDS.map((key) => (
-                <FieldCard
+                <ResourceFieldCard
                   key={key}
+                  endpoint={endpoint}
+                  resourceId={numericId}
+                  fieldKey={key}
                   label={FIELD_META[key].label}
                   value={detailView.data[key]}
                   source={detailView.provenance[key]}
@@ -599,8 +603,11 @@ export default function ResourceDetailPage() {
             <SectionHeader title="Production and geology" />
             <FieldGrid>
               {PRODUCTION_FIELDS.map((key) => (
-                <FieldCard
+                <ResourceFieldCard
                   key={key}
+                  endpoint={endpoint}
+                  resourceId={numericId}
+                  fieldKey={key}
                   label={FIELD_META[key].label}
                   value={detailView.data[key]}
                   source={detailView.provenance[key]}
diff --git a/deployments/stitch-frontend/src/pages/ResourceDetailPage.test.jsx b/deployments/stitch-frontend/src/pages/ResourceDetailPage.test.jsx
index 5a0a841f..028ee9dd 100644
--- a/deployments/stitch-frontend/src/pages/ResourceDetailPage.test.jsx
+++ b/deployments/stitch-frontend/src/pages/ResourceDetailPage.test.jsx
@@ -4,7 +4,11 @@ import { screen } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { auth0TestDefaults, renderWithQueryClient } from "../test/utils";
 import ResourceDetailPage from "./ResourceDetailPage";
-import { useResourceDetail, useSourceDetail } from "../hooks/useResources";
+import {
+  useResourceDetail,
+  useSourceDetail,
+  useFieldSourceValues,
+} from "../hooks/useResources";
 import * as apiModule from "../queries/api";
 
 vi.mock("../hooks/useResources");
@@ -80,6 +84,11 @@ beforeEach(() => {
     refetch: vi.fn(),
   });
   vi.mocked(useSourceDetail).mockReturnValue(defaultSourceDetailHookReturn);
+  vi.mocked(useFieldSourceValues).mockReturnValue({
+    data: [],
+    isLoading: false,
+    isError: false,
+  });
   vi.stubGlobal("crypto", {
     randomUUID: () => "persist-uuid-123",
   });
diff --git a/deployments/stitch-frontend/src/queries/api.js b/deployments/stitch-frontend/src/queries/api.js
index 63bc3d4d..ade766c2 100644
--- a/deployments/stitch-frontend/src/queries/api.js
+++ b/deployments/stitch-frontend/src/queries/api.js
@@ -65,6 +65,25 @@ export async function getResourceDetail(
   return data;
 }
 
+export async function getFieldSourceValues(
+  config,
+  id,
+  field,
+  fetcher,
+  endpoint = "oil-gas-fields",
+) {
+  const url = `${config.apiBaseUrl}/${endpoint}/${id}/fields/${encodeURIComponent(
+    field,
+  )}/sources`;
+  const response = await fetcher(url);
+  if (!response.ok) {
+    const error = new Error(`HTTP error! status: ${response.status}`);
+    error.status = response.status;
+    throw error;
+  }
+  return await response.json();
+}
+
 export async function createLLMSuggestion(
   config,
   id,
diff --git a/deployments/stitch-frontend/src/queries/resources.js b/deployments/stitch-frontend/src/queries/resources.js
index 55b4de94..9ebe280b 100644
--- a/deployments/stitch-frontend/src/queries/resources.js
+++ b/deployments/stitch-frontend/src/queries/resources.js
@@ -3,6 +3,7 @@ import {
   getResource,
   getResources,
   getResourceDetail,
+  getFieldSourceValues,
   getMergeCandidates,
   getMergeCandidate,
   getMergeCandidatePreview,
@@ -33,6 +34,11 @@ export const resourceKeys = {
     ...resourceKeys.details(endpoint),
     id,
   ],
+  fieldSources: (endpoint = "oil-gas-fields", id, field) => [
+    ...resourceKeys.detail(endpoint, id),
+    "field-sources",
+    field,
+  ],
   views: (endpoint = "resources") => [...resourceKeys.all(endpoint), "view"],
   view: (endpoint = "resources", id) => [...resourceKeys.views(endpoint), id],
 
@@ -100,6 +106,14 @@ export const resourceQueries = {
     enabled: false,
   }),
 
+  fieldSources: (config, endpoint = "oil-gas-fields", id, field) => ({
+    queryKey: resourceKeys.fieldSources(endpoint, id, field),
+    queryFn: (fetcher) =>
+      getFieldSourceValues(config, id, field, fetcher, endpoint),
+    enabled: false,
+    staleTime: DEFAULT_STALE_TIME,
+  }),
+
   view: (config, endpoint = "resources", id) => ({
     queryKey: resourceKeys.view(endpoint, id),
     queryFn: (fetcher) => getResource(config, id, fetcher, endpoint),
diff --git a/packages/stitch-ogsi/src/stitch/ogsi/model/__init__.py b/packages/stitch-ogsi/src/stitch/ogsi/model/__init__.py
index 49fbf477..ad778640 100644
--- a/packages/stitch-ogsi/src/stitch/ogsi/model/__init__.py
+++ b/packages/stitch-ogsi/src/stitch/ogsi/model/__init__.py
@@ -21,6 +21,7 @@
 __all__ = [
     "OGFieldSource",
     "OGFieldSourceView",
+    "OGFieldSourceValueView",
     "OGFieldResource",
     "OGFieldResourceView",
     "OGFieldView",
@@ -115,6 +116,22 @@ def _normalize_source_data(cls, value):
         return normalized
 
 
+class OGFieldSourceValueView(BaseModel):
+    """One source's value for a single field, with its effective priority.
+
+    Returned by the per-field source-values endpoint. ``priority`` is the
+    effective per-resource ranking (lower ``priority`` value = higher priority);
+    the winning value is the entry with the lowest ``priority`` value (ties
+    broken by ``id``). When priority becomes resource/field-scoped, only that
+    resolution changes -- this shape is stable.
+    """
+
+    source: OGSISrcKey
+    id: int
+    value: Any
+    priority: int
+
+
 class OGFieldResource(Resource[int, OGFieldSource]):
     provenance: dict[str, tuple[Any, OGSISrcKey, int] | None] = Field(
         default_factory=dict