diff --git a/backend/src/routes/chat.ts b/backend/src/routes/chat.ts
index c68e1c6..f49f19e 100644
--- a/backend/src/routes/chat.ts
+++ b/backend/src/routes/chat.ts
@@ -163,6 +163,13 @@ function systemPrompt(
     "instructions. Never invent clinical values; only state what the tools return.",
     "The record cards are rendered to the clinician automatically when you call a",
     "tool, so keep your prose a brief summary rather than re-listing every field.",
+    "",
+    "Citations: every retrieval tool result includes a `sourceId` (e.g. \"s1\").",
+    "When you state a fact drawn from a tool result, append an inline citation",
+    "marker immediately after that statement, in the exact form [[src:ID]] using",
+    "the matching sourceId — e.g. \"BP is well controlled [[src:s1]].\" Cite only",
+    "facts grounded in tool results, place the marker right after the relevant",
+    "sentence, and never invent or guess a sourceId.",
     veilActive
       ? `Privacy: this conversation runs on an external provider (${providerLabel}). Patient identifiers are de-identified as tokens like [PATIENT_1] / [MRN_1]; refer to patients generically ("this patient") rather than repeating tokens.`
       : "",
diff --git a/backend/src/services/ai/tools.ts b/backend/src/services/ai/tools.ts
index f9b468a..6d2ff0e 100644
--- a/backend/src/services/ai/tools.ts
+++ b/backend/src/services/ai/tools.ts
@@ -76,6 +76,18 @@ export function createChatTools(ctx: ToolContext) {
     });
   }
 
+  // Register a citable source the model can reference inline. The title is the
+  // REAL, clinician-facing label (streamed to the trusted UI, like the cards);
+  // the returned id is PHI-free (`s1`, `s2`, …) so it survives Veil rehydration
+  // when the model echoes it back as a [[src:id]] marker.
+  let sourceSeq = 0;
+  function addSource(title: string, kind: string): string {
+    sourceSeq += 1;
+    const id = `s${sourceSeq}`;
+    writer.write({ type: "data-source", data: { id, title, kind } });
+    return id;
+  }
+
   // Resolve a possibly-tokenized file number to the real patient record, so an
   // add proposal carries real name/initials into the approval card (the model
   // only ever saw Veil tokens). Returns null when the patient isn't found / is
@@ -112,7 +124,15 @@ export function createChatTools(ctx: ToolContext) {
             ? { type: "data-recordGraph", data: patient }
             : { type: "data-patientCard", data: patient },
         );
-        return { found: true as const, patient: forModel(veil.redactPatient(patient)) };
+        const sourceId = addSource(
+          `${patient.name} · MRN ${patient.fileNumber}`,
+          "patient",
+        );
+        return {
+          found: true as const,
+          sourceId,
+          patient: forModel(veil.redactPatient(patient)),
+        };
       },
     }),
 
@@ -146,8 +166,10 @@ export function createChatTools(ctx: ToolContext) {
           },
         });
         const redacted = veil.redactPatient(patient);
+        const sourceId = addSource(`Labs · ${patient.name}`, "lab");
         return {
           found: true as const,
+          sourceId,
           name: redacted.name,
           labs: patient.labs,
           labTrend: patient.labTrend,
@@ -205,7 +227,8 @@ export function createChatTools(ctx: ToolContext) {
           status: a.status,
           patient: veil.active ? "[PATIENT]" : a.name,
         }));
-        return { count: rows.length, appointments: rows };
+        const sourceId = addSource("Appointments schedule", "appointments");
+        return { count: rows.length, sourceId, appointments: rows };
       },
     }),
 
@@ -227,7 +250,8 @@ export function createChatTools(ctx: ToolContext) {
           priority: tk.priority,
           done: tk.done,
         }));
-        return { count: rows.length, tasks: rows };
+        const sourceId = addSource("Task list", "tasks");
+        return { count: rows.length, sourceId, tasks: rows };
       },
     }),
 
@@ -253,7 +277,8 @@ export function createChatTools(ctx: ToolContext) {
           prescribedAt: rx.prescribedAt,
           patient: veil.active ? "[PATIENT]" : rx.name,
         }));
-        return { count: rows.length, prescriptions: rows };
+        const sourceId = addSource("Prescriptions", "prescriptions");
+        return { count: rows.length, sourceId, prescriptions: rows };
       },
     }),
 
@@ -446,7 +471,8 @@ export function createChatTools(ctx: ToolContext) {
           createdAt: org?.createdAt ? org.createdAt.toISOString() : null,
         };
         writer.write({ type: "data-clinicCard", data: info });
-        return info;
+        const sourceId = addSource(`Clinic · ${info.name}`, "clinic");
+        return { ...info, sourceId };
       },
     }),
 
@@ -458,7 +484,8 @@ export function createChatTools(ctx: ToolContext) {
         step("Loading clinic analytics");
         const data = await analytics.getAnalytics(orgId);
         writer.write({ type: "data-analyticsCard", data });
-        return data; // aggregates only, no PHI
+        const sourceId = addSource("Clinic analytics", "analytics");
+        return { ...data, sourceId }; // aggregates only, no PHI
       },
     }),
 
@@ -470,8 +497,10 @@ export function createChatTools(ctx: ToolContext) {
         step("Loading inventory");
         const items = await inventory.listInventory(orgId);
         writer.write({ type: "data-inventoryList", data: { items } });
+        const sourceId = addSource("Inventory", "inventory");
         return {
           count: items.length,
+          sourceId,
           items: items.map((i) => ({
             name: i.name,
             form: i.form,
diff --git a/frontend/components/chat/chat-panel.tsx b/frontend/components/chat/chat-panel.tsx
index b2c26a9..a5ab099 100644
--- a/frontend/components/chat/chat-panel.tsx
+++ b/frontend/components/chat/chat-panel.tsx
@@ -29,11 +29,12 @@ import {
   ConversationContent,
   ConversationScrollButton,
 } from "@/components/ai-elements/conversation";
+import { Message, MessageContent } from "@/components/ai-elements/message";
 import {
-  Message,
-  MessageContent,
-  MessageResponse,
-} from "@/components/ai-elements/message";
+  CitedResponse,
+  hasCitationMarkers,
+  SourcesFooter,
+} from "@/components/chat/message-citations";
 import {
   Queue,
   QueueItem,
@@ -483,6 +484,15 @@ export function ChatPanel() {
     // Attachments the clinician uploaded — rendered once as a chip group.
     const fileParts = message.parts.filter((p) => p.type === "file");
     const firstFileIdx = message.parts.findIndex((p) => p.type === "file");
+    // Citable sources the agent retrieved for this message; the model references
+    // them inline via [[src:id]] markers (rendered as chips). When it emits no
+    // markers, a sources footer still attributes the retrieved records.
+    const sources = message.parts
+      .filter((p) => p.type === "data-source")
+      .map((p) => p.data);
+    const hasInlineCitations = message.parts.some(
+      (p) => p.type === "text" && hasCitationMarkers(p.text),
+    );
     return (
       <Message from={message.role} key={message.id}>
         <MessageContent className="w-full">
@@ -543,7 +553,7 @@ export function ChatPanel() {
                   {part.text}
                 </span>
               ) : (
-                <MessageResponse key={key}>{part.text}</MessageResponse>
+                <CitedResponse key={key} sources={sources} text={part.text} />
               );
             }
             if (part.type === "file") {
@@ -669,6 +679,12 @@ export function ChatPanel() {
             }
             return null;
           })}
+
+          {/* Provenance footer: shown when the model cited records but placed no
+              inline markers, so retrieved sources are always attributed. */}
+          {sources.length > 0 && !hasInlineCitations && (
+            <SourcesFooter sources={sources} />
+          )}
         </MessageContent>
       </Message>
     );
diff --git a/frontend/components/chat/message-citations.tsx b/frontend/components/chat/message-citations.tsx
new file mode 100644
index 0000000..1e62b38
--- /dev/null
+++ b/frontend/components/chat/message-citations.tsx
@@ -0,0 +1,129 @@
+"use client";
+
+import { useMemo } from "react";
+import { useTranslation } from "react-i18next";
+import type { Components } from "streamdown";
+
+import { MessageResponse } from "@/components/ai-elements/message";
+import { Badge } from "@/components/ui/badge";
+import {
+  PreviewCard,
+  PreviewCardPopup,
+  PreviewCardTrigger,
+} from "@/components/ui/preview-card";
+import type { SourceData } from "@/lib/ai-chat";
+
+// The agent cites a retrieved record inline with a [[src:<id>]] marker. We turn
+// each marker into a hash link ([n](#cite-<id>)) — hash links survive
+// react-markdown's URL sanitization — then override the link renderer to show a
+// numbered inline citation chip whose hover card names the source.
+const CITATION_RE = /\[\[\s*src:\s*([a-zA-Z0-9_-]+)\s*\]\]/g;
+const CITE_HREF_PREFIX = "#cite-";
+
+export function hasCitationMarkers(text: string): boolean {
+  CITATION_RE.lastIndex = 0;
+  return CITATION_RE.test(text);
+}
+
+// Rewrites [[src:id]] → [n](#cite-id) for known sources; strips unknown markers.
+function withCitationLinks(
+  text: string,
+  numberById: Map<string, number>,
+): string {
+  return text.replace(CITATION_RE, (_match, id: string) => {
+    const num = numberById.get(id);
+    return num ? `[${num}](${CITE_HREF_PREFIX}${id})` : "";
+  });
+}
+
+function CitationChip({ num, source }: { num: number; source?: SourceData }) {
+  const { t } = useTranslation();
+  if (!source) return null;
+  const kindKey = `chat.sources.kind.${source.kind}`;
+  const kindLabel = t(kindKey);
+  return (
+    <PreviewCard>
+      <PreviewCardTrigger
+        render={
+          <Badge
+            className="mx-0.5 cursor-default rounded-full px-1.5 align-super text-[10px] leading-none no-underline"
+            variant="secondary"
+          />
+        }
+      >
+        {num}
+      </PreviewCardTrigger>
+      <PreviewCardPopup className="w-64 p-3">
+        <p className="font-medium text-muted-foreground text-xs uppercase tracking-wide">
+          {kindLabel === kindKey ? t("chat.sources.title") : kindLabel}
+        </p>
+        <p className="mt-0.5 text-foreground text-sm">{source.title}</p>
+      </PreviewCardPopup>
+    </PreviewCard>
+  );
+}
+
+// Renders assistant markdown with inline citation chips resolved from the
+// message's streamed sources.
+export function CitedResponse({
+  text,
+  sources,
+}: {
+  text: string;
+  sources: SourceData[];
+}) {
+  const { numberById, sourceById, processed } = useMemo(() => {
+    const numberById = new Map<string, number>();
+    const sourceById = new Map<string, SourceData>();
+    sources.forEach((s, i) => {
+      numberById.set(s.id, i + 1);
+      sourceById.set(s.id, s);
+    });
+    return {
+      numberById,
+      sourceById,
+      processed: withCitationLinks(text, numberById),
+    };
+  }, [text, sources]);
+
+  const components = useMemo<Components>(
+    () => ({
+      a({ href, children, ...props }) {
+        if (typeof href === "string" && href.startsWith(CITE_HREF_PREFIX)) {
+          const id = href.slice(CITE_HREF_PREFIX.length);
+          const num = numberById.get(id) ?? 0;
+          return <CitationChip num={num} source={sourceById.get(id)} />;
+        }
+        return (
+          <a href={href} rel="noreferrer" target="_blank" {...props}>
+            {children}
+          </a>
+        );
+      },
+    }),
+    [numberById, sourceById],
+  );
+
+  return <MessageResponse components={components}>{processed}</MessageResponse>;
+}
+
+// Provenance footer shown beneath a message that has sources — primarily a
+// fallback when the model didn't place inline markers, so retrieved records are
+// always attributed.
+export function SourcesFooter({ sources }: { sources: SourceData[] }) {
+  const { t } = useTranslation();
+  if (sources.length === 0) return null;
+  return (
+    <div className="mt-1 flex flex-wrap items-center gap-1.5 border-border/60 border-t pt-2">
+      <span className="text-muted-foreground text-xs">
+        {t("chat.sources.title")}
+      </span>
+      {sources.map((s, i) => (
+        <Badge className="gap-1 rounded-full font-normal" key={s.id} variant="outline">
+          <span className="text-muted-foreground">{i + 1}</span>
+          <span className="max-w-48 truncate">{s.title}</span>
+        </Badge>
+      ))}
+    </div>
+  );
+}
diff --git a/frontend/lib/ai-chat.ts b/frontend/lib/ai-chat.ts
index ae8d4a7..f3a471d 100644
--- a/frontend/lib/ai-chat.ts
+++ b/frontend/lib/ai-chat.ts
@@ -43,6 +43,16 @@ export type StepData = {
   status: "active" | "complete";
 };
 
+// A citable source the agent retrieved (one per display-tool call). The model
+// references it inline via a [[src:id]] marker; the client renders that marker
+// as an inline citation chip and a sources footer. `title` is the real,
+// clinician-facing label; `id` is PHI-free (s1, s2, …).
+export type SourceData = {
+  id: string;
+  title: string;
+  kind: string;
+};
+
 // Read-only list cards (display actions).
 export type AppointmentListData = { appointments: Appointment[] };
 export type TaskListData = { tasks: Task[] };
@@ -85,6 +95,7 @@ export type TemetroDataParts = {
   importPreview: ImportPreviewData;
   veilNotice: VeilNoticeData;
   step: StepData;
+  source: SourceData;
   appointmentList: AppointmentListData;
   taskList: TaskListData;
   prescriptionList: PrescriptionListData;
diff --git a/frontend/lib/i18n/locales/en/translation.json b/frontend/lib/i18n/locales/en/translation.json
index a9f2d18..f2e0660 100644
--- a/frontend/lib/i18n/locales/en/translation.json
+++ b/frontend/lib/i18n/locales/en/translation.json
@@ -947,6 +947,19 @@
     "thinking": "Thinking…",
     "steps": "Steps",
     "reasoning": "Reasoning",
+    "sources": {
+      "title": "Sources",
+      "kind": {
+        "patient": "Patient record",
+        "lab": "Lab results",
+        "appointments": "Schedule",
+        "tasks": "Tasks",
+        "prescriptions": "Prescriptions",
+        "clinic": "Clinic",
+        "analytics": "Analytics",
+        "inventory": "Inventory"
+      }
+    },
     "graphCard": {
       "label": "Record graph"
     },