diff --git a/src/app/(app)/settings/ai/ai-settings-form.tsx b/src/app/(app)/settings/ai/ai-settings-form.tsx
index 5619087..de4a278 100644
--- a/src/app/(app)/settings/ai/ai-settings-form.tsx
+++ b/src/app/(app)/settings/ai/ai-settings-form.tsx
@@ -29,7 +29,13 @@ import { DEFAULT_QUOTES_AI_SYSTEM_PROMPT } from "@/lib/server/ai-system-prompt";
 import { DEFAULT_QUOTE_ASSISTANT_PROMPT } from "@/lib/server/quote-assistant-prompt";
 // Plain string export, no server-only imports, so it is safe in a client component.
 import { DEFAULT_COLLECTION_AI_PROMPT } from "@/lib/server/collection-ai-prompt";
-import type { CollectionAiRunSummary, QuoteAssistantRunSummary } from "@/lib/types";
+// Plain string export, no server-only imports, so it is safe in a client component.
+import { DEFAULT_ORDER_ASSISTANT_PROMPT } from "@/lib/server/order-assistant-prompt";
+import type {
+  CollectionAiRunSummary,
+  OrderAssistantRunSummary,
+  QuoteAssistantRunSummary,
+} from "@/lib/types";
 
 export interface AiSettingsFormInitial {
   provider: string;
@@ -57,6 +63,14 @@ export interface AiSettingsFormInitial {
   /** Empty string = use the built-in default prompt. */
   collection_ai_prompt: string;
   collection_ai_last_run_summary: CollectionAiRunSummary | null;
+  /** AI order assistant (matches orders to the quote they came from). */
+  order_assistant_enabled: boolean;
+  order_assistant_interval_minutes: number;
+  order_assistant_auto_link: boolean;
+  order_assistant_fill_lines: boolean;
+  /** Empty string = use the built-in default prompt. */
+  order_assistant_prompt: string;
+  order_assistant_last_run_summary: OrderAssistantRunSummary | null;
 }
 
 interface Props {
@@ -107,6 +121,12 @@ export function AiSettingsForm({ initial }: Props) {
   const [caEnabled, setCaEnabled] = useState(initial.collection_ai_enabled);
   const [caPrompt, setCaPrompt] = useState(initial.collection_ai_prompt);
   const [showCaDefault, setShowCaDefault] = useState(false);
+  const [oaEnabled, setOaEnabled] = useState(initial.order_assistant_enabled);
+  const [oaInterval, setOaInterval] = useState(String(initial.order_assistant_interval_minutes));
+  const [oaAutoLink, setOaAutoLink] = useState(initial.order_assistant_auto_link);
+  const [oaFillLines, setOaFillLines] = useState(initial.order_assistant_fill_lines);
+  const [oaPrompt, setOaPrompt] = useState(initial.order_assistant_prompt);
+  const [showOaDefault, setShowOaDefault] = useState(false);
   const [saveState, saveAction] = useActionState<ActionResult | null, FormData>(
     saveAiSettingsAction,
     null,
@@ -551,6 +571,150 @@ export function AiSettingsForm({ initial }: Props) {
       </CardContent>
     </Card>
 
+    <Card>
+      <CardHeader>
+        <div className="flex items-center gap-2">
+          <Sparkles className="h-4 w-4 text-primary" />
+          <CardTitle>Order assistant</CardTitle>
+        </div>
+        <CardDescription>
+          Works out which quote an order came from, and links the order to it
+          when it is sure. It never changes a line&apos;s status, never creates a
+          purchase order and never sends anything.
+        </CardDescription>
+      </CardHeader>
+      <CardContent className="space-y-6">
+          <div className="flex items-center justify-between gap-4 rounded-lg border border-border p-3">
+            <div>
+              <Label htmlFor="oa_enabled" className="text-base">
+                Order assistant enabled
+              </Label>
+              <p className="text-xs text-muted-foreground">
+                Needs the AI switch above to be on too. Runs on a timer and looks at
+                orders that have no quote yet.
+              </p>
+            </div>
+            <Switch
+              id="oa_enabled"
+              name="oa_enabled"
+              checked={oaEnabled}
+              onCheckedChange={setOaEnabled}
+            />
+          </div>
+
+          <div className="grid gap-4 sm:grid-cols-2">
+            <div className="grid gap-2">
+              <Label htmlFor="oa_interval_minutes">Run every (minutes)</Label>
+              <Input
+                id="oa_interval_minutes"
+                name="oa_interval_minutes"
+                type="number"
+                min={5}
+                max={1440}
+                step={1}
+                value={oaInterval}
+                onChange={(e) => setOaInterval(e.target.value)}
+              />
+              <p className="text-xs text-muted-foreground">Between 5 and 1440.</p>
+            </div>
+
+            <div className="grid gap-3">
+              <div className="flex items-center justify-between gap-4 rounded-lg border border-border p-3">
+                <div>
+                  <Label htmlFor="oa_auto_link" className="text-base">
+                    Auto-link when sure
+                  </Label>
+                  <p className="text-xs text-muted-foreground">
+                    Links the order itself when the AI is certain. When unsure it only
+                    suggests the quote and a person decides.
+                  </p>
+                </div>
+                <Switch
+                  id="oa_auto_link"
+                  name="oa_auto_link"
+                  checked={oaAutoLink}
+                  onCheckedChange={setOaAutoLink}
+                />
+              </div>
+
+              <div className="flex items-center justify-between gap-4 rounded-lg border border-border p-3">
+                <div>
+                  <Label htmlFor="oa_fill_lines" className="text-base">
+                    Fill lines from the quote
+                  </Label>
+                  <p className="text-xs text-muted-foreground">
+                    Pre-fills the order lines from the matched quote. Not in use yet —
+                    the assistant only matches orders to quotes.
+                  </p>
+                </div>
+                <Switch
+                  id="oa_fill_lines"
+                  name="oa_fill_lines"
+                  checked={oaFillLines}
+                  onCheckedChange={setOaFillLines}
+                />
+              </div>
+            </div>
+          </div>
+
+          <div className="grid gap-2">
+            <div className="flex items-center justify-between gap-3">
+              <Label htmlFor="oa_prompt">Order assistant prompt</Label>
+              <div className="flex items-center gap-2">
+                <Button
+                  type="button"
+                  variant="outline"
+                  size="sm"
+                  onClick={() => setShowOaDefault((s) => !s)}
+                  title="Toggle the built-in default for comparison"
+                >
+                  <Eye /> {showOaDefault ? "Hide" : "Show"} default
+                </Button>
+                <Button
+                  type="button"
+                  variant="outline"
+                  size="sm"
+                  onClick={() => {
+                    setOaPrompt(DEFAULT_ORDER_ASSISTANT_PROMPT);
+                    toast.success("Loaded the default prompt. Click Save to apply.");
+                  }}
+                  title="Copy the built-in default into the textarea"
+                >
+                  <RotateCcw /> Reset to default
+                </Button>
+              </div>
+            </div>
+            <Textarea
+              id="oa_prompt"
+              name="oa_prompt"
+              value={oaPrompt}
+              onChange={(e) => setOaPrompt(e.target.value)}
+              placeholder="Leave empty to use the built-in default."
+              maxLength={50000}
+              rows={10}
+              className="font-mono text-xs"
+              spellCheck={false}
+            />
+            <p className="text-xs text-muted-foreground">
+              Sent as <code className="rounded bg-muted px-1 py-0.5">system:</code> when
+              matching an order to a quote. Empty = use the built-in default. The rules
+              assume the{" "}
+              <code className="rounded bg-muted px-1 py-0.5">submit_order_quote_match</code>{" "}
+              tool.
+            </p>
+            {showOaDefault && (
+              <pre className="rounded-md border border-border bg-muted/40 p-3 text-xs font-mono whitespace-pre-wrap max-h-64 overflow-auto">
+                {DEFAULT_ORDER_ASSISTANT_PROMPT}
+              </pre>
+            )}
+          </div>
+
+          <p className="text-xs text-muted-foreground">
+            Last run: {formatOrderAssistantLastRun(initial.order_assistant_last_run_summary)}
+          </p>
+      </CardContent>
+    </Card>
+
     <div className="space-y-4">
           {/* Save / Test */}
           <div className="flex flex-wrap items-center gap-2">
@@ -607,6 +771,13 @@ function formatCollectionLastRun(summary: CollectionAiRunSummary | null): string
   return `${time} · ${summary.files_read} files read · ${summary.cards_checked} cards checked`;
 }
 
+function formatOrderAssistantLastRun(summary: OrderAssistantRunSummary | null): string {
+  if (!summary) return "Never";
+  const when = new Date(summary.finished_at || summary.started_at);
+  const time = Number.isNaN(when.getTime()) ? "Unknown time" : when.toLocaleString();
+  return `${time} · ${summary.orders_seen} orders · ${summary.linked} linked · ${summary.suggested} suggested · ${summary.no_match} no match`;
+}
+
 function SaveButton() {
   const { pending } = useFormStatus();
   return (
diff --git a/src/app/(app)/settings/ai/page.tsx b/src/app/(app)/settings/ai/page.tsx
index 4785482..d45ccad 100644
--- a/src/app/(app)/settings/ai/page.tsx
+++ b/src/app/(app)/settings/ai/page.tsx
@@ -50,6 +50,12 @@ export default async function AiSettingsPage() {
           collection_ai_enabled: settings.collection_ai_enabled,
           collection_ai_prompt: settings.collection_ai_prompt,
           collection_ai_last_run_summary: settings.collection_ai_last_run_summary,
+          order_assistant_enabled: settings.order_assistant_enabled,
+          order_assistant_interval_minutes: settings.order_assistant_interval_minutes,
+          order_assistant_auto_link: settings.order_assistant_auto_link,
+          order_assistant_fill_lines: settings.order_assistant_fill_lines,
+          order_assistant_prompt: settings.order_assistant_prompt,
+          order_assistant_last_run_summary: settings.order_assistant_last_run_summary,
         }}
       />
     </div>
diff --git a/src/app/(app)/settings/ai/settings-form-helpers.test.ts b/src/app/(app)/settings/ai/settings-form-helpers.test.ts
index f1468be..e33533e 100644
--- a/src/app/(app)/settings/ai/settings-form-helpers.test.ts
+++ b/src/app/(app)/settings/ai/settings-form-helpers.test.ts
@@ -98,6 +98,73 @@ describe("parseSettingsForm: quote assistant", () => {
   });
 });
 
+describe("parseSettingsForm: order assistant section", () => {
+  it("maps oa_enabled=on to true and a missing value to false", () => {
+    expect(parseSettingsForm(form({ oa_enabled: "on" })).patch.order_assistant_enabled).toBe(true);
+    expect(parseSettingsForm(form({})).patch.order_assistant_enabled).toBe(false);
+  });
+
+  it("parses a valid interval", () => {
+    const { patch, errors } = parseSettingsForm(form({ oa_interval_minutes: "15" }));
+    expect(errors).toEqual([]);
+    expect(patch.order_assistant_interval_minutes).toBe(15);
+  });
+
+  it("leaves the interval untouched when blank", () => {
+    const { patch, errors } = parseSettingsForm(form({ oa_interval_minutes: " " }));
+    expect(errors).toEqual([]);
+    expect(patch.order_assistant_interval_minutes).toBeUndefined();
+  });
+
+  it.each(["4", "1441", "abc"])("rejects interval %s", (value) => {
+    const { patch, errors } = parseSettingsForm(form({ oa_interval_minutes: value }));
+    expect(errors).toContain("Order assistant interval must be between 5 and 1440 minutes");
+    expect(patch.order_assistant_interval_minutes).toBeUndefined();
+  });
+
+  it("accepts the interval bounds", () => {
+    expect(parseSettingsForm(form({ oa_interval_minutes: "5" })).errors).toEqual([]);
+    expect(parseSettingsForm(form({ oa_interval_minutes: "1440" })).errors).toEqual([]);
+  });
+
+  it("reads the auto-link and fill-lines switches", () => {
+    const on = parseSettingsForm(
+      form({ oa_auto_link: "on", oa_fill_lines: "on" }),
+    ).patch;
+    expect(on.order_assistant_auto_link).toBe(true);
+    expect(on.order_assistant_fill_lines).toBe(true);
+
+    const off = parseSettingsForm(form({})).patch;
+    expect(off.order_assistant_auto_link).toBe(false);
+    expect(off.order_assistant_fill_lines).toBe(false);
+  });
+
+  it("passes the prompt through untrimmed, and leaves it untouched when absent", () => {
+    expect(parseSettingsForm(form({ oa_prompt: "  rules\n" })).patch.order_assistant_prompt).toBe(
+      "  rules\n",
+    );
+    expect(parseSettingsForm(form({ oa_prompt: "" })).patch.order_assistant_prompt).toBe("");
+    expect(parseSettingsForm(form({})).patch.order_assistant_prompt).toBeUndefined();
+  });
+
+  it("does not disturb the quote assistant or collection checks fields", () => {
+    const { patch, errors } = parseSettingsForm(
+      form({ qa_enabled: "on", qa_prompt: "q", ca_prompt: "c", oa_enabled: "on" }),
+    );
+    expect(errors).toEqual([]);
+    expect(patch.quote_assistant_enabled).toBe(true);
+    expect(patch.quote_assistant_prompt).toBe("q");
+    expect(patch.collection_ai_prompt).toBe("c");
+    expect(patch.order_assistant_enabled).toBe(true);
+  });
+
+  it("never writes the last-run fields", () => {
+    const patch = parseSettingsForm(form({ oa_enabled: "on" })).patch;
+    expect(patch).not.toHaveProperty("order_assistant_last_run_at");
+    expect(patch).not.toHaveProperty("order_assistant_last_run_summary");
+  });
+});
+
 describe("parseSettingsForm: collection checks section", () => {
   it("reads ca_enabled=on as true and missing as false", () => {
     expect(parseSettingsForm(form({ ca_enabled: "on" })).patch.collection_ai_enabled).toBe(true);
diff --git a/src/app/(app)/settings/ai/settings-form-helpers.ts b/src/app/(app)/settings/ai/settings-form-helpers.ts
index 6b75089..17c0b2e 100644
--- a/src/app/(app)/settings/ai/settings-form-helpers.ts
+++ b/src/app/(app)/settings/ai/settings-form-helpers.ts
@@ -113,5 +113,27 @@ export function parseSettingsForm(formData: FormData): ParseResult {
     patch.collection_ai_prompt = caPromptRaw;
   }
 
+  // ── Order assistant section (same <form>: missing checkbox = off).
+  patch.order_assistant_enabled = formData.get("oa_enabled") === "on";
+
+  const oaIntervalRaw = String(formData.get("oa_interval_minutes") ?? "").trim();
+  if (oaIntervalRaw !== "") {
+    const n = Number(oaIntervalRaw);
+    if (!Number.isFinite(n) || n < 5 || n > 1440) {
+      errors.push("Order assistant interval must be between 5 and 1440 minutes");
+    } else {
+      patch.order_assistant_interval_minutes = Math.round(n);
+    }
+  }
+
+  patch.order_assistant_auto_link = formData.get("oa_auto_link") === "on";
+  patch.order_assistant_fill_lines = formData.get("oa_fill_lines") === "on";
+
+  // Plain text, untrimmed. Empty means "use the built-in default".
+  const oaPromptRaw = formData.get("oa_prompt");
+  if (typeof oaPromptRaw === "string") {
+    patch.order_assistant_prompt = oaPromptRaw;
+  }
+
   return { patch, errors };
 }