diff --git a/packages/ui/__tests__/chat/source-citations.test.tsx b/packages/ui/__tests__/chat/source-citations.test.tsx
new file mode 100644
index 000000000..f9b990e26
--- /dev/null
+++ b/packages/ui/__tests__/chat/source-citations.test.tsx
@@ -0,0 +1,65 @@
+import { describe, it, expect } from "vitest";
+import { extractSources } from "../../src/chat/source-citations.js";
+import type { ChatUIToolCall } from "@repowise-dev/types/chat";
+
+function searchCall(results: Array<Record<string, unknown>>): ChatUIToolCall {
+  return {
+    id: "tc1",
+    name: "search_codebase",
+    arguments: { query: "where is auth handled" },
+    result: { results },
+    status: "done",
+  };
+}
+
+describe("extractSources", () => {
+  it("reads the rank-normalized confidence, not the raw backend score", () => {
+    // BM25 fallback scores are unbounded — reading relevance_score here is what
+    // rendered "1808%" in the sources list.
+    const sources = extractSources(
+      [
+        searchCall([
+          {
+            page_id: "file_page:auth.py",
+            title: "auth.py",
+            relevance_score: 18.08,
+            confidence_score: 1,
+          },
+        ]),
+      ],
+      "repo1",
+    );
+
+    expect(sources).toHaveLength(1);
+    expect(sources[0]?.confidence).toBe(1);
+  });
+
+  it("keeps every confidence renderable as a 0-100% badge", () => {
+    const sources = extractSources(
+      [
+        searchCall([
+          { page_id: "a", title: "a", relevance_score: 18.08, confidence_score: 1 },
+          { page_id: "b", title: "b", relevance_score: 14.75, confidence_score: 0.82 },
+          { page_id: "c", title: "c", relevance_score: 0.43, confidence_score: 0.02 },
+        ]),
+      ],
+      "repo1",
+    );
+
+    expect(sources).toHaveLength(3);
+    for (const s of sources) {
+      expect(s.confidence).toBeGreaterThanOrEqual(0);
+      expect(s.confidence).toBeLessThanOrEqual(1);
+    }
+  });
+
+  it("omits confidence when the server sends no confidence_score", () => {
+    const sources = extractSources(
+      [searchCall([{ page_id: "file_page:a.py", title: "a.py", relevance_score: 9.1 }])],
+      "repo1",
+    );
+
+    // Badge hides rather than falling back to the unbounded raw score.
+    expect(sources[0]?.confidence).toBeUndefined();
+  });
+});
diff --git a/packages/ui/src/chat/source-citations.tsx b/packages/ui/src/chat/source-citations.tsx
index 56a5a72c0..fb6bf50c9 100644
--- a/packages/ui/src/chat/source-citations.tsx
+++ b/packages/ui/src/chat/source-citations.tsx
@@ -11,7 +11,12 @@ export interface SourceReference {
   title: string;
   pageType: string;
   targetPath: string;
-  score?: number;
+  /**
+   * Rank-normalized 0–1 confidence, never the raw backend score: embedding
+   * hits are cosine (0–1) but the BM25 fallback is unbounded, so the raw
+   * score has no fixed scale to render as a percentage.
+   */
+  confidence?: number | undefined;
   toolName: string;
 }
 
@@ -39,7 +44,7 @@ export function extractSources(
           title: (r.title as string) ?? pageId,
           pageType: (r.page_type as string) ?? "file_page",
           targetPath: (r.target_path as string) ?? "",
-          score: r.relevance_score as number ?? r.score as number,
+          confidence: r.confidence_score as number | undefined,
           toolName: tc.name,
         });
       }
@@ -176,9 +181,9 @@ export function SourceCitations({
             </span>
             <SourceIcon pageType={source.pageType} className="h-3 w-3 shrink-0 opacity-60" />
             <span className="truncate max-w-[160px] font-medium">{source.title}</span>
-            {source.score != null && (
+            {source.confidence != null && (
               <span className="text-[10px] text-[var(--color-text-tertiary)] tabular-nums">
-                {(source.score * 100).toFixed(0)}%
+                {(source.confidence * 100).toFixed(0)}%
               </span>
             )}
             <ArrowUpRight className="h-2.5 w-2.5 opacity-0 group-hover:opacity-100 transition-opacity shrink-0" />