diff --git a/apps/loopover-ui/public/openapi.json b/apps/loopover-ui/public/openapi.json
index a84890ed11..ee022dac06 100644
--- a/apps/loopover-ui/public/openapi.json
+++ b/apps/loopover-ui/public/openapi.json
@@ -25897,6 +25897,12 @@
         "responses": {
           "200": {
             "description": "Badge payload"
+          },
+          "404": {
+            "description": "The repo has no public badge (unknown, private, uninstalled, or badgeEnabled off)"
+          },
+          "503": {
+            "description": "The badge data could not be loaded (a transient loader failure, short-cached)"
           }
         },
         "security": []
@@ -25930,6 +25936,12 @@
         "responses": {
           "200": {
             "description": "SVG badge"
+          },
+          "404": {
+            "description": "The repo has no public badge (unknown, private, uninstalled, or badgeEnabled off)"
+          },
+          "503": {
+            "description": "The badge data could not be loaded (a transient loader failure, short-cached)"
           }
         },
         "security": []
diff --git a/src/openapi/internal-and-public-route-specs.ts b/src/openapi/internal-and-public-route-specs.ts
index 6c5a60ade4..8ffbf79ac0 100644
--- a/src/openapi/internal-and-public-route-specs.ts
+++ b/src/openapi/internal-and-public-route-specs.ts
@@ -234,7 +234,11 @@ const PUBLIC_ROUTES: SpecEntry[] = [
     tags: ["Public"],
     summary: "Return a shields.io-compatible badge payload for a repo",
     auth: "public",
-    responses: { 200: { description: "Badge payload" } },
+    responses: {
+      200: { description: "Badge payload" },
+      404: { description: "The repo has no public badge (unknown, private, uninstalled, or badgeEnabled off)" },
+      503: { description: "The badge data could not be loaded (a transient loader failure, short-cached)" },
+    },
   },
   {
     method: "get",
@@ -243,7 +247,11 @@ const PUBLIC_ROUTES: SpecEntry[] = [
     tags: ["Public"],
     summary: "Return a rendered SVG badge for a repo",
     auth: "public",
-    responses: { 200: { description: "SVG badge" } },
+    responses: {
+      200: { description: "SVG badge" },
+      404: { description: "The repo has no public badge (unknown, private, uninstalled, or badgeEnabled off)" },
+      503: { description: "The badge data could not be loaded (a transient loader failure, short-cached)" },
+    },
   },
   {
     method: "get",
diff --git a/test/integration/api.test.ts b/test/integration/api.test.ts
index 64538696a3..3ce8c35307 100644
--- a/test/integration/api.test.ts
+++ b/test/integration/api.test.ts
@@ -37,6 +37,7 @@ import {
   upsertAgentRecommendationOutcome,
 } from "../../src/db/repositories";
 import { createApp } from "../../src/api/routes";
+import { renderUnavailableBadgeSvg } from "../../src/api/badge";
 import { clearPublicRepoStatsCacheForTests } from "../../src/github/public";
 import { getRepositoryCollaboratorPermission } from "../../src/github/app";
 import { BURDEN_FORECAST_MAX_AGE_MS } from "../../src/services/burden-forecast";
@@ -324,7 +325,13 @@ describe("api routes", () => {
     await upsertRepositoryFromGitHub(env, { name: "not-opted-in", full_name: "acme/not-opted-in", private: false, owner: { login: "acme" }, default_branch: "main" }, 556);
     const notOptedIn = await app.request("/v1/public/repos/acme/not-opted-in/badge.svg", {}, env);
     expect(notOptedIn.status).toBe(404);
-    expect(await notOptedIn.text()).toContain("unavailable");
+    // #9710: the "no public badge" 404 carries the SHORT cache (not the long stale-while-revalidate window) and
+    // renders the exact unavailable badge -- the same shape a monitor distinguishes from the 503 loader-failure.
+    expect(notOptedIn.headers.get("cache-control")).toBe("public, max-age=300");
+    expect(await notOptedIn.text()).toBe(renderUnavailableBadgeSvg());
+    const notOptedInJson = await app.request("/v1/public/repos/acme/not-opted-in/badge.json", {}, env);
+    expect(notOptedInJson.status).toBe(404);
+    expect(notOptedInJson.headers.get("cache-control")).toBe("public, max-age=300");
 
     // Private repos stay unavailable even when installed and explicitly opted in.
     await upsertRepositoryFromGitHub(env, { name: "private", full_name: "acme/private", private: true, owner: { login: "acme" }, default_branch: "main" }, 558);
@@ -358,7 +365,8 @@ describe("api routes", () => {
     expect(failedSvg.status).toBe(503);
     expect(failedSvg.headers.get("content-type")).toContain("image/svg+xml");
     expect(failedSvg.headers.get("cache-control")).toBe("public, max-age=300");
-    expect(await failedSvg.text()).toContain("unavailable");
+    // #9710: the 503 loader-failure branch renders the exact same unavailable badge as the 404 branch.
+    expect(await failedSvg.text()).toBe(renderUnavailableBadgeSvg());
 
     const failedJson = await app.request("/v1/public/repos/acme/badged/badge.json", {}, brokenEnv);
     expect(failedJson.status).toBe(503);
diff --git a/test/unit/openapi.test.ts b/test/unit/openapi.test.ts
index b566b441f9..721cf0b3ff 100644
--- a/test/unit/openapi.test.ts
+++ b/test/unit/openapi.test.ts
@@ -191,6 +191,14 @@ describe("OpenAPI contract", () => {
     expect(spec.paths["/v1/auth/github/token"]?.post?.security).toEqual([{ LoopOverSessionCookie: [] }]);
   });
 
+  it("#9710: both public badge routes declare 200, 404, and 503 -- the statuses a monitor distinguishes", () => {
+    const spec = buildOpenApiSpec();
+    for (const path of ["/v1/public/repos/{owner}/{repo}/badge.svg", "/v1/public/repos/{owner}/{repo}/badge.json"]) {
+      const responses = spec.paths[path]?.get?.responses ?? {};
+      expect(Object.keys(responses).sort()).toEqual(expect.arrayContaining(["200", "404", "503"]));
+    }
+  });
+
   // #9303: selftune-override routes were live but undocumented; assert both paths, their HTTP methods, and the
   // response schema keys matching each route's MCP tool output shape (selftuneOverrideAuditOutputSchema /
   // clearSelftuneOverrideOutputSchema in src/mcp/server.ts).