diff --git a/docs/README.md b/docs/README.md
index 096605bd..8251569b 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -8,6 +8,7 @@
 docs
 |-- changelog.md              # 사용자 영향 중심 변경 기록
 |-- evaluate.mjs              # 공개 문서 구조·내용 검증
+|-- public-contract-checks.mjs # 문서 원천·Pages 산출물·live 응답의 공통 공개 계약 검증
 `-- public
 |   |-- overview.md            # JSON Document: Why / How / What
 |   |-- api.md                 # JSON Document: 레퍼런스
@@ -133,8 +134,13 @@ reconciliation까지의 DOM 편집 정본은 `standards/dom-editing-lifecycle.md
 현재 v3 portable root의 compatibility 정본은 `standards/json-document-v3/profile.md`,
 `standards/json-document-v3/public-surface.json`, 그리고 profile이
 지정한 conformance vector와 language binding입니다. 이름 정본은 stable v3
-identifier나 동작을 바꾸지 않으며, 과거 version 문서는 v3 exact
-21-symbol·six-member 계약을 확장하지 않습니다.
+identifier나 동작을 바꾸지 않으며, 과거 version 문서는 정본 public surface의
+Root symbol·six-member 계약을 확장하지 않습니다.
+
+문서 원천, Pages 산출물, live 응답의 공개 계약 검사는
+`public-contract-checks.mjs`가 소유합니다. Root symbol 수는 Core의
+`public-contract.json`, 유효한 package 참조는 `api-reference/packages.mjs`에서
+읽습니다. 각 evaluator의 파일·HTTP 읽기와 재시도 정책은 그대로 유지합니다.
 
 ## 책임 기준
 
diff --git a/docs/evaluate.mjs b/docs/evaluate.mjs
index d7781544..1415c63a 100644
--- a/docs/evaluate.mjs
+++ b/docs/evaluate.mjs
@@ -2,6 +2,7 @@ import { readFileSync, readdirSync } from "node:fs";
 import { dirname, join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { spawnSync } from "node:child_process";
+import { validateLlmsContract, validatePublicPackageReferences } from "./public-contract-checks.mjs";
 
 const root = dirname(dirname(fileURLToPath(import.meta.url)));
 
@@ -137,34 +138,6 @@ const publicContract = readJson("packages/json-document/public-contract.json");
 const rootPackage = readJson("package.json");
 const implementationShape = read("standards/repository-implementation-shape.md");
 const domEditingLifecycle = read("standards/dom-editing-lifecycle.md");
-const activeCompanionPackages = new Set([
-  "@interactive-os/json-document-editing",
-  "@interactive-os/json-document-composer",
-  "@interactive-os/json-document-composer-react",
-  "@interactive-os/json-document-file-intake",
-  "@interactive-os/json-document-rich-text-suggestion",
-  "@interactive-os/json-document-rich-text-suggestion-react",
-  "@interactive-os/json-document-rich-text-mention",
-  "@interactive-os/json-document-rich-text-mention-react",
-  "@interactive-os/json-document-rich-text",
-  "@interactive-os/json-document-selection",
-  "@interactive-os/json-document-react",
-  "@interactive-os/json-document-react-hook-form",
-  "@interactive-os/json-document-ajv",
-  "@interactive-os/json-document-a2ui",
-  "@interactive-os/json-document-affordance",
-  "@interactive-os/json-document-ui-primitives-react",
-  "@interactive-os/json-document-animation-react",
-  "@interactive-os/json-document-markdown-react",
-  "@interactive-os/json-document-zod",
-  "@interactive-os/json-document-database",
-  "@interactive-os/json-document-calendar",
-  "@interactive-os/json-document-tanstack-table",
-  "@interactive-os/json-document-web",
-  "@interactive-os/json-document-contenteditable",
-  "@interactive-os/json-document-collaboration",
-  "@interactive-os/json-document-contenteditable-collaboration",
-]);
 
 if (JSON.stringify(fileNames("docs/public")) !== JSON.stringify([
   "adapter-clipboard.md",
@@ -299,25 +272,8 @@ if (misplacedMarkdown.length > 0) {
 }
 
 for (const [name, source] of Object.entries(surfaces)) {
-  if (/@interactive-os\/json-document\/(?:session|react)\b/.test(source)) {
-    fail(`${name}: removed package subpath is still documented.`);
-  }
-  for (
-    const match of source.matchAll(
-      /@interactive-os\/json-document-[a-z0-9-]+\b/g,
-    )
-  ) {
-    if (
-      !activeCompanionPackages.has(match[0])
-    ) {
-      fail(
-        `${name}: removed json-document extension is still documented as current: ${match[0]}.`,
-      );
-    }
-  }
-  if (/\blabs\/extensions\b/.test(source)) {
-    fail(`${name}: removed lab path is still documented as current.`);
-  }
+  const validate = name === "llms" ? validateLlmsContract : validatePublicPackageReferences;
+  validate(source, (message) => fail(`${name}: ${message}`));
 }
 
 for (const [name, source] of Object.entries(surfaces)) {
diff --git a/docs/public-contract-checks.mjs b/docs/public-contract-checks.mjs
new file mode 100644
index 00000000..0de7b85c
--- /dev/null
+++ b/docs/public-contract-checks.mjs
@@ -0,0 +1,35 @@
+import { readFileSync } from "node:fs";
+import { apiReferencePackages } from "./api-reference/packages.mjs";
+
+const publicContract = JSON.parse(readFileSync(new URL("../packages/json-document/public-contract.json", import.meta.url), "utf8"));
+const rootSymbolCount = publicContract.root.values.length + publicContract.root.types.length;
+const publicPackages = new Set(apiReferencePackages.map(({ packageName }) => packageName));
+
+/** Shared by source, artifact, and live documentation verification; no transport. */
+export function validatePublicPackageReferences(source, fail) {
+  if (/@interactive-os\/json-document\/(?:session|react)\b/.test(source)) {
+    fail("removed package subpath is still documented.");
+  }
+  for (const match of source.matchAll(/@interactive-os\/json-document-[a-z0-9-]+\b/g)) {
+    if (!publicPackages.has(match[0])) {
+      fail(`removed json-document extension is still documented as current: ${match[0]}.`);
+    }
+  }
+  if (/\blabs\/extensions\b/.test(source)) {
+    fail("removed lab path is still documented as current.");
+  }
+}
+
+/** Validate llms.txt against the current Core contract and documented ecosystem. */
+export function validateLlmsContract(source, fail) {
+  for (const [pattern, requirement] of [
+    [/^# json-document v3$/m, "v3 title"],
+    [new RegExp(`공개 Root는 정확히 다음 ${rootSymbolCount}개 symbol`), `${rootSymbolCount} Root symbols`],
+    [/`JSONDocument`의 필수 member는 정확히 여섯 개다/, "six-member JSONDocument contract"],
+    [/## Adapter, Connector와 companion/, "Adapter, Connector and companion boundary"],
+    [/@interactive-os\/editable/, "migration boundary for @interactive-os/editable"],
+  ]) {
+    if (!pattern.test(source)) fail(`llms.txt is missing ${requirement}.`);
+  }
+  validatePublicPackageReferences(source, fail);
+}
diff --git a/site/scripts/evaluate-live.mjs b/site/scripts/evaluate-live.mjs
index 236cd94d..19ddb478 100644
--- a/site/scripts/evaluate-live.mjs
+++ b/site/scripts/evaluate-live.mjs
@@ -1,23 +1,11 @@
 import { readFileSync } from "node:fs";
 import { validateSiteRoutes } from "./route-checks.mjs";
+import { validateLlmsContract } from "../../docs/public-contract-checks.mjs";
 
 const siteUrl = (process.env.SITE_URL ?? "https://developer-1px.github.io/json-document").replace(/\/$/, "");
 const attempts = Number(process.env.SITE_LIVE_ATTEMPTS ?? "18");
 const delayMs = Number(process.env.SITE_LIVE_DELAY_MS ?? "10000");
 const routes = JSON.parse(readFileSync(new URL("../site-routes.json", import.meta.url), "utf8"));
-const activeCompanionPackages = new Set([
-  "@interactive-os/json-document-selection",
-  "@interactive-os/json-document-editing",
-  "@interactive-os/json-document-react",
-  "@interactive-os/json-document-react-hook-form",
-  "@interactive-os/json-document-ajv",
-  "@interactive-os/json-document-zod",
-  "@interactive-os/json-document-tanstack-table",
-  "@interactive-os/json-document-web",
-  "@interactive-os/json-document-contenteditable",
-  "@interactive-os/json-document-collaboration",
-  "@interactive-os/json-document-contenteditable-collaboration",
-]);
 validateSiteRoutes(routes, fail);
 const rootRoute = routes.find((route) => route.path === "/");
 if (rootRoute === undefined) fail("live site routes are missing the root route.");
@@ -82,23 +70,7 @@ async function checkOnce() {
   }
 
   const llms = await fetchText("/llms.txt");
-  if (
-    !/^# json-document v3$/m.test(llms)
-    || !/공개 Root는 정확히 다음 21개 symbol/.test(llms)
-    || !/`JSONDocument`의 필수 member는 정확히 여섯 개다/.test(llms)
-    || !/## Adapter, Connector와 companion/.test(llms)
-    || !/@interactive-os\/editable/.test(llms)
-  ) {
-    fail("live llms.txt is missing the v3 Core contract.");
-  }
-  const packageReferences = llms.match(/@interactive-os\/json-document-[a-z0-9-]+/g) ?? [];
-  if (
-    packageReferences.some((packageName) => !activeCompanionPackages.has(packageName))
-    || /@interactive-os\/json-document\/(?:session|react)\b/.test(llms)
-    || /\blabs\/extensions\b/.test(llms)
-  ) {
-    fail("live llms.txt still exposes a removed legacy surface.");
-  }
+  validateLlmsContract(llms, (message) => fail(`live ${message}`));
 
   const manifest = JSON.parse(await fetchText("/site.webmanifest"));
   if (
diff --git a/site/scripts/evaluate.mjs b/site/scripts/evaluate.mjs
index 547b6808..145d14dc 100644
--- a/site/scripts/evaluate.mjs
+++ b/site/scripts/evaluate.mjs
@@ -1,6 +1,7 @@
 import { existsSync, readFileSync, readdirSync } from "node:fs";
 import { dirname, join, relative, resolve } from "node:path";
 import { routeFile, validateSiteRoutes } from "./route-checks.mjs";
+import { validateLlmsContract } from "../../docs/public-contract-checks.mjs";
 
 const siteRoot = new URL("..", import.meta.url).pathname;
 const dist = join(siteRoot, "dist");
@@ -110,6 +111,7 @@ const fallback = read("404.html");
 const robots = read("robots.txt");
 const sitemap = read("sitemap.xml");
 const manifest = JSON.parse(read("site.webmanifest"));
+validateLlmsContract(read("llms.txt"), (message) => fail(`site dist ${message}`));
 
 for (const pattern of [
   /<title>json-document - Agent artifact editing<\/title>/,
diff --git a/site/tests/unit/public-document-contract.test.ts b/site/tests/unit/public-document-contract.test.ts
new file mode 100644
index 00000000..7f00e582
--- /dev/null
+++ b/site/tests/unit/public-document-contract.test.ts
@@ -0,0 +1,65 @@
+// @vitest-environment node
+import { readFileSync } from "node:fs";
+import { describe, expect, test } from "vitest";
+import { apiReferencePackages } from "../../../docs/api-reference/packages.mjs";
+import { validateLlmsContract, validatePublicPackageReferences } from "../../../docs/public-contract-checks.mjs";
+
+const llms = readFileSync(new URL("../../../docs/public/llms.txt", import.meta.url), "utf8");
+const publicContract = JSON.parse(readFileSync(new URL("../../../packages/json-document/public-contract.json", import.meta.url), "utf8"));
+const symbolCount = publicContract.root.values.length + publicContract.root.types.length;
+
+function findings(source: string) {
+  const errors: string[] = [];
+  validateLlmsContract(source, (message: string) => errors.push(message));
+  return errors;
+}
+
+describe("public documentation contract", () => {
+  test("accepts the exact published llms source against the canonical Core contract", () => {
+    expect(symbolCount).toBe(23);
+    expect(findings(llms)).toEqual([]);
+  });
+
+  test.each([
+    ["old Root symbol count", llms.replace(`${symbolCount}개 symbol`, "21개 symbol")],
+    ["missing v3 title", llms.replace("# json-document v3", "# json-document")],
+    ["missing six-member contract", llms.replace("`JSONDocument`의 필수 member는 정확히 여섯 개다", "JSON Document")],
+    ["missing companion boundary", llms.replace("## Adapter, Connector와 companion", "## Integrations")],
+    ["missing migration boundary", llms.replaceAll("@interactive-os/editable", "retired editor")],
+  ])("rejects %s", (_name, source) => {
+    expect(source).not.toBe(llms);
+    expect(findings(source)).not.toEqual([]);
+  });
+
+  test("accepts every package registered at the canonical documentation owner", () => {
+    const references = apiReferencePackages.map(({ packageName }) => packageName).join("\n");
+    const errors: string[] = [];
+    validatePublicPackageReferences(references, (message: string) => errors.push(message));
+    expect(errors).toEqual([]);
+    expect(findings(`${llms}\n${references}`)).toEqual([]);
+  });
+
+  test.each([
+    "@interactive-os/json-document-removed-extension",
+    "@interactive-os/json-document/session",
+    "@interactive-os/json-document/react",
+    "labs/extensions",
+  ])("rejects retired reference %s in docs and llms", (reference) => {
+    const errors: string[] = [];
+    validatePublicPackageReferences(reference, (message: string) => errors.push(message));
+    expect(errors).not.toEqual([]);
+    expect(findings(`${llms}\n${reference}`)).not.toEqual([]);
+  });
+
+  test.each([
+    "../../../docs/evaluate.mjs",
+    "../../scripts/evaluate.mjs",
+    "../../scripts/evaluate-live.mjs",
+  ])("keeps %s wired to the canonical llms validator", (path) => {
+    const source = readFileSync(new URL(path, import.meta.url), "utf8");
+    expect(/import\s*\{[^}]*validateLlmsContract[^}]*\}\s*from\s*["'][^"']*public-contract-checks\.mjs["']/.test(source)).toBe(true);
+    expect(/validateLlmsContract(?:\(|\s*:)/.test(source)).toBe(true);
+    expect(source).not.toContain("21개 symbol");
+    expect(source).not.toContain("activeCompanionPackages");
+  });
+});