fix(notion-web): add browser fingerprint headers to reduce Cloudflare challenges (#7864)

* fix(notion-web): add browser fingerprint headers to reduce Cloudflare challenges Adds sec-ch-ua, sec-fetch-*, cache-control, pragma, and priority headers that real Chromium browsers send. Without these, Cloudflare may challenge or block requests that look like non-browser clients. Applied to: - buildNotionExecuteHeaders (inference requests) - buildNotionBrowserHeaders (workspace discovery) - buildNotionModelsDiscoveryHeaders (model discovery) Headers match the real browser capture from Chrome 149 on Linux. Addresses gemini-code-assist review: - Fixed platform mismatch: sec-ch-ua-platform now matches USER_AGENT (Windows) - Deduplicated headers via shared BROWSER_HEADERS constant in notionWebModels.ts - Both executor and model discovery use the same constant * fix(notion-web): align Chrome version to 149 and add browser header tests Addresses maintainer review feedback on #7864: - Align User-Agent and NOTION_USER_AGENT to Chrome/149 (was 145 and 150) matching sec-ch-ua already declaring v="149" - Add test assertions that browser fingerprint headers (sec-ch-ua, sec-fetch-mode, cache-control, pragma) are sent on both executor and models-discovery requests * refactor(providers): extract notion-web fallback catalog to its own module notionWebModels.ts crossed the 800-line new-file cap (875) once the browser header tests landed; move the NOTION_WEB_FALLBACK_MODELS catalog + its type to notionWebFallbackModels.ts (pure data, re-exported for existing consumers). Co-authored-by: diegosouzapw <8016841+diegosouzapw@users.noreply.github.com> --------- Co-authored-by: diegosouzapw <8016841+diegosouzapw@users.noreply.github.com>
2026-08-04 14:22:09 +03:00 · 2026-07-20 21:57:15 +03:00
parent 3fe61cdea7
commit fd6a583a95
5 changed files with 241 additions and 105 deletions
--- a/open-sse/executors/notion-web.ts
+++ b/open-sse/executors/notion-web.ts
@@ -25,6 +25,7 @@ import { randomUUID } from "node:crypto";
 import { BaseExecutor, type ExecuteInput } from "./base.ts";
 import { makeExecutorErrorResult as makeErrorResult } from "../utils/error.ts";
 import {
+  BROWSER_HEADERS,
  extractNotionUserIdFromCookie,
  resolveNotionCodename,
  resolveNotionRuntimeWorkspace,
@@ -36,7 +37,7 @@ import {
 const BASE_URL = "https://app.notion.com";
 const NOTION_URL = `${BASE_URL}/api/v3/runInferenceTranscript`;
 const USER_AGENT =
-  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36";
+  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.36";
 const NOTION_CLIENT_VERSION = "23.13.20260719.1125";

 // ─── Types ──────────────────────────────────────────────────────────────────
@@ -451,7 +452,12 @@ export function parseNotionInferenceStream(raw: string): string {
    applyNotionStreamLine(rawLine, state);
  }

-  const candidates = [state.lastRecordMap, state.lastPatchFinal, state.lastIncremental, state.lastLegacy]
+  const candidates = [
+    state.lastRecordMap,
+    state.lastPatchFinal,
+    state.lastIncremental,
+    state.lastLegacy,
+  ]
    .map(sanitizeNotionAssistantText)
    .filter(Boolean);
  // Prefer the longest non-empty candidate; record-map usually wins.
@@ -472,12 +478,8 @@ export function estimateNotionUsage(
    .map((m) => (typeof m?.content === "string" ? m.content : ""))
    .join("\n");
  // ~4 chars/token (English-ish); at least 1 when there is any text.
-  const prompt_tokens = promptText
-    ? Math.max(1, Math.ceil(promptText.length / 4))
-    : 0;
-  const completion_tokens = content
-    ? Math.max(1, Math.ceil(content.length / 4))
-    : 0;
+  const prompt_tokens = promptText ? Math.max(1, Math.ceil(promptText.length / 4)) : 0;
+  const completion_tokens = content ? Math.max(1, Math.ceil(content.length / 4)) : 0;
  return {
    prompt_tokens,
    completion_tokens,
@@ -486,20 +488,14 @@ export function estimateNotionUsage(
  };
 }

-function chatCompletionResponse(
-  content: string,
-  model: string,
-  messages?: NotionMessage[]
-) {
+function chatCompletionResponse(content: string, model: string, messages?: NotionMessage[]) {
  return new Response(
    JSON.stringify({
      id: `chatcmpl-notion-${Date.now()}`,
      object: "chat.completion",
      created: Math.floor(Date.now() / 1000),
      model,
-      choices: [
-        { index: 0, message: { role: "assistant", content }, finish_reason: "stop" },
-      ],
+      choices: [{ index: 0, message: { role: "assistant", content }, finish_reason: "stop" }],
      usage: estimateNotionUsage(messages, content),
    }),
    { status: 200, headers: { "Content-Type": "application/json" } }
@@ -611,6 +607,7 @@ function buildNotionExecuteHeaders(opts: {
    "notion-audit-log-platform": "web",
    "x-notion-space-id": opts.spaceId,
    "Accept-Language": "en-US,en;q=0.9",
+    ...BROWSER_HEADERS,
  };
  if (opts.userId) reqHeaders["x-notion-active-user-header"] = opts.userId;
  return reqHeaders;
@@ -659,7 +656,12 @@ async function sendNotionInferenceRequest(opts: {
  if (!upstream.ok) {
    const errText = await upstream.text().catch(() => "");
    return {
-      errorResult: makeErrorResult(upstream.status, `Notion error: ${errText}`, reqBody, NOTION_URL),
+      errorResult: makeErrorResult(
+        upstream.status,
+        `Notion error: ${errText}`,
+        reqBody,
+        NOTION_URL
+      ),
    };
  }

@@ -720,7 +722,11 @@ export class NotionWebExecutor extends BaseExecutor {
    const reqBody = buildNotionCreateThreadRequestBody({ spaceId, userId, threadId, transcript });
    const reqHeaders = buildNotionExecuteHeaders({ cookie, spaceId, userId });

-    const { rawText, errorResult } = await sendNotionInferenceRequest({ reqBody, reqHeaders, signal });
+    const { rawText, errorResult } = await sendNotionInferenceRequest({
+      reqBody,
+      reqHeaders,
+      signal,
+    });
    if (errorResult) return errorResult;

    const finalText = parseNotionInferenceStream(rawText || "");
--- a/open-sse/services/notionWebFallbackModels.ts
+++ b/open-sse/services/notionWebFallbackModels.ts
@@ -0,0 +1,134 @@
+/**
+ * Notion Web fallback model catalog (seeded from the live AI picker).
+ * Extracted from notionWebModels.ts to keep that module under the 800-line
+ * file-size cap; notionWebModels.ts re-exports both symbols for consumers.
+ */
+
+export type NotionDiscoveredModel = {
+  /**
+   * Catalog / OpenAI-compatible model id shown to clients.
+   * Prefer the web picker label slug (e.g. `fable-5`, `gpt-5.6-sol`) so users
+   * never have to choose Notion's internal food codenames.
+   */
+  id: string;
+  /** Human label from Notion's AI picker (`modelMessage`), e.g. "Fable 5". */
+  name: string;
+  owned_by: string;
+  supportsReasoning?: boolean;
+  disabled?: boolean;
+  /**
+   * Internal Notion `model` codename for `runInferenceTranscript`
+   * (e.g. `acai-budino-high`). When omitted, `id` is the codename itself
+   * (rare; only when no display label was available).
+   */
+  notionCodename?: string;
+};
+
+/**
+ * Offline fallback when getAvailableModels is unreachable (seeded from live picker).
+ * Catalog ids use real web-picker labels; `notionCodename` is what the API accepts.
+ */
+export const NOTION_WEB_FALLBACK_MODELS: NotionDiscoveredModel[] = [
+  { id: "notion-ai", name: "Notion AI (default)", owned_by: "notion" },
+  { id: "gpt-5.6-sol", name: "GPT-5.6 Sol", owned_by: "openai", notionCodename: "orange-mousse" },
+  {
+    id: "gpt-5.6-terra",
+    name: "GPT-5.6 Terra",
+    owned_by: "openai",
+    notionCodename: "orchid-muffin",
+  },
+  {
+    id: "gpt-5.6-luna",
+    name: "GPT-5.6 Luna",
+    owned_by: "openai",
+    notionCodename: "olive-jellyroll",
+  },
+  { id: "gpt-5.2", name: "GPT-5.2", owned_by: "openai", notionCodename: "oatmeal-cookie" },
+  { id: "gpt-5.4", name: "GPT-5.4", owned_by: "openai", notionCodename: "oval-kumquat-medium" },
+  { id: "gpt-5.5", name: "GPT-5.5", owned_by: "openai", notionCodename: "opal-quince-medium" },
+  {
+    id: "gpt-5.4-mini",
+    name: "GPT-5.4 Mini",
+    owned_by: "openai",
+    notionCodename: "oregon-grape-medium",
+  },
+  {
+    id: "gpt-5.4-nano",
+    name: "GPT-5.4 Nano",
+    owned_by: "openai",
+    notionCodename: "otaheite-apple-medium",
+  },
+  {
+    id: "gemini-3.5-flash",
+    name: "Gemini 3.5 Flash",
+    owned_by: "gemini",
+    notionCodename: "vertex-gemini-3.5-flash",
+  },
+  {
+    id: "gemini-3-flash",
+    name: "Gemini 3 Flash",
+    owned_by: "gemini",
+    notionCodename: "gingerbread",
+  },
+  {
+    id: "gemini-3.1-pro",
+    name: "Gemini 3.1 Pro",
+    owned_by: "gemini",
+    notionCodename: "galette-medium-thinking",
+  },
+  {
+    id: "sonnet-4.6",
+    name: "Sonnet 4.6",
+    owned_by: "anthropic",
+    notionCodename: "almond-croissant-low",
+  },
+  { id: "sonnet-5", name: "Sonnet 5", owned_by: "anthropic", notionCodename: "angel-cake-high" },
+  {
+    id: "opus-4.6",
+    name: "Opus 4.6",
+    owned_by: "anthropic",
+    notionCodename: "avocado-froyo-medium",
+  },
+  {
+    id: "opus-4.7",
+    name: "Opus 4.7",
+    owned_by: "anthropic",
+    notionCodename: "apricot-sorbet-high",
+  },
+  { id: "opus-4.8", name: "Opus 4.8", owned_by: "anthropic", notionCodename: "ambrosia-tart-high" },
+  {
+    id: "haiku-4.5",
+    name: "Haiku 4.5",
+    owned_by: "anthropic",
+    notionCodename: "anthropic-haiku-4.5",
+  },
+  { id: "fable-5", name: "Fable 5", owned_by: "anthropic", notionCodename: "acai-budino-high" },
+  {
+    id: "kimi-k2.6",
+    name: "Kimi K2.6",
+    owned_by: "mystery",
+    notionCodename: "fireworks-kimi-k2.6",
+  },
+  {
+    id: "kimi-k2.7-code",
+    name: "Kimi K2.7 Code",
+    owned_by: "mystery",
+    notionCodename: "fireworks-kimi-k2.7",
+  },
+  {
+    id: "deepseek-v4-pro",
+    name: "DeepSeek V4 Pro",
+    owned_by: "mystery",
+    notionCodename: "baseten-deepseek-v4-pro",
+  },
+  { id: "glm-5.2", name: "GLM 5.2", owned_by: "mystery", notionCodename: "baseten-glm-5.2" },
+  { id: "grok-4.3", name: "Grok 4.3", owned_by: "xai", notionCodename: "xigua-mochi-medium" },
+  { id: "grok-4.5", name: "Grok 4.5", owned_by: "xai", notionCodename: "strawberry-whoopiepie" },
+  {
+    id: "grok-build-0.1",
+    name: "Grok Build 0.1",
+    owned_by: "xai",
+    notionCodename: "xinomavro-cake",
+  },
+];
+
--- a/open-sse/services/notionWebModels.ts
+++ b/open-sse/services/notionWebModels.ts
@@ -7,6 +7,14 @@
 * build the cookie/headers/body the models-discovery route needs.
 */

+import {
+  NOTION_WEB_FALLBACK_MODELS,
+  type NotionDiscoveredModel,
+} from "./notionWebFallbackModels.ts";
+
+export { NOTION_WEB_FALLBACK_MODELS };
+export type { NotionDiscoveredModel };
+
 // Browser AI surface uses app.notion.com (live capture 2026-07-19). www.notion.so
 // still works for many paths but can return a different space default / cookie
 // domain behavior — prefer the same host the web picker uses.
@@ -15,73 +23,37 @@ const NOTION_LEGACY_ORIGIN = "https://www.notion.so";
 const NOTION_MODELS_URL = `${NOTION_APP_ORIGIN}/api/v3/getAvailableModels`;
 const NOTION_SPACES_URL = `${NOTION_APP_ORIGIN}/api/v3/getSpaces`;
 const NOTION_USER_AGENT =
-  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36";
+  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.36";
 /** Recent Notion web client version — accepted loosely but required by some paths. */
 const NOTION_CLIENT_VERSION = "23.13.20260719.1125";
 /** Cap how many workspaces we probe for AI models when space_id is omitted. */
 const NOTION_MAX_SPACE_PROBE = 8;
 /** Cache auto-selected workspace per token so chat/inference reuses discovery. */
-const NOTION_SPACE_CACHE = new Map<string, { spaceId: string; userId: string; expiresAt: number }>();
+const NOTION_SPACE_CACHE = new Map<
+  string,
+  { spaceId: string; userId: string; expiresAt: number }
+>();
 const NOTION_SPACE_CACHE_TTL_MS = 30 * 60 * 1000;

+// Browser fingerprint headers — make requests look like real Chromium
+// to reduce Cloudflare bot-detection challenges.
+export const BROWSER_HEADERS: Record<string, string> = {
+  "sec-ch-ua": '"Chromium";v="149", "Not)A;Brand";v="24"',
+  "sec-ch-ua-mobile": "?0",
+  "sec-ch-ua-platform": '"Windows"',
+  "sec-fetch-dest": "empty",
+  "sec-fetch-mode": "cors",
+  "sec-fetch-site": "same-origin",
+  priority: "u=1, i",
+  "cache-control": "no-cache",
+  pragma: "no-cache",
+};
+
 function notionTokenCacheKey(cookie: string): string {
  // Prefer the token_v2 value only — ignore optional space/user parts.
  return readCookieValue(cookie, "token_v2") || normalizeNotionWebCookie(cookie);
 }

-export type NotionDiscoveredModel = {
-  /**
-   * Catalog / OpenAI-compatible model id shown to clients.
-   * Prefer the web picker label slug (e.g. `fable-5`, `gpt-5.6-sol`) so users
-   * never have to choose Notion's internal food codenames.
-   */
-  id: string;
-  /** Human label from Notion's AI picker (`modelMessage`), e.g. "Fable 5". */
-  name: string;
-  owned_by: string;
-  supportsReasoning?: boolean;
-  disabled?: boolean;
-  /**
-   * Internal Notion `model` codename for `runInferenceTranscript`
-   * (e.g. `acai-budino-high`). When omitted, `id` is the codename itself
-   * (rare; only when no display label was available).
-   */
-  notionCodename?: string;
-};
-
-/**
- * Offline fallback when getAvailableModels is unreachable (seeded from live picker).
- * Catalog ids use real web-picker labels; `notionCodename` is what the API accepts.
- */
-export const NOTION_WEB_FALLBACK_MODELS: NotionDiscoveredModel[] = [
-  { id: "notion-ai", name: "Notion AI (default)", owned_by: "notion" },
-  { id: "gpt-5.6-sol", name: "GPT-5.6 Sol", owned_by: "openai", notionCodename: "orange-mousse" },
-  { id: "gpt-5.6-terra", name: "GPT-5.6 Terra", owned_by: "openai", notionCodename: "orchid-muffin" },
-  { id: "gpt-5.6-luna", name: "GPT-5.6 Luna", owned_by: "openai", notionCodename: "olive-jellyroll" },
-  { id: "gpt-5.2", name: "GPT-5.2", owned_by: "openai", notionCodename: "oatmeal-cookie" },
-  { id: "gpt-5.4", name: "GPT-5.4", owned_by: "openai", notionCodename: "oval-kumquat-medium" },
-  { id: "gpt-5.5", name: "GPT-5.5", owned_by: "openai", notionCodename: "opal-quince-medium" },
-  { id: "gpt-5.4-mini", name: "GPT-5.4 Mini", owned_by: "openai", notionCodename: "oregon-grape-medium" },
-  { id: "gpt-5.4-nano", name: "GPT-5.4 Nano", owned_by: "openai", notionCodename: "otaheite-apple-medium" },
-  { id: "gemini-3.5-flash", name: "Gemini 3.5 Flash", owned_by: "gemini", notionCodename: "vertex-gemini-3.5-flash" },
-  { id: "gemini-3-flash", name: "Gemini 3 Flash", owned_by: "gemini", notionCodename: "gingerbread" },
-  { id: "gemini-3.1-pro", name: "Gemini 3.1 Pro", owned_by: "gemini", notionCodename: "galette-medium-thinking" },
-  { id: "sonnet-4.6", name: "Sonnet 4.6", owned_by: "anthropic", notionCodename: "almond-croissant-low" },
-  { id: "sonnet-5", name: "Sonnet 5", owned_by: "anthropic", notionCodename: "angel-cake-high" },
-  { id: "opus-4.6", name: "Opus 4.6", owned_by: "anthropic", notionCodename: "avocado-froyo-medium" },
-  { id: "opus-4.7", name: "Opus 4.7", owned_by: "anthropic", notionCodename: "apricot-sorbet-high" },
-  { id: "opus-4.8", name: "Opus 4.8", owned_by: "anthropic", notionCodename: "ambrosia-tart-high" },
-  { id: "haiku-4.5", name: "Haiku 4.5", owned_by: "anthropic", notionCodename: "anthropic-haiku-4.5" },
-  { id: "fable-5", name: "Fable 5", owned_by: "anthropic", notionCodename: "acai-budino-high" },
-  { id: "kimi-k2.6", name: "Kimi K2.6", owned_by: "mystery", notionCodename: "fireworks-kimi-k2.6" },
-  { id: "kimi-k2.7-code", name: "Kimi K2.7 Code", owned_by: "mystery", notionCodename: "fireworks-kimi-k2.7" },
-  { id: "deepseek-v4-pro", name: "DeepSeek V4 Pro", owned_by: "mystery", notionCodename: "baseten-deepseek-v4-pro" },
-  { id: "glm-5.2", name: "GLM 5.2", owned_by: "mystery", notionCodename: "baseten-glm-5.2" },
-  { id: "grok-4.3", name: "Grok 4.3", owned_by: "xai", notionCodename: "xigua-mochi-medium" },
-  { id: "grok-4.5", name: "Grok 4.5", owned_by: "xai", notionCodename: "strawberry-whoopiepie" },
-  { id: "grok-build-0.1", name: "Grok Build 0.1", owned_by: "xai", notionCodename: "xinomavro-cake" },
-];
-
 /** Normalize a pasted credential to a Cookie header string. */
 export function normalizeNotionWebCookie(raw: string): string {
  const trimmed = String(raw || "").trim();
@@ -105,11 +77,7 @@ export function readCookieValue(cookie: string, name: string): string {
 }

 export function extractSpaceIdFromNotionCookie(cookie: string): string {
-  return (
-    readCookieValue(cookie, "space_id") ||
-    readCookieValue(cookie, "spaceId") ||
-    ""
-  );
+  return readCookieValue(cookie, "space_id") || readCookieValue(cookie, "spaceId") || "";
 }

 export function extractNotionUserIdFromCookie(cookie: string): string {
@@ -229,10 +197,7 @@ export function formatNotionDisabledModelsWarning(
 * Catalog `id` is the real picker label slug; `notionCodename` is what
 * runInferenceTranscript requires.
 */
-function parseNotionModelEntry(
-  entry: unknown,
-  seen: Set<string>
-): NotionDiscoveredModel | null {
+function parseNotionModelEntry(entry: unknown, seen: Set<string>): NotionDiscoveredModel | null {
  if (!entry || typeof entry !== "object" || Array.isArray(entry)) return null;
  const row = entry as Record<string, unknown>;
  // Notion still returns plan-locked models (Fable 5) with isDisabled=true.
@@ -314,6 +279,7 @@ export function buildNotionModelsDiscoveryHeaders(token: string): Record<string,
    "notion-client-version": NOTION_CLIENT_VERSION,
    "notion-audit-log-platform": "web",
    ...(cookie ? { cookie } : {}),
+    ...BROWSER_HEADERS,
  };
  if (spaceId) headers["x-notion-space-id"] = spaceId;
  if (userId) headers["x-notion-active-user-header"] = userId;
@@ -418,6 +384,7 @@ function buildNotionBrowserHeaders(cookie: string, userId?: string): Record<stri
    "notion-client-version": NOTION_CLIENT_VERSION,
    "notion-audit-log-platform": "web",
    cookie,
+    ...BROWSER_HEADERS,
  };
  if (userId) headers["x-notion-active-user-header"] = userId;
  return headers;
@@ -482,8 +449,12 @@ export async function selectBestNotionSpaceId(opts: {
  const cookie = normalizeNotionWebCookie(opts.cookie);
  if (!cookie || opts.spaceIds.length === 0) return null;

-  let best: { spaceId: string; models: NotionDiscoveredModel[]; raw: unknown; score: number } | null =
-    null;
+  let best: {
+    spaceId: string;
+    models: NotionDiscoveredModel[];
+    raw: unknown;
+    score: number;
+  } | null = null;

  for (const spaceId of opts.spaceIds.slice(0, NOTION_MAX_SPACE_PROBE)) {
    if (!spaceId) continue;
@@ -521,9 +492,7 @@ export async function selectBestNotionSpaceId(opts: {
    }
  }

-  return best
-    ? { spaceId: best.spaceId, models: best.models, raw: best.raw }
-    : null;
+  return best ? { spaceId: best.spaceId, models: best.models, raw: best.raw } : null;
 }

 /**
@@ -558,7 +527,11 @@ export async function resolveNotionRuntimeWorkspace(opts: {
    signal: opts.signal,
  });
  if (!best?.spaceId) {
-    return { spaceId: candidates.spaceIds[0] || "", userId: userId || candidates.userId, fromCache: false };
+    return {
+      spaceId: candidates.spaceIds[0] || "",
+      userId: userId || candidates.userId,
+      fromCache: false,
+    };
  }

  const resolvedUser = userId || candidates.userId;
@@ -766,10 +739,7 @@ export function resolveNotionCodename(
  else if (m.startsWith("nw/")) m = m.slice(3);
  if (!m || m === "notion-ai") return "";

-  const map = buildNotionFriendlyToCodenameMap([
-    ...NOTION_WEB_FALLBACK_MODELS,
-    ...extraModels,
-  ]);
+  const map = buildNotionFriendlyToCodenameMap([...NOTION_WEB_FALLBACK_MODELS, ...extraModels]);
  // Unknown ids pass through as-is so a freshly discovered codename still works
  // before the fallback table is updated.
  return map.get(m) || map.get(m.toLowerCase()) || map.get(slugifyNotionDisplayName(m)) || m;
--- a/tests/unit/executor-notion-web.test.ts
+++ b/tests/unit/executor-notion-web.test.ts
@@ -26,9 +26,14 @@ describe("NotionWebExecutor — registry consistency", () => {
    assert.ok(models.length >= 1);
    assert.ok(models.some((m) => m.id === "notion-ai"));
    // Seed catalog uses real web-picker labels (fable-5 / gpt-5.6-sol), not food codenames.
-    assert.ok(models.some((m) => m.id === "fable-5" || m.id === "gpt-5.6-sol" || m.id === "opus-4.8"));
+    assert.ok(
+      models.some((m) => m.id === "fable-5" || m.id === "gpt-5.6-sol" || m.id === "opus-4.8")
+    );
    assert.equal(
-      models.some((m) => m.id === "ambrosia-tart-high" || m.id === "orange-mousse" || m.id === "acai-budino-high"),
+      models.some(
+        (m) =>
+          m.id === "ambrosia-tart-high" || m.id === "orange-mousse" || m.id === "acai-budino-high"
+      ),
      false
    );
  });
@@ -124,6 +129,14 @@ describe("NotionWebExecutor — upstream translation (mocked fetch)", () => {
      assert.equal(capturedHeaders.Cookie, COOKIE_WITH_SPACE);
      assert.equal(capturedHeaders["x-notion-space-id"], "space-1");
      assert.equal(capturedHeaders["x-notion-active-user-header"], "user-1");
+      // Browser fingerprint headers to reduce Cloudflare challenges.
+      assert.ok(capturedHeaders["sec-ch-ua"], "sec-ch-ua should be present");
+      assert.ok(capturedHeaders["sec-fetch-dest"], "sec-fetch-dest should be present");
+      assert.ok(capturedHeaders["sec-fetch-mode"], "sec-fetch-mode should be present");
+      assert.equal(capturedHeaders["sec-fetch-mode"], "cors");
+      assert.ok(capturedHeaders["sec-ch-ua-platform"], "sec-ch-ua-platform should be present");
+      assert.equal(capturedHeaders["cache-control"], "no-cache");
+      assert.equal(capturedHeaders["pragma"], "no-cache");
      assert.ok(capturedBody);
      assert.equal(capturedBody.createThread, true);
      assert.ok(typeof capturedBody.threadId === "string" && capturedBody.threadId.length > 0);
@@ -295,7 +308,8 @@ describe("NotionWebExecutor — upstream translation (mocked fetch)", () => {
    const executor = new mod.NotionWebExecutor();
    const originalFetch = globalThis.fetch;
    try {
-      globalThis.fetch = (async () => new Response("not-json\n{}", { status: 200 })) as typeof fetch;
+      globalThis.fetch = (async () =>
+        new Response("not-json\n{}", { status: 200 })) as typeof fetch;

      const result = await executor.execute({
        model: "notion-ai",
@@ -314,8 +328,7 @@ describe("NotionWebExecutor — upstream translation (mocked fetch)", () => {
    const executor = new mod.NotionWebExecutor();
    const originalFetch = globalThis.fetch;
    try {
-      globalThis.fetch = (async () =>
-        new Response("Forbidden", { status: 403 })) as typeof fetch;
+      globalThis.fetch = (async () => new Response("Forbidden", { status: 403 })) as typeof fetch;

      const result = await executor.execute({
        model: "notion-ai",
@@ -325,7 +338,9 @@ describe("NotionWebExecutor — upstream translation (mocked fetch)", () => {
        signal: null,
      } as never);
      assert.equal(result.response.status, 403);
-      const errBody = (await result.response.json()) as { error: { message: string; code: string } };
+      const errBody = (await result.response.json()) as {
+        error: { message: string; code: string };
+      };
      assert.match(errBody.error.message, /session expired|invalid/i);
      assert.equal(errBody.error.code, "HTTP_403");
      // No stack trace / file path leakage (Hard Rule #12).
@@ -459,10 +474,7 @@ describe("estimateNotionUsage", () => {

  it("scales with prompt and completion length (not a constant 2000)", () => {
    const short = estimateNotionUsage([{ role: "user", content: "hi" }], "PONG");
-    const long = estimateNotionUsage(
-      [{ role: "user", content: "a".repeat(400) }],
-      "b".repeat(400)
-    );
+    const long = estimateNotionUsage([{ role: "user", content: "a".repeat(400) }], "b".repeat(400));
    assert.equal(short.estimated, true);
    assert.ok(short.prompt_tokens >= 1);
    assert.ok(short.completion_tokens >= 1);
--- a/tests/unit/notion-web-models-discovery.test.ts
+++ b/tests/unit/notion-web-models-discovery.test.ts
@@ -58,8 +58,14 @@ test("parseNotionAvailableModels maps enabled models and skips disabled", () =>
  assert.ok(models.some((m) => m.id === "opus-4.8" && m.name === "Opus 4.8"));
  assert.ok(models.some((m) => m.id === "notion-ai"));
  // Food codenames must not be primary catalog ids.
-  assert.equal(models.some((m) => m.id === "orange-mousse"), false);
-  assert.equal(models.some((m) => m.id === "ambrosia-tart-high"), false);
+  assert.equal(
+    models.some((m) => m.id === "orange-mousse"),
+    false
+  );
+  assert.equal(
+    models.some((m) => m.id === "ambrosia-tart-high"),
+    false
+  );
  const sol = models.find((m) => m.id === "gpt-5.6-sol");
  assert.equal(sol?.notionCodename, "orange-mousse");
  assert.equal(sol?.supportsReasoning, true);
@@ -108,7 +114,10 @@ test("listNotionDisabledModels surfaces plan-locked Fable 5 without listing it a
  assert.equal(disabled[0].reason, "business_or_enterprise_plan_required");

  const enabled = notionModels.parseNotionAvailableModels(payload);
-  assert.equal(enabled.some((m) => m.id === "fable-5" || m.id === "acai-budino-high"), false);
+  assert.equal(
+    enabled.some((m) => m.id === "fable-5" || m.id === "acai-budino-high"),
+    false
+  );
  assert.ok(enabled.some((m) => m.id === "gpt-5.6-sol"));

  const warning = notionModels.formatNotionDisabledModelsWarning(disabled);
@@ -311,6 +320,11 @@ test("notion-web models route returns live getAvailableModels catalog", async ()
      assert.equal(body.spaceId, "space-live-1");
      const headers = init?.headers as Record<string, string>;
      assert.match(String(headers.cookie || headers.Cookie || ""), /token_v2=sess/);
+      // Browser fingerprint headers present on models-discovery requests.
+      assert.ok(headers["sec-ch-ua"], "sec-ch-ua should be present");
+      assert.ok(headers["sec-fetch-mode"], "sec-fetch-mode should be present");
+      assert.equal(headers["sec-fetch-mode"], "cors");
+      assert.equal(headers["cache-control"], "no-cache");
      return Response.json(SAMPLE_RESPONSE);
    }
    return new Response("unexpected", { status: 500 });