diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d27029f04..ae270e1079 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,8 @@
 
 ### 🐛 Bug Fixes
 
+- **fix(core):** Strip `reasoning_content` from OpenAI format messages for non-reasoning models to prevent upstream HTTP 400 validation errors. (#1505)
+- **fix(ui):** Add missing UI wiring for "Add Memory" and "Import" buttons on the `/dashboard/memory` page. (#1506)
 - **fix(core):** Add periodic runtime log rotation checks to prevent disk exhaustion in long-running instances. (#1504 — thanks @ether-btc)
 - **fix(build):** Resolve missing `process` module in webpack client build for pino-abstract-transport. (#1509 — thanks @hartmark)
 - **fix(ui):** Add dark mode support for native dropdown `<option>` elements on Linux/Windows, resolving invisible text in settings and combo builders (#1488)
diff --git a/open-sse/executors/muse-spark-web.ts b/open-sse/executors/muse-spark-web.ts
index 20d8e8598a..146ebc1cc0 100644
--- a/open-sse/executors/muse-spark-web.ts
+++ b/open-sse/executors/muse-spark-web.ts
@@ -5,13 +5,20 @@ import {
   type ExecuteInput,
 } from "./base.ts";
 import { FETCH_TIMEOUT_MS } from "../config/constants.ts";
-import { normalizeSessionCookieHeader } from "@/lib/providers/webCookieAuth";
+import { getRotatingApiKey } from "../services/apiKeyRotator.ts";
+import {
+  normalizeSessionCookieHeader,
+  normalizeSessionCookieHeaders,
+} from "@/lib/providers/webCookieAuth";
 
 const META_AI_GRAPHQL_API = "https://www.meta.ai/api/graphql";
 const META_AI_DEFAULT_COOKIE = "abra_sess";
 const META_AI_SEND_MESSAGE_DOC_ID = "078dfdff6fb0d420d8011b49073e6886";
 const META_AI_ROOT_BRANCH_PATH = "0";
 const META_AI_ENTRY_POINT = "KADABRA__CHAT__UNIFIED_INPUT_BAR";
+const META_AI_FRIENDLY_NAME = "useAbraSendMessageMutation";
+const META_AI_REQUEST_ANALYTICS_TAGS = "graphservice";
+const META_AI_ASBD_ID = "129477";
 const META_AI_USER_AGENT =
   "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36";
 const BASE62_ALPHABET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
@@ -35,6 +42,8 @@ type MetaSseFrame = {
 type ParsedMetaAiResponse = {
   content: string;
   deltas: string[];
+  reasoningContent: string;
+  reasoningDeltas: string[];
   errorCode: string | null;
   errorMessage: string | null;
   status: number;
@@ -295,6 +304,37 @@ function readMetaJsonPayloads(text: string): Array<Record<string, unknown>> {
     .filter((frame): frame is Record<string, unknown> => !!frame);
 }
 
+const META_AI_REASONING_KEYS = [
+  "reasoning",
+  "reasoningContent",
+  "reasoning_content",
+  "reasoningText",
+  "thinking",
+  "thinkingContent",
+  "thinkingText",
+  "thought",
+  "thoughtText",
+  "thoughts",
+  "internalThoughts",
+  "chainOfThought",
+  "thinkingTrace",
+  "thinking_trace",
+] as const;
+
+const META_AI_NESTED_RENDERER_KEYS = [
+  "contentRenderer",
+  "textContent",
+  "message",
+  "mediaContent",
+  "unified_response",
+  "unifiedResponseContent",
+  "sections",
+  "view_model",
+  "primitive",
+  "primitives",
+  "nested_responses",
+] as const;
+
 function collectRendererTexts(value: unknown, seen: Set<string>, depth = 0): string[] {
   if (depth > 8) {
     return [];
@@ -343,6 +383,56 @@ function collectRendererTexts(value: unknown, seen: Set<string>, depth = 0): str
   return parts;
 }
 
+function collectReasoningTexts(
+  value: unknown,
+  seen: Set<string>,
+  depth = 0,
+  force = false
+): string[] {
+  if (depth > 8) {
+    return [];
+  }
+
+  if (typeof value === "string") {
+    const normalized = value.trim();
+    if (!force || !normalized || seen.has(normalized)) {
+      return [];
+    }
+    seen.add(normalized);
+    return [normalized];
+  }
+
+  if (Array.isArray(value)) {
+    return value.flatMap((item) => collectReasoningTexts(item, seen, depth + 1, force));
+  }
+
+  if (!isRecord(value)) {
+    return [];
+  }
+
+  const typename = typeof value.__typename === "string" ? value.__typename : "";
+  const localForce = force || /reasoning|thinking|thought/i.test(typename);
+  const parts: string[] = [];
+
+  if (typeof value.text === "string" && localForce) {
+    parts.push(...collectReasoningTexts(value.text, seen, depth + 1, true));
+  }
+
+  for (const key of META_AI_REASONING_KEYS) {
+    if (key in value) {
+      parts.push(...collectReasoningTexts(value[key], seen, depth + 1, true));
+    }
+  }
+
+  for (const key of META_AI_NESTED_RENDERER_KEYS) {
+    if (key in value) {
+      parts.push(...collectReasoningTexts(value[key], seen, depth + 1, localForce));
+    }
+  }
+
+  return parts;
+}
+
 function extractAssistantContent(message: Record<string, unknown>): string {
   if (typeof message.content === "string" && message.content.length > 0) {
     return message.content;
@@ -357,6 +447,11 @@ function extractAssistantContent(message: Record<string, unknown>): string {
   return parts.join("\n\n").trim();
 }
 
+function extractAssistantReasoning(message: Record<string, unknown>): string {
+  const parts = collectReasoningTexts(message, new Set());
+  return parts.join("\n\n").trim();
+}
+
 function extractAssistantError(message: Record<string, unknown>) {
   const error = isRecord(message.error) ? message.error : null;
   const streamingState =
@@ -405,9 +500,11 @@ function classifyMetaAiError(errorMessage: string | null, content: string) {
   return null;
 }
 
-function parseMetaAiResponseText(text: string): ParsedMetaAiResponse {
+function parseMetaAiResponseText(text: string, isThinkingModel: boolean): ParsedMetaAiResponse {
   let lastContent = "";
   const deltas: string[] = [];
+  let lastReasoning = "";
+  const reasoningDeltas: string[] = [];
   let errorCode: string | null = null;
   let errorMessage: string | null = null;
 
@@ -433,6 +530,16 @@ function parseMetaAiResponseText(text: string): ParsedMetaAiResponse {
       lastContent = content;
     }
 
+    if (isThinkingModel) {
+      const reasoning = extractAssistantReasoning(sendMessageStream);
+      if (reasoning && reasoning !== content && reasoning !== lastReasoning) {
+        reasoningDeltas.push(
+          reasoning.startsWith(lastReasoning) ? reasoning.slice(lastReasoning.length) : reasoning
+        );
+        lastReasoning = reasoning;
+      }
+    }
+
     const upstreamError = extractAssistantError(sendMessageStream);
     if (upstreamError.message) {
       errorMessage = upstreamError.message;
@@ -442,12 +549,14 @@ function parseMetaAiResponseText(text: string): ParsedMetaAiResponse {
 
   const classifiedError = classifyMetaAiError(errorMessage, lastContent);
   if (classifiedError) {
-    return {
-      content: lastContent,
-      deltas,
-      errorCode,
-      errorMessage: classifiedError.message,
-      status: classifiedError.status,
+      return {
+        content: lastContent,
+        deltas,
+        reasoningContent: lastReasoning,
+        reasoningDeltas,
+        errorCode,
+        errorMessage: classifiedError.message,
+        status: classifiedError.status,
     };
   }
 
@@ -455,6 +564,8 @@ function parseMetaAiResponseText(text: string): ParsedMetaAiResponse {
     return {
       content: lastContent,
       deltas,
+      reasoningContent: lastReasoning,
+      reasoningDeltas,
       errorCode,
       errorMessage: `Meta AI returned an error: ${errorMessage}`,
       status: 502,
@@ -465,6 +576,8 @@ function parseMetaAiResponseText(text: string): ParsedMetaAiResponse {
     return {
       content: "",
       deltas: [],
+      reasoningContent: lastReasoning,
+      reasoningDeltas,
       errorCode: null,
       errorMessage: "Meta AI returned no assistant content",
       status: 502,
@@ -474,6 +587,8 @@ function parseMetaAiResponseText(text: string): ParsedMetaAiResponse {
   return {
     content: lastContent,
     deltas: deltas.filter((delta) => delta.length > 0),
+    reasoningContent: lastReasoning,
+    reasoningDeltas: reasoningDeltas.filter((delta) => delta.length > 0),
     errorCode: null,
     errorMessage: null,
     status: 200,
@@ -486,6 +601,7 @@ function sseChunk(data: unknown): string {
 
 function buildStreamingResponse(
   deltas: string[],
+  reasoningDeltas: string[],
   model: string,
   id: string,
   created: number
@@ -514,6 +630,29 @@ function buildStreamingResponse(
         )
       );
 
+      for (const delta of reasoningDeltas) {
+        if (!delta) continue;
+        controller.enqueue(
+          encoder.encode(
+            sseChunk({
+              id,
+              object: "chat.completion.chunk",
+              created,
+              model,
+              system_fingerprint: null,
+              choices: [
+                {
+                  index: 0,
+                  delta: { reasoning_content: delta },
+                  finish_reason: null,
+                  logprobs: null,
+                },
+              ],
+            })
+          )
+        );
+      }
+
       for (const delta of deltas) {
         if (!delta) continue;
         controller.enqueue(
@@ -555,8 +694,18 @@ function buildStreamingResponse(
   });
 }
 
-function buildNonStreamingResponse(content: string, model: string, id: string, created: number) {
+function buildNonStreamingResponse(
+  content: string,
+  reasoningContent: string,
+  model: string,
+  id: string,
+  created: number
+) {
   const completionTokens = estimateTokens(content);
+  const message: Record<string, unknown> = { role: "assistant", content };
+  if (reasoningContent) {
+    message.reasoning_content = reasoningContent;
+  }
 
   return new Response(
     JSON.stringify({
@@ -568,7 +717,7 @@ function buildNonStreamingResponse(content: string, model: string, id: string, c
       choices: [
         {
           index: 0,
-          message: { role: "assistant", content },
+          message,
           finish_reason: "stop",
           logprobs: null,
         },
@@ -629,6 +778,47 @@ export function normalizeMetaAiCookieHeader(apiKey: string): string {
   return normalizeSessionCookieHeader(apiKey, META_AI_DEFAULT_COOKIE);
 }
 
+function selectMetaAiCookieHeader(credentials: ExecuteInput["credentials"]): string {
+  const extraCookieValues = Array.isArray(credentials.providerSpecificData?.extraApiKeys)
+    ? credentials.providerSpecificData.extraApiKeys.filter(
+        (value): value is string => typeof value === "string" && value.trim().length > 0
+      )
+    : [];
+
+  const normalizedPool = normalizeSessionCookieHeaders(
+    [credentials.apiKey || "", ...extraCookieValues],
+    META_AI_DEFAULT_COOKIE
+  );
+
+  if (normalizedPool.length === 0) {
+    return "";
+  }
+
+  if (normalizedPool.length === 1 || !credentials.connectionId) {
+    return normalizedPool[0];
+  }
+
+  return getRotatingApiKey(credentials.connectionId, normalizedPool[0], normalizedPool.slice(1));
+}
+
+function buildMetaAiHeaders(cookieHeader: string): Record<string, string> {
+  return {
+    Accept: "text/event-stream",
+    "Accept-Language": "en-US,en;q=0.9",
+    "Content-Type": "application/json",
+    Cookie: cookieHeader,
+    Origin: "https://www.meta.ai",
+    Referer: "https://www.meta.ai/",
+    "Sec-Fetch-Dest": "empty",
+    "Sec-Fetch-Mode": "cors",
+    "Sec-Fetch-Site": "same-origin",
+    "User-Agent": META_AI_USER_AGENT,
+    "X-ASBD-ID": META_AI_ASBD_ID,
+    "X-FB-Friendly-Name": META_AI_FRIENDLY_NAME,
+    "X-FB-Request-Analytics-Tags": META_AI_REQUEST_ANALYTICS_TAGS,
+  };
+}
+
 export class MuseSparkWebExecutor extends BaseExecutor {
   constructor() {
     super("muse-spark-web", { id: "muse-spark-web", baseUrl: META_AI_GRAPHQL_API });
@@ -669,16 +859,10 @@ export class MuseSparkWebExecutor extends BaseExecutor {
       };
     }
 
+    const modelInfo = getMuseSparkModelInfo(model);
     const transformedBody = buildMetaAiRequestBody(prompt, model);
-    const cookieHeader = normalizeMetaAiCookieHeader(credentials.apiKey || "");
-    const headers: Record<string, string> = {
-      Accept: "text/event-stream",
-      "Content-Type": "application/json",
-      Cookie: cookieHeader,
-      Origin: "https://www.meta.ai",
-      Referer: "https://www.meta.ai/",
-      "User-Agent": META_AI_USER_AGENT,
-    };
+    const cookieHeader = selectMetaAiCookieHeader(credentials);
+    const headers = buildMetaAiHeaders(cookieHeader);
     mergeUpstreamExtraHeaders(headers, upstreamExtraHeaders);
 
     const timeoutSignal = AbortSignal.timeout(FETCH_TIMEOUT_MS);
@@ -741,7 +925,7 @@ export class MuseSparkWebExecutor extends BaseExecutor {
     }
 
     const responseText = await readTextResponse(upstreamResponse.body, signal);
-    const parsed = parseMetaAiResponseText(responseText);
+    const parsed = parseMetaAiResponseText(responseText, modelInfo.isThinking);
     if (parsed.status !== 200 || parsed.errorMessage) {
       return {
         response: buildErrorResponse(
@@ -758,10 +942,11 @@ export class MuseSparkWebExecutor extends BaseExecutor {
     const id = `chatcmpl-meta-${crypto.randomUUID().slice(0, 12)}`;
     const created = Math.floor(Date.now() / 1000);
     const deltas = parsed.deltas.length > 0 ? parsed.deltas : [parsed.content];
+    const reasoningDeltas = parsed.reasoningDeltas;
 
     return {
       response: stream
-        ? new Response(buildStreamingResponse(deltas, model, id, created), {
+        ? new Response(buildStreamingResponse(deltas, reasoningDeltas, model, id, created), {
             status: 200,
             headers: {
               "Content-Type": "text/event-stream",
@@ -769,7 +954,7 @@ export class MuseSparkWebExecutor extends BaseExecutor {
               "X-Accel-Buffering": "no",
             },
           })
-        : buildNonStreamingResponse(parsed.content, model, id, created),
+        : buildNonStreamingResponse(parsed.content, parsed.reasoningContent, model, id, created),
       url: META_AI_GRAPHQL_API,
       headers,
       transformedBody,
diff --git a/open-sse/translator/index.ts b/open-sse/translator/index.ts
index 6055716a36..08040237b4 100644
--- a/open-sse/translator/index.ts
+++ b/open-sse/translator/index.ts
@@ -221,6 +221,12 @@ export function translateRequest(
         msg.reasoning_content = "";
       }
     }
+  } else if (!isReasoner && targetFormat === FORMATS.OPENAI && result.messages && Array.isArray(result.messages)) {
+    for (const msg of result.messages) {
+      if (msg.reasoning_content !== undefined) {
+        delete msg.reasoning_content;
+      }
+    }
   }
 
   return result;
diff --git a/src/app/(dashboard)/dashboard/memory/page.tsx b/src/app/(dashboard)/dashboard/memory/page.tsx
index aff574e193..6d36927b8e 100644
--- a/src/app/(dashboard)/dashboard/memory/page.tsx
+++ b/src/app/(dashboard)/dashboard/memory/page.tsx
@@ -1,7 +1,7 @@
 "use client";
 
-import { useState, useEffect, useCallback } from "react";
-import { Card, Badge, Button, Input, Select } from "@/shared/components";
+import { useState, useEffect, useCallback, useRef } from "react";
+import { Card, Badge, Button, Input, Select, Modal } from "@/shared/components";
 import { useTranslations } from "next-intl";
 
 interface Memory {
@@ -39,6 +39,10 @@ export default function MemoryPage() {
   const [total, setTotal] = useState(0);
   const [health, setHealth] = useState<{ working: boolean; latencyMs: number } | null>(null);
   const [checkingHealth, setCheckingHealth] = useState(false);
+  const [addDialogOpen, setAddDialogOpen] = useState(false);
+  const [newMemory, setNewMemory] = useState<Partial<Memory>>({ type: "factual", key: "", content: "" });
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const fileInputRef = useRef<HTMLInputElement>(null);
 
   const fetchMemories = useCallback(async () => {
     try {
@@ -94,6 +98,58 @@ export default function MemoryPage() {
     link.click();
   };
 
+  const handleImportClick = () => {
+    fileInputRef.current?.click();
+  };
+
+  const handleFileChange = async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const file = e.target.files?.[0];
+    if (!file) return;
+    
+    setIsSubmitting(true);
+    try {
+      const text = await file.text();
+      const data = JSON.parse(text);
+      const memoriesToImport = Array.isArray(data) ? data : [data];
+      
+      for (const m of memoriesToImport) {
+        if (!m.key || !m.content) continue;
+        await fetch("/api/memory", {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify({ type: m.type || "factual", key: m.key, content: m.content, metadata: m.metadata || {} }),
+        });
+      }
+      fetchMemories();
+    } catch (error) {
+      console.error("Failed to import memories:", error);
+    } finally {
+      setIsSubmitting(false);
+      if (fileInputRef.current) fileInputRef.current.value = "";
+    }
+  };
+
+  const handleAddMemory = async () => {
+    if (!newMemory.key || !newMemory.content) return;
+    setIsSubmitting(true);
+    try {
+      const response = await fetch("/api/memory", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(newMemory),
+      });
+      if (response.ok) {
+        setAddDialogOpen(false);
+        setNewMemory({ type: "factual", key: "", content: "" });
+        fetchMemories();
+      }
+    } catch (error) {
+      console.error("Failed to add memory:", error);
+    } finally {
+      setIsSubmitting(false);
+    }
+  };
+
   const checkHealth = async () => {
     setCheckingHealth(true);
     try {
@@ -155,11 +211,22 @@ export default function MemoryPage() {
           </div>
         </div>
         <div className="flex gap-2">
+          <input 
+            type="file" 
+            ref={fileInputRef} 
+            onChange={handleFileChange} 
+            accept=".json" 
+            className="hidden" 
+          />
           <Button variant="outline" onClick={handleExport}>
             {t("export")}
           </Button>
-          <Button variant="outline">{t("import")}</Button>
-          <Button>{t("addMemory")}</Button>
+          <Button variant="outline" onClick={handleImportClick} loading={isSubmitting}>
+            {t("import")}
+          </Button>
+          <Button onClick={() => setAddDialogOpen(true)}>
+            {t("addMemory")}
+          </Button>
         </div>
       </div>
 
@@ -270,6 +337,56 @@ export default function MemoryPage() {
           </div>
         </div>
       </Card>
+
+      <Modal
+        isOpen={addDialogOpen}
+        onClose={() => setAddDialogOpen(false)}
+        title={t("addMemory")}
+        footer={
+          <>
+            <Button variant="outline" onClick={() => setAddDialogOpen(false)} disabled={isSubmitting}>
+              Cancel
+            </Button>
+            <Button onClick={handleAddMemory} loading={isSubmitting} disabled={!newMemory.key || !newMemory.content}>
+              Save
+            </Button>
+          </>
+        }
+      >
+        <div className="space-y-4">
+          <div>
+            <label className="block text-sm font-medium mb-1">Type</label>
+            <Select
+              value={newMemory.type}
+              onChange={(e) => setNewMemory({ ...newMemory, type: e.target.value as any })}
+              className="w-full"
+            >
+              <option value="factual">Factual</option>
+              <option value="episodic">Episodic</option>
+              <option value="procedural">Procedural</option>
+              <option value="semantic">Semantic</option>
+            </Select>
+          </div>
+          <div>
+            <label className="block text-sm font-medium mb-1">Key</label>
+            <Input
+              value={newMemory.key}
+              onChange={(e) => setNewMemory({ ...newMemory, key: e.target.value })}
+              placeholder="e.g., user_preference_theme"
+              className="w-full"
+            />
+          </div>
+          <div>
+            <label className="block text-sm font-medium mb-1">Content</label>
+            <Input
+              value={newMemory.content}
+              onChange={(e) => setNewMemory({ ...newMemory, content: e.target.value })}
+              placeholder="e.g., Prefers dark mode"
+              className="w-full"
+            />
+          </div>
+        </div>
+      </Modal>
     </div>
   );
 }
diff --git a/src/lib/providers/validation.ts b/src/lib/providers/validation.ts
index a601781b4a..f9223ca263 100644
--- a/src/lib/providers/validation.ts
+++ b/src/lib/providers/validation.ts
@@ -1189,6 +1189,9 @@ const SEARCH_VALIDATOR_CONFIGS: Record<
 };
 
 const META_AI_SEND_MESSAGE_DOC_ID = "078dfdff6fb0d420d8011b49073e6886";
+const META_AI_FRIENDLY_NAME = "useAbraSendMessageMutation";
+const META_AI_REQUEST_ANALYTICS_TAGS = "graphservice";
+const META_AI_ASBD_ID = "129477";
 const META_AI_USER_AGENT =
   "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36";
 const META_AI_BASE62_ALPHABET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
@@ -1589,10 +1592,17 @@ async function validateMuseSparkWebProvider({ apiKey, providerSpecificData = {}
         {
           "Content-Type": "application/json",
           Accept: "text/event-stream",
+          "Accept-Language": "en-US,en;q=0.9",
           Cookie: cookieHeader,
           Origin: "https://www.meta.ai",
           Referer: "https://www.meta.ai/",
+          "Sec-Fetch-Dest": "empty",
+          "Sec-Fetch-Mode": "cors",
+          "Sec-Fetch-Site": "same-origin",
           "User-Agent": META_AI_USER_AGENT,
+          "X-ASBD-ID": META_AI_ASBD_ID,
+          "X-FB-Friendly-Name": META_AI_FRIENDLY_NAME,
+          "X-FB-Request-Analytics-Tags": META_AI_REQUEST_ANALYTICS_TAGS,
         },
         providerSpecificData
       ),
diff --git a/src/lib/providers/webCookieAuth.ts b/src/lib/providers/webCookieAuth.ts
index 3425ff8cf7..de95eda53c 100644
--- a/src/lib/providers/webCookieAuth.ts
+++ b/src/lib/providers/webCookieAuth.ts
@@ -16,3 +16,21 @@ export function normalizeSessionCookieHeader(rawValue: string, defaultCookieName
 
   return `${defaultCookieName}=${normalized}`;
 }
+
+export function normalizeSessionCookieHeaders(
+  rawValues: Array<string | null | undefined>,
+  defaultCookieName: string
+): string[] {
+  const seen = new Set<string>();
+  const normalizedHeaders: string[] = [];
+
+  for (const rawValue of rawValues) {
+    if (typeof rawValue !== "string") continue;
+    const normalized = normalizeSessionCookieHeader(rawValue, defaultCookieName);
+    if (!normalized || seen.has(normalized)) continue;
+    seen.add(normalized);
+    normalizedHeaders.push(normalized);
+  }
+
+  return normalizedHeaders;
+}
diff --git a/tests/unit/muse-spark-web.test.ts b/tests/unit/muse-spark-web.test.ts
index 83e574a239..dbc9114fab 100644
--- a/tests/unit/muse-spark-web.test.ts
+++ b/tests/unit/muse-spark-web.test.ts
@@ -72,6 +72,34 @@ function mockFetchCapture(status = 200, text = metaAiSseText([])) {
   };
 }
 
+function mockFetchCaptureMany(status = 200, text = metaAiSseText([])) {
+  const original = globalThis.fetch;
+  const calls: Array<{
+    url: string;
+    headers: Record<string, string>;
+    body: Record<string, unknown>;
+  }> = [];
+
+  globalThis.fetch = async (url: any, opts: any) => {
+    calls.push({
+      url: String(url),
+      headers: opts?.headers || {},
+      body: JSON.parse(opts?.body || "{}"),
+    });
+    return new Response(mockTextStream(text), {
+      status,
+      headers: { "Content-Type": "text/event-stream" },
+    });
+  };
+
+  return {
+    restore: () => {
+      globalThis.fetch = original;
+    },
+    calls,
+  };
+}
+
 test("MuseSparkWebExecutor is registered in executor index", () => {
   assert.ok(hasSpecializedExecutor("muse-spark-web"));
   assert.ok(hasSpecializedExecutor("ms-web"));
@@ -139,12 +167,14 @@ test("Streaming: produces valid SSE chunks", async () => {
         id: "meta-msg-1",
         content: "Hello ",
         streamingState: "STREAMING",
+        thinkingText: "First thought",
       },
       {
         __typename: "AssistantMessage",
         id: "meta-msg-1",
         content: "Hello from Muse Spark",
         streamingState: "DONE",
+        thinkingText: "First thought\nSecond thought",
       },
     ])
   );
@@ -167,14 +197,22 @@ test("Streaming: produces valid SSE chunks", async () => {
     const lines = text.split("\n").filter((line) => line.startsWith("data: "));
     assert.ok(lines.length >= 4, `Expected at least 4 SSE data lines, got ${lines.length}`);
 
-    const first = JSON.parse(lines[0].slice(6));
+    const payloads = lines
+      .filter((line) => line !== "data: [DONE]")
+      .map((line) => JSON.parse(line.slice(6)));
+
+    const first = payloads[0];
     assert.equal(first.choices[0].delta.role, "assistant");
 
-    const second = JSON.parse(lines[1].slice(6));
-    assert.equal(second.choices[0].delta.content, "Hello ");
+    const reasoningChunks = payloads.filter((payload) => payload.choices[0].delta.reasoning_content);
+    assert.ok(reasoningChunks.length >= 2);
+    assert.equal(reasoningChunks[0].choices[0].delta.reasoning_content, "First thought");
+    assert.equal(reasoningChunks[1].choices[0].delta.reasoning_content, "\nSecond thought");
 
-    const third = JSON.parse(lines[2].slice(6));
-    assert.equal(third.choices[0].delta.content, "from Muse Spark");
+    const contentChunks = payloads.filter((payload) => payload.choices[0].delta.content);
+    assert.ok(contentChunks.length >= 2);
+    assert.equal(contentChunks[0].choices[0].delta.content, "Hello ");
+    assert.equal(contentChunks[1].choices[0].delta.content, "from Muse Spark");
 
     const lastLine = text.trim().split("\n").filter(Boolean).pop();
     assert.equal(lastLine, "data: [DONE]");
@@ -183,6 +221,40 @@ test("Streaming: produces valid SSE chunks", async () => {
   }
 });
 
+test("Non-streaming thinking mode includes reasoning_content", async () => {
+  const restore = mockFetch(
+    200,
+    metaAiSseText([
+      {
+        __typename: "AssistantMessage",
+        id: "meta-msg-2",
+        content: "Answer",
+        streamingState: "DONE",
+        thinkingText: "Reason through the plan",
+      },
+    ])
+  );
+
+  try {
+    const executor = new MuseSparkWebExecutor();
+    const result = await executor.execute({
+      model: "muse-spark-thinking",
+      body: { messages: [{ role: "user", content: "hi" }], stream: false },
+      stream: false,
+      credentials: { apiKey: "abra-session-token" },
+      signal: AbortSignal.timeout(10000),
+      log: null,
+    });
+
+    assert.equal(result.response.status, 200);
+    const json = (await result.response.json()) as any;
+    assert.equal(json.choices[0].message.content, "Answer");
+    assert.equal(json.choices[0].message.reasoning_content, "Reason through the plan");
+  } finally {
+    restore();
+  }
+});
+
 test("Error: auth failure from Meta SSE returns cookie error", async () => {
   const restore = mockFetch(
     200,
@@ -260,6 +332,8 @@ test("Request: posts to correct Meta endpoint with normalized cookie", async ()
     assert.equal(cap.url, "https://www.meta.ai/api/graphql");
     assert.equal(cap.headers.Cookie, "abra_sess=raw-session-token");
     assert.equal(cap.headers.Accept, "text/event-stream");
+    assert.equal(cap.headers["X-FB-Friendly-Name"], "useAbraSendMessageMutation");
+    assert.equal(cap.headers["X-ASBD-ID"], "129477");
     assert.equal(cap.headers.Origin, "https://www.meta.ai");
     assert.equal(cap.headers.Referer, "https://www.meta.ai/");
   } finally {
@@ -267,6 +341,47 @@ test("Request: posts to correct Meta endpoint with normalized cookie", async ()
   }
 });
 
+test("Request: rotates across extra abra_sess cookies with round-robin", async () => {
+  const cap = mockFetchCaptureMany(
+    200,
+    metaAiSseText([
+      {
+        __typename: "AssistantMessage",
+        id: "meta-msg-3",
+        content: "ok",
+        streamingState: "DONE",
+      },
+    ])
+  );
+
+  try {
+    const executor = new MuseSparkWebExecutor();
+    for (let i = 0; i < 3; i++) {
+      await executor.execute({
+        model: "muse-spark",
+        body: { messages: [{ role: "user", content: `test ${i}` }], stream: false },
+        stream: false,
+        credentials: {
+          apiKey: "primary-cookie",
+          connectionId: "muse-spark-rotation",
+          providerSpecificData: {
+            extraApiKeys: ["secondary-cookie", "abra_sess=third-cookie"],
+          },
+        },
+        signal: AbortSignal.timeout(10000),
+        log: null,
+      });
+    }
+
+    assert.deepEqual(
+      cap.calls.map((call) => call.headers.Cookie),
+      ["abra_sess=primary-cookie", "abra_sess=secondary-cookie", "abra_sess=third-cookie"]
+    );
+  } finally {
+    cap.restore();
+  }
+});
+
 test("Request: payload carries persisted doc id, model mapping and Meta defaults", async () => {
   const cap = mockFetchCapture(
     200,
diff --git a/tests/unit/provider-validation-specialty.test.ts b/tests/unit/provider-validation-specialty.test.ts
index e2df96693d..2a866a154e 100644
--- a/tests/unit/provider-validation-specialty.test.ts
+++ b/tests/unit/provider-validation-specialty.test.ts
@@ -188,6 +188,7 @@ test("web-cookie provider validators accept valid Grok, Perplexity, Blackbox and
     "__Secure-authjs.session-token=bb-cookie"
   );
   assert.equal(museSparkCall?.init.headers.Cookie, "abra_sess=meta-cookie");
+  assert.equal(museSparkCall?.init.headers["X-FB-Friendly-Name"], "useAbraSendMessageMutation");
 });
 
 test("web-cookie provider validators surface auth and subscription failures", async () => {