diff --git a/api/server/controllers/agents/client.js b/api/server/controllers/agents/client.js
index 8e8a993a5d..49240a6b3b 100644
--- a/api/server/controllers/agents/client.js
+++ b/api/server/controllers/agents/client.js
@@ -6,18 +6,22 @@ const {
   Tokenizer,
   checkAccess,
   buildToolSet,
-  logAxiosError,
   sanitizeTitle,
+  logToolError,
+  payloadParser,
   resolveHeaders,
   createSafeUser,
   initializeAgent,
   getBalanceConfig,
   getProviderConfig,
+  omitTitleOptions,
   memoryInstructions,
   applyContextToAgent,
+  createTokenCounter,
   GenerationJobManager,
   getTransactionsConfig,
   createMemoryProcessor,
+  createMultiAgentMapper,
   filterMalformedContentParts,
 } = require('@librechat/api');
 const {
@@ -25,9 +29,7 @@ const {
   Providers,
   TitleMethod,
   formatMessage,
-  labelContentByAgent,
   formatAgentMessages,
-  getTokenCountForMessage,
   createMetadataAggregator,
 } = require('@librechat/agents');
 const {
@@ -51,177 +53,6 @@ const { loadAgent } = require('~/models/Agent');
 const { getMCPManager } = require('~/config');
 const db = require('~/models');
 
-const omitTitleOptions = new Set([
-  'stream',
-  'thinking',
-  'streaming',
-  'clientOptions',
-  'thinkingConfig',
-  'thinkingBudget',
-  'includeThoughts',
-  'maxOutputTokens',
-  'additionalModelRequestFields',
-]);
-
-/**
- * @param {ServerRequest} req
- * @param {Agent} agent
- * @param {string} endpoint
- */
-const payloadParser = ({ req, endpoint }) => {
-  if (isAgentsEndpoint(endpoint)) {
-    return;
-  }
-  return req.body?.endpointOption?.model_parameters;
-};
-
-function createTokenCounter(encoding) {
-  return function (message) {
-    const countTokens = (text) => Tokenizer.getTokenCount(text, encoding);
-    return getTokenCountForMessage(message, countTokens);
-  };
-}
-
-function logToolError(graph, error, toolId) {
-  logAxiosError({
-    error,
-    message: `[api/server/controllers/agents/client.js #chatCompletion] Tool Error "${toolId}"`,
-  });
-}
-
-/** Regex pattern to match agent ID suffix (____N) */
-const AGENT_SUFFIX_PATTERN = /____(\d+)$/;
-
-/**
- * Finds the primary agent ID within a set of agent IDs.
- * Primary = no suffix (____N) or lowest suffix number.
- * @param {Set<string>} agentIds
- * @returns {string | null}
- */
-function findPrimaryAgentId(agentIds) {
-  let primaryAgentId = null;
-  let lowestSuffixIndex = Infinity;
-
-  for (const agentId of agentIds) {
-    const suffixMatch = agentId.match(AGENT_SUFFIX_PATTERN);
-    if (!suffixMatch) {
-      return agentId;
-    }
-    const suffixIndex = parseInt(suffixMatch[1], 10);
-    if (suffixIndex < lowestSuffixIndex) {
-      lowestSuffixIndex = suffixIndex;
-      primaryAgentId = agentId;
-    }
-  }
-
-  return primaryAgentId;
-}
-
-/**
- * Creates a mapMethod for getMessagesForConversation that processes agent content.
- * - Strips agentId/groupId metadata from all content
- * - For parallel agents (addedConvo with groupId): filters each group to its primary agent
- * - For handoffs (agentId without groupId): keeps all content from all agents
- * - For multi-agent: applies agent labels to content
- *
- * The key distinction:
- * - Parallel execution (addedConvo): Parts have both agentId AND groupId
- * - Handoffs: Parts only have agentId, no groupId
- *
- * @param {Agent} primaryAgent - Primary agent configuration
- * @param {Map<string, Agent>} [agentConfigs] - Additional agent configurations
- * @returns {(message: TMessage) => TMessage} Map method for processing messages
- */
-function createMultiAgentMapper(primaryAgent, agentConfigs) {
-  const hasMultipleAgents = (primaryAgent.edges?.length ?? 0) > 0 || (agentConfigs?.size ?? 0) > 0;
-
-  /** @type {Record<string, string> | null} */
-  let agentNames = null;
-  if (hasMultipleAgents) {
-    agentNames = { [primaryAgent.id]: primaryAgent.name || 'Assistant' };
-    if (agentConfigs) {
-      for (const [agentId, agentConfig] of agentConfigs.entries()) {
-        agentNames[agentId] = agentConfig.name || agentConfig.id;
-      }
-    }
-  }
-
-  return (message) => {
-    if (message.isCreatedByUser || !Array.isArray(message.content)) {
-      return message;
-    }
-
-    // Check for metadata
-    const hasAgentMetadata = message.content.some((part) => part?.agentId || part?.groupId != null);
-    if (!hasAgentMetadata) {
-      return message;
-    }
-
-    try {
-      // Build a map of groupId -> Set of agentIds, to find primary per group
-      /** @type {Map<number, Set<string>>} */
-      const groupAgentMap = new Map();
-
-      for (const part of message.content) {
-        const groupId = part?.groupId;
-        const agentId = part?.agentId;
-        if (groupId != null && agentId) {
-          if (!groupAgentMap.has(groupId)) {
-            groupAgentMap.set(groupId, new Set());
-          }
-          groupAgentMap.get(groupId).add(agentId);
-        }
-      }
-
-      // For each group, find the primary agent
-      /** @type {Map<number, string>} */
-      const groupPrimaryMap = new Map();
-      for (const [groupId, agentIds] of groupAgentMap) {
-        const primary = findPrimaryAgentId(agentIds);
-        if (primary) {
-          groupPrimaryMap.set(groupId, primary);
-        }
-      }
-
-      /** @type {Array<TMessageContentParts>} */
-      const filteredContent = [];
-      /** @type {Record<number, string>} */
-      const agentIdMap = {};
-
-      for (const part of message.content) {
-        const agentId = part?.agentId;
-        const groupId = part?.groupId;
-
-        // Filtering logic:
-        // - No groupId (handoffs): always include
-        // - Has groupId (parallel): only include if it's the primary for that group
-        const isParallelPart = groupId != null;
-        const groupPrimary = isParallelPart ? groupPrimaryMap.get(groupId) : null;
-        const shouldInclude = !isParallelPart || !agentId || agentId === groupPrimary;
-
-        if (shouldInclude) {
-          const newIndex = filteredContent.length;
-          const { agentId: _a, groupId: _g, ...cleanPart } = part;
-          filteredContent.push(cleanPart);
-          if (agentId && hasMultipleAgents) {
-            agentIdMap[newIndex] = agentId;
-          }
-        }
-      }
-
-      const finalContent =
-        Object.keys(agentIdMap).length > 0 && agentNames
-          ? labelContentByAgent(filteredContent, agentIdMap, agentNames)
-          : filteredContent;
-
-      return { ...message, content: finalContent };
-    } catch (error) {
-      logger.error('[AgentClient] Error processing multi-agent message:', error);
-      return message;
-    }
-  };
-}
-
 class AgentClient extends BaseClient {
   constructor(options = {}) {
     super(null, options);
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 9990e0fc35..f53c4e83dd 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -291,6 +291,15 @@ export default [
     files: ['./packages/api/**/*.ts'],
     rules: {
       'lines-between-class-members': ['error', 'always', { exceptAfterSingleLine: true }],
+      '@typescript-eslint/no-unused-vars': [
+        'warn',
+        {
+          argsIgnorePattern: '^_',
+          varsIgnorePattern: '^_',
+          caughtErrorsIgnorePattern: '^_',
+          destructuredArrayIgnorePattern: '^_',
+        },
+      ],
     },
   },
   {
diff --git a/packages/api/src/agents/client.ts b/packages/api/src/agents/client.ts
new file mode 100644
index 0000000000..fd5d50f211
--- /dev/null
+++ b/packages/api/src/agents/client.ts
@@ -0,0 +1,162 @@
+import { logger } from '@librechat/data-schemas';
+import { isAgentsEndpoint } from 'librechat-data-provider';
+import { labelContentByAgent, getTokenCountForMessage } from '@librechat/agents';
+import type { MessageContentComplex } from '@librechat/agents';
+import type { Agent, TMessage } from 'librechat-data-provider';
+import type { BaseMessage } from '@langchain/core/messages';
+import type { ServerRequest } from '~/types';
+import Tokenizer from '~/utils/tokenizer';
+import { logAxiosError } from '~/utils';
+
+export const omitTitleOptions = new Set([
+  'stream',
+  'thinking',
+  'streaming',
+  'clientOptions',
+  'thinkingConfig',
+  'thinkingBudget',
+  'includeThoughts',
+  'maxOutputTokens',
+  'additionalModelRequestFields',
+]);
+
+export function payloadParser({ req, endpoint }: { req: ServerRequest; endpoint: string }) {
+  if (isAgentsEndpoint(endpoint)) {
+    return;
+  }
+  return req.body?.endpointOption?.model_parameters;
+}
+
+export function createTokenCounter(encoding: Parameters<typeof Tokenizer.getTokenCount>[1]) {
+  return function (message: BaseMessage) {
+    const countTokens = (text: string) => Tokenizer.getTokenCount(text, encoding);
+    return getTokenCountForMessage(message, countTokens);
+  };
+}
+
+export function logToolError(_graph: unknown, error: unknown, toolId: string) {
+  logAxiosError({
+    error,
+    message: `[api/server/controllers/agents/client.js #chatCompletion] Tool Error "${toolId}"`,
+  });
+}
+
+const AGENT_SUFFIX_PATTERN = /____(\d+)$/;
+
+/** Finds the primary agent ID within a set of agent IDs (no suffix or lowest suffix number) */
+export function findPrimaryAgentId(agentIds: Set<string>): string | null {
+  let primaryAgentId: string | null = null;
+  let lowestSuffixIndex = Infinity;
+
+  for (const agentId of agentIds) {
+    const suffixMatch = agentId.match(AGENT_SUFFIX_PATTERN);
+    if (!suffixMatch) {
+      return agentId;
+    }
+    const suffixIndex = parseInt(suffixMatch[1], 10);
+    if (suffixIndex < lowestSuffixIndex) {
+      lowestSuffixIndex = suffixIndex;
+      primaryAgentId = agentId;
+    }
+  }
+
+  return primaryAgentId;
+}
+
+type ContentPart = TMessage['content'] extends (infer U)[] | undefined ? U : never;
+
+/**
+ * Creates a mapMethod for getMessagesForConversation that processes agent content.
+ * - Strips agentId/groupId metadata from all content
+ * - For parallel agents (addedConvo with groupId): filters each group to its primary agent
+ * - For handoffs (agentId without groupId): keeps all content from all agents
+ * - For multi-agent: applies agent labels to content
+ *
+ * The key distinction:
+ * - Parallel execution (addedConvo): Parts have both agentId AND groupId
+ * - Handoffs: Parts only have agentId, no groupId
+ */
+export function createMultiAgentMapper(primaryAgent: Agent, agentConfigs?: Map<string, Agent>) {
+  const hasMultipleAgents = (primaryAgent.edges?.length ?? 0) > 0 || (agentConfigs?.size ?? 0) > 0;
+
+  let agentNames: Record<string, string> | null = null;
+  if (hasMultipleAgents) {
+    agentNames = { [primaryAgent.id]: primaryAgent.name || 'Assistant' };
+    if (agentConfigs) {
+      for (const [agentId, agentConfig] of agentConfigs.entries()) {
+        agentNames[agentId] = agentConfig.name || agentConfig.id;
+      }
+    }
+  }
+
+  return (message: TMessage): TMessage => {
+    if (message.isCreatedByUser || !Array.isArray(message.content)) {
+      return message;
+    }
+
+    const hasAgentMetadata = message.content.some(
+      (part) =>
+        (part as ContentPart & { agentId?: string; groupId?: number })?.agentId ||
+        (part as ContentPart & { groupId?: number })?.groupId != null,
+    );
+    if (!hasAgentMetadata) {
+      return message;
+    }
+
+    try {
+      const groupAgentMap = new Map<number, Set<string>>();
+
+      for (const part of message.content) {
+        const p = part as ContentPart & { agentId?: string; groupId?: number };
+        const groupId = p?.groupId;
+        const agentId = p?.agentId;
+        if (groupId != null && agentId) {
+          if (!groupAgentMap.has(groupId)) {
+            groupAgentMap.set(groupId, new Set());
+          }
+          groupAgentMap.get(groupId)!.add(agentId);
+        }
+      }
+
+      const groupPrimaryMap = new Map<number, string>();
+      for (const [groupId, agentIds] of groupAgentMap) {
+        const primary = findPrimaryAgentId(agentIds);
+        if (primary) {
+          groupPrimaryMap.set(groupId, primary);
+        }
+      }
+
+      const filteredContent: ContentPart[] = [];
+      const agentIdMap: Record<number, string> = {};
+
+      for (const part of message.content) {
+        const p = part as ContentPart & { agentId?: string; groupId?: number };
+        const agentId = p?.agentId;
+        const groupId = p?.groupId;
+
+        const isParallelPart = groupId != null;
+        const groupPrimary = isParallelPart ? groupPrimaryMap.get(groupId) : null;
+        const shouldInclude = !isParallelPart || !agentId || agentId === groupPrimary;
+
+        if (shouldInclude) {
+          const newIndex = filteredContent.length;
+          const { agentId: _a, groupId: _g, ...cleanPart } = p;
+          filteredContent.push(cleanPart as ContentPart);
+          if (agentId && hasMultipleAgents) {
+            agentIdMap[newIndex] = agentId;
+          }
+        }
+      }
+
+      const finalContent =
+        Object.keys(agentIdMap).length > 0 && agentNames
+          ? labelContentByAgent(filteredContent as MessageContentComplex[], agentIdMap, agentNames)
+          : filteredContent;
+
+      return { ...message, content: finalContent as TMessage['content'] };
+    } catch (error) {
+      logger.error('[AgentClient] Error processing multi-agent message:', error);
+      return message;
+    }
+  };
+}
diff --git a/packages/api/src/agents/index.ts b/packages/api/src/agents/index.ts
index a5a0c340fe..9d13b3dd8e 100644
--- a/packages/api/src/agents/index.ts
+++ b/packages/api/src/agents/index.ts
@@ -1,5 +1,6 @@
 export * from './avatars';
 export * from './chain';
+export * from './client';
 export * from './context';
 export * from './edges';
 export * from './handlers';
diff --git a/packages/api/src/types/http.ts b/packages/api/src/types/http.ts
index 6544447310..c304e9089e 100644
--- a/packages/api/src/types/http.ts
+++ b/packages/api/src/types/http.ts
@@ -1,5 +1,6 @@
-import type { Request } from 'express';
 import type { IUser, AppConfig } from '@librechat/data-schemas';
+import type { TEndpointOption } from 'librechat-data-provider';
+import type { Request } from 'express';
 
 /**
  * LibreChat-specific request body type that extends Express Request body
@@ -11,8 +12,10 @@ export type RequestBody = {
   conversationId?: string;
   parentMessageId?: string;
   endpoint?: string;
+  endpointType?: string;
   model?: string;
   key?: string;
+  endpointOption?: Partial<TEndpointOption>;
 };
 
 export type ServerRequest = Request<unknown, unknown, RequestBody> & {