Add LangSearch as web search provider

env.example

@@ -17,10 +17,11 @@ OLLAMA_BASE_URL=http://127.0.0.1:11434
 # Stock Market API Key
 FINANCIAL_DATASETS_API_KEY=your-financial-datasets-api-key
 
-# Web Search API Keys (Exa → Perplexity → Tavily)
+# Web Search API Keys (Exa → Perplexity → Tavily → LangSearch)
 EXASEARCH_API_KEY=your-exa-api-key
 PERPLEXITY_API_KEY=your-perplexity-api-key
 TAVILY_API_KEY=your-tavily-api-key
+LANGSEARCH_API_KEY=your-langsearch-api-key
 
 # X/Twitter API (enables x_search tool for public sentiment research)
 X_BEARER_TOKEN=your-X-bearer-token

src/components/select-list.ts

@@ -56,20 +56,21 @@ export function createProviderSelector(
 
 export function createSearchProviderSelector(
   currentProvider: string,
-  onSelect: (providerId: 'exa' | 'perplexity' | 'tavily') => void,
+  onSelect: (providerId: 'exa' | 'perplexity' | 'tavily' | 'langsearch') => void,
   onCancel: () => void,
 ) {
-  const providers: { id: 'exa' | 'perplexity' | 'tavily'; displayName: string }[] = [
+  const providers: { id: 'exa' | 'perplexity' | 'tavily' | 'langsearch'; displayName: string }[] = [
     { id: 'exa', displayName: 'Exa' },
     { id: 'perplexity', displayName: 'Perplexity' },
     { id: 'tavily', displayName: 'Tavily' },
+    { id: 'langsearch', displayName: 'LangSearch' },
   ];
   const items: SelectItem[] = providers.map((provider, index) => ({
     value: provider.id,
     label: `${index + 1}. ${provider.displayName}${currentProvider === provider.id ? ' ✓' : ''}`,
   }));
   const list = new VimSelectList(items, 5, selectListTheme);
-  list.onSelect = (item) => onSelect(item.value as 'exa' | 'perplexity' | 'tavily');
+  list.onSelect = (item) => onSelect(item.value as 'exa' | 'perplexity' | 'tavily' | 'langsearch');
   list.onCancel = () => onCancel();
   return list;
 }

src/controllers/search-selection.ts

@@ -111,13 +111,7 @@ export class SearchSelectionController {
       return;
     }
 
-    const providerId = this.pendingProviderValue;
-    const displayName = getSearchProviderDisplayName(providerId);
-    this.commitPreference(providerId);
-
-    if (providerId !== 'perplexity') {
-      this.onError(`API key saved. Restart Dexter to use ${displayName}.`);
-    }
+    this.commitPreference(this.pendingProviderValue);
   }
 
   private commitPreference(providerId: SearchProviderId) {

src/tools/registry.ts

@@ -1,6 +1,6 @@
 import { StructuredToolInterface } from '@langchain/core/tools';
 import { createGetFinancials, createGetMarketData, createReadFilings, createScreenStocks } from './finance/index.js';
-import { exaSearch, perplexitySearch, tavilySearch, WEB_SEARCH_DESCRIPTION, xSearchTool, X_SEARCH_DESCRIPTION } from './search/index.js';
+import { exaSearch, perplexitySearch, tavilySearch, langSearch, WEB_SEARCH_DESCRIPTION, xSearchTool, X_SEARCH_DESCRIPTION } from './search/index.js';
 import { createWebSearchTool, type WebSearchProvider } from './search/web-search.js';
 import { getSetting } from '../utils/config.js';
 import type { SearchProviderId } from '../utils/env.js';
@@ -156,6 +156,9 @@ export function getToolRegistry(model: string): RegisteredTool[] {
   if (process.env.TAVILY_API_KEY) {
     allWebSearchProviders.push({ id: 'tavily', name: 'Tavily', tool: tavilySearch });
   }
+  if (process.env.LANGSEARCH_API_KEY) {
+    allWebSearchProviders.push({ id: 'langsearch', name: 'LangSearch', tool: langSearch });
+  }
 
   if (allWebSearchProviders.length > 0) {
     const preferred = getSetting<SearchProviderId | undefined>('webSearchPreferredProvider', undefined);

src/tools/search/index.ts

@@ -29,4 +29,5 @@ Search the web for current information on any topic. Returns relevant search res
 export { tavilySearch } from './tavily.js';
 export { exaSearch } from './exa.js';
 export { perplexitySearch } from './perplexity.js';
+export { langSearch } from './langsearch.js';
 export { xSearchTool, X_SEARCH_DESCRIPTION } from './x-search.js';

src/tools/search/langsearch.ts

@@ -0,0 +1,91 @@
+import { DynamicStructuredTool } from '@langchain/core/tools';
+import { z } from 'zod';
+import { formatToolResult } from '../types.js';
+import { logger } from '@/utils';
+
+const LANGSEARCH_API_URL = 'https://api.langsearch.com/v1/web-search';
+
+interface LangSearchWebPage {
+  name: string;
+  url: string;
+  snippet?: string;
+  summary?: string;
+}
+
+interface LangSearchResponse {
+  code: number;
+  msg?: string | null;
+  data?: {
+    _type?: string;
+    queryContext?: { originalQuery?: string };
+    webPages?: {
+      totalEstimatedMatches?: number | null;
+      value?: LangSearchWebPage[];
+    };
+  };
+}
+
+async function callLangSearch(query: string): Promise<LangSearchResponse> {
+  const apiKey = process.env.LANGSEARCH_API_KEY;
+  if (!apiKey) {
+    throw new Error('[LangSearch API] LANGSEARCH_API_KEY is not set');
+  }
+
+  const response = await fetch(LANGSEARCH_API_URL, {
+    method: 'POST',
+    headers: {
+      Authorization: `Bearer ${apiKey}`,
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({
+      query,
+      summary: true,
+      count: 10,
+    }),
+  });
+
+  if (!response.ok) {
+    const text = await response.text();
+    throw new Error(`[LangSearch API] ${response.status}: ${text}`);
+  }
+
+  return response.json() as Promise<LangSearchResponse>;
+}
+
+export const langSearch = new DynamicStructuredTool({
+  name: 'web_search',
+  description:
+    'Search the web for current information on any topic. Returns relevant search results with URLs and content snippets.',
+  schema: z.object({
+    query: z.string().describe('The search query to look up on the web'),
+  }),
+  func: async (input) => {
+    try {
+      const res = await callLangSearch(input.query);
+
+      if (res.code !== 200) {
+        throw new Error(`[LangSearch API] Error code ${res.code}: ${res.msg ?? 'Unknown error'}`);
+      }
+
+      const results = res.data?.webPages?.value ?? [];
+      const urls: string[] = [];
+      const formattedResults = results.map((r) => {
+        if (r.url && !urls.includes(r.url)) {
+          urls.push(r.url);
+        }
+        return {
+          title: r.name,
+          url: r.url,
+          snippet: r.summary ?? r.snippet ?? undefined,
+        };
+      });
+
+      const data = { results: formattedResults };
+      return formatToolResult(data, urls.length ? urls : undefined);
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error);
+      logger.error(`[LangSearch API] error: ${message}`);
+      throw new Error(`[LangSearch API] ${message}`);
+    }
+  },
+});

src/utils/env.ts

@@ -100,12 +100,13 @@ export function saveApiKeyForProvider(providerId: string, apiKey: string): boole
   return saveApiKeyToEnv(apiKeyName, apiKey);
 }
 
-export type SearchProviderId = 'exa' | 'perplexity' | 'tavily';
+export type SearchProviderId = 'exa' | 'perplexity' | 'tavily' | 'langsearch';
 
 export const SEARCH_PROVIDERS: Record<SearchProviderId, { displayName: string; apiKeyEnvVar: string }> = {
   exa: { displayName: 'Exa', apiKeyEnvVar: 'EXASEARCH_API_KEY' },
   perplexity: { displayName: 'Perplexity', apiKeyEnvVar: 'PERPLEXITY_API_KEY' },
   tavily: { displayName: 'Tavily', apiKeyEnvVar: 'TAVILY_API_KEY' },
+  langsearch: { displayName: 'LangSearch', apiKeyEnvVar: 'LANGSEARCH_API_KEY' },
 };
 
 export function getSearchProviderDisplayName(providerId: SearchProviderId): string {