feat(backend): replace custom aiClient with @bytelyst/llm platform package

- Import PerplexityProvider, OpenAIProvider, GeminiProvider from @bytelyst/llm
- Use createFallbackChain() instead of manual axios fallback loop
- Remove axios and @types/axios — no longer needed
- Preserve AIClient class interface (generateAnalysis, getProviderHealth) —
  no changes required in apiServer.ts or AIAnalysisRule.ts
- Fallback order still driven by config.AI.FALLBACK_LIST

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/package.json

@@ -53,11 +53,11 @@
     "@azure/cosmos": "^4.3.0",
     "@bytelyst/auth": "link:../../../learning_ai/learning_ai_common_plat/packages/auth",
     "@bytelyst/cosmos": "link:../../../learning_ai/learning_ai_common_plat/packages/cosmos",
+    "@bytelyst/llm": "link:../../../learning_ai/learning_ai_common_plat/packages/llm",
     "@alpacahq/alpaca-trade-api": "^3.1.3",
     "@supabase/supabase-js": "^2.90.1",
     "@types/cors": "^2.8.19",
     "@types/express": "^5.0.6",
-    "axios": "^1.13.2",
     "ccxt": "^4.5.31",
     "cors": "^2.8.5",
     "dotenv": "^17.2.3",
@@ -68,7 +68,6 @@
     "winston": "^3.19.0"
   },
   "devDependencies": {
-    "@types/axios": "^0.14.4",
     "@types/node": "^25.0.3",
     "c8": "^10.1.3",
     "ts-node": "^10.9.2",

backend/src/services/aiClient.ts

@@ -1,4 +1,10 @@
-import axios from 'axios';
+import {
+    createFallbackChain,
+    GeminiProvider,
+    OpenAIProvider,
+    PerplexityProvider,
+    type LLMProvider,
+} from '@bytelyst/llm';
 import { config } from '../config/index.js';
 import logger from '../utils/logger.js';
 
@@ -14,224 +20,106 @@ export interface AIProviderHealth {
     message: string;
 }
 
+interface ProviderEntry {
+    name: AIProvider;
+    make: () => LLMProvider;
+    defaultModel: string;
+}
+
+function resolveModel(provider: AIProvider): string {
+    switch (provider) {
+        case 'perplexity':
+            return config.AI.MODEL.includes('sonar') ? config.AI.MODEL : 'sonar';
+        case 'openai':
+            return config.AI.MODEL.includes('gpt') ? config.AI.MODEL : 'gpt-4o-mini';
+        case 'gemini':
+            return config.AI.MODEL.includes('gemini') ? config.AI.MODEL : 'gemini-1.5-flash';
+    }
+}
+
+const PROVIDER_REGISTRY: ProviderEntry[] = [
+    {
+        name: 'perplexity',
+        make: () => new PerplexityProvider({ apiKey: config.AI.PERPLEXITY_API_KEY, model: resolveModel('perplexity') }),
+        defaultModel: 'sonar',
+    },
+    {
+        name: 'openai',
+        make: () => new OpenAIProvider({ apiKey: config.AI.OPENAI_API_KEY, model: resolveModel('openai') }),
+        defaultModel: 'gpt-4o-mini',
+    },
+    {
+        name: 'gemini',
+        make: () => new GeminiProvider({ apiKey: config.AI.GEMINI_API_KEY, model: resolveModel('gemini') }),
+        defaultModel: 'gemini-1.5-flash',
+    },
+];
+
 export class AIClient {
-    public async generateAnalysis(prompt: string): Promise<string | null> {
+    public async generateAnalysis(prompt: string): Promise<string | null> {
-        const fallbackList = config.AI.FALLBACK_LIST;
+        const ordered = this.buildOrderedProviders();
-
+        const chain = createFallbackChain(ordered.map(e => e.make()));
-        for (const provider of fallbackList) {
+
-            try {
+        if (!chain.isConfigured()) {
-                logger.info(`[AI] Attempting analysis with provider: ${provider}...`);
+            logger.warn('[AI] No providers configured — skipping analysis');
-                let result: string | null = null;
+            return null;
-
+        }
-                switch (provider) {
+
-                    case 'openai':
+        try {
-                        result = await this.callOpenAI(prompt);
+            const result = await chain.chatCompletion({
-                        break;
+                messages: [
-                    case 'perplexity':
+                    { role: 'system', content: 'You are an expert crypto trading assistant. Strictly output JSON.' },
-                        result = await this.callPerplexity(prompt);
+                    { role: 'user', content: prompt },
-                        break;
+                ],
-                    case 'gemini':
+                temperature: 0.2,
-                        result = await this.callGemini(prompt);
+            });
-                        break;
+            logger.info('[AI] Analysis generated successfully');
-                    default:
+            return result.content;
-                        logger.warn(`[AI] Unsupported provider in fallback list: ${provider}`);
+        } catch (error: any) {
-                        continue;
+            logger.error(`[AI] All providers failed: ${error.message}`);
-                }
+            return null;
-
+        }
-                if (result) {
-                    logger.info(`[AI] Successfully generated analysis using ${provider}.`);
-                    return result;
-                }
-            } catch (error: any) {
-                logger.error(`[AI] Provider ${provider} failed: ${error.message}`);
-                // Continue to next provider in fallback list
-            }
-        }
-
-        logger.error('[AI] All providers in fallback list failed or were not configured.');
-        return null;
     }
 
     public async getProviderHealth(probe: boolean = false): Promise<AIProviderHealth[]> {
         const fallbackList = config.AI.FALLBACK_LIST;
-        const providers: AIProvider[] = ['openai', 'perplexity', 'gemini'];
-
         const results: AIProviderHealth[] = [];
-        for (const provider of providers) {
+
-            const configured = this.isProviderConfigured(provider);
+        for (const entry of PROVIDER_REGISTRY) {
-            const model = this.resolveModel(provider);
+            const provider = entry.make();
-            const fallbackIndex = fallbackList.indexOf(provider);
+            const configured = provider.isConfigured();
+            const fallbackIndex = fallbackList.indexOf(entry.name);
             const inFallbackList = fallbackIndex >= 0;
+            const model = resolveModel(entry.name);
 
             if (!configured) {
-                results.push({
+                results.push({ provider: entry.name, configured: false, model, inFallbackList, fallbackIndex: inFallbackList ? fallbackIndex : null, status: 'missing_key', message: 'API key missing' });
-                    provider,
-                    configured: false,
-                    model,
-                    inFallbackList,
-                    fallbackIndex: inFallbackList ? fallbackIndex : null,
-                    status: 'missing_key',
-                    message: 'API key missing'
-                });
                 continue;
             }
 
             if (!probe) {
-                results.push({
+                results.push({ provider: entry.name, configured: true, model, inFallbackList, fallbackIndex: inFallbackList ? fallbackIndex : null, status: 'configured', message: 'Configured (probe skipped)' });
-                    provider,
-                    configured: true,
-                    model,
-                    inFallbackList,
-                    fallbackIndex: inFallbackList ? fallbackIndex : null,
-                    status: 'configured',
-                    message: 'Configured (probe skipped)'
-                });
                 continue;
             }
 
             try {
-                await this.probeProvider(provider);
+                await provider.chatCompletion({
-                results.push({
+                    messages: [{ role: 'user', content: 'Return JSON: {"action":"HOLD","confidence":0,"reasoning":"probe"}' }],
-                    provider,
+                    temperature: 0,
-                    configured: true,
-                    model,
-                    inFallbackList,
-                    fallbackIndex: inFallbackList ? fallbackIndex : null,
-                    status: 'ok',
-                    message: 'Provider probe succeeded'
                 });
+                results.push({ provider: entry.name, configured: true, model, inFallbackList, fallbackIndex: inFallbackList ? fallbackIndex : null, status: 'ok', message: 'Provider probe succeeded' });
             } catch (error: any) {
-                results.push({
+                results.push({ provider: entry.name, configured: true, model, inFallbackList, fallbackIndex: inFallbackList ? fallbackIndex : null, status: 'error', message: error?.message || 'Provider probe failed' });
-                    provider,
-                    configured: true,
-                    model,
-                    inFallbackList,
-                    fallbackIndex: inFallbackList ? fallbackIndex : null,
-                    status: 'error',
-                    message: error?.message || 'Provider probe failed'
-                });
             }
         }
 
         return results;
     }
 
-    private isProviderConfigured(provider: AIProvider): boolean {
+    private buildOrderedProviders(): ProviderEntry[] {
-        switch (provider) {
+        const fallbackList = config.AI.FALLBACK_LIST;
-            case 'openai':
+        return fallbackList
-                return !!config.AI.OPENAI_API_KEY;
+            .map(name => PROVIDER_REGISTRY.find(e => e.name === name))
-            case 'perplexity':
+            .filter((e): e is ProviderEntry => e !== undefined);
-                return !!config.AI.PERPLEXITY_API_KEY;
-            case 'gemini':
-                return !!config.AI.GEMINI_API_KEY;
-            default:
-                return false;
-        }
     }
-
+}
-    private resolveModel(provider: AIProvider): string {
-        switch (provider) {
-            case 'openai':
-                return config.AI.MODEL.includes('gpt') ? config.AI.MODEL : 'gpt-4o-mini';
-            case 'perplexity':
-                return config.AI.MODEL.includes('sonar') ? config.AI.MODEL : 'sonar';
-            case 'gemini':
-                return config.AI.MODEL.includes('gemini') ? config.AI.MODEL : 'gemini-1.5-flash';
-            default:
-                return config.AI.MODEL;
-        }
-    }
-
-    private async probeProvider(provider: AIProvider): Promise<void> {
-        const probePrompt = 'Return JSON: {"action":"HOLD","confidence":0,"reasoning":"probe"}';
-        let response: string | null = null;
-
-        switch (provider) {
-            case 'openai':
-                response = await this.callOpenAI(probePrompt);
-                break;
-            case 'perplexity':
-                response = await this.callPerplexity(probePrompt);
-                break;
-            case 'gemini':
-                response = await this.callGemini(probePrompt);
-                break;
-            default:
-                throw new Error(`Unsupported provider: ${provider}`);
-        }
-
-        if (!response || !String(response).trim()) {
-            throw new Error('Empty response from provider');
-        }
-    }
-
-    private async callOpenAI(prompt: string): Promise<string | null> {
-        const apiKey = config.AI.OPENAI_API_KEY;
-        if (!apiKey) return null;
-
-        const model = config.AI.MODEL.includes('gpt') ? config.AI.MODEL : 'gpt-4o-mini';
-
-        const response = await axios.post(
-            'https://api.openai.com/v1/chat/completions',
-            {
-                model: model,
-                messages: [
-                    { role: 'system', content: 'You are an expert crypto trading assistant. strictly output JSON.' },
-                    { role: 'user', content: prompt }
-                ],
-                temperature: 0.2
-            },
-            {
-                headers: {
-                    'Authorization': `Bearer ${apiKey}`,
-                    'Content-Type': 'application/json'
-                },
-                timeout: 10000
-            }
-        );
-        return response.data.choices[0].message.content;
-    }
-
-    private async callPerplexity(prompt: string): Promise<string | null> {
-        const apiKey = config.AI.PERPLEXITY_API_KEY;
-        if (!apiKey) return null;
-
-        const model = config.AI.MODEL.includes('sonar') ? config.AI.MODEL : 'sonar';
-
-        const response = await axios.post(
-            'https://api.perplexity.ai/chat/completions',
-            {
-                model: model,
-                messages: [
-                    { role: 'system', content: 'You are an expert crypto trading assistant. Strictly output JSON.' },
-                    { role: 'user', content: prompt }
-                ],
-                temperature: 0.2
-            },
-            {
-                headers: {
-                    'Authorization': `Bearer ${apiKey}`,
-                    'Content-Type': 'application/json'
-                },
-                timeout: 10000
-            }
-        );
-        return response.data.choices[0].message.content;
-    }
-
-    private async callGemini(prompt: string): Promise<string | null> {
-        const apiKey = config.AI.GEMINI_API_KEY;
-        if (!apiKey) return null;
-
-        const model = config.AI.MODEL.includes('gemini') ? config.AI.MODEL : 'gemini-1.5-flash';
-        const url = `https://generativelanguage.googleapis.com/v1beta/models/${model}:generateContent?key=${apiKey}`;
-
-        const response = await axios.post(url, {
-            contents: [{
-                parts: [{ text: `You are an expert crypto trading assistant. Strictly output JSON.\n\n${prompt}` }]
-            }]
-        }, { timeout: 10000 });
-
-        return response.data.candidates[0].content.parts[0].text;
-    }
-}

pnpm-lock.yaml

@@ -39,6 +39,9 @@ importers:
       '@bytelyst/cosmos':
         specifier: link:../../../learning_ai/learning_ai_common_plat/packages/cosmos
         version: link:../../../learning_ai/learning_ai_common_plat/packages/cosmos
+      '@bytelyst/llm':
+        specifier: link:../../../learning_ai/learning_ai_common_plat/packages/llm
+        version: link:../../../learning_ai/learning_ai_common_plat/packages/llm
       '@supabase/supabase-js':
         specifier: ^2.90.1
         version: 2.101.1
@@ -48,9 +51,6 @@ importers:
       '@types/express':
         specifier: ^5.0.6
         version: 5.0.6
-      axios:
-        specifier: ^1.13.2
-        version: 1.14.0
       ccxt:
         specifier: ^4.5.31
         version: 4.5.46
@@ -76,9 +76,6 @@ importers:
         specifier: ^3.19.0
         version: 3.19.0
     devDependencies:
-      '@types/axios':
-        specifier: ^0.14.4
-        version: 0.14.4
       '@types/node':
         specifier: ^25.0.3
         version: 25.5.2
@@ -2168,10 +2165,6 @@ packages:
   '@types/aria-query@5.0.4':
     resolution: {integrity: sha512-rfT93uj5s0PRL7EzccGMs3brplhcrghnDoV26NqKhCAS1hVo+WdNsPvE/yb6ilfr5hi2MEk6d5EWJTKdxg8jVw==}
 
-  '@types/axios@0.14.4':
-    resolution: {integrity: sha512-9JgOaunvQdsQ/qW2OPmE5+hCeUB52lQSolecrFrthct55QekhmXEwT203s20RL+UHtCQc15y3VXpby9E7Kkh/g==}
-    deprecated: This is a stub types definition. axios provides its own type definitions, so you do not need this installed.
-
   '@types/babel__core@7.20.5':
     resolution: {integrity: sha512-qoQprZvz5wQFJwMDqeseRXWv3rqMvhgpbXFfVyWhbx9X47POIA6i/+dXefEmZKoAgOaTdaIgNSMqMIU61yRyzA==}
 
@@ -2684,9 +2677,6 @@ packages:
   async@3.2.6:
     resolution: {integrity: sha512-htCUDlxyyCLMgaM3xXg0C0LW2xqfuQ6p05pCEIsXuyQ+a1koYKTuBMzRNwmybfLgvJDMd0r1LTn4+E0Ti6C2AA==}
 
-  asynckit@0.4.0:
-    resolution: {integrity: sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==}
-
   autoprefixer@10.4.27:
     resolution: {integrity: sha512-NP9APE+tO+LuJGn7/9+cohklunJsXWiaWEfV3si4Gi/XHDwVNgkwr1J3RQYFIvPy76GmJ9/bW8vyoU1LcxwKHA==}
     engines: {node: ^10 || ^12 || >=14}
@@ -2701,9 +2691,6 @@ packages:
   axios@0.21.4:
     resolution: {integrity: sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==}
 
-  axios@1.14.0:
-    resolution: {integrity: sha512-3Y8yrqLSwjuzpXuZ0oIYZ/XGgLwUIBU3uLvbcpb0pidD9ctpShJd43KSlEEkVQg6DS0G9NKyzOvBfUtDKEyHvQ==}
-
   babel-jest@29.7.0:
     resolution: {integrity: sha512-BrvGY3xZSwEcCzKvKsCi2GgHqDqsYkOP4/by5xCgIwGXQxIEh+8ew3gmrE1y7XRR6LHZIj6yLYnUi/mm2KXKBg==}
     engines: {node: ^14.15.0 || ^16.10.0 || >=18.0.0}
@@ -2988,10 +2975,6 @@ packages:
     resolution: {integrity: sha512-ezmVcLR3xAVp8kYOm4GS45ZLLgIE6SPAFoduLr6hTDajwb3KZ2F46gulK3XpcwRFb5KKGCSezCBAY4Dw4HsyXA==}
     engines: {node: '>=18'}
 
-  combined-stream@1.0.8:
-    resolution: {integrity: sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==}
-    engines: {node: '>= 0.8'}
-
   commander@12.1.0:
     resolution: {integrity: sha512-Vw8qHK3bZM9y/P10u3Vib8o/DdkvA2OtPtZvD871QKjy74Wj1WSKFILMPRPSdUSx5RFK1arlJzEtA4PkFgnbuA==}
     engines: {node: '>=18'}
@@ -3207,10 +3190,6 @@ packages:
     resolution: {integrity: sha512-8QmQKqEASLd5nx0U1B1okLElbUuuttJ/AnYmRXbbbGDWh6uS208EjD4Xqq/I9wK7u0v6O08XhTWnt5XtEbR6Dg==}
     engines: {node: '>= 0.4'}
 
-  delayed-stream@1.0.0:
-    resolution: {integrity: sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==}
-    engines: {node: '>=0.4.0'}
-
   depd@2.0.0:
     resolution: {integrity: sha512-g7nH6P6dyDioJogAAGprGpCtVImJhpPk/roCzdb3fIh61/s/nPsfR6onyMwkCAR/OlC3yBC0lESvUoQEAssIrw==}
     engines: {node: '>= 0.8'}
@@ -3850,10 +3829,6 @@ packages:
     resolution: {integrity: sha512-gIXjKqtFuWEgzFRJA9WCQeSJLZDjgJUOMCMzxtvFq/37KojM1BFGufqsCy0r4qSQmYLsZYMeyRqzIWOMup03sw==}
     engines: {node: '>=14'}
 
-  form-data@4.0.5:
-    resolution: {integrity: sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w==}
-    engines: {node: '>= 6'}
-
   forwarded@0.2.0:
     resolution: {integrity: sha512-buRG0fpBtRHSTCOASe6hD258tEubFoRLb4ZNA6NxMVHNw2gOcwHo9wyablzMzOA5z9xA9L1KNjk/Nt6MT9aYow==}
     engines: {node: '>= 0.6'}
@@ -5105,10 +5080,6 @@ packages:
     resolution: {integrity: sha512-llQsMLSUDUPT44jdrU/O37qlnifitDP+ZwrmmZcoSKyLKvtZxpyV0n2/bD/N4tBAAZ/gJEdZU7KMraoK1+XYAg==}
     engines: {node: '>= 0.10'}
 
-  proxy-from-env@2.1.0:
-    resolution: {integrity: sha512-cJ+oHTW1VAEa8cJslgmUZrc+sjRKgAKl3Zyse6+PV38hZe/V6Z14TbCuXcan9F9ghlz4QrFr2c92TNF82UkYHA==}
-    engines: {node: '>=10'}
-
   punycode@2.3.1:
     resolution: {integrity: sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==}
     engines: {node: '>=6'}
@@ -8596,12 +8567,6 @@ snapshots:
 
   '@types/aria-query@5.0.4': {}
 
-  '@types/axios@0.14.4':
-    dependencies:
-      axios: 1.14.0
-    transitivePeerDependencies:
-      - debug
-
   '@types/babel__core@7.20.5':
     dependencies:
       '@babel/parser': 7.29.2
@@ -9171,8 +9136,6 @@ snapshots:
 
   async@3.2.6: {}
 
-  asynckit@0.4.0: {}
-
   autoprefixer@10.4.27(postcss@8.5.8):
     dependencies:
       browserslist: 4.28.2
@@ -9192,14 +9155,6 @@ snapshots:
     transitivePeerDependencies:
       - debug
 
-  axios@1.14.0:
-    dependencies:
-      follow-redirects: 1.15.11
-      form-data: 4.0.5
-      proxy-from-env: 2.1.0
-    transitivePeerDependencies:
-      - debug
-
   babel-jest@29.7.0(@babel/core@7.29.0):
     dependencies:
       '@babel/core': 7.29.0
@@ -9565,10 +9520,6 @@ snapshots:
       color-convert: 3.1.3
       color-string: 2.1.4
 
-  combined-stream@1.0.8:
-    dependencies:
-      delayed-stream: 1.0.0
-
   commander@12.1.0: {}
 
   commander@2.20.3: {}
@@ -9777,8 +9728,6 @@ snapshots:
       has-property-descriptors: 1.0.2
       object-keys: 1.1.1
 
-  delayed-stream@1.0.0: {}
-
   depd@2.0.0: {}
 
   dequal@2.0.3: {}
@@ -10667,14 +10616,6 @@ snapshots:
       cross-spawn: 7.0.6
       signal-exit: 4.1.0
 
-  form-data@4.0.5:
-    dependencies:
-      asynckit: 0.4.0
-      combined-stream: 1.0.8
-      es-set-tostringtag: 2.1.0
-      hasown: 2.0.2
-      mime-types: 2.1.35
-
   forwarded@0.2.0: {}
 
   fraction.js@5.3.4: {}
@@ -12135,8 +12076,6 @@ snapshots:
       forwarded: 0.2.0
       ipaddr.js: 1.9.1
 
-  proxy-from-env@2.1.0: {}
-
   punycode@2.3.1: {}
 
   qrcode-terminal@0.11.0: {}