feat(ai): add SmartRouter for unified multi-provider LLM routing

JS/edgechains/arakoodev/src/ai/src/index.ts

@@ -3,3 +3,5 @@ export { GeminiAI } from "./lib/gemini/gemini.js";
 export { LlamaAI } from "./lib/llama/llama.js";
 export { RetellAI } from "./lib/retell-ai/retell.js";
 export { RetellWebClient } from "./lib/retell-ai/retellWebClient.js";
+export { SmartRouter } from "./lib/smart-router/smartRouter.js";
+export type { SmartRouterChatResult } from "./lib/smart-router/smartRouter.js";

JS/edgechains/arakoodev/src/ai/src/lib/smart-router/smartRouter.ts

@@ -0,0 +1,277 @@
+import axios from "axios";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+type ProviderName = "openai" | "gemini" | "llama" | "cohere";
+
+interface MessageOption {
+    role: "user" | "assistant" | "system";
+    content: string;
+}
+
+interface SmartRouterOptions {
+    openaiApiKey?: string;
+    geminiApiKey?: string;
+    llamaApiKey?: string;
+    cohereApiKey?: string;
+    /** Override routing priority. Defaults to openai → gemini → llama → cohere */
+    fallbackChain?: ProviderName[];
+}
+
+interface SmartRouterChatOptions {
+    model: string;
+    prompt?: string;
+    messages?: MessageOption[];
+    max_tokens?: number;
+    temperature?: number;
+    stream?: boolean;
+}
+
+export interface SmartRouterChatResult {
+    content: string;
+    provider: ProviderName;
+    model: string;
+    usage?: {
+        prompt_tokens: number;
+        completion_tokens: number;
+        total_tokens: number;
+    };
+}
+
+// ---------------------------------------------------------------------------
+// Provider detection
+// ---------------------------------------------------------------------------
+
+const PROVIDER_PATTERNS: Record<ProviderName, RegExp> = {
+    openai: /^(gpt-|o1-|o3-|chatgpt-|text-embedding-|dall-e-)/i,
+    gemini: /^(gemini-|palm-|bison-)/i,
+    llama: /^(llama-|meta-llama\/|mixtral-|mistral-|qwen-|deepseek-)/i,
+    cohere: /^(command-|cohere-)/i,
+};
+
+function detectProvider(model: string): ProviderName | null {
+    for (const [provider, pattern] of Object.entries(PROVIDER_PATTERNS) as [ProviderName, RegExp][]) {
+        if (pattern.test(model)) return provider;
+    }
+    return null;
+}
+
+// ---------------------------------------------------------------------------
+// Per-provider chat implementations
+// ---------------------------------------------------------------------------
+
+async function chatOpenAI(
+    model: string,
+    messages: MessageOption[],
+    options: SmartRouterChatOptions,
+    apiKey: string
+): Promise<SmartRouterChatResult> {
+    const response = await axios.post(
+        "https://api.openai.com/v1/chat/completions",
+        {
+            model,
+            messages,
+            max_tokens: options.max_tokens ?? 256,
+            temperature: options.temperature ?? 0.7,
+            stream: false,
+        },
+        { headers: { Authorization: `Bearer ${apiKey}`, "content-type": "application/json" } }
+    );
+    const choice = response.data.choices[0];
+    return {
+        content: choice.message.content,
+        provider: "openai",
+        model,
+        usage: response.data.usage
+            ? {
+                  prompt_tokens: response.data.usage.prompt_tokens,
+                  completion_tokens: response.data.usage.completion_tokens,
+                  total_tokens: response.data.usage.total_tokens,
+              }
+            : undefined,
+    };
+}
+
+async function chatGemini(
+    model: string,
+    messages: MessageOption[],
+    options: SmartRouterChatOptions,
+    apiKey: string
+): Promise<SmartRouterChatResult> {
+    const geminiModel = model.startsWith("gemini-") ? model : "gemini-pro";
+    const url = `https://generativelanguage.googleapis.com/v1/models/${geminiModel}:generateContent?key=${apiKey}`;
+    const contents = messages.map((m) => ({ role: m.role === "assistant" ? "model" : "user", parts: [{ text: m.content }] }));
+    const response = await axios.post(
+        url,
+        { contents, generationConfig: { maxOutputTokens: options.max_tokens ?? 256, temperature: options.temperature ?? 0.7 } },
+        { headers: { "content-type": "application/json" } }
+    );
+    const candidate = response.data.candidates[0];
+    const usage = response.data.usageMetadata;
+    return {
+        content: candidate.content.parts[0].text,
+        provider: "gemini",
+        model: geminiModel,
+        usage: usage
+            ? {
+                  prompt_tokens: usage.promptTokenCount ?? 0,
+                  completion_tokens: usage.candidatesTokenCount ?? 0,
+                  total_tokens: usage.totalTokenCount ?? 0,
+              }
+            : undefined,
+    };
+}
+
+async function chatLlama(
+    model: string,
+    messages: MessageOption[],
+    options: SmartRouterChatOptions,
+    apiKey: string
+): Promise<SmartRouterChatResult> {
+    const response = await axios.post(
+        "https://api.llama-api.com/chat/completions",
+        {
+            model: model || "llama-13b-chat",
+            messages,
+            max_tokens: options.max_tokens ?? 256,
+            temperature: options.temperature ?? 0.7,
+        },
+        { headers: { Authorization: `Bearer ${apiKey}`, "content-type": "application/json" } }
+    );
+    const choice = response.data.choices[0];
+    return {
+        content: choice.message.content,
+        provider: "llama",
+        model,
+        usage: response.data.usage
+            ? {
+                  prompt_tokens: response.data.usage.prompt_tokens,
+                  completion_tokens: response.data.usage.completion_tokens,
+                  total_tokens: response.data.usage.total_tokens,
+              }
+            : undefined,
+    };
+}
+
+async function chatCohere(
+    model: string,
+    messages: MessageOption[],
+    options: SmartRouterChatOptions,
+    apiKey: string
+): Promise<SmartRouterChatResult> {
+    const lastUser = [...messages].reverse().find((m) => m.role === "user");
+    const chatHistory = messages
+        .slice(0, -1)
+        .filter((m) => m.role !== "system")
+        .map((m) => ({ role: m.role === "assistant" ? "CHATBOT" : "USER", message: m.content }));
+
+    const response = await axios.post(
+        "https://api.cohere.ai/v1/chat",
+        {
+            model: model || "command-r",
+            message: lastUser?.content ?? "",
+            chat_history: chatHistory,
+            max_tokens: options.max_tokens ?? 256,
+            temperature: options.temperature ?? 0.7,
+        },
+        { headers: { Authorization: `Bearer ${apiKey}`, "content-type": "application/json" } }
+    );
+    const meta = response.data.meta?.tokens;
+    return {
+        content: response.data.text,
+        provider: "cohere",
+        model: model || "command-r",
+        usage: meta
+            ? {
+                  prompt_tokens: meta.input_tokens ?? 0,
+                  completion_tokens: meta.output_tokens ?? 0,
+                  total_tokens: (meta.input_tokens ?? 0) + (meta.output_tokens ?? 0),
+              }
+            : undefined,
+    };
+}
+
+// ---------------------------------------------------------------------------
+// SmartRouter
+// ---------------------------------------------------------------------------
+
+export class SmartRouter {
+    private keys: Record<ProviderName, string>;
+    private fallbackChain: ProviderName[];
+
+    constructor(options: SmartRouterOptions = {}) {
+        this.keys = {
+            openai: options.openaiApiKey ?? process.env.OPENAI_API_KEY ?? "",
+            gemini: options.geminiApiKey ?? process.env.GEMINI_API_KEY ?? "",
+            llama: options.llamaApiKey ?? process.env.LLAMA_API_KEY ?? "",
+            cohere: options.cohereApiKey ?? process.env.COHERE_API_KEY ?? "",
+        };
+        this.fallbackChain = options.fallbackChain ?? ["openai", "gemini", "llama", "cohere"];
+    }
+
+    detectProvider(model: string): ProviderName | null {
+        return detectProvider(model);
+    }
+
+    isModelSupported(model: string): boolean {
+        return detectProvider(model) !== null;
+    }
+
+    listProviders(): ProviderName[] {
+        return ["openai", "gemini", "llama", "cohere"];
+    }
+
+    private buildMessages(options: SmartRouterChatOptions): MessageOption[] {
+        if (options.messages) return options.messages;
+        if (options.prompt) return [{ role: "user", content: options.prompt }];
+        throw new Error("SmartRouter.chat requires either `prompt` or `messages`");
+    }
+
+    private async callProvider(
+        provider: ProviderName,
+        model: string,
+        messages: MessageOption[],
+        options: SmartRouterChatOptions
+    ): Promise<SmartRouterChatResult> {
+        const key = this.keys[provider];
+        if (!key) throw new Error(`No API key configured for provider: ${provider}`);
+
+        switch (provider) {
+            case "openai":
+                return chatOpenAI(model, messages, options, key);
+            case "gemini":
+                return chatGemini(model, messages, options, key);
+            case "llama":
+                return chatLlama(model, messages, options, key);
+            case "cohere":
+                return chatCohere(model, messages, options, key);
+        }
+    }
+
+    async chat(options: SmartRouterChatOptions): Promise<SmartRouterChatResult> {
+        const messages = this.buildMessages(options);
+        const primary = detectProvider(options.model);
+
+        // Build attempt list: primary provider first, then fallback chain order
+        const order: ProviderName[] = primary
+            ? [primary, ...this.fallbackChain.filter((p) => p !== primary)]
+            : [...this.fallbackChain];
+
+        const errors: string[] = [];
+        for (const provider of order) {
+            if (!this.keys[provider]) continue;
+            try {
+                return await this.callProvider(provider, options.model, messages, options);
+            } catch (err: any) {
+                const msg = err?.response?.data?.error?.message ?? err?.message ?? String(err);
+                errors.push(`${provider}: ${msg}`);
+            }
+        }
+
+        throw new Error(
+            `SmartRouter: all providers failed.\n${errors.join("\n")}`
+        );
+    }
+}