feat: add multi-provider AI support (Groq, OpenAI, Anthropic, Google)

apps/chat/.env.example

@@ -41,16 +41,21 @@ CALCOM_WEBHOOK_SECRET=your-calcom-webhook-secret
 CALCOM_APP_URL=https://app.cal.com
 
 # ─── AI / LLM ────────────────────────────────────────────────────────────────
-# Groq (fast inference). Get your key at console.groq.com
+# Which AI provider to use. Options: groq | openai | anthropic | google
+AI_PROVIDER=groq
+
+# Model to use (optional). Each provider has a sensible default:
+#   groq:      llama-3.3-70b-versatile
+#   openai:    gpt-4o-mini
+#   anthropic: claude-haiku-4-5
+#   google:    gemini-2.0-flash
+# AI_MODEL=
+
+# Provider API keys — only the key for your chosen AI_PROVIDER is required.
 GROQ_API_KEY=your-groq-api-key
-# Model to use (optional). Default: openai/gpt-oss-120b
-# AI_MODEL=openai/gpt-oss-120b
-#
-# If you hit rate limits (TPD), try another Groq model with a separate quota:
-# AI_MODEL=llama-3.3-70b-versatile
-# AI_MODEL=llama-3.1-8b-instant
-#
-# To switch providers entirely, edit lib/ai-provider.ts (Anthropic, OpenAI, etc.)
+# OPENAI_API_KEY=your-openai-api-key
+# ANTHROPIC_API_KEY=your-anthropic-api-key
+# GOOGLE_GENERATIVE_AI_API_KEY=your-google-api-key
 
 # ─── App ──────────────────────────────────────────────────────────────────────
 # Your deployed app URL (used for OAuth redirect URI and install page CTA)

apps/chat/README.md

@@ -33,7 +33,7 @@ app/
 lib/
   bot.ts                           # Chat instance + all event handlers
   agent.ts                         # AI agent tools (bookings, availability, etc.)
-  ai-provider.ts                   # AI provider config (Groq by default; swap to OpenAI, Anthropic, etc.)
+  ai-provider.ts                   # AI provider config (Groq, OpenAI, Anthropic, Google — set via AI_PROVIDER env var)
   notifications.ts                 # Booking notification card builders
   user-linking.ts                  # Redis: platform user <-> Cal.com account linking + token refresh
   format-for-telegram.ts           # Converts markdown/cards to Telegram-safe HTML
@@ -106,8 +106,12 @@ cp .env.example .env
 | `CALCOM_WEBHOOK_SECRET`       | ✅       | Set in Cal.com → Settings → Webhooks                                        |
 | `CALCOM_APP_URL`              | ✅       | `https://app.cal.com`                                                       |
 | `NEXT_PUBLIC_APP_URL`         | ✅       | Your deployed app URL (used for OAuth redirects and install page)           |
-| `GROQ_API_KEY`                | ✅       | From [console.groq.com](https://console.groq.com) — required for AI features |
-| `AI_MODEL`                    | —        | Override the default Groq model (e.g. `llama-3.3-70b-versatile`)           |
+| `AI_PROVIDER`                 | —        | AI provider: `groq` \| `openai` \| `anthropic` \| `google` (default: `groq`) |
+| `AI_MODEL`                    | —        | Override the default model for the selected provider                        |
+| `GROQ_API_KEY`                | ✅*      | Required when `AI_PROVIDER=groq` (default). From [console.groq.com](https://console.groq.com) |
+| `OPENAI_API_KEY`              | ✅*      | Required when `AI_PROVIDER=openai`                                         |
+| `ANTHROPIC_API_KEY`           | ✅*      | Required when `AI_PROVIDER=anthropic`                                      |
+| `GOOGLE_GENERATIVE_AI_API_KEY`| ✅*      | Required when `AI_PROVIDER=google`                                         |
 | `TELEGRAM_BOT_TOKEN`          | —        | From [@BotFather](https://t.me/BotFather) — required to enable Telegram     |
 | `TELEGRAM_BOT_USERNAME`       | —        | Your bot's username (e.g. `CalcomBot`) — required when `TELEGRAM_BOT_TOKEN` is set |
 | `TELEGRAM_WEBHOOK_SECRET_TOKEN` | —      | Optional secret to verify incoming Telegram webhook requests                |

apps/chat/lib/agent.ts

@@ -1997,35 +1997,36 @@ export function isAIToolCallError(err: unknown): boolean {
   const msg = err.message.toLowerCase();
   const cause = err.cause as Error | undefined;
   const causeMsg = cause?.message?.toLowerCase() ?? "";
+  const combined = `${msg} ${causeMsg}`;
   return (
-    msg.includes("failed to call a function") ||
-    msg.includes("failed_generation") ||
-    msg.includes("invalid_request_error") ||
-    msg.includes("tool call validation failed") ||
-    msg.includes("which was not in request.tools") ||
-    msg.includes("tool choice is none") ||
-    causeMsg.includes("failed to call a function") ||
-    causeMsg.includes("failed_generation") ||
-    causeMsg.includes("tool call validation failed") ||
-    causeMsg.includes("tool choice is none")
+    combined.includes("failed to call a function") ||
+    combined.includes("failed_generation") ||
+    combined.includes("invalid_request_error") ||
+    combined.includes("tool call validation failed") ||
+    combined.includes("which was not in request.tools") ||
+    combined.includes("tool choice is none") ||
+    combined.includes("tool_use_failed") ||
+    combined.includes("invalid_tool_call")
   );
 }
 
-/** True if the error is an AI/LLM rate limit (e.g. Groq tokens-per-day). */
+/** True if the error is an AI/LLM rate limit (e.g. tokens-per-day, quota exceeded). */
 export function isAIRateLimitError(err: unknown): boolean {
   if (!(err instanceof Error)) return false;
   const msg = err.message.toLowerCase();
   const cause = err.cause as Error | undefined;
   const causeMsg = cause?.message?.toLowerCase() ?? "";
+  const combined = `${msg} ${causeMsg}`;
   const hasRateLimit =
-    msg.includes("rate limit") ||
-    msg.includes("tokens per day") ||
-    causeMsg.includes("rate limit") ||
-    causeMsg.includes("tokens per day");
+    combined.includes("rate limit") ||
+    combined.includes("tokens per day") ||
+    combined.includes("quota_exceeded") ||
+    combined.includes("resource_exhausted") ||
+    combined.includes("insufficient_quota");
   const status429 =
     (err as { statusCode?: number }).statusCode === 429 ||
     (cause as { statusCode?: number } | undefined)?.statusCode === 429;
-  return hasRateLimit || (status429 && (msg.includes("retry") || causeMsg.includes("retry")));
+  return hasRateLimit || (status429 && (combined.includes("retry") || combined.includes("quota") || combined.includes("limit") || combined.includes("exhausted")));
 }
 
 // ─── Agent stream ─────────────────────────────────────────────────────────────

apps/chat/lib/ai-provider.ts

@@ -1,38 +1,59 @@
 /**
  * AI model provider configuration.
  *
- * To switch providers, change the import and the `getModel()` call below.
- * The rest of the codebase only imports `getModel()` from this file.
- *
- * Examples:
- *
- *   Groq (default — fast + cheap):
- *     import { createGroq } from "@ai-sdk/groq";
- *     const groq = createGroq({ apiKey: process.env.GROQ_API_KEY });
- *     return groq("llama-3.3-70b-versatile");
- *
- *   Anthropic:
- *     import { anthropic } from "@ai-sdk/anthropic";
- *     return anthropic("claude-sonnet-4-20250514");
- *
- *   OpenAI:
- *     import { openai } from "@ai-sdk/openai";
- *     return openai("gpt-4o");
+ * Controlled by two env vars:
+ *   - AI_PROVIDER: which service to use (groq | openai | anthropic | google). Default: groq
+ *   - AI_MODEL:    optional model override (each provider has a sensible default)
  *
- *   Any OpenAI-compatible provider (Together, Fireworks, etc.):
- *     import { createOpenAI } from "@ai-sdk/openai";
- *     const provider = createOpenAI({ baseURL: "https://api.together.xyz/v1", apiKey: "..." });
- *     return provider("meta-llama/Llama-3.3-70B-Instruct-Turbo");
+ * The rest of the codebase only imports `getModel()` from this file.
  */
 
+import { createAnthropic } from "@ai-sdk/anthropic";
+import { createGoogleGenerativeAI } from "@ai-sdk/google";
 import { createGroq } from "@ai-sdk/groq";
+import { createOpenAI } from "@ai-sdk/openai";
 import type { LanguageModel } from "ai";
 
-const groq = createGroq({
-  apiKey: process.env.GROQ_API_KEY,
-});
+export type AIProvider = "groq" | "openai" | "anthropic" | "google";
+
+export const PROVIDER_CONFIG: Record<AIProvider, { defaultModel: string; apiKeyEnv: string }> = {
+  groq: {
+    defaultModel: "openai/gpt-oss-120b",
+    apiKeyEnv: "GROQ_API_KEY",
+  },
+  openai: { defaultModel: "gpt-4o-mini", apiKeyEnv: "OPENAI_API_KEY" },
+  anthropic: {
+    defaultModel: "claude-haiku-4-5",
+    apiKeyEnv: "ANTHROPIC_API_KEY",
+  },
+  google: {
+    defaultModel: "gemini-2.0-flash",
+    apiKeyEnv: "GOOGLE_GENERATIVE_AI_API_KEY",
+  },
+};
+
+export const SUPPORTED_PROVIDERS = Object.keys(PROVIDER_CONFIG) as AIProvider[];
 
 export function getModel(): LanguageModel {
-  // Model is configurable via AI_MODEL env var. See .env.example for alternatives.
-  return groq(process.env.AI_MODEL ?? "openai/gpt-oss-120b");
+  const provider = (process.env.AI_PROVIDER ?? "groq") as AIProvider;
+  const config = PROVIDER_CONFIG[provider];
+  if (!config) {
+    throw new Error(
+      `Unsupported AI_PROVIDER: "${provider}". Use one of: ${SUPPORTED_PROVIDERS.join(", ")}`
+    );
+  }
+
+  const model = process.env.AI_MODEL ?? config.defaultModel;
+  const apiKey = process.env[config.apiKeyEnv];
+
+  switch (provider) {
+    case "groq":
+      return createGroq({ apiKey })(model);
+    case "openai":
+      return createOpenAI({ apiKey })(model);
+    case "anthropic":
+      return createAnthropic({ apiKey })(model);
+    case "google":
+      return createGoogleGenerativeAI({ apiKey })(model);
+  }
 }

apps/chat/lib/env.ts

@@ -2,6 +2,9 @@
  * Validates required environment variables for the chat bot.
  * Call at startup to fail fast if critical config is missing.
  */
+
+import { type AIProvider, PROVIDER_CONFIG, SUPPORTED_PROVIDERS } from "./ai-provider";
+
 export function validateRequiredEnv(): void {
   const missing: string[] = [];
 
@@ -14,6 +17,20 @@ export function validateRequiredEnv(): void {
     missing.push("TELEGRAM_BOT_USERNAME (required when TELEGRAM_BOT_TOKEN is set)");
   }
 
+  // Validate AI_PROVIDER value
+  const provider = (process.env.AI_PROVIDER ?? "groq") as string;
+  if (!SUPPORTED_PROVIDERS.includes(provider as AIProvider)) {
+    throw new Error(
+      `Invalid AI_PROVIDER: "${provider}". Must be one of: ${SUPPORTED_PROVIDERS.join(", ")}`
+    );
+  }
+
+  // Validate that the selected provider's API key is present
+  const config = PROVIDER_CONFIG[provider as AIProvider];
+  if (config && !process.env[config.apiKeyEnv]) {
+    missing.push(`${config.apiKeyEnv} (required for AI_PROVIDER=${provider})`);
+  }
+
   if (process.env.NODE_ENV === "production" && !process.env.REDIS_URL) {
     throw new Error(
       "REDIS_URL is required in production. The in-memory state adapter is not suitable for production (state is lost on restart, locks don't work across instances)."

apps/chat/package.json

@@ -15,6 +15,8 @@
     "deploy": "npx vercel --prod --yes"
   },
   "dependencies": {
+    "@ai-sdk/anthropic": "^3.0.58",
+    "@ai-sdk/google": "^3.0.43",
     "@ai-sdk/groq": "3.0.29",
     "@ai-sdk/openai": "3.0.41",
     "@chat-adapter/shared": "4.19.0",