Classic Chat UI & Offline Demo Mode

src/config/load.ts

@@ -96,10 +96,11 @@ export function isConfigured(): boolean {
     process.env.NIM_API_KEY ||
     process.env.OPENAI_API_KEY ||
     process.env.ANTHROPIC_API_KEY ||
-    process.env.ARROWCODE_API_KEY;
+    process.env.ARROWCODE_API_KEY ||
+    process.env.DEMO_API_KEY;
   if (key) return true;
 
-  if (process.env.ARROWCODE_PROVIDER === "ollama") return true;
+  if (process.env.ARROWCODE_PROVIDER === "ollama" || process.env.ARROWCODE_PROVIDER === "demo" || process.env.ARROWCODE_PROVIDER === "mock") return true;
 
   for (const p of ["ORCH", "FE", "BE", "QA"]) {
     if (process.env[`ARROW_${p}_API_KEY`]) return true;
@@ -108,7 +109,7 @@ export function isConfigured(): boolean {
   if (existsSync(CONFIG_PATH)) {
     try {
       const c = parseYaml(readFileSync(CONFIG_PATH, "utf8")) as Partial<ArrowConfig>;
-      if (c.provider === "ollama" || c.apiKey) return true;
+      if (c.provider === "ollama" || c.provider === "demo" || c.provider === "mock" || c.apiKey) return true;
     } catch {
       /* */
     }
@@ -122,6 +123,13 @@ function providerDefaults(provider: ProviderId): {
   envKey: string;
 } {
   switch (provider) {
+    case "demo":
+    case "mock":
+      return {
+        baseUrl: "demo",
+        model: "demo-v1",
+        envKey: "DEMO_API_KEY",
+      };
     case "nim":
       return {
         baseUrl: DEFAULT_NIM_BASE,
@@ -314,7 +322,7 @@ export function loadConfig(overrides: Partial<ArrowConfig> = {}): ArrowConfig {
     process.env.OPENAI_API_KEY ||
     process.env.ANTHROPIC_API_KEY ||
     file.apiKey ||
-    (provider === "ollama" ? "ollama" : "");
+    (provider === "ollama" ? "ollama" : (provider === "demo" || provider === "mock" ? "demo" : ""));
 
   const baseUrl =
     overrides.baseUrl ||

src/config/types.ts

@@ -1,6 +1,6 @@
 /** Shared types for ArrowCode — swarm multi-agent coding harness. */
 
-export type ProviderId = "nim" | "openai" | "anthropic" | "ollama" | "groq" | "deepseek" | "gemini" | "openrouter" | "custom";
+export type ProviderId = "nim" | "openai" | "anthropic" | "ollama" | "groq" | "deepseek" | "gemini" | "openrouter" | "custom" | "demo" | "mock";
 
 export type AgentId = "orchestrator" | "frontend" | "backend" | "tester";
 

src/index.ts

@@ -138,14 +138,46 @@ async function main() {
   if (!isConfigured()) {
     printBanner({ compact: true });
     console.log("ArrowCode is not configured yet.\n");
-    console.log(
-      "This will create ~/.arrowcode from packaged defaults/ and ask for an API key.\n",
-    );
+    console.log("Welcome to ArrowCode! Since you don't have an API key configured yet,");
+    console.log("you can choose one of the following options to get started immediately:");
+    console.log("  1) Use Mock / Demo mode (free, runs locally, no keys needed)");
+    console.log("  2) Configure a real LLM provider (NVIDIA NIM, OpenAI, Anthropic, etc.)");
+    console.log("");
+    const readline = await import("node:readline");
+    const rl = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout,
+    });
+    const choice = await new Promise<string>((res) => {
+      rl.question("Choose [1-2] (default 1): ", (ans) => res((ans || "").trim()));
+    });
+    rl.close();
+
     bootstrapUserHome();
-    const ok = await runSetupWizard();
-    if (!ok) process.exit(1);
-    if (!isConfigured()) {
-      process.exit(0);
+
+    if (choice === "2") {
+      const ok = await runSetupWizard();
+      if (!ok) process.exit(1);
+      if (!isConfigured()) {
+        process.exit(0);
+      }
+    } else {
+      // Setup demo/mock mode
+      const { saveEnv, saveConfig } = await import("./config/load");
+      saveEnv({
+        ARROWCODE_PROVIDER: "demo",
+        ARROWCODE_MODEL: "demo-v1",
+        ARROWCODE_BASE_URL: "demo",
+        DEMO_API_KEY: "demo",
+      });
+      saveConfig({
+        provider: "demo",
+        model: "demo-v1",
+        baseUrl: "demo",
+        apiKey: "demo",
+      });
+      console.log("\nDemo Mode configured! Starting ArrowCode...\n");
+      await new Promise((resolve) => setTimeout(resolve, 1000));
     }
   }
 

src/llm/client.ts

@@ -36,14 +36,14 @@ export class LLMClient {
     this.endpoint = endpoint;
     this.model = endpoint.model;
     this.provider = endpoint.provider;
-    if (!endpoint.apiKey && endpoint.provider !== "ollama") {
+    if (!endpoint.apiKey && endpoint.provider !== "ollama" && endpoint.provider !== "demo" && endpoint.provider !== "mock") {
       throw new LLMError(
         "No API key for this agent. Set global key or ARROW_<AGENT>_API_KEY / agents.yaml",
       );
     }
     this.client = new OpenAI({
       apiKey: endpoint.apiKey || "ollama",
-      baseURL: endpoint.baseUrl,
+      baseURL: endpoint.provider === "demo" || endpoint.provider === "mock" ? "http://demo-url" : endpoint.baseUrl,
       timeout: 120_000,
       maxRetries: 0,
     });
@@ -54,6 +54,58 @@ export class LLMClient {
     tools?: OpenAITool[],
     opts?: { onToken?: (t: string) => void; stream?: boolean },
   ): Promise<LLMResponse> {
+    if (this.provider === "demo" || this.provider === "mock") {
+      // Mock LLM response generator for instant works/tryout!
+      const userMessage = messages[messages.length - 1]?.content || "";
+      let replyContent = "Let's explore the workspace and carry out your request.";
+      const toolCalls: ToolCall[] = [];
+
+      // Determine the kind of reply based on the message content
+      const lower = typeof userMessage === "string" ? userMessage.toLowerCase() : "";
+      if (lower.includes("[mode=plan]") || lower.includes("plan")) {
+        replyContent = `\`\`\`arrow-plan
+title: Demo Implementation Plan
+summary: A mockup flow to demonstrate clean and fast execution.
+steps:
+  1. Explore local directories and files.
+  2. Setup frontend core elements.
+  3. Validate using offline tests.
+risks:
+  - Mock mode doesn't execute actual remote files.
+acceptance:
+  - UI works fine.
+  - Tests pass with green indicators.
+agents:
+  frontend: Core UI setup
+  backend: API endpoints mocking
+  tester: Verify everything
+\`\`\``;
+      } else if (lower.includes("[execute]") || lower.includes("execute") || lower.includes("confirm")) {
+        replyContent = `\`\`\`arrow-ready
+Verification: Verified that all mock procedures ran fine and the application is highly optimized.
+All tests are passing.
+\`\`\``;
+      } else if (lower.includes("health") || lower.includes("status")) {
+        replyContent = "Everything is functioning correctly under the demo environment.";
+      }
+
+      if (opts?.onToken) {
+        // simulate streaming
+        const parts = replyContent.split(" ");
+        for (const p of parts) {
+          opts.onToken(p + " ");
+          await Bun.sleep(5);
+        }
+      }
+
+      return {
+        content: replyContent,
+        toolCalls,
+        finishReason: "stop",
+        usage: { prompt_tokens: messages.length * 10, completion_tokens: replyContent.length / 4 }
+      };
+    }
+
     const stream = Boolean(opts?.stream && opts.onToken);
     const body: OpenAI.Chat.ChatCompletionCreateParams = {
       model: this.model,