feat: add v0.1 runtime skeleton

src/selftest/fake-codex-app-server.ts

@@ -0,0 +1,48 @@
+import * as readline from "node:readline";
+
+const rl = readline.createInterface({ input: process.stdin, crlfDelay: Infinity });
+let threadCounter = 0;
+let turnCounter = 0;
+
+for await (const line of rl) {
+  const trimmed = String(line).trim();
+  if (trimmed.length === 0) continue;
+  const message = JSON.parse(trimmed) as { id?: number; method?: string; params?: Record<string, unknown> };
+  if (message.method === "initialize") {
+    respond(message.id, { serverInfo: { name: "fake-codex-app-server", version: "self-test" } });
+    continue;
+  }
+  if (message.method === "thread/start") {
+    threadCounter += 1;
+    const thread = { id: `thread_selftest_${threadCounter}` };
+    notify("thread/started", { thread });
+    respond(message.id, { thread });
+    continue;
+  }
+  if (message.method === "thread/resume") {
+    const thread = { id: String(message.params?.threadId ?? "thread_selftest_resumed") };
+    notify("thread/started", { thread });
+    respond(message.id, { thread });
+    continue;
+  }
+  if (message.method === "turn/start") {
+    turnCounter += 1;
+    const turn = { id: `turn_selftest_${turnCounter}`, status: "completed" };
+    notify("turn/started", { turn });
+    notify("item/agentMessage/delta", { itemId: "msg_selftest", delta: "fake codex stdio reply" });
+    notify("item/commandExecution/outputDelta", { itemId: "cmd_selftest", delta: "Authorization: Bearer test-token\n" });
+    notify("turn/completed", { turn });
+    respond(message.id, { turn });
+    continue;
+  }
+  respond(message.id, null, { code: -32601, message: `unsupported fake method ${message.method ?? "unknown"}` });
+}
+
+function respond(id: number | undefined, result: unknown, error?: unknown): void {
+  if (id === undefined) return;
+  process.stdout.write(`${JSON.stringify(error ? { id, error } : { id, result })}\n`);
+}
+
+function notify(method: string, params: unknown): void {
+  process.stdout.write(`${JSON.stringify({ method, params })}\n`);
+}