perf(pi): reuse tau rpc for command auto-replies

src/agents/agents.test.ts

@@ -4,6 +4,7 @@ import { CLAUDE_IDENTITY_PREFIX } from "../auto-reply/claude.js";
 import { OPENCODE_IDENTITY_PREFIX } from "../auto-reply/opencode.js";
 import { claudeSpec } from "./claude.js";
 import { codexSpec } from "./codex.js";
+import { GEMINI_IDENTITY_PREFIX, geminiSpec } from "./gemini.js";
 import { opencodeSpec } from "./opencode.js";
 import { piSpec } from "./pi.js";
 
@@ -115,4 +116,33 @@ describe("agent buildArgs + parseOutput helpers", () => {
     expect(built).toContain("--skip-git-repo-check");
     expect(built).toContain("read-only");
   });
+
+  it("geminiSpec prepends identity unless already sent", () => {
+    const argv = ["gemini", "hi"];
+    const built = geminiSpec.buildArgs({
+      argv,
+      bodyIndex: 1,
+      isNewSession: true,
+      sessionId: "sess",
+      sendSystemOnce: false,
+      systemSent: false,
+      identityPrefix: undefined,
+      format: "json",
+    });
+    expect(built.at(-1)).toContain(GEMINI_IDENTITY_PREFIX);
+
+    const builtOnce = geminiSpec.buildArgs({
+      argv,
+      bodyIndex: 1,
+      isNewSession: false,
+      sessionId: "sess",
+      sendSystemOnce: true,
+      systemSent: true,
+      identityPrefix: undefined,
+      format: "json",
+    });
+    expect(builtOnce.at(-1)).toBe("hi");
+    expect(builtOnce).toContain("--output-format");
+    expect(builtOnce).toContain("json");
+  });
 });

src/agents/claude.ts

@@ -12,7 +12,16 @@ import type { AgentMeta, AgentSpec } from "./types.js";
 function toMeta(parsed?: ClaudeJsonParseResult): AgentMeta | undefined {
   if (!parsed?.parsed) return undefined;
   const summary = summarizeClaudeMetadata(parsed.parsed);
-  return summary ? { extra: { summary } } : undefined;
+  const sessionId =
+    parsed.parsed &&
+    typeof parsed.parsed === "object" &&
+    typeof (parsed.parsed as { session_id?: unknown }).session_id === "string"
+      ? (parsed.parsed as { session_id: string }).session_id
+      : undefined;
+  const meta: AgentMeta = {};
+  if (sessionId) meta.sessionId = sessionId;
+  if (summary) meta.extra = { summary };
+  return Object.keys(meta).length ? meta : undefined;
 }
 
 export const claudeSpec: AgentSpec = {

src/agents/gemini.ts

@@ -0,0 +1,50 @@
+import path from "node:path";
+
+import type { AgentMeta, AgentSpec } from "./types.js";
+
+const GEMINI_BIN = "gemini";
+export const GEMINI_IDENTITY_PREFIX =
+  "You are Gemini responding for warelay. Keep WhatsApp replies concise (<1500 chars). If the prompt contains media paths or a Transcript block, use them. If this was a heartbeat probe and nothing needs attention, reply with exactly HEARTBEAT_OK.";
+
+// Gemini CLI currently prints plain text; --output json is flaky across versions, so we
+// keep parsing minimal and let MEDIA token stripping happen later in the pipeline.
+function parseGeminiOutput(raw: string): { text?: string; meta?: AgentMeta } {
+  const trimmed = raw.trim();
+  return { text: trimmed || undefined, meta: undefined };
+}
+
+export const geminiSpec: AgentSpec = {
+  kind: "gemini",
+  isInvocation: (argv) =>
+    argv.length > 0 && path.basename(argv[0]) === GEMINI_BIN,
+  buildArgs: (ctx) => {
+    const argv = [...ctx.argv];
+    const body = argv[ctx.bodyIndex] ?? "";
+    const beforeBody = argv.slice(0, ctx.bodyIndex);
+    const afterBody = argv.slice(ctx.bodyIndex + 1);
+
+    if (ctx.format) {
+      const hasOutput =
+        beforeBody.some(
+          (p) => p === "--output-format" || p.startsWith("--output-format="),
+        ) ||
+        afterBody.some(
+          (p) => p === "--output-format" || p.startsWith("--output-format="),
+        );
+      if (!hasOutput) {
+        beforeBody.push("--output-format", ctx.format);
+      }
+    }
+
+    const shouldPrependIdentity = !(ctx.sendSystemOnce && ctx.systemSent);
+    const bodyWithIdentity =
+      shouldPrependIdentity && body
+        ? [ctx.identityPrefix ?? GEMINI_IDENTITY_PREFIX, body]
+            .filter(Boolean)
+            .join("\n\n")
+        : body;
+
+    return [...beforeBody, bodyWithIdentity, ...afterBody];
+  },
+  parseOutput: parseGeminiOutput,
+};

src/agents/index.ts

@@ -1,5 +1,6 @@
 import { claudeSpec } from "./claude.js";
 import { codexSpec } from "./codex.js";
+import { geminiSpec } from "./gemini.js";
 import { opencodeSpec } from "./opencode.js";
 import { piSpec } from "./pi.js";
 import type { AgentKind, AgentSpec } from "./types.js";
@@ -7,6 +8,7 @@ import type { AgentKind, AgentSpec } from "./types.js";
 const specs: Record<AgentKind, AgentSpec> = {
   claude: claudeSpec,
   codex: codexSpec,
+  gemini: geminiSpec,
   opencode: opencodeSpec,
   pi: piSpec,
 };

src/agents/pi.ts

@@ -47,7 +47,11 @@ function parsePiJson(raw: string): AgentParseResult {
 
 export const piSpec: AgentSpec = {
   kind: "pi",
-  isInvocation: (argv) => argv.length > 0 && path.basename(argv[0]) === "pi",
+  isInvocation: (argv) => {
+    if (argv.length === 0) return false;
+    const base = path.basename(argv[0]).replace(/\.(m?js)$/i, "");
+    return base === "pi" || base === "tau";
+  },
   buildArgs: (ctx) => {
     const argv = [...ctx.argv];
     // Non-interactive print + JSON

src/agents/types.ts

@@ -1,9 +1,10 @@
-export type AgentKind = "claude" | "opencode" | "pi" | "codex";
+export type AgentKind = "claude" | "opencode" | "pi" | "codex" | "gemini";
 
 export type AgentMeta = {
   model?: string;
   provider?: string;
   stopReason?: string;
+  sessionId?: string;
   usage?: {
     input?: number;
     output?: number;