feat(paths): honor PI_CODING_AGENT_DIR for intercom state

broker/broker.ts

@@ -1,13 +1,12 @@
 import net from "net";
 import { writeFileSync, unlinkSync, mkdirSync } from "fs";
 import { join } from "path";
-import { homedir } from "os";
 import { randomUUID } from "crypto";
 import { writeMessage, createMessageReader } from "./framing.js";
-import { getBrokerSocketPath } from "./paths.js";
+import { getBrokerSocketPath, getIntercomDir } from "./paths.js";
 import type { SessionInfo, Message, Attachment, BrokerMessage } from "../types.js";
 
-const INTERCOM_DIR = join(homedir(), ".pi/agent/intercom");
+const INTERCOM_DIR = getIntercomDir();
 const SOCKET_PATH = getBrokerSocketPath();
 const PID_PATH = join(INTERCOM_DIR, "broker.pid");
 

broker/paths.test.ts

@@ -1,6 +1,18 @@
 import test from "node:test";
 import assert from "node:assert/strict";
-import { getBrokerSocketPath } from "./paths.js";
+import { getAgentDir, getBrokerSocketPath, getIntercomDir } from "./paths.js";
+
+function withAgentDirEnv<T>(value: string | undefined, fn: () => T): T {
+  const prev = process.env.PI_CODING_AGENT_DIR;
+  if (value === undefined) delete process.env.PI_CODING_AGENT_DIR;
+  else process.env.PI_CODING_AGENT_DIR = value;
+  try {
+    return fn();
+  } finally {
+    if (prev === undefined) delete process.env.PI_CODING_AGENT_DIR;
+    else process.env.PI_CODING_AGENT_DIR = prev;
+  }
+}
 
 test("getBrokerSocketPath uses named pipe on Windows", () => {
   const pipePath = getBrokerSocketPath("win32", "C:/Users/rcroh");
@@ -9,7 +21,29 @@ test("getBrokerSocketPath uses named pipe on Windows", () => {
 });
 
 test("getBrokerSocketPath uses broker.sock on non-Windows", () => {
-  const socketPath = getBrokerSocketPath("linux", "/home/rcroh");
+  const socketPath = withAgentDirEnv(undefined, () => getBrokerSocketPath("linux", "/home/rcroh"));
   assert.match(socketPath, /broker\.sock$/);
   assert.match(socketPath, /rcroh/);
 });
+
+test("getAgentDir falls back to ~/.pi/agent and expands ~", () => {
+  withAgentDirEnv(undefined, () => {
+    assert.equal(getAgentDir("/home/rcroh"), "/home/rcroh/.pi/agent");
+  });
+  withAgentDirEnv("~", () => {
+    assert.equal(getAgentDir("/home/rcroh"), "/home/rcroh");
+  });
+  withAgentDirEnv("~/relocated", () => {
+    assert.equal(getAgentDir("/home/rcroh"), "/home/rcroh/relocated");
+  });
+  withAgentDirEnv("/abs/agent", () => {
+    assert.equal(getAgentDir("/home/rcroh"), "/abs/agent");
+  });
+});
+
+test("getIntercomDir and broker socket honor PI_CODING_AGENT_DIR", () => {
+  withAgentDirEnv("/abs/agent", () => {
+    assert.equal(getIntercomDir("/home/rcroh"), "/abs/agent/intercom");
+    assert.equal(getBrokerSocketPath("linux", "/home/rcroh"), "/abs/agent/intercom/broker.sock");
+  });
+});

broker/paths.ts

@@ -8,6 +8,29 @@ function sanitizePipeSegment(value: string): string {
     .toLowerCase() || "default";
 }
 
+function expandAgentDir(value: string, homeDir: string): string {
+  if (value === "~") return homeDir;
+  if (value.startsWith("~/")) return join(homeDir, value.slice(2));
+  return value;
+}
+
+/**
+ * Resolve the Pi agent directory. Honors PI_CODING_AGENT_DIR (with `~` / `~/`
+ * expansion) to stay consistent with pi-subagents' getAgentDir, so a relocated
+ * agent dir keeps the intercom broker socket, pid, and config co-located with
+ * the rest of Pi's writable state. Falls back to `~/.pi/agent`.
+ */
+export function getAgentDir(homeDir: string = homedir()): string {
+  const configured = process.env.PI_CODING_AGENT_DIR;
+  if (configured) return expandAgentDir(configured, homeDir);
+  return join(homeDir, ".pi", "agent");
+}
+
+/** Resolve the intercom state directory (broker socket/pid/config) under the agent dir. */
+export function getIntercomDir(homeDir: string = homedir()): string {
+  return join(getAgentDir(homeDir), "intercom");
+}
+
 export function getBrokerSocketPath(
   platform: NodeJS.Platform = process.platform,
   homeDir: string = homedir(),
@@ -16,5 +39,5 @@ export function getBrokerSocketPath(
     return `\\\\.\\pipe\\pi-intercom-${sanitizePipeSegment(homeDir)}`;
   }
 
-  return join(homeDir, ".pi/agent/intercom/broker.sock");
+  return join(getIntercomDir(homeDir), "broker.sock");
 }

broker/spawn.ts

@@ -2,11 +2,10 @@ import { spawn } from "child_process";
 import { existsSync, mkdirSync, readFileSync, unlinkSync, writeFileSync } from "fs";
 import { join, dirname } from "path";
 import { fileURLToPath } from "url";
-import { homedir } from "os";
 import net from "net";
-import { getBrokerSocketPath } from "./paths.js";
+import { getBrokerSocketPath, getIntercomDir } from "./paths.js";
 
-const INTERCOM_DIR = join(homedir(), ".pi/agent/intercom");
+const INTERCOM_DIR = getIntercomDir();
 const EXTENSION_DIR = join(dirname(fileURLToPath(import.meta.url)), "..");
 const BROKER_SOCKET = getBrokerSocketPath();
 const BROKER_PID = join(INTERCOM_DIR, "broker.pid");

config.ts

@@ -1,6 +1,6 @@
 import { existsSync, readFileSync } from "fs";
 import { join } from "path";
-import { homedir } from "os";
+import { getIntercomDir } from "./broker/paths.js";
 
 export interface IntercomConfig {
   /** Broker command used to spawn the broker process (e.g. "npx" or "bun") */
@@ -22,7 +22,9 @@ export interface IntercomConfig {
   replyHint: boolean;
 }
 
-const CONFIG_PATH = join(homedir(), ".pi/agent/intercom/config.json");
+function getConfigPath(): string {
+  return join(getIntercomDir(), "config.json");
+}
 
 const defaults: IntercomConfig = {
   brokerCommand: "npx",
@@ -33,12 +35,13 @@ const defaults: IntercomConfig = {
 };
 
 export function loadConfig(): IntercomConfig {
-  if (!existsSync(CONFIG_PATH)) {
+  const configPath = getConfigPath();
+  if (!existsSync(configPath)) {
     return { ...defaults };
   }
-  
+
   try {
-    const raw = readFileSync(CONFIG_PATH, "utf-8");
+    const raw = readFileSync(configPath, "utf-8");
     const parsed: unknown = JSON.parse(raw);
     if (typeof parsed !== "object" || parsed === null || Array.isArray(parsed)) {
       throw new Error("Config must be a JSON object");
@@ -102,7 +105,7 @@ export function loadConfig(): IntercomConfig {
 
     return config;
   } catch (error) {
-    console.error(`Failed to load intercom config at ${CONFIG_PATH}:`, error);
+    console.error(`Failed to load intercom config at ${configPath}:`, error);
     return { ...defaults };
   }
 }