feat(agent): add pi coding agent integration in-tree

CLAUDE.md

@@ -13,7 +13,7 @@ This repo contains the CLI for Entire.
 - `entire/`: Main CLI entry point. Also home to kubectl-style external-command resolution (`entire <name>` → `entire-<name>` on PATH) — see [External Commands](docs/architecture/external-commands.md).
 - `entire/cli`: CLI utilities and helpers (Cobra commands, helpers, group roots)
 - `entire/cli/commands`: actual command implementations
-- `entire/cli/agent`: agent implementations (Claude Code, Gemini CLI, OpenCode, Cursor, Factory AI Droid, Copilot CLI) - see [Agent Integration Checklist](docs/architecture/agent-integration-checklist.md) and [Agent Implementation Guide](docs/architecture/agent-guide.md)
+- `entire/cli/agent`: agent implementations (Claude Code, Gemini CLI, OpenCode, Cursor, Factory AI Droid, Copilot CLI, Pi) - see [Agent Integration Checklist](docs/architecture/agent-integration-checklist.md) and [Agent Implementation Guide](docs/architecture/agent-guide.md)
 - `entire/cli/strategy`: strategy implementation (manual-commit) - see section below
 - `entire/cli/checkpoint`: checkpoint storage abstractions (temporary and committed)
 - `entire/cli/session`: session state management
@@ -115,16 +115,17 @@ mise run test:e2e --agent opencode [filter]          # OpenCode only
 mise run test:e2e --agent cursor [filter]            # Cursor only
 mise run test:e2e --agent factoryai-droid [filter]   # Factory AI Droid only
 mise run test:e2e --agent copilot-cli [filter]       # Copilot CLI only
+mise run test:e2e --agent pi [filter]                # Pi only
 ```
 
 E2E tests:
 
 - Use the `//go:build e2e` build tag
 - Located in `e2e/tests/`
 - See [`e2e/README.md`](e2e/README.md) for full documentation (structure, debugging, adding agents)
-- Test real agent interactions (Claude Code, Gemini CLI, OpenCode, Cursor, Factory AI Droid, Copilot CLI, or Vogon creating files, committing, etc.)
+- Test real agent interactions (Claude Code, Gemini CLI, OpenCode, Cursor, Factory AI Droid, Copilot CLI, Pi, or Vogon creating files, committing, etc.)
 - Validate checkpoint scenarios documented in `docs/architecture/checkpoint-scenarios.md`
-- Support multiple agents via `E2E_AGENT` env var (`claude-code`, `gemini`, `opencode`, `cursor`, `factoryai-droid`, `copilot-cli`, `vogon`)
+- Support multiple agents via `E2E_AGENT` env var (`claude-code`, `gemini`, `opencode`, `cursor`, `factoryai-droid`, `copilot-cli`, `pi`, `vogon`)
 
 **Environment variables:**
 

cmd/entire/cli/agent/pi/entire_extension.ts

@@ -0,0 +1,73 @@
+// Entire CLI extension for Pi
+// Auto-generated by `entire enable --agent pi`
+// Do not edit manually — changes will be overwritten on next install.
+//
+// Forwards Pi lifecycle events to `entire hooks pi <event>` so Entire can
+// create checkpoints, capture transcripts, and offer rewind/resume.
+//
+// ENTIRE_CMD is replaced at install time by Entire's installer.
+
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+import { execFile } from "node:child_process";
+
+export default function (pi: ExtensionAPI) {
+  const ENTIRE_CMD = "__ENTIRE_CMD__";
+
+  function fireHook(hookName: string, data: Record<string, unknown>): Promise<void> {
+    return new Promise((resolve) => {
+      try {
+        const child = execFile(
+          "sh",
+          ["-c", `${ENTIRE_CMD} hooks pi ${hookName}`],
+          { timeout: 10000, windowsHide: true },
+          () => resolve(),
+        );
+        child.stdin?.end(JSON.stringify(data));
+      } catch {
+        // best effort — never block the agent on a hook failure
+        resolve();
+      }
+    });
+  }
+
+  // Agent-driven bash subprocesses inherit a real TTY but cannot answer
+  // hook prompts. Disable git/Entire terminal prompts for bash calls so
+  // Entire treats agent-driven commits as non-interactive.
+  pi.on("tool_call", async (event) => {
+    if (event.toolName !== "bash") return;
+    const input = event.input as { command?: string };
+    if (typeof input.command !== "string" || input.command.includes("GIT_TERMINAL_PROMPT=")) {
+      return;
+    }
+    input.command = "export GIT_TERMINAL_PROMPT=0\n" + input.command;
+  });
+
+  pi.on("session_start", async (_event, ctx) => {
+    await fireHook("session_start", {
+      type: "session_start",
+      cwd: ctx.cwd,
+      session_file: ctx.sessionManager.getSessionFile(),
+    });
+  });
+
+  pi.on("before_agent_start", async (event, ctx) => {
+    await fireHook("before_agent_start", {
+      type: "before_agent_start",
+      cwd: ctx.cwd,
+      session_file: ctx.sessionManager.getSessionFile(),
+      prompt: event.prompt,
+    });
+  });
+
+  pi.on("agent_end", async (_event, ctx) => {
+    await fireHook("agent_end", {
+      type: "agent_end",
+      cwd: ctx.cwd,
+      session_file: ctx.sessionManager.getSessionFile(),
+    });
+  });
+
+  pi.on("session_shutdown", async () => {
+    await fireHook("session_shutdown", { type: "session_shutdown" });
+  });
+}

cmd/entire/cli/agent/pi/hooks.go

@@ -0,0 +1,124 @@
+package pi
+
+import (
+	"context"
+	_ "embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/entireio/cli/cmd/entire/cli/agent"
+	"github.com/entireio/cli/cmd/entire/cli/paths"
+)
+
+// Compile-time interface assertion
+var _ agent.HookSupport = (*PiAgent)(nil)
+
+//go:embed entire_extension.ts
+var extensionTemplate string
+
+const (
+	// extensionDirName is the directory pi auto-discovers project-local
+	// extensions from.
+	extensionDirName = ".pi/extensions/entire"
+
+	// extensionFileName is the file pi loads from extensionDirName.
+	extensionFileName = "index.ts"
+
+	// entireMarker identifies the file as Entire-owned. Substring of the
+	// auto-generated header so AreHooksInstalled can verify ownership by
+	// content (and so it survives the ENTIRE_CMD placeholder substitution).
+	entireMarker = "Auto-generated by `entire enable --agent pi`"
+
+	// entireCmdPlaceholder is replaced at install time with either `entire`
+	// (production) or a `go run …` path (local-dev).
+	entireCmdPlaceholder = "__ENTIRE_CMD__"
+)
+
+func extensionPath(ctx context.Context) (string, error) {
+	root, err := paths.WorktreeRoot(ctx)
+	if err != nil {
+		// Fall back to CWD for tests run outside a git repo.
+		//nolint:forbidigo // explicit fallback when WorktreeRoot fails
+		root, err = os.Getwd()
+		if err != nil {
+			return "", fmt.Errorf("resolve repo root: %w", err)
+		}
+	}
+	return filepath.Join(root, extensionDirName, extensionFileName), nil
+}
+
+func renderExtension(localDev bool) string {
+	var cmd string
+	if localDev {
+		cmd = `go run "$(git rev-parse --show-toplevel)"/cmd/entire/main.go`
+	} else {
+		cmd = "entire"
+	}
+	return strings.ReplaceAll(extensionTemplate, entireCmdPlaceholder, cmd)
+}
+
+// InstallHooks writes the Entire pi extension to .pi/extensions/entire/index.ts.
+// Returns 1 if the extension was written, 0 if already up-to-date (idempotent).
+// If the file exists but content differs (e.g., localDev vs production), it is
+// rewritten as long as it is recognisable as Entire-owned (contains the
+// marker). A foreign file at the same path is left untouched unless force is
+// true — this protects user-authored extensions that happen to live at
+// .pi/extensions/entire/index.ts.
+func (a *PiAgent) InstallHooks(ctx context.Context, localDev bool, force bool) (int, error) {
+	path, err := extensionPath(ctx)
+	if err != nil {
+		return 0, err
+	}
+	content := renderExtension(localDev)
+
+	if !force {
+		//nolint:gosec // path constructed from validated repo root
+		existing, readErr := os.ReadFile(path)
+		switch {
+		case readErr == nil && string(existing) == content:
+			return 0, nil // already up-to-date
+		case readErr == nil && !strings.Contains(string(existing), entireMarker):
+			return 0, fmt.Errorf("refusing to overwrite foreign file at %s; remove it or pass --force", path)
+		}
+	}
+
+	//nolint:gosec // G301: pi reads the directory; standard 0755 permissions
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return 0, fmt.Errorf("create extension dir: %w", err)
+	}
+	//nolint:gosec // G306: pi reads the file; standard 0644 permissions
+	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+		return 0, fmt.Errorf("write extension: %w", err)
+	}
+	return 1, nil
+}
+
+// UninstallHooks removes the entire pi extension directory (if present).
+func (a *PiAgent) UninstallHooks(ctx context.Context) error {
+	path, err := extensionPath(ctx)
+	if err != nil {
+		return err
+	}
+	dir := filepath.Dir(path)
+	if err := os.RemoveAll(dir); err != nil {
+		return fmt.Errorf("remove pi extension dir: %w", err)
+	}
+	return nil
+}
+
+// AreHooksInstalled returns true when the extension file exists and is
+// recognisable as Entire-owned (contains the marker string).
+func (a *PiAgent) AreHooksInstalled(ctx context.Context) bool {
+	path, err := extensionPath(ctx)
+	if err != nil {
+		return false
+	}
+	//nolint:gosec // path from validated repo root
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return false
+	}
+	return strings.Contains(string(data), entireMarker)
+}