feat: add first-class pi target with mcporter/subagent compatibility

src/targets/index.ts

@@ -3,14 +3,17 @@ import type { OpenCodeBundle } from "../types/opencode"
 import type { CodexBundle } from "../types/codex"
 import type { DroidBundle } from "../types/droid"
 import type { CursorBundle } from "../types/cursor"
+import type { PiBundle } from "../types/pi"
 import { convertClaudeToOpenCode, type ClaudeToOpenCodeOptions } from "../converters/claude-to-opencode"
 import { convertClaudeToCodex } from "../converters/claude-to-codex"
 import { convertClaudeToDroid } from "../converters/claude-to-droid"
 import { convertClaudeToCursor } from "../converters/claude-to-cursor"
+import { convertClaudeToPi } from "../converters/claude-to-pi"
 import { writeOpenCodeBundle } from "./opencode"
 import { writeCodexBundle } from "./codex"
 import { writeDroidBundle } from "./droid"
 import { writeCursorBundle } from "./cursor"
+import { writePiBundle } from "./pi"
 
 export type TargetHandler<TBundle = unknown> = {
   name: string
@@ -44,4 +47,10 @@ export const targets: Record<string, TargetHandler> = {
     convert: convertClaudeToCursor as TargetHandler<CursorBundle>["convert"],
     write: writeCursorBundle as TargetHandler<CursorBundle>["write"],
   },
+  pi: {
+    name: "pi",
+    implemented: true,
+    convert: convertClaudeToPi as TargetHandler<PiBundle>["convert"],
+    write: writePiBundle as TargetHandler<PiBundle>["write"],
+  },
 }

src/targets/pi.ts

@@ -0,0 +1,131 @@
+import path from "path"
+import {
+  backupFile,
+  copyDir,
+  ensureDir,
+  pathExists,
+  readText,
+  writeJson,
+  writeText,
+} from "../utils/files"
+import type { PiBundle } from "../types/pi"
+
+const PI_AGENTS_BLOCK_START = "<!-- BEGIN COMPOUND PI TOOL MAP -->"
+const PI_AGENTS_BLOCK_END = "<!-- END COMPOUND PI TOOL MAP -->"
+
+const PI_AGENTS_BLOCK_BODY = `## Compound Engineering (Pi compatibility)
+
+This block is managed by compound-plugin.
+
+Compatibility notes:
+- Claude Task(agent, args) maps to the subagent extension tool
+- For parallel agent runs, batch multiple subagent calls with multi_tool_use.parallel
+- AskUserQuestion maps to the ask_user_question extension tool
+- MCP access uses MCPorter via mcporter_list and mcporter_call extension tools
+- MCPorter config path: .pi/compound-engineering/mcporter.json (project) or ~/.pi/agent/compound-engineering/mcporter.json (global)
+`
+
+export async function writePiBundle(outputRoot: string, bundle: PiBundle): Promise<void> {
+  const paths = resolvePiPaths(outputRoot)
+
+  await ensureDir(paths.skillsDir)
+  await ensureDir(paths.promptsDir)
+  await ensureDir(paths.extensionsDir)
+
+  for (const prompt of bundle.prompts) {
+    await writeText(path.join(paths.promptsDir, `${prompt.name}.md`), prompt.content + "\n")
+  }
+
+  for (const skill of bundle.skillDirs) {
+    await copyDir(skill.sourceDir, path.join(paths.skillsDir, skill.name))
+  }
+
+  for (const skill of bundle.generatedSkills) {
+    await writeText(path.join(paths.skillsDir, skill.name, "SKILL.md"), skill.content + "\n")
+  }
+
+  for (const extension of bundle.extensions) {
+    await writeText(path.join(paths.extensionsDir, extension.name), extension.content + "\n")
+  }
+
+  if (bundle.mcporterConfig) {
+    const backupPath = await backupFile(paths.mcporterConfigPath)
+    if (backupPath) {
+      console.log(`Backed up existing MCPorter config to ${backupPath}`)
+    }
+    await writeJson(paths.mcporterConfigPath, bundle.mcporterConfig)
+  }
+
+  await ensurePiAgentsBlock(paths.agentsPath)
+}
+
+function resolvePiPaths(outputRoot: string) {
+  const base = path.basename(outputRoot)
+
+  // Global install root: ~/.pi/agent
+  if (base === "agent") {
+    return {
+      skillsDir: path.join(outputRoot, "skills"),
+      promptsDir: path.join(outputRoot, "prompts"),
+      extensionsDir: path.join(outputRoot, "extensions"),
+      mcporterConfigPath: path.join(outputRoot, "compound-engineering", "mcporter.json"),
+      agentsPath: path.join(outputRoot, "AGENTS.md"),
+    }
+  }
+
+  // Project local .pi directory
+  if (base === ".pi") {
+    return {
+      skillsDir: path.join(outputRoot, "skills"),
+      promptsDir: path.join(outputRoot, "prompts"),
+      extensionsDir: path.join(outputRoot, "extensions"),
+      mcporterConfigPath: path.join(outputRoot, "compound-engineering", "mcporter.json"),
+      agentsPath: path.join(outputRoot, "AGENTS.md"),
+    }
+  }
+
+  // Custom output root -> nest under .pi
+  return {
+    skillsDir: path.join(outputRoot, ".pi", "skills"),
+    promptsDir: path.join(outputRoot, ".pi", "prompts"),
+    extensionsDir: path.join(outputRoot, ".pi", "extensions"),
+    mcporterConfigPath: path.join(outputRoot, ".pi", "compound-engineering", "mcporter.json"),
+    agentsPath: path.join(outputRoot, "AGENTS.md"),
+  }
+}
+
+async function ensurePiAgentsBlock(filePath: string): Promise<void> {
+  const block = buildPiAgentsBlock()
+
+  if (!(await pathExists(filePath))) {
+    await writeText(filePath, block + "\n")
+    return
+  }
+
+  const existing = await readText(filePath)
+  const updated = upsertBlock(existing, block)
+  if (updated !== existing) {
+    await writeText(filePath, updated)
+  }
+}
+
+function buildPiAgentsBlock(): string {
+  return [PI_AGENTS_BLOCK_START, PI_AGENTS_BLOCK_BODY.trim(), PI_AGENTS_BLOCK_END].join("\n")
+}
+
+function upsertBlock(existing: string, block: string): string {
+  const startIndex = existing.indexOf(PI_AGENTS_BLOCK_START)
+  const endIndex = existing.indexOf(PI_AGENTS_BLOCK_END)
+
+  if (startIndex !== -1 && endIndex !== -1 && endIndex > startIndex) {
+    const before = existing.slice(0, startIndex).trimEnd()
+    const after = existing.slice(endIndex + PI_AGENTS_BLOCK_END.length).trimStart()
+    return [before, block, after].filter(Boolean).join("\n\n") + "\n"
+  }
+
+  if (existing.trim().length === 0) {
+    return block + "\n"
+  }
+
+  return existing.trimEnd() + "\n\n" + block + "\n"
+}