feat(pi): first-class support via pi-subagents + pi-ask-user (#651)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/pi-writer.test.ts

@@ -47,6 +47,7 @@ describe("writePiBundle", () => {
       prompts: [],
       skillDirs: [],
       generatedSkills: [],
+      agents: [],
       extensions: [],
     }
 
@@ -69,7 +70,8 @@ describe("writePiBundle", () => {
           sourceDir: path.join(import.meta.dir, "fixtures", "sample-plugin", "skills", "skill-one"),
         },
       ],
-      generatedSkills: [{ name: "repo-research-analyst", content: "---\nname: repo-research-analyst\n---\n\nBody" }],
+      generatedSkills: [],
+      agents: [{ name: "repo-research-analyst", content: "---\nname: repo-research-analyst\n---\n\nBody" }],
       extensions: [{ name: "compound-engineering-compat.ts", content: "export default function () {}" }],
       mcporterConfig: {
         mcpServers: {
@@ -82,7 +84,10 @@ describe("writePiBundle", () => {
 
     expect(await exists(path.join(outputRoot, "prompts", "workflows-plan.md"))).toBe(true)
     expect(await exists(path.join(outputRoot, "skills", "skill-one", "SKILL.md"))).toBe(true)
-    expect(await exists(path.join(outputRoot, "skills", "repo-research-analyst", "SKILL.md"))).toBe(true)
+    // Claude agents are now written as Pi agent files (.pi/agents/<name>.md),
+    // not skill directories, so nicobailon/pi-subagents can resolve them via
+    // the `subagent` tool.
+    expect(await exists(path.join(outputRoot, "agents", "repo-research-analyst.md"))).toBe(true)
     expect(await exists(path.join(outputRoot, "extensions", "compound-engineering-compat.ts"))).toBe(true)
     expect(await exists(path.join(outputRoot, "compound-engineering", "mcporter.json"))).toBe(true)
     expect(await exists(path.join(outputRoot, "compound-engineering", "install-manifest.json"))).toBe(true)
@@ -90,7 +95,8 @@ describe("writePiBundle", () => {
     const agentsPath = path.join(outputRoot, "AGENTS.md")
     const agentsContent = await fs.readFile(agentsPath, "utf8")
     expect(agentsContent).toContain("BEGIN COMPOUND PI TOOL MAP")
-    expect(agentsContent).toContain("MCPorter")
+    expect(agentsContent).toContain("pi-subagents")
+    expect(agentsContent).toContain("pi-ask-user")
   })
 
   test("transforms Task calls in copied SKILL.md files", async () => {
@@ -117,6 +123,7 @@ Run these research agents:
       prompts: [],
       skillDirs: [{ name: "ce-plan", sourceDir: sourceSkillDir }],
       generatedSkills: [],
+      agents: [],
       extensions: [],
     }
 
@@ -141,6 +148,7 @@ Run these research agents:
       prompts: [{ name: "workflows-work", content: "Prompt content" }],
       skillDirs: [],
       generatedSkills: [],
+      agents: [],
       extensions: [],
     }
 
@@ -162,6 +170,7 @@ Run these research agents:
       prompts: [],
       skillDirs: [],
       generatedSkills: [],
+      agents: [],
       extensions: [],
       mcporterConfig: {
         mcpServers: {
@@ -193,7 +202,8 @@ Run these research agents:
           sourceDir: path.join(import.meta.dir, "fixtures", "sample-plugin", "skills", "skill-one"),
         },
       ],
-      generatedSkills: [{ name: "old-agent", content: "---\nname: old-agent\n---\n\nBody" }],
+      generatedSkills: [],
+      agents: [{ name: "old-agent", content: "---\nname: old-agent\n---\n\nBody" }],
       extensions: [{ name: "compound-engineering-compat.ts", content: "export default function first() {}" }],
     })
 
@@ -201,15 +211,16 @@ Run these research agents:
       pluginName: "compound-engineering",
       prompts: [{ name: "new-prompt", content: "Prompt content" }],
       skillDirs: [],
-      generatedSkills: [{ name: "new-agent", content: "---\nname: new-agent\n---\n\nBody" }],
+      generatedSkills: [],
+      agents: [{ name: "new-agent", content: "---\nname: new-agent\n---\n\nBody" }],
       extensions: [],
     })
 
     expect(await exists(path.join(outputRoot, "prompts", "old-prompt.md"))).toBe(false)
     expect(await exists(path.join(outputRoot, "prompts", "new-prompt.md"))).toBe(true)
     expect(await exists(path.join(outputRoot, "skills", "skill-one", "SKILL.md"))).toBe(false)
-    expect(await exists(path.join(outputRoot, "skills", "old-agent", "SKILL.md"))).toBe(false)
-    expect(await exists(path.join(outputRoot, "skills", "new-agent", "SKILL.md"))).toBe(true)
+    expect(await exists(path.join(outputRoot, "agents", "old-agent.md"))).toBe(false)
+    expect(await exists(path.join(outputRoot, "agents", "new-agent.md"))).toBe(true)
     expect(await exists(path.join(outputRoot, "extensions", "compound-engineering-compat.ts"))).toBe(false)
   })
 
@@ -228,6 +239,7 @@ Run these research agents:
         },
       ],
       generatedSkills: [{ name: "ce-gen-skill", content: "---\nname: ce-gen-skill\n---\n\nBody" }],
+      agents: [],
       extensions: [{ name: "ce-ext.ts", content: "export default function () {}" }],
     })
 
@@ -242,6 +254,7 @@ Run these research agents:
         },
       ],
       generatedSkills: [{ name: "tutor-gen-skill", content: "---\nname: tutor-gen-skill\n---\n\nBody" }],
+      agents: [],
       extensions: [{ name: "tutor-ext.ts", content: "export default function () {}" }],
     })
 
@@ -258,6 +271,7 @@ Run these research agents:
       prompts: [],
       skillDirs: [],
       generatedSkills: [],
+      agents: [],
       extensions: [],
     })
 
@@ -272,6 +286,53 @@ Run these research agents:
     expect(await exists(path.join(outputRoot, "coding-tutor", "install-manifest.json"))).toBe(true)
   })
 
+  test("moves stale compound-engineering mcporter.json to legacy backup when bundle has no mcporterConfig", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "pi-legacy-mcporter-"))
+    const outputRoot = path.join(tempRoot, ".pi")
+    const staleConfigPath = path.join(outputRoot, "compound-engineering", "mcporter.json")
+
+    await fs.mkdir(path.dirname(staleConfigPath), { recursive: true })
+    await fs.writeFile(
+      staleConfigPath,
+      JSON.stringify({ mcpServers: { stale: { baseUrl: "https://example.invalid/mcp" } } }, null, 2),
+    )
+
+    const bundle: PiBundle = {
+      pluginName: "compound-engineering",
+      prompts: [],
+      skillDirs: [],
+      generatedSkills: [],
+      agents: [],
+      extensions: [],
+      // No mcporterConfig — the compound-engineering plugin ships no MCP
+      // servers, so the file written by the removed compat extension should
+      // be swept into legacy-backup rather than lingering on disk.
+    }
+
+    await writePiBundle(outputRoot, bundle)
+
+    expect(await exists(staleConfigPath)).toBe(false)
+
+    const legacyBackupRoot = path.join(outputRoot, "compound-engineering", "legacy-backup")
+    expect(await exists(legacyBackupRoot)).toBe(true)
+
+    const timestamps = await fs.readdir(legacyBackupRoot)
+    const mcporterBackup = (
+      await Promise.all(
+        timestamps.map(async (timestamp) => {
+          const candidate = path.join(legacyBackupRoot, timestamp, "mcporter", "mcporter.json")
+          return (await exists(candidate)) ? candidate : null
+        }),
+      )
+    ).find((candidate): candidate is string => candidate !== null)
+
+    expect(mcporterBackup).toBeDefined()
+    const backedUp = JSON.parse(await fs.readFile(mcporterBackup!, "utf8")) as {
+      mcpServers: Record<string, { baseUrl?: string }>
+    }
+    expect(backedUp.mcpServers.stale?.baseUrl).toBe("https://example.invalid/mcp")
+  })
+
   test("moves legacy flat Pi CE artifacts to a namespaced backup", async () => {
     const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "pi-legacy-artifacts-"))
     const outputRoot = path.join(tempRoot, ".pi")
@@ -297,7 +358,9 @@ Run these research agents:
     expect(await exists(path.join(outputRoot, "prompts", "reproduce-bug.md"))).toBe(false)
     expect(await exists(path.join(outputRoot, "prompts", "report-bug.md"))).toBe(false)
     expect(await exists(path.join(outputRoot, "skills", "ce-plan", "SKILL.md"))).toBe(true)
-    expect(await exists(path.join(outputRoot, "skills", "ce-repo-research-analyst", "SKILL.md"))).toBe(true)
+    // ce-repo-research-analyst is a Claude agent, so it installs to .pi/agents/<name>.md
+    // (not .pi/skills/<name>/SKILL.md) so nicobailon/pi-subagents can resolve it.
+    expect(await exists(path.join(outputRoot, "agents", "ce-repo-research-analyst.md"))).toBe(true)
     expect(await exists(path.join(outputRoot, "compound-engineering", "legacy-backup"))).toBe(true)
   })
 })