feat(progress): humanize subagent updates

docs/superpowers/plans/2026-04-12-subagent-live-progress.md

@@ -0,0 +1,216 @@
+# Subagent Live Progress Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [x]`) syntax for tracking.
+
+**Goal:** Make running subagents show assistant intent text or humanized tool activity instead of raw `tool_call` / `tool_result` labels.
+
+**Architecture:** Add one shared event-to-status formatter in `src/` so parent live updates and wrapper transcript lines use the same wording. Keep wrapper protocol, runner behavior, artifact layout, and `result.json` unchanged; only change formatting and the tiny call sites that consume it.
+
+**Tech Stack:** TypeScript, Node ESM `.mjs`, Node test runner via `tsx --test`
+
+---
+
+## File structure
+
+- Create: `src/progress.mjs` — shared, stateful formatter for normalized child events
+- Modify: `src/tool.ts` — use formatter for parent `onUpdate` progress messages
+- Modify: `src/wrapper/render.mjs` — use same formatter for transcript lines
+- Modify: `src/wrapper/cli.mjs` — skip transcript/log output when formatter returns no line for blank assistant text
+- Modify: `src/tool.test.ts` — regressions for parent live progress
+- Modify: `src/wrapper/render.test.ts` — regressions for transcript rendering
+
+### Task 1: Shared formatter + transcript rendering
+
+**Files:**
+- Create: `src/progress.mjs`
+- Modify: `src/wrapper/render.mjs`
+- Modify: `src/wrapper/cli.mjs`
+- Test: `src/wrapper/render.test.ts`
+
+- [x] **Step 1: Write the failing transcript-render tests**
+
+Add tests to `src/wrapper/render.test.ts` for three behaviors:
+
+```ts
+import { createEventLineRenderer, renderHeader, renderEventLine } from "./render.mjs";
+
+test("renderEventLine humanizes read and result lines", () => {
+  const render = createEventLineRenderer();
+  assert.equal(render({ type: "tool_call", toolName: "read", args: { path: "src/auth.ts" } }), "Reading src/auth.ts");
+  assert.equal(render({ type: "tool_result", toolName: "read", isError: false }), "Finished reading src/auth.ts");
+});
+
+test("renderEventLine prefers assistant text and drops blank assistant text", () => {
+  const render = createEventLineRenderer();
+  assert.equal(render({ type: "assistant_text", text: "Inspecting auth flow" }), "Inspecting auth flow");
+  assert.equal(render({ type: "assistant_text", text: "   " }), null);
+});
+
+test("renderEventLine keeps bash commands concise and humanizes grep failures", () => {
+  const render = createEventLineRenderer();
+  assert.equal(render({ type: "tool_call", toolName: "bash", args: { command: "rg -n authentication src" } }), "$ rg -n authentication src");
+  assert.equal(render({ type: "tool_call", toolName: "grep", args: { pattern: "auth" } }), "Searching code for auth");
+  assert.equal(render({ type: "tool_result", toolName: "grep", isError: true }), "Search failed");
+});
+```
+
+- [x] **Step 2: Run transcript-render tests to verify they fail**
+
+Run: `cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress && npx tsx --test src/wrapper/render.test.ts`
+Expected: FAIL because `createEventLineRenderer` does not exist and current renderer emits JSON-like tool lines / `(no assistant text)`.
+
+- [x] **Step 3: Write the minimal shared formatter and transcript integration**
+
+Implement `src/progress.mjs` with a stateful formatter API and wire `src/wrapper/render.mjs` to use it:
+
+```js
+export function createProgressFormatter() {
+  let lastTool = null;
+
+  return {
+    format(event) {
+      if (event.type === "assistant_text") {
+        const text = typeof event.text === "string" ? event.text.trim() : "";
+        return text || null;
+      }
+      if (event.type === "tool_call") {
+        lastTool = { toolName: event.toolName, args: event.args ?? {} };
+        return formatToolCall(lastTool.toolName, lastTool.args);
+      }
+      if (event.type === "tool_result") {
+        return formatToolResult(event, lastTool);
+      }
+      return JSON.stringify(event);
+    },
+  };
+}
+```
+
+In `src/wrapper/render.mjs`, export both:
+
+```js
+export function createEventLineRenderer() {
+  const formatter = createProgressFormatter();
+  return (event) => formatter.format(event);
+}
+
+const defaultRenderEventLine = createEventLineRenderer();
+export function renderEventLine(event) {
+  return defaultRenderEventLine(event);
+}
+```
+
+In `src/wrapper/cli.mjs`, only append/log transcript lines when the rendered value is not `null`.
+
+- [x] **Step 4: Run transcript-render tests to verify they pass**
+
+Run: `cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress && npx tsx --test src/wrapper/render.test.ts`
+Expected: PASS.
+
+### Task 2: Parent live progress updates
+
+**Files:**
+- Modify: `src/tool.ts`
+- Test: `src/tool.test.ts`
+
+- [x] **Step 1: Write the failing parent-progress tests**
+
+Add tests to `src/tool.test.ts` for assistant-text priority and humanized fallback:
+
+```ts
+test("single-mode subagent prefers assistant text for live progress", async () => {
+  const updates: string[] = [];
+  const tool = createSubagentTool({
+    runSingleTask: async ({ onEvent, meta }: any) => {
+      onEvent?.({ type: "assistant_text", text: "Inspecting auth flow" });
+      onEvent?.({ type: "tool_call", toolName: "read", args: { path: "src/auth.ts" } });
+      onEvent?.({ type: "tool_result", toolName: "read", isError: false });
+      return { runId: "run-1", task: meta.task, exitCode: 0, finalText: "done" };
+    },
+  } as any);
+
+  await tool.execute(/* existing ctx setup */, (partial: any) => {
+    const first = partial.content?.[0];
+    if (first?.type === "text") updates.push(first.text);
+  }, /* existing ctx */);
+
+  assert.deepEqual(updates.slice(0, 3), [
+    "Inspecting auth flow",
+    "Reading src/auth.ts",
+    "Finished reading src/auth.ts",
+  ]);
+  assert.doesNotMatch(updates.join("\n"), /tool_call|tool_result/);
+});
+
+test("single-mode subagent ignores blank assistant text and falls back to tool text", async () => {
+  const updates: string[] = [];
+  const tool = createSubagentTool({
+    runSingleTask: async ({ onEvent, meta }: any) => {
+      onEvent?.({ type: "assistant_text", text: "   " });
+      onEvent?.({ type: "tool_call", toolName: "grep", args: { pattern: "auth" } });
+      return { runId: "run-1", task: meta.task, exitCode: 0, finalText: "done" };
+    },
+  } as any);
+
+  await tool.execute(/* existing ctx setup */, (partial: any) => {
+    const first = partial.content?.[0];
+    if (first?.type === "text") updates.push(first.text);
+  }, /* existing ctx */);
+
+  assert.deepEqual(updates, ["Searching code for auth"]);
+});
+```
+
+- [x] **Step 2: Run parent-progress tests to verify they fail**
+
+Run: `cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress && npx tsx --test src/tool.test.ts`
+Expected: FAIL because `src/tool.ts` still emits `Running subagent: <event.type>`.
+
+- [x] **Step 3: Write the minimal parent integration**
+
+Update `src/tool.ts` to create one formatter per child run and emit only formatted lines:
+
+```ts
+import { createProgressFormatter } from "./progress.mjs";
+
+const formatter = createProgressFormatter();
+
+onEvent(event) {
+  const text = formatter.format(event);
+  if (!text) return;
+  onUpdate?.({
+    content: [{ type: "text", text }],
+    details: makeDetails(input.mode, []),
+  });
+}
+```
+
+Keep parallel/chain completion summaries and all result handling unchanged.
+
+- [x] **Step 4: Run parent-progress tests to verify they pass**
+
+Run: `cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress && npx tsx --test src/tool.test.ts`
+Expected: PASS.
+
+### Task 3: Verification
+
+**Files:**
+- Verify only
+
+- [x] **Step 1: Run touched regression tests together**
+
+Run: `cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress && npx tsx --test src/tool.test.ts src/wrapper/render.test.ts src/wrapper/cli.test.ts`
+Expected: PASS.
+
+- [x] **Step 2: Run full package test suite**
+
+Run: `cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress && npm test`
+Expected: PASS. If it fails, stop and investigate before claiming completion.
+
+- [ ] **Step 3: Commit implementation**
+
+```bash
+cd /home/dev/pi-packages/pi-subagents/.worktree/subagent-live-progress
+git add src/progress.mjs src/tool.ts src/tool.test.ts src/wrapper/render.mjs src/wrapper/render.test.ts src/wrapper/cli.mjs docs/superpowers/plans/2026-04-12-subagent-live-progress.md
+git commit -m "feat(progress): humanize subagent live updates"
+```

src/progress.mjs

@@ -0,0 +1,150 @@
+function shortenText(text, max = 100) {
+  return text.length > max ? `${text.slice(0, max)}…` : text;
+}
+
+function readString(value) {
+  return typeof value === "string" ? value.trim() : "";
+}
+
+function readPath(args) {
+  return readString(args?.path);
+}
+
+function readPattern(args) {
+  return readString(args?.pattern);
+}
+
+function readCommand(args) {
+  return readString(args?.command);
+}
+
+function readQuery(args) {
+  return readString(args?.query);
+}
+
+function formatSearchScope(path) {
+  return path && path !== "." ? shortenText(path) : "code";
+}
+
+function formatToolCall(toolName, args) {
+  const path = readPath(args);
+
+  switch (toolName) {
+    case "bash": {
+      const command = readCommand(args);
+      return command ? `$ ${shortenText(command)}` : "Running command";
+    }
+    case "read":
+      return path ? `Reading ${shortenText(path)}` : "Reading file";
+    case "grep": {
+      const pattern = readPattern(args);
+      if (pattern) return `Searching ${formatSearchScope(path)} for ${shortenText(pattern)}`;
+      return path ? `Searching ${shortenText(path)}` : "Searching code";
+    }
+    case "find": {
+      const pattern = readPattern(args);
+      if (path && pattern) return `Scanning ${shortenText(path)} for ${shortenText(pattern)}`;
+      if (pattern) return `Scanning for ${shortenText(pattern)}`;
+      return path ? `Scanning ${shortenText(path)}` : "Scanning files";
+    }
+    case "ls":
+      return path ? `Listing ${shortenText(path)}` : "Listing current directory";
+    case "edit":
+      return path ? `Editing ${shortenText(path)}` : "Editing file";
+    case "write":
+      return path ? `Writing ${shortenText(path)}` : "Writing file";
+    case "web_search": {
+      const query = readQuery(args);
+      return query ? `Searching web for ${shortenText(query)}` : "Searching web";
+    }
+    case "web_fetch":
+      return "Fetching web page";
+    case "question":
+      return "Asking question";
+    default:
+      return toolName ? `Running ${toolName}` : "Running tool";
+  }
+}
+
+function formatToolResult(toolName, isError, args) {
+  const path = readPath(args);
+
+  switch (toolName) {
+    case "bash":
+      return isError ? "Command failed" : "Command finished";
+    case "read":
+      return path
+        ? isError
+          ? `Read failed: ${shortenText(path)}`
+          : `Finished reading ${shortenText(path)}`
+        : isError
+          ? "Read failed"
+          : "Read finished";
+    case "grep":
+      return isError ? "Search failed" : "Search finished";
+    case "find":
+      return isError ? "Scan failed" : "Scan finished";
+    case "ls":
+      return path
+        ? isError
+          ? `Listing failed: ${shortenText(path)}`
+          : `Finished listing ${shortenText(path)}`
+        : isError
+          ? "Listing failed"
+          : "Listing finished";
+    case "edit":
+      return path
+        ? isError
+          ? `Edit failed: ${shortenText(path)}`
+          : `Finished editing ${shortenText(path)}`
+        : isError
+          ? "Edit failed"
+          : "Edit finished";
+    case "write":
+      return path
+        ? isError
+          ? `Write failed: ${shortenText(path)}`
+          : `Finished writing ${shortenText(path)}`
+        : isError
+          ? "Write failed"
+          : "Write finished";
+    case "web_search":
+      return isError ? "Web search failed" : "Web search finished";
+    case "web_fetch":
+      return isError ? "Fetch failed" : "Fetch finished";
+    case "question":
+      return isError ? "Question failed" : "Question finished";
+    default:
+      return toolName ? `${toolName} ${isError ? "failed" : "finished"}` : isError ? "Tool failed" : "Tool finished";
+  }
+}
+
+export function createProgressFormatter() {
+  let lastTool = null;
+
+  return {
+    format(event) {
+      if (event?.type === "assistant_text") {
+        const text = readString(event.text);
+        return text || null;
+      }
+
+      if (event?.type === "tool_call") {
+        lastTool = {
+          toolName: readString(event.toolName),
+          args: event.args ?? {},
+        };
+        return formatToolCall(lastTool.toolName, lastTool.args);
+      }
+
+      if (event?.type === "tool_result") {
+        const toolName = readString(event.toolName);
+        const context = lastTool?.toolName === toolName ? lastTool : { toolName, args: {} };
+        if (lastTool?.toolName === toolName) lastTool = null;
+        return formatToolResult(context.toolName, Boolean(event.isError), context.args);
+      }
+
+      return JSON.stringify(event);
+    },
+  };
+}

src/tool.test.ts

@@ -2,12 +2,14 @@ import test from "node:test";
 import assert from "node:assert/strict";
 import { createSubagentTool } from "./tool.ts";
 
-test("single-mode subagent uses the required top-level model, emits progress, and returns final text plus metadata", async () => {
+test("single-mode subagent uses the required top-level model and emits humanized live progress", async () => {
   const updates: string[] = [];
 
   const tool = createSubagentTool({
     runSingleTask: async ({ onEvent, meta }: any) => {
+      onEvent?.({ type: "assistant_text", text: "Inspecting auth flow" });
       onEvent?.({ type: "tool_call", toolName: "read", args: { path: "src/auth.ts" } });
+      onEvent?.({ type: "tool_result", toolName: "read", isError: false });
       return {
         runId: "run-1",
         task: "inspect auth",
@@ -49,7 +51,49 @@ test("single-mode subagent uses the required top-level model, emits progress, an
   assert.equal(result.details.results[0]?.paneId, "%3");
   assert.equal(result.details.results[0]?.requestedModel, "anthropic/claude-sonnet-4-5");
   assert.equal("agent" in (result.details.results[0] ?? {}), false);
-  assert.match(updates.join("\n"), /Running subagent/);
+  assert.deepEqual(updates, ["Inspecting auth flow", "Reading src/auth.ts", "Finished reading src/auth.ts"]);
+  assert.doesNotMatch(updates.join("\n"), /tool_call|tool_result/);
+});
+
+test("single-mode subagent ignores blank assistant text and falls back to tool activity", async () => {
+  const updates: string[] = [];
+
+  const tool = createSubagentTool({
+    runSingleTask: async ({ onEvent, meta }: any) => {
+      onEvent?.({ type: "assistant_text", text: "   " });
+      onEvent?.({ type: "tool_call", toolName: "grep", args: { pattern: "auth" } });
+      return {
+        runId: "run-1",
+        task: meta.task,
+        requestedModel: meta.requestedModel,
+        resolvedModel: meta.resolvedModel,
+        exitCode: 0,
+        finalText: "Auth search done",
+      };
+    },
+  } as any);
+
+  await tool.execute(
+    "tool-1",
+    {
+      task: "inspect auth",
+      model: "anthropic/claude-sonnet-4-5",
+    },
+    undefined,
+    (partial: any) => {
+      const first = partial.content?.[0];
+      if (first?.type === "text") updates.push(first.text);
+    },
+    {
+      cwd: "/repo",
+      modelRegistry: {
+        getAvailable: () => [{ provider: "anthropic", id: "claude-sonnet-4-5" }],
+      },
+      hasUI: false,
+    } as any,
+  );
+
+  assert.deepEqual(updates, ["Searching code for auth"]);
 });
 
 test("single-mode subagent requires a top-level model even when execute is called directly", async () => {

src/tool.ts

@@ -9,6 +9,7 @@ import {
   type SubagentRunResult,
   type SubagentToolDetails,
 } from "./schema.ts";
+import { createProgressFormatter } from "./progress.mjs";
 
 const MAX_PARALLEL_TASKS = 8;
 const MAX_CONCURRENCY = 4;
@@ -141,11 +142,15 @@ export function createSubagentTool(deps: {
           topLevelModel: params.model,
         });
 
+        const progressFormatter = createProgressFormatter();
+
         return deps.runSingleTask?.({
           cwd: input.cwd ?? ctx.cwd,
           onEvent(event) {
+            const text = progressFormatter.format(event);
+            if (!text) return;
             onUpdate?.({
-              content: [{ type: "text", text: `Running subagent: ${event.type}` }],
+              content: [{ type: "text", text }],
               details: makeDetails(input.mode, []),
             });
           },

src/wrapper/cli.mjs

@@ -117,8 +117,10 @@ async function runWrapper(meta, startedAt) {
 
     await appendJsonLine(meta.eventsPath, normalized);
     const rendered = renderEventLine(normalized);
+    if (rendered !== null) {
       await appendBestEffort(meta.transcriptPath, `${rendered}\n`);
       console.log(rendered);
+    }
 
     if (normalized.type === "assistant_text") {
       finalText = normalized.text;

src/wrapper/cli.test.ts

@@ -250,6 +250,66 @@ test("wrapper does not exit early on non-terminal toolUse assistant messages", a
   assert.match(eventsText, /"type":"tool_call"/);
 });
 
+test("wrapper skips blank assistant transcript lines before later tool activity", async () => {
+  const dir = await mkdtemp(join(tmpdir(), "pi-subagents-wrapper-"));
+  const metaPath = join(dir, "meta.json");
+  const resultPath = join(dir, "result.json");
+  const transcriptPath = join(dir, "transcript.log");
+  const piPath = join(dir, "pi");
+
+  await writeFile(
+    piPath,
+    [
+      `#!${process.execPath}`,
+      "console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'   '}],model:'openai/gpt-5',stopReason:'toolUse'}}));",
+      "setTimeout(() => console.log(JSON.stringify({type:'tool_execution_start',toolName:'read',args:{path:'src/auth.ts'}})), 100);",
+      "setTimeout(() => console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'done'}],model:'openai/gpt-5',stopReason:'stop'}})), 200);",
+      "setTimeout(() => process.exit(0), 400);",
+    ].join("\n"),
+    "utf8",
+  );
+  await chmod(piPath, 0o755);
+
+  await writeFile(
+    metaPath,
+    JSON.stringify(
+      {
+        runId: "run-1",
+        mode: "single",
+        task: "inspect auth",
+        cwd: dir,
+        requestedModel: "openai/gpt-5",
+        resolvedModel: "openai/gpt-5",
+        startedAt: "2026-04-09T00:00:00.000Z",
+        sessionPath: join(dir, "child-session.jsonl"),
+        eventsPath: join(dir, "events.jsonl"),
+        resultPath,
+        stdoutPath: join(dir, "stdout.log"),
+        stderrPath: join(dir, "stderr.log"),
+        transcriptPath,
+        systemPromptPath: join(dir, "system-prompt.md"),
+      },
+      null,
+      2,
+    ),
+    "utf8",
+  );
+
+  const wrapperPath = join(dirname(fileURLToPath(import.meta.url)), "cli.mjs");
+  const child = spawn(process.execPath, [wrapperPath, metaPath], {
+    env: { ...process.env, PATH: dir },
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+
+  const exitCode = await waitForExit(child, 2500);
+  assert.equal(exitCode, 0);
+
+  const transcript = await readFile(transcriptPath, "utf8");
+  assert.doesNotMatch(transcript, /\nnull\n/);
+  assert.match(transcript, /Reading src\/auth.ts/);
+  assert.match(transcript, /done/);
+});
+
 test("wrapper exits and writes result.json after terminal output even if the pi child lingers", async () => {
   const dir = await mkdtemp(join(tmpdir(), "pi-subagents-wrapper-"));
   const metaPath = join(dir, "meta.json");

src/wrapper/render.mjs

@@ -1,6 +1,4 @@
-function shortenCommand(command) {
+import { createProgressFormatter } from "../progress.mjs";
-  return command.length > 100 ? `${command.slice(0, 100)}…` : command;
-}
 
 export function renderHeader(meta) {
   return [
@@ -14,19 +12,13 @@ export function renderHeader(meta) {
   ].join("\n");
 }
 
-export function renderEventLine(event) {
+export function createEventLineRenderer() {
-  if (event.type === "tool_call") {
+  const formatter = createProgressFormatter();
-    if (event.toolName === "bash") return `$ ${shortenCommand(event.args.command ?? "")}`;
+  return (event) => formatter.format(event);
-    return `→ ${event.toolName} ${JSON.stringify(event.args)}`;
+}
-  }
+
-
+const defaultRenderEventLine = createEventLineRenderer();
-  if (event.type === "tool_result") {
+
-    return event.isError ? `✗ ${event.toolName} failed` : `✓ ${event.toolName} done`;
+export function renderEventLine(event) {
-  }
+  return defaultRenderEventLine(event);
-
-  if (event.type === "assistant_text") {
-    return event.text || "(no assistant text)";
-  }
-
-  return JSON.stringify(event);
 }

src/wrapper/render.test.ts

@@ -1,6 +1,6 @@
 import test from "node:test";
 import assert from "node:assert/strict";
-import { renderHeader, renderEventLine } from "./render.mjs";
+import { createEventLineRenderer, renderHeader, renderEventLine } from "./render.mjs";
 
 test("renderHeader prints generic subagent metadata", () => {
   const header = renderHeader({
@@ -17,7 +17,7 @@ test("renderHeader prints generic subagent metadata", () => {
   assert.match(header, /Session: \/repo\/\.pi\/subagents\/runs\/run-1\/child-session\.jsonl/);
 });
 
-test("renderEventLine makes tool calls readable for subagent transcript output", () => {
+test("renderEventLine keeps bash commands readable for subagent transcript output", () => {
   const line = renderEventLine({
     type: "tool_call",
     toolName: "bash",
@@ -26,3 +26,24 @@ test("renderEventLine makes tool calls readable for subagent transcript output",
 
   assert.equal(line, "$ rg -n authentication src");
 });
+
+test("createEventLineRenderer humanizes read calls and result lines", () => {
+  const render = createEventLineRenderer();
+
+  assert.equal(render({ type: "tool_call", toolName: "read", args: { path: "src/auth.ts" } }), "Reading src/auth.ts");
+  assert.equal(render({ type: "tool_result", toolName: "read", isError: false }), "Finished reading src/auth.ts");
+});
+
+test("createEventLineRenderer prefers assistant text and drops blank assistant text", () => {
+  const render = createEventLineRenderer();
+
+  assert.equal(render({ type: "assistant_text", text: "Inspecting auth flow" }), "Inspecting auth flow");
+  assert.equal(render({ type: "assistant_text", text: "   " }), null);
+});
+
+test("createEventLineRenderer humanizes grep failures", () => {
+  const render = createEventLineRenderer();
+
+  assert.equal(render({ type: "tool_call", toolName: "grep", args: { pattern: "auth" } }), "Searching code for auth");
+  assert.equal(render({ type: "tool_result", toolName: "grep", isError: true }), "Search failed");
+});