refactor: extract @uncaged/workflow-util-agent + smart prompt

- New package: spawn-cli + build-agent-prompt shared utils
- Smart prompt: start + meta summaries for middle steps + last step full
- Cursor/Hermes adapters now import from util-agent (no duplicate code)
- 109 tests pass, biome clean

Closes #14
小橘 <xiaoju@shazhou.work>

packages/workflow-agent-cursor/__tests__/cursor-agent.test.ts

@@ -1,26 +1,5 @@
 import { describe, expect, test } from "bun:test";
-import { START, type ThreadContext } from "@uncaged/workflow";
-
-import { buildAgentPrompt, createCursorAgent, validateCursorAgentConfig } from "../src/index.js";
-
-function makeCtx(): ThreadContext {
-  return {
-    start: {
-      role: START,
-      content: "user task",
-      meta: { maxRounds: 5 },
-      timestamp: 1,
-    },
-    steps: [
-      {
-        role: "coder",
-        content: "first draft",
-        meta: {},
-        timestamp: 2,
-      },
-    ],
-  };
-}
+import { createCursorAgent, validateCursorAgentConfig } from "../src/index.js";
 
 describe("validateCursorAgentConfig", () => {
   test("accepts valid config", () => {
@@ -54,16 +33,6 @@ describe("validateCursorAgentConfig", () => {
   });
 });
 
-describe("buildAgentPrompt", () => {
-  test("includes system prompt, start, and steps", () => {
-    const text = buildAgentPrompt(makeCtx(), "Be helpful.");
-    expect(text).toContain("Be helpful.");
-    expect(text).toContain("user task");
-    expect(text).toContain("coder");
-    expect(text).toContain("first draft");
-  });
-});
-
 describe("createCursorAgent", () => {
   test("returns an AgentFn", () => {
     const agent = createCursorAgent({

packages/workflow-agent-cursor/package.json

@@ -9,6 +9,7 @@
     "test": "bun test"
   },
   "dependencies": {
-    "@uncaged/workflow": "workspace:*"
+    "@uncaged/workflow": "workspace:*",
+    "@uncaged/workflow-util-agent": "workspace:*"
   }
 }

packages/workflow-agent-cursor/src/build-agent-prompt.ts

@@ -1,17 +0,0 @@
-import type { ThreadContext } from "@uncaged/workflow";
-
-/** Combines the role system prompt with thread start content and prior role outputs. */
-export function buildAgentPrompt(ctx: ThreadContext, systemPrompt: string): string {
-  const blocks: string[] = [];
-  blocks.push("# System instructions");
-  blocks.push(systemPrompt);
-  blocks.push("");
-  blocks.push("# Thread");
-  blocks.push("## Start");
-  blocks.push(ctx.start.content);
-  for (const step of ctx.steps) {
-    blocks.push(`## Role: ${step.role}`);
-    blocks.push(step.content);
-  }
-  return blocks.join("\n");
-}

packages/workflow-agent-cursor/src/index.ts

@@ -1,11 +1,10 @@
 import type { AgentFn } from "@uncaged/workflow";
+import { buildAgentPrompt, type SpawnCliError, spawnCli } from "@uncaged/workflow-util-agent";
 
-import { buildAgentPrompt } from "./build-agent-prompt.js";
-import { type SpawnCliError, spawnCli } from "./spawn-cli.js";
 import type { CursorAgentConfig } from "./types.js";
 import { validateCursorAgentConfig } from "./validate-config.js";
 
-export { buildAgentPrompt } from "./build-agent-prompt.js";
+export { buildAgentPrompt } from "@uncaged/workflow-util-agent";
 export type { CursorAgentConfig } from "./types.js";
 export { validateCursorAgentConfig } from "./validate-config.js";
 
@@ -39,7 +38,7 @@ export function createCursorAgent(config: CursorAgentConfig): AgentFn {
   const timeoutMs = config.timeout;
 
   return async (ctx, systemPrompt) => {
-    const fullPrompt = buildAgentPrompt(ctx, systemPrompt);
+    const fullPrompt = buildAgentPrompt(systemPrompt, ctx);
     const args = [
       "-p",
       fullPrompt,

packages/workflow-agent-cursor/src/spawn-cli.ts

@@ -1,63 +0,0 @@
-import { spawn } from "node:child_process";
-
-import { err, ok, type Result } from "@uncaged/workflow";
-
-export type SpawnCliError =
-  | { kind: "non_zero_exit"; exitCode: number | null; stdout: string; stderr: string }
-  | { kind: "timeout" }
-  | { kind: "spawn_failed"; message: string };
-
-export function spawnCli(
-  command: string,
-  args: string[],
-  options: { cwd: string | null; timeoutMs: number | null },
-): Promise<Result<string, SpawnCliError>> {
-  return new Promise((resolve) => {
-    const child = spawn(command, args, {
-      cwd: options.cwd === null ? undefined : options.cwd,
-      shell: false,
-      stdio: ["ignore", "pipe", "pipe"],
-    });
-
-    let stdout = "";
-    let stderr = "";
-    child.stdout?.on("data", (chunk: Buffer) => {
-      stdout += chunk.toString();
-    });
-    child.stderr?.on("data", (chunk: Buffer) => {
-      stderr += chunk.toString();
-    });
-
-    let timedOut = false;
-    let timeoutId: ReturnType<typeof setTimeout> | null = null;
-    if (options.timeoutMs !== null) {
-      timeoutId = setTimeout(() => {
-        timedOut = true;
-        child.kill("SIGTERM");
-      }, options.timeoutMs);
-    }
-
-    child.on("error", (cause) => {
-      if (timeoutId !== null) {
-        clearTimeout(timeoutId);
-      }
-      const message = cause instanceof Error ? cause.message : String(cause);
-      resolve(err({ kind: "spawn_failed", message }));
-    });
-
-    child.on("close", (code) => {
-      if (timeoutId !== null) {
-        clearTimeout(timeoutId);
-      }
-      if (timedOut) {
-        resolve(err({ kind: "timeout" }));
-        return;
-      }
-      if (code === 0) {
-        resolve(ok(stdout));
-        return;
-      }
-      resolve(err({ kind: "non_zero_exit", exitCode: code, stdout, stderr }));
-    });
-  });
-}

packages/workflow-agent-cursor/tsconfig.json

@@ -6,5 +6,5 @@
     "composite": true
   },
   "include": ["src/**/*.ts"],
-  "references": [{ "path": "../workflow" }]
+  "references": [{ "path": "../workflow" }, { "path": "../workflow-util-agent" }]
 }