feat: add @uncaged/uwf-agent-hermes — Hermes agent CLI adapter

Spawns 'hermes chat' with assembled prompt from agent-kit context.
Agent-kit handles extract, StepNode write, and stdout output.

Refs #309, #316

packages/uwf-agent-hermes/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "@uncaged/uwf-agent-hermes",
+  "version": "0.1.0",
+  "files": [
+    "src",
+    "dist",
+    "package.json"
+  ],
+  "type": "module",
+  "bin": {
+    "uwf-hermes": "./src/cli.ts"
+  },
+  "exports": {
+    ".": {
+      "bun": "./src/index.ts",
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
+    }
+  },
+  "scripts": {
+    "test": "bun test"
+  },
+  "dependencies": {
+    "@uncaged/uwf-agent-kit": "workspace:^"
+  },
+  "devDependencies": {
+    "typescript": "^5.8.3"
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}

packages/uwf-agent-hermes/src/cli.ts

@@ -0,0 +1,6 @@
+#!/usr/bin/env bun
+
+import { createHermesAgent } from "./hermes.js";
+
+const main = createHermesAgent();
+void main();

packages/uwf-agent-hermes/src/hermes.ts

@@ -0,0 +1,90 @@
+import { spawn } from "node:child_process";
+
+import { type AgentContext, createAgent } from "@uncaged/uwf-agent-kit";
+
+const HERMES_COMMAND = "hermes";
+const HERMES_MAX_TURNS = 90;
+
+function buildHistorySummary(history: AgentContext["history"]): string {
+  if (history.length === 0) {
+    return "";
+  }
+
+  const lines: string[] = ["## Previous Steps"];
+  for (let i = 0; i < history.length; i++) {
+    const step = history[i];
+    if (step === undefined) {
+      continue;
+    }
+    lines.push("");
+    lines.push(`### Step ${i + 1}: ${step.role}`);
+    lines.push(`Output: ${JSON.stringify(step.output)}`);
+    lines.push(`Agent: ${step.agent}`);
+  }
+  return lines.join("\n");
+}
+
+/** Assemble system prompt, task, and prior step outputs for Hermes. */
+export function buildHermesPrompt(ctx: AgentContext): string {
+  const parts: string[] = [ctx.systemPrompt, "", "## Task", ctx.prompt];
+  const historyBlock = buildHistorySummary(ctx.history);
+  if (historyBlock !== "") {
+    parts.push("", historyBlock);
+  }
+  return parts.join("\n");
+}
+
+function spawnHermesChat(prompt: string): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const args = [
+      "chat",
+      "-q",
+      prompt,
+      "--yolo",
+      "--max-turns",
+      String(HERMES_MAX_TURNS),
+      "--quiet",
+    ];
+    const child = spawn(HERMES_COMMAND, args, {
+      env: process.env,
+      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();
+    });
+
+    child.on("error", (cause) => {
+      const message = cause instanceof Error ? cause.message : String(cause);
+      reject(new Error(`hermes spawn failed: ${message}`));
+    });
+
+    child.on("close", (code) => {
+      if (code === 0) {
+        resolve(stdout);
+        return;
+      }
+      const detail = stderr.trim() !== "" ? ` stderr=${stderr.trim()}` : "";
+      reject(new Error(`hermes exited with code ${code ?? "null"}${detail}`));
+    });
+  });
+}
+
+async function runHermes(ctx: AgentContext): Promise<string> {
+  const fullPrompt = buildHermesPrompt(ctx);
+  return spawnHermesChat(fullPrompt);
+}
+
+/** Agent CLI factory: parses argv, runs Hermes, extracts output, writes StepNode. */
+export function createHermesAgent(): () => Promise<void> {
+  return createAgent({
+    name: "hermes",
+    run: runHermes,
+  });
+}

packages/uwf-agent-hermes/src/index.ts

@@ -0,0 +1 @@
+export { buildHermesPrompt, createHermesAgent } from "./hermes.js";

packages/uwf-agent-hermes/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src"],
+  "references": [{ "path": "../uwf-agent-kit" }]
+}