refactor: extract wrapAgentAsAdapter to util-agent, support childThread in RoleFn (#222)

packages/workflow-util-agent/package.json

@@ -14,6 +14,7 @@
     "test": "bun test"
   },
   "dependencies": {
-    "@uncaged/workflow-runtime": "workspace:*"
+    "@uncaged/workflow-runtime": "workspace:*",
+    "@uncaged/workflow-cas": "workspace:*"
   }
 }

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

@@ -1,3 +1,4 @@
 export { buildAgentPrompt, buildThreadInput } from "./build-agent-prompt.js";
 export type { SpawnCliConfig, SpawnCliError, SpawnCliResult } from "./spawn-cli.js";
 export { spawnCli } from "./spawn-cli.js";
+export { wrapAgentAsAdapter } from "./wrap-agent-as-adapter.js";

packages/workflow-util-agent/src/wrap-agent-as-adapter.ts

@@ -0,0 +1,31 @@
+import { putContentNodeWithRefs } from "@uncaged/workflow-cas";
+import type {
+  AdapterFn,
+  AgentContext,
+  AgentFnResult,
+  RoleResult,
+  ThreadContext,
+  WorkflowRuntime,
+} from "@uncaged/workflow-runtime";
+import type * as z from "zod/v4";
+
+/**
+ * Wraps a legacy AgentFn into an AdapterFn.
+ * The agent produces a string (or { output, childThread }); the adapter
+ * stores the output in CAS, runs extract, and returns typed meta + childThread.
+ */
+export function wrapAgentAsAdapter(
+  agentFn: (ctx: AgentContext) => Promise<AgentFnResult>,
+): AdapterFn {
+  return <T>(prompt: string, schema: z.ZodType<T>) => {
+    return async (ctx: ThreadContext, runtime: WorkflowRuntime): Promise<RoleResult<T>> => {
+      const agentCtx: AgentContext = { ...ctx, currentRole: { name: "agent", systemPrompt: prompt } };
+      const result = await agentFn(agentCtx);
+      const output = typeof result === "string" ? result : result.output;
+      const childThread = typeof result === "string" ? null : result.childThread;
+      const contentHash = await putContentNodeWithRefs(runtime.cas, output, []);
+      const extracted = await runtime.extract(schema as z.ZodType<Record<string, unknown>>, contentHash);
+      return { meta: extracted.meta as T, childThread };
+    };
+  };
+}

packages/workflow-util-agent/tsconfig.json

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