diff --git a/biome.json b/biome.json
index 61030ca..34776b4 100644
--- a/biome.json
+++ b/biome.json
@@ -1,7 +1,7 @@
 {
   "$schema": "https://biomejs.dev/schemas/2.4.14/schema.json",
   "files": {
-    "includes": ["**", "!**/dist", "!**/node_modules"]
+    "includes": ["**", "!**/dist", "!**/node_modules", "!packages/workflow/workflow"]
   },
   "assist": { "actions": { "source": { "organizeImports": "on" } } },
   "formatter": {
diff --git a/packages/cli-workflow/src/commands/serve/routes-live.ts b/packages/cli-workflow/src/commands/serve/routes-live.ts
index 8301ea3..c28dd1c 100644
--- a/packages/cli-workflow/src/commands/serve/routes-live.ts
+++ b/packages/cli-workflow/src/commands/serve/routes-live.ts
@@ -60,8 +60,9 @@ export function createLiveRoutes(storageRoot: string): Hono {
     if (dataPath === null) {
       return c.json({ error: `thread not found: ${threadId}` }, 404);
     }
+    const resolvedDataPath = dataPath;
 
-    const infoPath = join(dirname(dataPath), `${threadId}.info.jsonl`);
+    const infoPath = join(dirname(resolvedDataPath), `${threadId}.info.jsonl`);
 
     return streamSSE(c, async (stream) => {
       const dataState: PumpState = { contentOffset: 0, carry: "" };
@@ -71,7 +72,7 @@ export function createLiveRoutes(storageRoot: string): Hono {
       async function pumpData(): Promise<boolean> {
         let text: string;
         try {
-          text = await readFile(dataPath, "utf8");
+          text = await readFile(resolvedDataPath, "utf8");
         } catch {
           return false;
         }
@@ -131,7 +132,7 @@ export function createLiveRoutes(storageRoot: string): Hono {
       const controller = new AbortController();
       let completed = false;
 
-      const dataWatcher = watch(dataPath, async () => {
+      const dataWatcher = watch(resolvedDataPath, async () => {
         if (completed) return;
         const finished = await pumpData();
         if (finished) {
diff --git a/packages/dashboard/src/api.ts b/packages/dashboard/src/api.ts
index 6bf0410..4afe307 100644
--- a/packages/dashboard/src/api.ts
+++ b/packages/dashboard/src/api.ts
@@ -7,7 +7,7 @@ async function postJson<T>(path: string, body: unknown): Promise<T> {
     body: JSON.stringify(body),
   });
   if (!res.ok) {
-    const err = await res.json().catch(() => ({ error: res.statusText })) as { error: string };
+    const err = (await res.json().catch(() => ({ error: res.statusText }))) as { error: string };
     throw new Error(err.error || `API ${res.status}`);
   }
   return res.json() as Promise<T>;
@@ -59,7 +59,11 @@ export function getThread(id: string): Promise<{ records: ThreadRecord[] }> {
   return fetchJson(`/threads/${id}`);
 }
 
-export function runThread(workflow: string, prompt: string, maxRounds: number = 10): Promise<{ threadId: string }> {
+export function runThread(
+  workflow: string,
+  prompt: string,
+  maxRounds: number = 10,
+): Promise<{ threadId: string }> {
   return postJson("/threads", { workflow, prompt, maxRounds });
 }
 
diff --git a/packages/dashboard/src/app.tsx b/packages/dashboard/src/app.tsx
index 6cf9b9d..0d65b8c 100644
--- a/packages/dashboard/src/app.tsx
+++ b/packages/dashboard/src/app.tsx
@@ -1,10 +1,10 @@
 import { useState } from "react";
-import { Sidebar } from "./components/sidebar.tsx";
-import { ThreadList } from "./components/thread-list.tsx";
-import { ThreadDetail } from "./components/thread-detail.tsx";
-import { WorkflowList } from "./components/workflow-list.tsx";
-import { StatusBar } from "./components/status-bar.tsx";
 import { RunDialog } from "./components/run-dialog.tsx";
+import { Sidebar } from "./components/sidebar.tsx";
+import { StatusBar } from "./components/status-bar.tsx";
+import { ThreadDetail } from "./components/thread-detail.tsx";
+import { ThreadList } from "./components/thread-list.tsx";
+import { WorkflowList } from "./components/workflow-list.tsx";
 
 type View = "threads" | "workflows";
 
@@ -19,9 +19,7 @@ export function App() {
       <main className="flex-1 overflow-hidden flex flex-col">
         <StatusBar onRun={() => setShowRun(true)} />
         <div className="flex-1 overflow-auto p-6">
-          {view === "threads" && !selectedThread && (
-            <ThreadList onSelect={setSelectedThread} />
-          )}
+          {view === "threads" && !selectedThread && <ThreadList onSelect={setSelectedThread} />}
           {view === "threads" && selectedThread && (
             <ThreadDetail threadId={selectedThread} onBack={() => setSelectedThread(null)} />
           )}
diff --git a/packages/dashboard/src/components/run-dialog.tsx b/packages/dashboard/src/components/run-dialog.tsx
index d4362c3..84a79d5 100644
--- a/packages/dashboard/src/components/run-dialog.tsx
+++ b/packages/dashboard/src/components/run-dialog.tsx
@@ -41,10 +41,15 @@ export function RunDialog({ onClose, onCreated }: Props) {
         <h3 className="text-lg font-semibold mb-4">Run Thread</h3>
         <form onSubmit={handleSubmit} className="space-y-4">
           <div>
-            <label className="text-sm block mb-1" style={{ color: "var(--color-text-muted)" }}>
+            <label
+              htmlFor="run-workflow"
+              className="text-sm block mb-1"
+              style={{ color: "var(--color-text-muted)" }}
+            >
               Workflow
             </label>
             <select
+              id="run-workflow"
               value={workflow}
               onChange={(e) => setWorkflow(e.target.value)}
               className="w-full px-3 py-2 rounded border text-sm"
@@ -64,10 +69,15 @@ export function RunDialog({ onClose, onCreated }: Props) {
             </select>
           </div>
           <div>
-            <label className="text-sm block mb-1" style={{ color: "var(--color-text-muted)" }}>
+            <label
+              htmlFor="run-prompt"
+              className="text-sm block mb-1"
+              style={{ color: "var(--color-text-muted)" }}
+            >
               Prompt
             </label>
             <textarea
+              id="run-prompt"
               value={prompt}
               onChange={(e) => setPrompt(e.target.value)}
               rows={4}
@@ -81,10 +91,15 @@ export function RunDialog({ onClose, onCreated }: Props) {
             />
           </div>
           <div>
-            <label className="text-sm block mb-1" style={{ color: "var(--color-text-muted)" }}>
+            <label
+              htmlFor="run-max-rounds"
+              className="text-sm block mb-1"
+              style={{ color: "var(--color-text-muted)" }}
+            >
               Max Rounds
             </label>
             <input
+              id="run-max-rounds"
               type="number"
               value={maxRounds}
               onChange={(e) => setMaxRounds(Number(e.target.value))}
@@ -98,7 +113,11 @@ export function RunDialog({ onClose, onCreated }: Props) {
               }}
             />
           </div>
-          {error && <p className="text-sm" style={{ color: "var(--color-error)" }}>{error}</p>}
+          {error && (
+            <p className="text-sm" style={{ color: "var(--color-error)" }}>
+              {error}
+            </p>
+          )}
           <div className="flex gap-2 justify-end">
             <button
               type="button"
diff --git a/packages/dashboard/src/components/sidebar.tsx b/packages/dashboard/src/components/sidebar.tsx
index 7f82c27..5c4cb36 100644
--- a/packages/dashboard/src/components/sidebar.tsx
+++ b/packages/dashboard/src/components/sidebar.tsx
@@ -10,16 +10,22 @@ export function Sidebar({ view, onViewChange }: Props) {
   ];
 
   return (
-    <aside className="w-56 border-r flex flex-col" style={{ borderColor: "var(--color-border)", background: "var(--color-surface)" }}>
+    <aside
+      className="w-56 border-r flex flex-col"
+      style={{ borderColor: "var(--color-border)", background: "var(--color-surface)" }}
+    >
       <div className="p-4 border-b" style={{ borderColor: "var(--color-border)" }}>
         <h1 className="text-lg font-semibold" style={{ color: "var(--color-accent)" }}>
           ⚙ Workflow
         </h1>
-        <p className="text-xs mt-1" style={{ color: "var(--color-text-muted)" }}>Dashboard</p>
+        <p className="text-xs mt-1" style={{ color: "var(--color-text-muted)" }}>
+          Dashboard
+        </p>
       </div>
       <nav className="flex-1 p-2 space-y-1">
         {items.map((item) => (
           <button
+            type="button"
             key={item.key}
             onClick={() => onViewChange(item.key)}
             className="w-full text-left px-3 py-2 rounded text-sm transition-colors"
diff --git a/packages/dashboard/src/components/status-bar.tsx b/packages/dashboard/src/components/status-bar.tsx
index 9a55210..69e81bf 100644
--- a/packages/dashboard/src/components/status-bar.tsx
+++ b/packages/dashboard/src/components/status-bar.tsx
@@ -16,6 +16,7 @@ export function StatusBar({ onRun }: Props) {
       <div className="flex items-center gap-4">
         <span style={{ color: "var(--color-text-muted)" }}>Local API: 127.0.0.1:7860</span>
         <button
+          type="button"
           onClick={onRun}
           className="px-3 py-1 rounded text-xs font-medium"
           style={{ background: "var(--color-accent)", color: "#fff" }}
diff --git a/packages/dashboard/src/components/thread-detail.tsx b/packages/dashboard/src/components/thread-detail.tsx
index b2a57c1..36da442 100644
--- a/packages/dashboard/src/components/thread-detail.tsx
+++ b/packages/dashboard/src/components/thread-detail.tsx
@@ -26,6 +26,7 @@ export function ThreadDetail({ threadId, onBack }: Props) {
     <div>
       <div className="flex items-center justify-between mb-4">
         <button
+          type="button"
           onClick={onBack}
           className="text-sm hover:underline"
           style={{ color: "var(--color-accent)" }}
@@ -34,6 +35,7 @@ export function ThreadDetail({ threadId, onBack }: Props) {
         </button>
         <div className="flex gap-2">
           <button
+            type="button"
             onClick={() => handleAction("pause")}
             className="px-3 py-1 text-xs rounded border"
             style={{ borderColor: "var(--color-warning)", color: "var(--color-warning)" }}
@@ -41,6 +43,7 @@ export function ThreadDetail({ threadId, onBack }: Props) {
             ⏸ Pause
           </button>
           <button
+            type="button"
             onClick={() => handleAction("resume")}
             className="px-3 py-1 text-xs rounded border"
             style={{ borderColor: "var(--color-success)", color: "var(--color-success)" }}
@@ -48,6 +51,7 @@ export function ThreadDetail({ threadId, onBack }: Props) {
             ▶ Resume
           </button>
           <button
+            type="button"
             onClick={() => handleAction("kill")}
             className="px-3 py-1 text-xs rounded border"
             style={{ borderColor: "var(--color-error)", color: "var(--color-error)" }}
@@ -68,9 +72,9 @@ export function ThreadDetail({ threadId, onBack }: Props) {
       {status === "error" && <p style={{ color: "var(--color-error)" }}>Error: {error}</p>}
       {status === "ok" && (
         <div className="space-y-3">
-          {data.records.map((r, i) => (
+          {data.records.map((r) => (
             <div
-              key={i}
+              key={`${r.type}:${r.role ?? ""}:${r.timestamp ?? 0}:${String(r.content ?? "")}`}
               className="p-3 rounded border text-sm"
               style={{ background: "var(--color-surface)", borderColor: "var(--color-border)" }}
             >
@@ -93,7 +97,10 @@ export function ThreadDetail({ threadId, onBack }: Props) {
                 )}
               </div>
               {r.content && (
-                <pre className="whitespace-pre-wrap text-xs mt-1" style={{ color: "var(--color-text)" }}>
+                <pre
+                  className="whitespace-pre-wrap text-xs mt-1"
+                  style={{ color: "var(--color-text)" }}
+                >
                   {typeof r.content === "string" ? r.content : JSON.stringify(r.content, null, 2)}
                 </pre>
               )}
diff --git a/packages/dashboard/src/components/thread-list.tsx b/packages/dashboard/src/components/thread-list.tsx
index 1e71cb7..8f2f083 100644
--- a/packages/dashboard/src/components/thread-list.tsx
+++ b/packages/dashboard/src/components/thread-list.tsx
@@ -8,7 +8,8 @@ type Props = {
 export function ThreadList({ onSelect }: Props) {
   const { status, data, error } = useFetch(() => listThreads(), []);
 
-  if (status === "loading") return <p style={{ color: "var(--color-text-muted)" }}>Loading threads...</p>;
+  if (status === "loading")
+    return <p style={{ color: "var(--color-text-muted)" }}>Loading threads...</p>;
   if (status === "error") return <p style={{ color: "var(--color-error)" }}>Error: {error}</p>;
 
   const threads = data.threads;
@@ -22,6 +23,7 @@ export function ThreadList({ onSelect }: Props) {
         <div className="space-y-2">
           {threads.map((t) => (
             <button
+              type="button"
               key={t.threadId}
               onClick={() => onSelect(t.threadId)}
               className="w-full text-left p-4 rounded-lg border transition-colors hover:border-[var(--color-accent-dim)]"
diff --git a/packages/dashboard/src/components/workflow-list.tsx b/packages/dashboard/src/components/workflow-list.tsx
index 8023db7..6b28bb5 100644
--- a/packages/dashboard/src/components/workflow-list.tsx
+++ b/packages/dashboard/src/components/workflow-list.tsx
@@ -4,7 +4,8 @@ import { useFetch } from "../hooks.ts";
 export function WorkflowList() {
   const { status, data, error } = useFetch(() => listWorkflows(), []);
 
-  if (status === "loading") return <p style={{ color: "var(--color-text-muted)" }}>Loading workflows...</p>;
+  if (status === "loading")
+    return <p style={{ color: "var(--color-text-muted)" }}>Loading workflows...</p>;
   if (status === "error") return <p style={{ color: "var(--color-error)" }}>Error: {error}</p>;
 
   const workflows = data.workflows;
@@ -28,7 +29,10 @@ export function WorkflowList() {
                   {w.versions} version{w.versions !== 1 ? "s" : ""}
                 </span>
               </div>
-              <code className="text-xs mt-1 block font-mono" style={{ color: "var(--color-accent)" }}>
+              <code
+                className="text-xs mt-1 block font-mono"
+                style={{ color: "var(--color-accent)" }}
+              >
                 {w.currentHash}
               </code>
             </div>
diff --git a/packages/dashboard/src/hooks.ts b/packages/dashboard/src/hooks.ts
index ebddd2a..ab78cfd 100644
--- a/packages/dashboard/src/hooks.ts
+++ b/packages/dashboard/src/hooks.ts
@@ -30,6 +30,7 @@ export function useFetch<T>(fetcher: () => Promise<T>, deps: unknown[] = []): Fe
     return () => {
       cancelled = true;
     };
+    // biome-ignore lint/correctness/useExhaustiveDependencies: this helper intentionally accepts caller-provided dependency arrays
   }, deps);
 
   return state;
diff --git a/packages/dashboard/vite.config.ts b/packages/dashboard/vite.config.ts
index 68ca093..25341b6 100644
--- a/packages/dashboard/vite.config.ts
+++ b/packages/dashboard/vite.config.ts
@@ -2,6 +2,7 @@ import tailwindcss from "@tailwindcss/vite";
 import react from "@vitejs/plugin-react";
 import { defineConfig } from "vite";
 
+// biome-ignore lint/style/noDefaultExport: Vite loads config from default export.
 export default defineConfig({
   plugins: [react(), tailwindcss()],
   server: {
diff --git a/packages/workflow-agent-llm/__tests__/create-llm-adapter.test.ts b/packages/workflow-agent-llm/__tests__/create-llm-adapter.test.ts
index 0065f40..387812e 100644
--- a/packages/workflow-agent-llm/__tests__/create-llm-adapter.test.ts
+++ b/packages/workflow-agent-llm/__tests__/create-llm-adapter.test.ts
@@ -1,15 +1,8 @@
 import { describe, expect, test } from "bun:test";
-import { mkdtempSync } from "node:fs";
-import { tmpdir } from "node:os";
-import { join } from "node:path";
-import { createCasStore } from "@uncaged/workflow";
-import { START, type AgentContext } from "@uncaged/workflow-runtime";
+import { type AgentContext, START } from "@uncaged/workflow-runtime";
 
 import { createLlmAdapter } from "../src/create-llm-adapter.js";
 
-const casDir = mkdtempSync(join(tmpdir(), "wf-llm-adapter-cas-"));
-const testCas = createCasStore(casDir);
-
 function makeCtx(userContent: string): AgentContext {
   return {
     start: {
@@ -22,7 +15,6 @@ function makeCtx(userContent: string): AgentContext {
     steps: [],
     threadId: "01TEST000000000000000000TR",
     currentRole: { name: "planner", systemPrompt: "system instructions" },
-    cas: testCas,
   };
 }
 
diff --git a/packages/workflow-runtime/src/engine/create-workflow.ts b/packages/workflow-runtime/src/engine/create-workflow.ts
index 4da2983..186cf26 100644
--- a/packages/workflow-runtime/src/engine/create-workflow.ts
+++ b/packages/workflow-runtime/src/engine/create-workflow.ts
@@ -80,7 +80,6 @@ async function advanceOneRound<M extends RoleMeta>(
   const agentCtx: AgentContext<M> = {
     ...modCtx,
     currentRole: { name: next, systemPrompt: roleDef.systemPrompt },
-    cas: runtime.cas,
   };
 
   const agent = agentForRole(binding, next);
diff --git a/packages/workflow-runtime/src/index.ts b/packages/workflow-runtime/src/index.ts
index f853d5e..2416179 100644
--- a/packages/workflow-runtime/src/index.ts
+++ b/packages/workflow-runtime/src/index.ts
@@ -24,8 +24,8 @@ export type {
   WorkflowCompletion,
   WorkflowDefinition,
   WorkflowFn,
-  WorkflowRuntime,
   WorkflowResult,
+  WorkflowRuntime,
 } from "./types.js";
 export { END, START } from "./types.js";
 export type { Result } from "./util/index.js";
diff --git a/packages/workflow-runtime/src/types.ts b/packages/workflow-runtime/src/types.ts
index 68caefb..1019132 100644
--- a/packages/workflow-runtime/src/types.ts
+++ b/packages/workflow-runtime/src/types.ts
@@ -89,7 +89,6 @@ export type AgentContext<M extends RoleMeta = RoleMeta> = ModeratorContext<M> &
     name: string;
     systemPrompt: string;
   };
-  cas: CasStore;
 };
 
 /** Phase 3: Extractor runs — has agent output; the extraction instruction is a separate argument to the extract function. */
diff --git a/packages/workflow-template-solve-issue/__tests__/solve-issue-template.test.ts b/packages/workflow-template-solve-issue/__tests__/solve-issue-template.test.ts
index dc2bfdb..b10ff6f 100644
--- a/packages/workflow-template-solve-issue/__tests__/solve-issue-template.test.ts
+++ b/packages/workflow-template-solve-issue/__tests__/solve-issue-template.test.ts
@@ -72,7 +72,9 @@ function buildToolCallResponse(args: Record<string, unknown>): Response {
   });
 }
 
-function installMockToolCallCompletions(sequence: ReadonlyArray<Record<string, unknown>>): () => void {
+function installMockToolCallCompletions(
+  sequence: ReadonlyArray<Record<string, unknown>>,
+): () => void {
   const origFetch = globalThis.fetch;
   let i = 0;
   const mockFetch = async (
@@ -160,11 +162,16 @@ function submitterStep(meta: SubmitterMeta): RoleStep<SolveIssueMeta> {
   };
 }
 
-const stubExtract = createExtract({
-  baseUrl: "http://127.0.0.1:9",
-  apiKey: "",
-  model: "test",
-});
+function createStubExtract(casDir: string) {
+  return createExtract(
+    {
+      baseUrl: "http://127.0.0.1:9",
+      apiKey: "",
+      model: "test",
+    },
+    { cas: createCasStore(casDir) },
+  );
+}
 
 function makeThread(prompt: string) {
   return {
@@ -260,13 +267,10 @@ describe("solveIssueWorkflowDefinition + createWorkflow", () => {
       agent: async () => "",
       overrides: { developer: async () => "stub-root-hash" },
     });
-    const gen = run(
-      makeThread("task"),
-      {
-        cas,
-        extract: stubExtract,
-      },
-    );
+    const gen = run(makeThread("task"), {
+      cas,
+      extract: createStubExtract(casDir),
+    });
     const first = await gen.next();
     expect(first.done).toBe(false);
     if (first.done) {
@@ -297,13 +301,10 @@ describe("solveIssueWorkflowDefinition + createWorkflow", () => {
       agent: async () => "",
       overrides: { developer: async () => "stub-root-hash" },
     });
-    const gen = run(
-      makeThread("task"),
-      {
-        cas,
-        extract: stubExtract,
-      },
-    );
+    const gen = run(makeThread("task"), {
+      cas,
+      extract: createStubExtract(casDir),
+    });
     const first = await gen.next();
     expect(first.done).toBe(false);
     if (first.done) {
@@ -356,13 +357,10 @@ describe("solveIssueWorkflowDefinition + createWorkflow", () => {
         },
       },
     });
-    const gen = run(
-      makeThread("task"),
-      {
-        cas,
-        extract: stubExtract,
-      },
-    );
+    const gen = run(makeThread("task"), {
+      cas,
+      extract: createStubExtract(casDir),
+    });
     await gen.next();
     expect(calls).toEqual(["preparer"]);
 
@@ -374,7 +372,6 @@ describe("solveIssueWorkflowDefinition + createWorkflow", () => {
     await gen.next();
     expect(calls).toEqual(["submitter"]);
   });
-
 });
 
 describe("buildSolveIssueDescriptor", () => {
diff --git a/packages/workflow-util-agent/__tests__/build-agent-prompt.test.ts b/packages/workflow-util-agent/__tests__/build-agent-prompt.test.ts
index bbd5199..c49f664 100644
--- a/packages/workflow-util-agent/__tests__/build-agent-prompt.test.ts
+++ b/packages/workflow-util-agent/__tests__/build-agent-prompt.test.ts
@@ -1,9 +1,5 @@
-import { afterEach, beforeEach, describe, expect, test } from "bun:test";
-import { mkdtemp, rm } from "node:fs/promises";
-import { tmpdir } from "node:os";
-import { join } from "node:path";
-import { createCasStore, putContentMerkleNode } from "@uncaged/workflow";
-import { START, type AgentContext } from "@uncaged/workflow-runtime";
+import { describe, expect, test } from "bun:test";
+import { type AgentContext, START } from "@uncaged/workflow-runtime";
 
 import { buildAgentPrompt } from "../src/index.js";
 
@@ -17,25 +13,13 @@ function startTask(content: string): AgentContext["start"] {
 }
 
 describe("buildAgentPrompt", () => {
-  let casRoot: string;
-
-  beforeEach(async () => {
-    casRoot = await mkdtemp(join(tmpdir(), "wf-build-prompt-cas-"));
-  });
-
-  afterEach(async () => {
-    await rm(casRoot, { recursive: true, force: true });
-  });
-
   test("includes system prompt and full task; omits tools when there are no steps", async () => {
-    const cas = createCasStore(casRoot);
     const ctx: AgentContext = {
       start: startTask("fix the bug"),
       depth: 0,
       steps: [],
       threadId: "01TEST000000000000000000TR",
       currentRole: { name: START, systemPrompt: "You are an agent." },
-      cas,
     };
     const text = await buildAgentPrompt(ctx);
     expect(text).toContain("You are an agent.");
@@ -44,15 +28,13 @@ describe("buildAgentPrompt", () => {
     expect(text).not.toContain("## Tools");
   });
 
-  test("single step shows full content and meta, and includes tools", async () => {
-    const cas = createCasStore(casRoot);
-    const onlyHash = await putContentMerkleNode(cas, "only step full body");
+  test("single step shows hash and meta, and includes tools", async () => {
+    const onlyHash = "01HASHSINGLESTEP0000000001";
     const ctx: AgentContext = {
       start: startTask("user task"),
       depth: 0,
       threadId: "01TEST000000000000000000TR",
       currentRole: { name: "coder", systemPrompt: "Be helpful." },
-      cas,
       steps: [
         {
           role: "coder",
@@ -67,22 +49,20 @@ describe("buildAgentPrompt", () => {
     expect(text).toContain("## Task");
     expect(text).toContain("user task");
     expect(text).toContain("## Step: coder");
-    expect(text).toContain("only step full body");
+    expect(text).toContain(`ContentHash: ${onlyHash}`);
     expect(text).toContain('Meta: {"files":["a.ts"]}');
     expect(text).toContain("## Tools");
     expect(text).toContain("uncaged-workflow thread 01TEST000000000000000000TR");
   });
 
-  test("two or more steps: previous steps are meta-only; latest step is full", async () => {
-    const cas = createCasStore(casRoot);
-    const plannerHash = await putContentMerkleNode(cas, "PLANNER_SECRET_FULL_TEXT");
-    const coderHash = await putContentMerkleNode(cas, "last step full content");
+  test("two or more steps: previous steps are meta-only; latest step includes hash", async () => {
+    const plannerHash = "01HASHPLANNER0000000000001";
+    const coderHash = "01HASHCODER0000000000000001";
     const ctx: AgentContext = {
       start: startTask("first message full: task content here"),
       depth: 0,
       threadId: "01TEST000000000000000000TR",
       currentRole: { name: "coder", systemPrompt: "System." },
-      cas,
       steps: [
         {
           role: "planner",
@@ -105,25 +85,22 @@ describe("buildAgentPrompt", () => {
     expect(text).toContain("## Previous Steps");
     expect(text).toContain("### Step 1: planner");
     expect(text).toContain('Summary: {"plan":"short"}');
-    expect(text).not.toContain("PLANNER_SECRET_FULL_TEXT");
     expect(text).toContain("## Latest Step: coder");
-    expect(text).toContain("last step full content");
+    expect(text).toContain(`ContentHash: ${coderHash}`);
     expect(text).toContain('Meta: {"done":true}');
     expect(text).toContain("## Tools");
     expect(text).toContain("uncaged-workflow thread 01TEST000000000000000000TR");
   });
 
-  test("middle steps show meta summary only, not full content", async () => {
-    const cas = createCasStore(casRoot);
-    const ha = await putContentMerkleNode(cas, "HIDDEN_A");
-    const hb = await putContentMerkleNode(cas, "HIDDEN_B_MIDDLE");
-    const hc = await putContentMerkleNode(cas, "VISIBLE_LAST");
+  test("middle steps show meta summary only and latest shows hash", async () => {
+    const ha = "01HASHA00000000000000000001";
+    const hb = "01HASHB00000000000000000001";
+    const hc = "01HASHC00000000000000000001";
     const ctx: AgentContext = {
       start: startTask("start"),
       depth: 0,
       threadId: "01TEST000000000000000000TR",
       currentRole: { name: "c", systemPrompt: "S" },
-      cas,
       steps: [
         {
           role: "a",
@@ -149,11 +126,9 @@ describe("buildAgentPrompt", () => {
       ],
     };
     const text = await buildAgentPrompt(ctx);
-    expect(text).not.toContain("HIDDEN_A");
-    expect(text).not.toContain("HIDDEN_B_MIDDLE");
     expect(text).toContain('Summary: {"n":1}');
     expect(text).toContain('Summary: {"n":2}');
-    expect(text).toContain("VISIBLE_LAST");
+    expect(text).toContain(`ContentHash: ${hc}`);
     expect(text).toContain("## Latest Step: c");
   });
 });
diff --git a/packages/workflow-util-agent/src/build-agent-prompt.ts b/packages/workflow-util-agent/src/build-agent-prompt.ts
index f3ffd64..2345ee1 100644
--- a/packages/workflow-util-agent/src/build-agent-prompt.ts
+++ b/packages/workflow-util-agent/src/build-agent-prompt.ts
@@ -1,14 +1,5 @@
-import { getContentMerklePayload } from "@uncaged/workflow";
 import type { AgentContext } from "@uncaged/workflow-runtime";
 
-async function resolveStepText(ctx: AgentContext, contentHash: string): Promise<string> {
-  const text = await getContentMerklePayload(ctx.cas, contentHash);
-  if (text === null) {
-    throw new Error(`buildAgentPrompt: missing CAS blob for ${contentHash}`);
-  }
-  return text;
-}
-
 /** Builds the full agent prompt: system instructions plus summarized thread history. */
 export async function buildAgentPrompt(ctx: AgentContext): Promise<string> {
   const lines: string[] = [];
@@ -24,12 +15,10 @@ export async function buildAgentPrompt(ctx: AgentContext): Promise<string> {
 
   if (steps.length === 1) {
     const s = steps[0];
-    const body = await resolveStepText(ctx, s.contentHash);
     lines.push("");
     lines.push(`## Step: ${s.role}`);
     lines.push("");
-    lines.push(body);
-    lines.push("");
+    lines.push(`ContentHash: ${s.contentHash}`);
     lines.push(`Meta: ${JSON.stringify(s.meta)}`);
   } else {
     lines.push("");
@@ -41,12 +30,10 @@ export async function buildAgentPrompt(ctx: AgentContext): Promise<string> {
       lines.push(`Summary: ${JSON.stringify(s.meta)}`);
     }
     const last = steps[steps.length - 1];
-    const lastBody = await resolveStepText(ctx, last.contentHash);
     lines.push("");
     lines.push(`## Latest Step: ${last.role}`);
     lines.push("");
-    lines.push(lastBody);
-    lines.push("");
+    lines.push(`ContentHash: ${last.contentHash}`);
     lines.push(`Meta: ${JSON.stringify(last.meta)}`);
   }
 
diff --git a/packages/workflow/__tests__/workflow-as-agent.test.ts b/packages/workflow/__tests__/workflow-as-agent.test.ts
index daa90bb..18219e1 100644
--- a/packages/workflow/__tests__/workflow-as-agent.test.ts
+++ b/packages/workflow/__tests__/workflow-as-agent.test.ts
@@ -34,7 +34,6 @@ function makeAgentCtx(params: {
       name: "caller",
       systemPrompt: "caller",
     },
-    cas: createCasStore(join(params.storageRoot, "agent-ctx-cas")),
   };
 }
 
diff --git a/packages/workflow/src/engine/engine.ts b/packages/workflow/src/engine/engine.ts
index 10b28f8..0cf4154 100644
--- a/packages/workflow/src/engine/engine.ts
+++ b/packages/workflow/src/engine/engine.ts
@@ -6,8 +6,8 @@ import type {
   ThreadContext,
   WorkflowCompletion,
   WorkflowFn,
-  WorkflowRuntime,
   WorkflowResult,
+  WorkflowRuntime,
 } from "@uncaged/workflow-runtime";
 import { START } from "@uncaged/workflow-runtime";
 import {
@@ -24,7 +24,10 @@ import { err, type LogFn, normalizeRefsField, ok, type Result } from "../util/in
 import { runSupervisor } from "./supervisor.js";
 import type { ExecuteThreadIo, ExecuteThreadOptions } from "./types.js";
 
-async function resolveEngineRegistryRuntime(storageRoot: string): Promise<
+async function resolveEngineRegistryRuntime(
+  storageRoot: string,
+  cas: CasStore,
+): Promise<
   Result<
     {
       extract: ReturnType<typeof createExtract>;
@@ -51,7 +54,7 @@ async function resolveEngineRegistryRuntime(storageRoot: string): Promise<
     apiKey: ex.apiKey,
     model: ex.model,
   };
-  return ok({ extract: createExtract(llmProvider), workflowConfig: cfg });
+  return ok({ extract: createExtract(llmProvider, { cas }), workflowConfig: cfg });
 }
 
 async function appendDataLine(path: string, record: unknown): Promise<void> {
@@ -368,7 +371,7 @@ export async function executeThread(
     });
   }
 
-  const registryRuntime = await resolveEngineRegistryRuntime(options.storageRoot);
+  const registryRuntime = await resolveEngineRegistryRuntime(options.storageRoot, io.cas);
   if (!registryRuntime.ok) {
     throw new Error(registryRuntime.error);
   }
diff --git a/packages/workflow/src/extract/extract-fn.ts b/packages/workflow/src/extract/extract-fn.ts
index 1fc046e..5f79380 100644
--- a/packages/workflow/src/extract/extract-fn.ts
+++ b/packages/workflow/src/extract/extract-fn.ts
@@ -1,12 +1,17 @@
 import type { ExtractContext, ExtractFn, LlmProvider } from "@uncaged/workflow-runtime";
 import type * as z from "zod/v4";
-import { getContentMerklePayload } from "../cas/index.js";
+import { type CasStore, getContentMerklePayload } from "../cas/index.js";
 import { reactExtract } from "./react-extract.js";
 
+export type ExtractDeps = {
+  cas: CasStore;
+};
+
 /** Builds the user-side extraction prompt (thread + agent output + instruction). */
 export async function buildExtractUserContent(
   ctx: ExtractContext,
   prompt: string,
+  deps: ExtractDeps,
 ): Promise<string> {
   const lines: string[] = [];
   lines.push(`## Role: ${ctx.currentRole.name}`);
@@ -18,7 +23,7 @@ export async function buildExtractUserContent(
   if (ctx.steps.length > 0) {
     lines.push("## Thread History");
     for (const step of ctx.steps) {
-      const body = await getContentMerklePayload(ctx.cas, step.contentHash);
+      const body = await getContentMerklePayload(deps.cas, step.contentHash);
       if (body === null) {
         throw new Error(`extract: missing CAS blob for step ${step.role}: ${step.contentHash}`);
       }
@@ -44,14 +49,14 @@ export async function buildExtractUserContent(
  * Merkle DAG and a schema-shaped `extract` tool); the loop also accepts a plain-JSON
  * assistant reply as a short-circuit, which covers the legacy "single" extraction path.
  */
-export function createExtract(provider: LlmProvider): ExtractFn {
+export function createExtract(provider: LlmProvider, deps: ExtractDeps): ExtractFn {
   return async <T extends Record<string, unknown>>(
     schema: z.ZodType<T>,
     prompt: string,
     ctx: ExtractContext,
   ): Promise<T> => {
-    const text = await buildExtractUserContent(ctx, prompt);
-    const result = await reactExtract({ text, schema, provider, cas: ctx.cas });
+    const text = await buildExtractUserContent(ctx, prompt, deps);
+    const result = await reactExtract({ text, schema, provider, cas: deps.cas });
     if (!result.ok) {
       throw new Error(`extract failed: ${result.error}`);
     }
diff --git a/tsconfig.json b/tsconfig.json
index d207f42..9257070 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,4 +1,5 @@
 {
+  "files": [],
   "compilerOptions": {
     "target": "ES2022",
     "lib": ["ES2022"],