fix(uwf-hermes): read turn data from Hermes session file instead of ACP stream

Closes #519

The ACP protocol's tool_call updates only carry a display title (not a
structured tool name) and omit rawInput for polished tools, making the
reconstructed messages unusable for step read/show.

Changes:
- hermes.ts: storePromptResult reads ~/.hermes/sessions/session_{id}.json
  via loadHermesSession() instead of using ACP-reconstructed messages
- acp-client.ts: strip message/tool-call collection logic, keep only
  text chunk accumulation for final response extraction
- step.ts: TurnData gains role + toolCalls fields; formatTurnBody
  renders them in step read markdown output
- README: document sessions.write_json_snapshots requirement

packages/cli-workflow/src/__tests__/step-read.test.ts

@@ -453,7 +453,78 @@ describe("step read", () => {
     expect(markdown).not.toContain("## Turn");
   });
 
-  test("test 6: turn content with special characters", async () => {
+  test("test 6: displays role and tool calls in turn body", async () => {
+    const casDir = join(tmpDir, "cas");
+    await mkdir(casDir, { recursive: true });
+    const store = createFsStore(casDir);
+    const schemas = await registerUwfSchemas(store);
+    const detailSchemas = await registerDetailSchemas(store);
+
+    const workflowHash = await store.put(schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        worker: {
+          description: "Worker",
+          goal: "You are a worker agent.",
+          capabilities: [],
+          procedure: "Do the work.",
+          output: "Summarize the work.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await store.put(schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Test task",
+    });
+
+    const outputHash = await store.put(schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content: "",
+      toolCalls: [{ name: "terminal", args: '{"command":"echo hi"}' }],
+      reasoning: null,
+    });
+
+    const detailHash = await store.put(detailSchemas.detail, {
+      sessionId: "session-1",
+      model: "test-model",
+      duration: 1000,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await store.put(schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "worker",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-hermes",
+      startedAtMs: 1000000000000,
+      completedAtMs: 1000000005000,
+    });
+
+    const markdown = await cmdStepRead(tmpDir, stepHash, 4000);
+
+    expect(markdown).toContain("**Turn role:** assistant");
+    expect(markdown).toContain("**terminal**");
+    expect(markdown).toContain('{"command":"echo hi"}');
+  });
+
+  test("test 7: turn content with special characters", async () => {
     const casDir = join(tmpDir, "cas");
     await mkdir(casDir, { recursive: true });
     const store = createFsStore(casDir);

packages/cli-workflow/src/commands/step.ts

@@ -19,9 +19,16 @@ import {
   walkChain,
 } from "./shared.js";
 
+type TurnToolCall = {
+  name: string;
+  args: string;
+};
+
 type TurnData = {
   index: number;
+  role: string;
   content: string;
+  toolCalls: TurnToolCall[] | null;
 };
 
 /**
@@ -128,8 +135,74 @@ function loadStepDetail(store: BootstrapCapableStore, detailRef: CasRef): Record
   return detailNode.payload as Record<string, unknown>;
 }
 
+function parseTurnToolCalls(raw: unknown): TurnToolCall[] | null {
+  if (!Array.isArray(raw) || raw.length === 0) {
+    return null;
+  }
+  const calls: TurnToolCall[] = [];
+  for (const entry of raw) {
+    if (typeof entry !== "object" || entry === null) {
+      continue;
+    }
+    const record = entry as Record<string, unknown>;
+    const name = record.name;
+    const args = record.args;
+    if (typeof name === "string") {
+      calls.push({ name, args: typeof args === "string" ? args : "" });
+    }
+  }
+  return calls.length > 0 ? calls : null;
+}
+
+function formatTurnBody(turn: TurnData): string {
+  const parts: string[] = [];
+  parts.push(`**Turn role:** ${turn.role}`);
+
+  if (turn.toolCalls !== null) {
+    for (const call of turn.toolCalls) {
+      const argsSuffix = call.args !== "" ? ` — \`${call.args}\`` : "";
+      parts.push(`- **${call.name}**${argsSuffix}`);
+    }
+  }
+
+  if (turn.content !== "") {
+    if (parts.length > 0) {
+      parts.push("");
+    }
+    parts.push(turn.content);
+  }
+
+  return parts.join("\n");
+}
+
+function parseSingleTurn(
+  store: BootstrapCapableStore,
+  turnRef: unknown,
+  fallbackIndex: number,
+): TurnData | null {
+  if (typeof turnRef !== "string") {
+    return null;
+  }
+  const turnNode = store.get(turnRef as CasRef);
+  if (turnNode === null) {
+    return null;
+  }
+  const turn = turnNode.payload as Record<string, unknown>;
+  const content = typeof turn.content === "string" ? turn.content : "";
+  const toolCalls = parseTurnToolCalls(turn.toolCalls);
+  if (content === "" && toolCalls === null) {
+    return null;
+  }
+  return {
+    index: typeof turn.index === "number" ? turn.index : fallbackIndex,
+    role: typeof turn.role === "string" ? turn.role : "assistant",
+    content,
+    toolCalls,
+  };
+}
+
 /**
- * Load all turn nodes from CAS store and extract content
+ * Load all turn nodes from CAS store and extract display fields
  */
 function loadTurnData(store: BootstrapCapableStore, turns: unknown): TurnData[] {
   if (!Array.isArray(turns) || turns.length === 0) {
@@ -138,19 +211,9 @@ function loadTurnData(store: BootstrapCapableStore, turns: unknown): TurnData[]
 
   const turnData: TurnData[] = [];
   for (const turnRef of turns) {
-    if (typeof turnRef !== "string") {
-      continue;
-    }
-    const turnNode = store.get(turnRef as CasRef);
-    if (turnNode === null) {
-      continue;
-    }
-    const turn = turnNode.payload as Record<string, unknown>;
-    if (typeof turn.content === "string") {
-      turnData.push({
-        index: typeof turn.index === "number" ? turn.index : turnData.length,
-        content: turn.content,
-      });
+    const parsed = parseSingleTurn(store, turnRef, turnData.length);
+    if (parsed !== null) {
+      turnData.push(parsed);
     }
   }
   return turnData;
@@ -168,7 +231,7 @@ function selectTurnsForQuota(turnData: TurnData[], availableQuota: number): Turn
     if (turn === undefined) continue;
 
     const turnHeader = `## Turn ${turn.index + 1}\n\n`;
-    const turnBlock = turnHeader + turn.content;
+    const turnBlock = turnHeader + formatTurnBody(turn);
     const separatorCost = selectedTurns.length > 0 ? 2 : 0;
     const addCost = turnBlock.length + separatorCost;
 
@@ -213,7 +276,7 @@ function formatStepMarkdown(
     parts.push("");
     parts.push(`## Turn ${turn.index + 1}`);
     parts.push("");
-    parts.push(turn.content);
+    parts.push(formatTurnBody(turn));
   }
 
   return parts.join("\n");

packages/workflow-agent-hermes/README.md

@@ -18,6 +18,15 @@ bun add -g @uncaged/workflow-agent-hermes
 
 Requires the `hermes` CLI on `PATH`.
 
+Hermes must write session JSON snapshots so `uwf-hermes` can load structured tool calls from disk. Add this to `~/.hermes/config.yaml`:
+
+```yaml
+sessions:
+  write_json_snapshots: true
+```
+
+Session files are stored at `~/.hermes/sessions/session_{sessionId}.json`.
+
 ## CLI Usage
 
 Invoked by `uwf thread step` (not typically run directly):

packages/workflow-agent-hermes/__tests__/acp-client.test.ts

@@ -2,7 +2,7 @@ import { afterEach, beforeEach, describe, expect, it } from "bun:test";
 
 import { HermesAcpClient } from "../src/acp-client.js";
 
-describe("handleSessionUpdate — helper extraction", () => {
+describe("handleSessionUpdate — text extraction", () => {
   let client: HermesAcpClient;
 
   beforeEach(() => {
@@ -14,80 +14,41 @@ describe("handleSessionUpdate — helper extraction", () => {
   });
 
   it("agent_message_chunk accumulates text in messageChunks", () => {
-    (client as any).handleSessionUpdate({
+    (
+      client as unknown as { handleSessionUpdate: (u: Record<string, unknown>) => void }
+    ).handleSessionUpdate({
       sessionUpdate: "agent_message_chunk",
       content: { type: "text", text: "hello" },
     });
-    (client as any).handleSessionUpdate({
+    (
+      client as unknown as { handleSessionUpdate: (u: Record<string, unknown>) => void }
+    ).handleSessionUpdate({
       sessionUpdate: "agent_message_chunk",
       content: { type: "text", text: " world" },
     });
-    expect((client as any).messageChunks).toEqual(["hello", " world"]);
+    expect((client as unknown as { messageChunks: string[] }).messageChunks).toEqual([
+      "hello",
+      " world",
+    ]);
   });
 
-  it("agent_thought_chunk accumulates reasoning in reasoningChunks", () => {
-    (client as any).handleSessionUpdate({
-      sessionUpdate: "agent_thought_chunk",
-      content: { type: "text", text: "thinking" },
+  it("non-text chunks and other update types are ignored", () => {
+    (
+      client as unknown as { handleSessionUpdate: (u: Record<string, unknown>) => void }
+    ).handleSessionUpdate({
+      sessionUpdate: "agent_message_chunk",
+      content: { type: "image", text: "ignored" },
     });
-    expect((client as any).reasoningChunks).toEqual(["thinking"]);
-  });
-
-  it("tool_call registers a pending tool and flushes message chunks", () => {
-    (client as any).messageChunks = ["pre-tool text"];
-    (client as any).handleSessionUpdate({
+    (
+      client as unknown as { handleSessionUpdate: (u: Record<string, unknown>) => void }
+    ).handleSessionUpdate({
       sessionUpdate: "tool_call",
       title: "Bash",
-      rawInput: { command: "ls" },
       toolCallId: "tc-1",
     });
-    expect((client as any).pendingTools.get("tc-1")).toEqual({
-      name: "Bash",
-      args: JSON.stringify({ command: "ls" }),
-    });
-    expect((client as any).messageChunks).toEqual([]);
-    expect((client as any).messages).toHaveLength(1);
-    expect((client as any).messages[0].role).toBe("assistant");
-  });
-
-  it("tool_call_update completed pushes tool_call and tool messages", () => {
-    (client as any).pendingTools.set("tc-2", { name: "Read", args: '{"path":"/foo"}' });
-    (client as any).handleSessionUpdate({
-      sessionUpdate: "tool_call_update",
-      status: "completed",
-      toolCallId: "tc-2",
-      rawOutput: "file contents",
-    });
-    const msgs = (client as any).messages as Array<{
-      role: string;
-      tool_calls: unknown;
-      content: string | null;
-    }>;
-    expect(msgs).toHaveLength(2);
-    expect(msgs[0].role).toBe("assistant");
-    expect(msgs[0].tool_calls).toEqual([
-      { function: { name: "Read", arguments: '{"path":"/foo"}' } },
-    ]);
-    expect(msgs[1].role).toBe("tool");
-    expect(msgs[1].content).toBe("file contents");
-    expect((client as any).pendingTools.has("tc-2")).toBe(false);
-  });
-
-  it("tool_call_update with non-string rawOutput JSON-stringifies it", () => {
-    (client as any).pendingTools.set("tc-3", { name: "Fetch", args: "" });
-    (client as any).handleSessionUpdate({
-      sessionUpdate: "tool_call_update",
-      status: "completed",
-      toolCallId: "tc-3",
-      rawOutput: { html: "<p>page</p>" },
-    });
-    const msgs = (client as any).messages as Array<{ role: string; content: string | null }>;
-    expect(msgs[1].content).toBe(JSON.stringify({ html: "<p>page</p>" }));
-  });
-
-  it("unknown updateType is a no-op", () => {
-    (client as any).handleSessionUpdate({ sessionUpdate: "unknown_type", data: {} });
-    expect((client as any).messages).toHaveLength(0);
-    expect((client as any).messageChunks).toHaveLength(0);
+    (
+      client as unknown as { handleSessionUpdate: (u: Record<string, unknown>) => void }
+    ).handleSessionUpdate({ sessionUpdate: "unknown_type", data: {} });
+    expect((client as unknown as { messageChunks: string[] }).messageChunks).toHaveLength(0);
   });
 });

packages/workflow-agent-hermes/__tests__/integration/acp-client.integration.test.ts

@@ -53,23 +53,4 @@ describe("HermesAcpClient", () => {
     },
     { timeout: 2 * 60 * 1000 },
   );
-
-  // TODO(#435): flaky — depends on live LLM; mock or move to integration suite
-  it.skip(
-    "prompt() collects structured messages including tool calls",
-    async () => {
-      await client.connect(process.cwd());
-      const result = await client.prompt("Run this command: echo TOOL_DETAIL_TEST");
-      expect(result.messages.length).toBeGreaterThan(0);
-      const toolMessages = result.messages.filter((m) => m.role === "tool");
-      expect(toolMessages.length).toBeGreaterThan(0);
-      const toolContent = toolMessages[0]?.content ?? "";
-      expect(toolContent).toContain("TOOL_DETAIL_TEST");
-      const assistantWithTools = result.messages.filter(
-        (m) => m.role === "assistant" && m.tool_calls !== null,
-      );
-      expect(assistantWithTools.length).toBeGreaterThan(0);
-    },
-    { timeout: 2 * 60 * 1000 },
-  );
 });

packages/workflow-agent-hermes/src/acp-client.ts

@@ -2,8 +2,6 @@ import type { ChildProcess } from "node:child_process";
 import { spawn } from "node:child_process";
 import { createInterface } from "node:readline";
 
-import type { HermesSessionMessage } from "./types.js";
-
 const HERMES_COMMAND = "hermes";
 const PROTOCOL_VERSION = 1;
 
@@ -19,16 +17,9 @@ type PendingRequest = {
   reject: (reason: Error) => void;
 };
 
-/** Tracks in-flight tool calls so we can build complete messages when they finish. */
-type PendingToolCall = {
-  name: string;
-  args: string;
-};
-
 export type AcpPromptResult = {
   text: string;
   sessionId: string;
-  messages: HermesSessionMessage[];
 };
 
 export class HermesAcpClient {
@@ -38,11 +29,8 @@ export class HermesAcpClient {
   private stderrBuffer = "";
   private pending = new Map<number, PendingRequest>();
 
-  // Message collection state
+  /** Accumulated assistant text chunks from agent_message_chunk updates. */
   private messageChunks: string[] = [];
-  private reasoningChunks: string[] = [];
-  private pendingTools = new Map<string, PendingToolCall>();
-  messages: HermesSessionMessage[] = [];
 
   /** Spawn hermes acp, initialize, create session */
   async connect(cwd: string): Promise<string> {
@@ -84,14 +72,13 @@ export class HermesAcpClient {
     return sessionId;
   }
 
-  /** Send prompt and collect full response text + structured messages. */
+  /** Send prompt and collect final assistant text from ACP stream chunks. */
   async prompt(text: string): Promise<AcpPromptResult> {
     if (this.sessionId === null) {
       throw new Error("Not connected — call connect() first");
     }
 
     this.messageChunks = [];
-    this.reasoningChunks = [];
 
     const response = await this.sendRequest("session/prompt", {
       sessionId: this.sessionId,
@@ -104,28 +91,9 @@ export class HermesAcpClient {
       );
     }
 
-    // Flush any trailing assistant text that wasn't followed by a tool call.
-    this.flushAssistantMessage();
-
-    // Extract the final assistant text from collected messages.
-    let finalText = "";
-    for (let i = this.messages.length - 1; i >= 0; i--) {
-      const msg = this.messages[i];
-      if (
-        msg !== undefined &&
-        msg.role === "assistant" &&
-        msg.content !== null &&
-        msg.content.trim() !== ""
-      ) {
-        finalText = msg.content;
-        break;
-      }
-    }
-
     return {
-      text: finalText,
+      text: this.messageChunks.join(""),
       sessionId: this.sessionId,
-      messages: this.messages,
     };
   }
 
@@ -242,94 +210,16 @@ export class HermesAcpClient {
     }
   }
 
-  // ---- Session update → structured messages ----
-
   private handleSessionUpdate(update: Record<string, unknown>): void {
-    switch (update.sessionUpdate as string) {
-      case "agent_message_chunk":
-        this.handleAgentMessageChunk(update);
-        break;
-      case "agent_thought_chunk":
-        this.handleAgentThoughtChunk(update);
-        break;
-      case "tool_call":
-        this.handleToolCall(update);
-        break;
-      case "tool_call_update":
-        this.handleToolCallUpdate(update);
-        break;
-      default:
-        break;
+    if (update.sessionUpdate !== "agent_message_chunk") {
+      return;
     }
-  }
-
-  private handleAgentMessageChunk(update: Record<string, unknown>): void {
     const content = update.content as { type?: string; text?: string } | undefined;
     if (content?.type === "text" && typeof content.text === "string") {
       this.messageChunks.push(content.text);
     }
   }
 
-  private handleAgentThoughtChunk(update: Record<string, unknown>): void {
-    const content = update.content as { type?: string; text?: string } | undefined;
-    if (content?.type === "text" && typeof content.text === "string") {
-      this.reasoningChunks.push(content.text);
-    }
-  }
-
-  private handleToolCall(update: Record<string, unknown>): void {
-    const title = (update.title as string) ?? "";
-    const rawInput = update.rawInput;
-    const args = rawInput !== undefined && rawInput !== null ? JSON.stringify(rawInput) : "";
-    const toolCallId = update.toolCallId as string;
-    this.pendingTools.set(toolCallId, { name: title, args });
-    this.flushAssistantMessage();
-  }
-
-  private handleToolCallUpdate(update: Record<string, unknown>): void {
-    const status = update.status as string | undefined;
-    if (status !== "completed" && status !== "failed") return;
-    const toolCallId = update.toolCallId as string;
-    const pending = this.pendingTools.get(toolCallId);
-    const toolName = pending?.name ?? toolCallId;
-    const rawOutput = update.rawOutput;
-    const outputStr =
-      rawOutput !== undefined && rawOutput !== null
-        ? typeof rawOutput === "string"
-          ? rawOutput
-          : JSON.stringify(rawOutput)
-        : "";
-    this.messages.push({
-      role: "assistant",
-      content: null,
-      reasoning: null,
-      tool_calls: [{ function: { name: toolName, arguments: pending?.args ?? "" } }],
-    });
-    this.messages.push({
-      role: "tool",
-      content: outputStr,
-      reasoning: null,
-      tool_calls: null,
-    });
-    this.pendingTools.delete(toolCallId);
-  }
-
-  /** Flush any accumulated text/reasoning into an assistant message. */
-  private flushAssistantMessage(): void {
-    const text = this.messageChunks.join("");
-    const reasoning = this.reasoningChunks.join("");
-    if (text !== "" || reasoning !== "") {
-      this.messages.push({
-        role: "assistant",
-        content: text || null,
-        reasoning: reasoning || null,
-        tool_calls: null,
-      });
-    }
-    this.messageChunks = [];
-    this.reasoningChunks = [];
-  }
-
   private rejectAll(err: Error): void {
     for (const handler of this.pending.values()) {
       handler.reject(err);

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

@@ -10,7 +10,7 @@ import {
 
 import { HermesAcpClient } from "./acp-client.js";
 import { getCachedSessionId, isResumeDisabled, setCachedSessionId } from "./session-cache.js";
-import { storeHermesSessionDetail } from "./session-detail.js";
+import { loadHermesSession, storeHermesSessionDetail } from "./session-detail.js";
 
 const log = createLogger({ sink: { kind: "stderr" } });
 
@@ -49,17 +49,11 @@ export function buildHermesPrompt(ctx: AgentContext): string {
   return parts.join("\n");
 }
 
-async function storePromptResult(
-  store: Store,
-  sessionId: string,
-  messages: Awaited<ReturnType<HermesAcpClient["prompt"]>>["messages"],
-): Promise<{ detailHash: string }> {
-  const session = {
-    session_id: sessionId,
-    model: "",
-    session_start: new Date().toISOString(),
-    messages,
-  };
+async function storePromptResult(store: Store, sessionId: string): Promise<{ detailHash: string }> {
+  const session = await loadHermesSession(sessionId);
+  if (session === null) {
+    throw new Error(`Hermes session file not found: ${sessionId}`);
+  }
   return storeHermesSessionDetail(store, session);
 }
 
@@ -116,8 +110,8 @@ export function createHermesAgent(): () => Promise<void> {
   async function runPrompt(ctx: AgentContext, useContinuation: boolean): Promise<AgentRunResult> {
     const effectiveCtx = useContinuation ? ctx : { ...ctx, isFirstVisit: true };
     const fullPrompt = buildHermesPrompt(effectiveCtx);
-    const { text, sessionId, messages } = await client.prompt(fullPrompt);
-    const { detailHash } = await storePromptResult(ctx.store, sessionId, messages);
+    const { text, sessionId } = await client.prompt(fullPrompt);
+    const { detailHash } = await storePromptResult(ctx.store, sessionId);
 
     if (!isResumeDisabled()) {
       await setCachedSessionId(ctx.threadId, ctx.role, sessionId);
@@ -152,8 +146,8 @@ export function createHermesAgent(): () => Promise<void> {
   ): Promise<AgentRunResult> {
     // Client is already connected from runHermes — same ACP session,
     // so the agent sees the full conversation history (crucial for retries).
-    const { text, sessionId, messages } = await client.prompt(message);
-    const { detailHash } = await storePromptResult(store, sessionId, messages);
+    const { text, sessionId } = await client.prompt(message);
+    const { detailHash } = await storePromptResult(store, sessionId);
     return { output: text, detailHash, sessionId };
   }