feat: inject thread progress into agent prompt (#127)

Agents now receive a Thread Progress section showing current step number
and role visit count, eliminating tool calls to count turns.

- util-agent: new buildThreadProgress() helper
- agent-hermes: inject before continuation/first-visit prompt
- agent-claude-code: same injection point

Fixes #127

.changeset/inject-thread-progress.md

@@ -0,0 +1,12 @@
+---
+"@united-workforce/agent-hermes": patch
+"@united-workforce/agent-claude-code": patch
+"@united-workforce/util-agent": patch
+---
+
+feat: inject thread progress into agent prompt (#127)
+
+Agents now receive a "Thread Progress" section in their prompt showing the
+current step number and how many times the current role has spoken before.
+This eliminates the need for agents to make tool calls (terminal, delegate_task)
+just to count their own turn history.

packages/agent-claude-code/src/claude-code.ts

@@ -7,6 +7,7 @@ import {
   type AgentRunResult,
   buildContinuationPrompt,
   buildRolePrompt,
+  buildThreadProgress,
   createAgent,
   getCachedSessionId,
   setCachedSessionId,
@@ -27,6 +28,10 @@ export function buildClaudeCodePrompt(ctx: AgentContext): string {
   if (ctx.outputFormatInstruction !== undefined && ctx.outputFormatInstruction !== "") {
     parts.push(ctx.outputFormatInstruction, "");
   }
+
+  // Inject thread progress so the agent knows step count and role visit count
+  parts.push(buildThreadProgress(ctx.steps, ctx.role), "");
+
   parts.push(rolePrompt, "", "## Task", ctx.start.prompt);
 
   if (!ctx.isFirstVisit) {

packages/agent-hermes/src/hermes.ts

@@ -6,6 +6,7 @@ import {
   type AgentRunResult,
   buildContinuationPrompt,
   buildRolePrompt,
+  buildThreadProgress,
   createAgent,
 } from "@united-workforce/util-agent";
 import type { AcpUsage } from "./acp-client.js";
@@ -60,6 +61,9 @@ export function buildHermesPrompt(ctx: AgentContext): string {
     parts.push(ctx.outputFormatInstruction, "");
   }
 
+  // Inject thread progress so the agent knows step count and role visit count
+  parts.push(buildThreadProgress(ctx.steps, ctx.role), "");
+
   if (!ctx.isFirstVisit) {
     // Re-entry: show only steps since last visit, meta only
     parts.push(buildContinuationPrompt(ctx.steps, ctx.role, ctx.edgePrompt));

packages/util-agent/__tests__/build-thread-progress.test.ts

@@ -0,0 +1,59 @@
+import type { StepContext } from "@united-workforce/protocol";
+import { describe, expect, test } from "vitest";
+import { buildThreadProgress } from "../src/build-thread-progress.js";
+
+function makeStep(role: string): StepContext {
+  return {
+    role,
+    output: {},
+    detail: "0000000000000" as string,
+    agent: "uwf-mock",
+    edgePrompt: "",
+    startedAtMs: 0,
+    completedAtMs: 0,
+    cwd: "",
+    assembledPrompt: null,
+    usage: null,
+    content: null,
+  };
+}
+
+describe("buildThreadProgress", () => {
+  test("first step of thread", () => {
+    const result = buildThreadProgress([], "proponent");
+    expect(result).toContain("## Thread Progress");
+    expect(result).toContain("first step");
+    expect(result).toContain("first time");
+    expect(result).toContain("proponent");
+  });
+
+  test("second step, role not seen before", () => {
+    const steps = [makeStep("opponent")];
+    const result = buildThreadProgress(steps, "proponent");
+    expect(result).toContain("Thread step 2");
+    expect(result).toContain("spoken 0 times");
+  });
+
+  test("role has spoken once before", () => {
+    const steps = [makeStep("proponent"), makeStep("opponent")];
+    const result = buildThreadProgress(steps, "proponent");
+    expect(result).toContain("Thread step 3");
+    expect(result).toContain("spoken 1 time before");
+    // singular "time" not "times"
+    expect(result).not.toContain("1 times");
+  });
+
+  test("role has spoken multiple times", () => {
+    const steps = [
+      makeStep("proponent"),
+      makeStep("opponent"),
+      makeStep("proponent"),
+      makeStep("opponent"),
+      makeStep("proponent"),
+      makeStep("opponent"),
+    ];
+    const result = buildThreadProgress(steps, "proponent");
+    expect(result).toContain("Thread step 7");
+    expect(result).toContain("spoken 3 times");
+  });
+});

packages/util-agent/src/build-thread-progress.ts

@@ -0,0 +1,27 @@
+import type { StepContext } from "@united-workforce/protocol";
+
+/**
+ * Build a compact thread-progress summary so the agent knows where it is
+ * in the conversation without making tool calls to count steps.
+ *
+ * Example output:
+ *   ## Thread Progress
+ *   Thread step 6. You (proponent) have spoken 2 times before this turn.
+ */
+export function buildThreadProgress(steps: StepContext[], role: string): string {
+  const totalSteps = steps.length;
+  const roleVisits = steps.filter((s) => s.role === role).length;
+
+  const parts = [`## Thread Progress`];
+  if (totalSteps === 0) {
+    parts.push(
+      `This is the first step of the thread. You (${role}) are speaking for the first time.`,
+    );
+  } else {
+    parts.push(
+      `Thread step ${totalSteps + 1}. You (${role}) have spoken ${roleVisits} time${roleVisits === 1 ? "" : "s"} before this turn.`,
+    );
+  }
+
+  return parts.join("\n");
+}

packages/util-agent/src/index.ts

@@ -1,6 +1,7 @@
 export { buildContinuationPrompt } from "./build-continuation-prompt.js";
 export { buildOutputFormatInstruction } from "./build-output-format-instruction.js";
 export { buildRolePrompt } from "./build-role-prompt.js";
+export { buildThreadProgress } from "./build-thread-progress.js";
 export type { BuildContextMeta } from "./context.js";
 export { buildContext, buildContextWithMeta } from "./context.js";
 export type { ExtractResult, ResolvedLlmProvider } from "./extract.js";