feat(FN-1984): enrich chat and heartbeat prompts with agent context

- Add agent memory support to instruction resolution and introduce/export buildAgentChatPrompt for identity-aware prompt assembly with optional project memory
- Wire ChatManager to AgentStore so chat sessions can enrich system prompts per agent and include recent conversation context in prompt payloads
- Update server chat wiring to provide an AgentStore for prompt enrichment and keep graceful fallback behavior when agent context is unavailable
- Enrich HeartbeatMonitor system prompts with resolved agent instructions/ratings while preserving base-prompt fallback paths
- Expand dashboard and engine tests to cover prompt enrichment, fallback behavior, conversation context assembly, and AgentStore route mocks

packages/engine/src/__tests__/agent-instructions.test.ts

@@ -1,11 +1,12 @@
 import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
-import { mkdtemp, rm, writeFile } from "node:fs/promises";
+import { mkdtemp, mkdir, rm, writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import { tmpdir } from "node:os";
 import type { Agent, AgentRating, AgentRatingSummary, AgentStore } from "@fusion/core";
 import {
   resolveAgentInstructions,
   resolveAgentInstructionsWithRatings,
+  buildAgentChatPrompt,
   buildSystemPromptWithInstructions,
 } from "../agent-instructions.js";
 
@@ -84,6 +85,19 @@ describe("resolveAgentInstructions", () => {
     expect(result).toBe("## Soul\n\nBe thorough and analytical.");
   });
 
+  it("returns memory section when memory is set", async () => {
+    const agent = makeAgent({ memory: "Remember to keep CI green." });
+    const result = await resolveAgentInstructions(agent, testDir);
+    expect(result).toBe("## Memory\n\nRemember to keep CI green.");
+  });
+
+  it("omits memory section when memory is empty", async () => {
+    const agent = makeAgent({ instructionsText: "Base instructions", memory: "   " });
+    const result = await resolveAgentInstructions(agent, testDir);
+    expect(result).toBe("Base instructions");
+    expect(result).not.toContain("## Memory");
+  });
+
   it("returns instructionsText when set", async () => {
     const agent = makeAgent({ instructionsText: "Always write tests." });
     const result = await resolveAgentInstructions(agent, testDir);
@@ -219,7 +233,7 @@ describe("resolveAgentInstructions", () => {
     expect(result.length).toBe(10000 + "## Soul\n\n".length);
   });
 
-  it("places soul section after instructionsText and before performance feedback", async () => {
+  it("places memory section after soul", async () => {
     const filePath = join(testDir, "file-instructions.md");
     await writeFile(filePath, "File-based instructions here.");
 
@@ -227,18 +241,20 @@ describe("resolveAgentInstructions", () => {
       instructionsText: "Inline instructions.",
       instructionsPath: "file-instructions.md",
       soul: "Be methodical and detailed.",
+      memory: "Remember that this repository uses pnpm workspaces.",
     });
 
     const result = await resolveAgentInstructions(agent, testDir);
 
-    // Verify section order
-    const soulIndex = result.indexOf("## Soul");
     const instructionsTextIndex = result.indexOf("Inline instructions.");
     const instructionsFileIndex = result.indexOf("File-based instructions here.");
+    const soulIndex = result.indexOf("## Soul");
+    const memoryIndex = result.indexOf("## Memory");
 
     expect(instructionsTextIndex).toBeLessThan(soulIndex);
     expect(instructionsFileIndex).toBeLessThan(soulIndex);
-    expect(soulIndex).toBeLessThan(result.indexOf("## Soul") + 10); // Soul section is present
+    expect(soulIndex).toBeLessThan(memoryIndex);
+    expect(result).toContain("## Memory\n\nRemember that this repository uses pnpm workspaces.");
   });
 });
 
@@ -279,10 +295,11 @@ describe("resolveAgentInstructions with rating summary", () => {
     expect(result).toContain('  - "Could communicate blockers sooner" (score: 4.0)');
   });
 
-  it("places soul section before performance feedback and after instructions", async () => {
+  it("places soul and memory sections before performance feedback and after instructions", async () => {
     const agent = makeAgent({
       instructionsText: "Implement the feature.",
       soul: "Be pragmatic and efficient.",
+      memory: "Past tasks with flaky tests needed retries.",
     });
     const summary = makeRatingSummary({
       totalRatings: 3,
@@ -291,14 +308,16 @@ describe("resolveAgentInstructions with rating summary", () => {
 
     const result = await resolveAgentInstructions(agent, testDir, summary);
 
-    // Verify section order: instructionsText → soul → Performance Feedback
+    // Verify section order: instructionsText → soul → memory → Performance Feedback
     const instructionsIndex = result.indexOf("Implement the feature.");
     const soulIndex = result.indexOf("## Soul");
+    const memoryIndex = result.indexOf("## Memory");
     const feedbackIndex = result.indexOf("## Performance Feedback");
 
     expect(instructionsIndex).toBeLessThan(soulIndex);
-    expect(soulIndex).toBeLessThan(feedbackIndex);
-    expect(result).toContain("## Soul");
+    expect(soulIndex).toBeLessThan(memoryIndex);
+    expect(memoryIndex).toBeLessThan(feedbackIndex);
+    expect(result).toContain("## Memory");
     expect(result).toContain("## Performance Feedback");
   });
 
@@ -465,6 +484,49 @@ describe("resolveAgentInstructionsWithRatings", () => {
   });
 });
 
+describe("buildAgentChatPrompt", () => {
+  let testDir: string;
+
+  beforeEach(async () => {
+    testDir = await mkdtemp(join(tmpdir(), "agent-chat-prompt-"));
+  });
+
+  afterEach(async () => {
+    await rm(testDir, { recursive: true, force: true });
+  });
+
+  it("builds an identity-aware prompt with soul, memory, instructions, and project memory", async () => {
+    await mkdir(join(testDir, ".fusion"), { recursive: true });
+    await writeFile(join(testDir, ".fusion", "memory.md"), "Project preference: avoid force pushes.");
+
+    const agent = makeAgent({
+      name: "Avery",
+      title: "Senior Engineer",
+      role: "reviewer",
+      instructionsText: "Always include focused tests.",
+      soul: "Be calm, direct, and empathetic.",
+      memory: "The team values short progress updates.",
+    });
+
+    const prompt = await buildAgentChatPrompt({
+      agent,
+      rootDir: testDir,
+      basePrompt: "You are a chat assistant.",
+      includeProjectMemory: true,
+    });
+
+    expect(prompt).toContain("You are a chat assistant.");
+    expect(prompt).toContain("## Custom Instructions");
+    expect(prompt).toContain(
+      "## Identity\n\nYou are Avery, Senior Engineer (agent ID: agent-test, role: reviewer).",
+    );
+    expect(prompt).toContain("Always include focused tests.");
+    expect(prompt).toContain("## Soul\n\nBe calm, direct, and empathetic.");
+    expect(prompt).toContain("## Memory\n\nThe team values short progress updates.");
+    expect(prompt).toContain("## Project Memory\n\nProject preference: avoid force pushes.");
+  });
+});
+
 describe("buildSystemPromptWithInstructions", () => {
   it("returns base prompt when instructions are empty", () => {
     const result = buildSystemPromptWithInstructions("Base prompt", "");

packages/engine/src/agent-heartbeat.test.ts

@@ -1159,6 +1159,7 @@ describe("HeartbeatMonitor", () => {
             status: "completed" as const,
           };
         }),
+        getRatingSummary: vi.fn().mockResolvedValue(undefined),
         endHeartbeatRun: vi.fn().mockResolvedValue(undefined),
         getBudgetStatus: vi.fn().mockResolvedValue(createBudgetStatus()),
         getCachedAgent: vi.fn().mockReturnValue(null),
@@ -1967,8 +1968,12 @@ describe("HeartbeatMonitor", () => {
     });
 
     describe("execution", () => {
-      it("creates session with correct system prompt and tools", async () => {
-        const store = createStoreWithAgentForExec();
+      it("creates session with enriched system prompt and expected tools", async () => {
+        const store = createStoreWithAgentForExec({
+          soul: "Act like a practical teammate who prioritizes clarity.",
+          memory: "Recent runs found flaky tests in integration suites.",
+          instructionsText: "Always log blockers with actionable next steps.",
+        });
         const mockSession = createMockAgentSession();
         mockedCreateKbAgent.mockResolvedValue({
           session: mockSession as any,
@@ -1981,7 +1986,12 @@ describe("HeartbeatMonitor", () => {
         expect(mockedCreateKbAgent).toHaveBeenCalledOnce();
         const callArgs = mockedCreateKbAgent.mock.calls[0]![0];
         expect(callArgs.cwd).toBe("/tmp/test");
-        expect(callArgs.systemPrompt).toBe(HEARTBEAT_SYSTEM_PROMPT);
+        expect(callArgs.systemPrompt).toContain(HEARTBEAT_SYSTEM_PROMPT);
+        expect(callArgs.systemPrompt).toContain("## Soul");
+        expect(callArgs.systemPrompt).toContain("Act like a practical teammate who prioritizes clarity.");
+        expect(callArgs.systemPrompt).toContain("## Memory");
+        expect(callArgs.systemPrompt).toContain("Recent runs found flaky tests in integration suites.");
+        expect(callArgs.systemPrompt).toContain("Always log blockers with actionable next steps.");
         expect(callArgs.tools).toBe("readonly");
         // Tools: task_create, task_log, task_document_write, task_document_read, list_agents, delegate_task, heartbeat_done
         expect(callArgs.customTools).toHaveLength(7);
@@ -1995,6 +2005,26 @@ describe("HeartbeatMonitor", () => {
         expect(callArgs.customTools![6]!.name).toBe("heartbeat_done");
       });
 
+      it("falls back to the base heartbeat prompt when agent has no custom instructions", async () => {
+        const store = createStoreWithAgentForExec({
+          soul: undefined,
+          memory: undefined,
+          instructionsText: undefined,
+          instructionsPath: undefined,
+        });
+        const mockSession = createMockAgentSession();
+        mockedCreateKbAgent.mockResolvedValue({
+          session: mockSession as any,
+        });
+
+        const monitor = new HeartbeatMonitor({ store, taskStore: mockTaskStore, rootDir: "/tmp/test" });
+
+        await monitor.executeHeartbeat({ agentId: "agent-001", source: "timer" });
+
+        const callArgs = mockedCreateKbAgent.mock.calls[0]![0];
+        expect(callArgs.systemPrompt).toBe(HEARTBEAT_SYSTEM_PROMPT);
+      });
+
       it("includes document tools in heartbeat session", async () => {
         const store = createStoreWithAgentForExec();
         const mockSession = createMockAgentSession();
@@ -3883,6 +3913,7 @@ describe("executeHeartbeat — skill selection resolver contract (FN-1510/FN-151
           status: "completed" as const,
         };
       }),
+      getRatingSummary: vi.fn().mockResolvedValue(undefined),
       endHeartbeatRun: vi.fn().mockResolvedValue(undefined),
       getBudgetStatus: vi.fn().mockResolvedValue(createBudgetStatus()),
       getCachedAgent: vi.fn().mockReturnValue(null),
@@ -4069,6 +4100,7 @@ describe("executeHeartbeat — skill selection non-fatal (FN-1510/FN-1511)", ()
           status: "completed" as const,
         };
       }),
+      getRatingSummary: vi.fn().mockResolvedValue(undefined),
       endHeartbeatRun: vi.fn().mockResolvedValue(undefined),
       getBudgetStatus: vi.fn().mockResolvedValue(createBudgetStatus()),
       getCachedAgent: vi.fn().mockReturnValue(null),

packages/engine/src/agent-heartbeat.ts

@@ -22,6 +22,7 @@ import type { ToolDefinition } from "@mariozechner/pi-coding-agent";
 import { Type, type Static } from "@mariozechner/pi-ai";
 import { createTaskCreateTool, createTaskLogToolWithContext, createTaskDocumentWriteTool, createTaskDocumentReadTool, createListAgentsTool, createDelegateTaskTool, createSendMessageTool, createReadMessagesTool, taskCreateParams } from "./agent-tools.js";
 import { AgentLogger } from "./agent-logger.js";
+import { resolveAgentInstructionsWithRatings, buildSystemPromptWithInstructions } from "./agent-instructions.js";
 import { heartbeatLog } from "./logger.js";
 import { createRunAuditor, type EngineRunContext } from "./run-audit.js";
 
@@ -936,10 +937,19 @@ export class HeartbeatMonitor {
         // Build skill selection context for heartbeat session (uses waking agent's skills, no role fallback)
         const skillContext = buildSessionSkillContextSync(agent, "heartbeat", rootDir);
 
+        let systemPrompt = HEARTBEAT_SYSTEM_PROMPT;
+        try {
+          const agentInstructions = await resolveAgentInstructionsWithRatings(agent, rootDir, this.store);
+          systemPrompt = buildSystemPromptWithInstructions(HEARTBEAT_SYSTEM_PROMPT, agentInstructions);
+        } catch (instructionError) {
+          const message = instructionError instanceof Error ? instructionError.message : String(instructionError);
+          heartbeatLog.warn(`Failed to enrich heartbeat system prompt for ${agentId}: ${message}`);
+        }
+
         // Create agent session
         const { session } = await createKbAgent({
           cwd: rootDir,
-          systemPrompt: HEARTBEAT_SYSTEM_PROMPT,
+          systemPrompt,
           tools: "readonly",
           customTools: heartbeatTools,
           defaultProvider: agent.runtimeConfig?.modelProvider as string | undefined,

packages/engine/src/agent-instructions.ts

@@ -1,10 +1,16 @@
 import { readFile } from "node:fs/promises";
 import { isAbsolute, resolve, relative, normalize, sep } from "node:path";
-import type { Agent, AgentRatingSummary, AgentStore } from "@fusion/core";
+import {
+  readProjectMemory,
+  type Agent,
+  type AgentRatingSummary,
+  type AgentStore,
+} from "@fusion/core";
 
 const MAX_INSTRUCTIONS_PATH_LENGTH = 500;
 const MAX_INSTRUCTIONS_TEXT_LENGTH = 50_000;
 const MAX_SOUL_LENGTH = 10_000;
+const MAX_MEMORY_LENGTH = 50_000;
 
 function trimAndClamp(value: string, maxLength: number, label: string, agentId: string): string {
   const trimmed = value.trim();
@@ -86,6 +92,14 @@ function formatSoulSection(soul: string, agentId: string): string {
   return `## Soul\n\n${trimmed}`;
 }
 
+function formatMemorySection(memory: string, agentId: string): string {
+  const trimmed = trimAndClamp(memory, MAX_MEMORY_LENGTH, "memory", agentId);
+  if (!trimmed) {
+    return "";
+  }
+  return `## Memory\n\n${trimmed}`;
+}
+
 function formatPerformanceFeedbackSection(ratingSummary: AgentRatingSummary): string {
   const lines: string[] = [
     "## Performance Feedback",
@@ -179,7 +193,7 @@ export async function resolveAgentInstructions(
     }
   }
 
-  // Soul/personality section (after instructions, before performance feedback)
+  // Soul/personality section (after instructions, before memory/performance feedback)
   if (agent.soul?.trim()) {
     const soulSection = formatSoulSection(agent.soul, agent.id);
     if (soulSection) {
@@ -187,6 +201,13 @@ export async function resolveAgentInstructions(
     }
   }
 
+  if (agent.memory?.trim()) {
+    const memorySection = formatMemorySection(agent.memory, agent.id);
+    if (memorySection) {
+      parts.push(memorySection);
+    }
+  }
+
   if (ratingSummary && ratingSummary.totalRatings > 0) {
     parts.push(formatPerformanceFeedbackSection(ratingSummary));
   }
@@ -221,6 +242,42 @@ export async function resolveAgentInstructionsWithRatings(
   }
 }
 
+export async function buildAgentChatPrompt(options: {
+  agent: Agent;
+  rootDir: string;
+  agentStore?: AgentStore;
+  basePrompt: string;
+  includeProjectMemory?: boolean;
+}): Promise<string> {
+  const { agent, rootDir, agentStore, basePrompt, includeProjectMemory = false } = options;
+
+  const titleSuffix = agent.title?.trim() ? `, ${agent.title.trim()}` : "";
+  const identitySection = `## Identity\n\nYou are ${agent.name}${titleSuffix} (agent ID: ${agent.id}, role: ${agent.role}).`;
+
+  const instructionParts = [identitySection];
+
+  const resolvedInstructions = await resolveAgentInstructionsWithRatings(agent, rootDir, agentStore);
+  if (resolvedInstructions.trim()) {
+    instructionParts.push(resolvedInstructions);
+  }
+
+  if (includeProjectMemory) {
+    try {
+      const projectMemory = (await readProjectMemory(rootDir)).trim();
+      if (projectMemory) {
+        instructionParts.push(`## Project Memory\n\n${projectMemory}`);
+      }
+    } catch (error: unknown) {
+      // Graceful fallback for chat/heartbeat: if project memory cannot be read,
+      // continue with available identity + agent instructions.
+      const message = error instanceof Error ? error.message : String(error);
+      console.warn(`[agent-instructions] Failed to read project memory for agent ${agent.id}: ${message}`);
+    }
+  }
+
+  return buildSystemPromptWithInstructions(basePrompt, instructionParts.join("\n\n"));
+}
+
 /**
  * Append a custom instructions block to a base system prompt.
  * If instructions are empty, returns the base prompt unchanged.

packages/engine/src/index.ts

@@ -26,6 +26,12 @@ export {
   type SkillDiagnostic,
 } from "./skill-resolver.js";
 export { AgentReflectionService, type AgentReflectionServiceOptions } from "./agent-reflection.js";
+export {
+  buildAgentChatPrompt,
+  resolveAgentInstructionsWithRatings,
+  resolveAgentInstructions,
+  buildSystemPromptWithInstructions,
+} from "./agent-instructions.js";
 export { WorktreePool, scanIdleWorktrees, cleanupOrphanedWorktrees } from "./worktree-pool.js";
 export { createLogger, type Logger } from "./logger.js";
 export { isUsageLimitError, UsageLimitPauser } from "./usage-limit-detector.js";