feat(orchestrator): add internal agent provider adapter

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/orchestrator/src/agent-ingestion/agent-ingestion.service.ts

@@ -25,14 +25,14 @@ export class AgentIngestionService {
       where: { sessionId: agentId },
       create: {
         sessionId: agentId,
-        parentSessionId: parentAgentId,
+        parentSessionId: parentAgentId ?? null,
         missionId,
         taskId,
         agentType,
         status: "spawning",
       },
       update: {
-        parentSessionId: parentAgentId,
+        parentSessionId: parentAgentId ?? null,
         missionId,
         taskId,
         agentType,

apps/orchestrator/src/api/agents/agent-control.service.spec.ts

@@ -0,0 +1,172 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { AgentControlService } from "./agent-control.service";
+import { PrismaService } from "../../prisma/prisma.service";
+import { KillswitchService } from "../../killswitch/killswitch.service";
+
+describe("AgentControlService", () => {
+  let service: AgentControlService;
+  let prisma: {
+    agentSessionTree: {
+      findUnique: ReturnType<typeof vi.fn>;
+      updateMany: ReturnType<typeof vi.fn>;
+    };
+    agentConversationMessage: {
+      create: ReturnType<typeof vi.fn>;
+    };
+    operatorAuditLog: {
+      create: ReturnType<typeof vi.fn>;
+    };
+  };
+  let killswitchService: {
+    killAgent: ReturnType<typeof vi.fn>;
+  };
+
+  beforeEach(() => {
+    prisma = {
+      agentSessionTree: {
+        findUnique: vi.fn(),
+        updateMany: vi.fn().mockResolvedValue({ count: 1 }),
+      },
+      agentConversationMessage: {
+        create: vi.fn().mockResolvedValue(undefined),
+      },
+      operatorAuditLog: {
+        create: vi.fn().mockResolvedValue(undefined),
+      },
+    };
+
+    killswitchService = {
+      killAgent: vi.fn().mockResolvedValue(undefined),
+    };
+
+    service = new AgentControlService(
+      prisma as unknown as PrismaService,
+      killswitchService as unknown as KillswitchService
+    );
+  });
+
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe("injectMessage", () => {
+    it("creates conversation message and audit log when tree entry exists", async () => {
+      prisma.agentSessionTree.findUnique.mockResolvedValue({ id: "tree-1" });
+
+      await service.injectMessage("agent-123", "operator-abc", "Please continue");
+
+      expect(prisma.agentSessionTree.findUnique).toHaveBeenCalledWith({
+        where: { sessionId: "agent-123" },
+        select: { id: true },
+      });
+      expect(prisma.agentConversationMessage.create).toHaveBeenCalledWith({
+        data: {
+          sessionId: "agent-123",
+          role: "operator",
+          content: "Please continue",
+          provider: "internal",
+          metadata: {},
+        },
+      });
+      expect(prisma.operatorAuditLog.create).toHaveBeenCalledWith({
+        data: {
+          sessionId: "agent-123",
+          userId: "operator-abc",
+          provider: "internal",
+          action: "inject",
+          metadata: {
+            payload: {
+              message: "Please continue",
+            },
+          },
+        },
+      });
+    });
+
+    it("creates only audit log when no tree entry exists", async () => {
+      prisma.agentSessionTree.findUnique.mockResolvedValue(null);
+
+      await service.injectMessage("agent-456", "operator-def", "Nudge message");
+
+      expect(prisma.agentConversationMessage.create).not.toHaveBeenCalled();
+      expect(prisma.operatorAuditLog.create).toHaveBeenCalledWith({
+        data: {
+          sessionId: "agent-456",
+          userId: "operator-def",
+          provider: "internal",
+          action: "inject",
+          metadata: {
+            payload: {
+              message: "Nudge message",
+            },
+          },
+        },
+      });
+    });
+  });
+
+  describe("pauseAgent", () => {
+    it("updates tree status to paused and creates audit log", async () => {
+      await service.pauseAgent("agent-789", "operator-pause");
+
+      expect(prisma.agentSessionTree.updateMany).toHaveBeenCalledWith({
+        where: { sessionId: "agent-789" },
+        data: { status: "paused" },
+      });
+      expect(prisma.operatorAuditLog.create).toHaveBeenCalledWith({
+        data: {
+          sessionId: "agent-789",
+          userId: "operator-pause",
+          provider: "internal",
+          action: "pause",
+          metadata: {
+            payload: {},
+          },
+        },
+      });
+    });
+  });
+
+  describe("resumeAgent", () => {
+    it("updates tree status to running and creates audit log", async () => {
+      await service.resumeAgent("agent-321", "operator-resume");
+
+      expect(prisma.agentSessionTree.updateMany).toHaveBeenCalledWith({
+        where: { sessionId: "agent-321" },
+        data: { status: "running" },
+      });
+      expect(prisma.operatorAuditLog.create).toHaveBeenCalledWith({
+        data: {
+          sessionId: "agent-321",
+          userId: "operator-resume",
+          provider: "internal",
+          action: "resume",
+          metadata: {
+            payload: {},
+          },
+        },
+      });
+    });
+  });
+
+  describe("killAgent", () => {
+    it("delegates kill to killswitch and logs audit", async () => {
+      await service.killAgent("agent-654", "operator-kill", false);
+
+      expect(killswitchService.killAgent).toHaveBeenCalledWith("agent-654");
+      expect(prisma.operatorAuditLog.create).toHaveBeenCalledWith({
+        data: {
+          sessionId: "agent-654",
+          userId: "operator-kill",
+          provider: "internal",
+          action: "kill",
+          metadata: {
+            payload: {
+              force: false,
+            },
+          },
+        },
+      });
+    });
+  });
+});

apps/orchestrator/src/api/agents/agent-control.service.ts

@@ -0,0 +1,77 @@
+import { Injectable } from "@nestjs/common";
+import type { Prisma } from "@prisma/client";
+import { KillswitchService } from "../../killswitch/killswitch.service";
+import { PrismaService } from "../../prisma/prisma.service";
+
+@Injectable()
+export class AgentControlService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly killswitchService: KillswitchService
+  ) {}
+
+  private toJsonValue(value: Record<string, unknown>): Prisma.InputJsonValue {
+    return value as Prisma.InputJsonValue;
+  }
+
+  private async createOperatorAuditLog(
+    agentId: string,
+    operatorId: string,
+    action: "inject" | "pause" | "resume" | "kill",
+    payload: Record<string, unknown>
+  ): Promise<void> {
+    await this.prisma.operatorAuditLog.create({
+      data: {
+        sessionId: agentId,
+        userId: operatorId,
+        provider: "internal",
+        action,
+        metadata: this.toJsonValue({ payload }),
+      },
+    });
+  }
+
+  async injectMessage(agentId: string, operatorId: string, message: string): Promise<void> {
+    const treeEntry = await this.prisma.agentSessionTree.findUnique({
+      where: { sessionId: agentId },
+      select: { id: true },
+    });
+
+    if (treeEntry) {
+      await this.prisma.agentConversationMessage.create({
+        data: {
+          sessionId: agentId,
+          role: "operator",
+          content: message,
+          provider: "internal",
+          metadata: this.toJsonValue({}),
+        },
+      });
+    }
+
+    await this.createOperatorAuditLog(agentId, operatorId, "inject", { message });
+  }
+
+  async pauseAgent(agentId: string, operatorId: string): Promise<void> {
+    await this.prisma.agentSessionTree.updateMany({
+      where: { sessionId: agentId },
+      data: { status: "paused" },
+    });
+
+    await this.createOperatorAuditLog(agentId, operatorId, "pause", {});
+  }
+
+  async resumeAgent(agentId: string, operatorId: string): Promise<void> {
+    await this.prisma.agentSessionTree.updateMany({
+      where: { sessionId: agentId },
+      data: { status: "running" },
+    });
+
+    await this.createOperatorAuditLog(agentId, operatorId, "resume", {});
+  }
+
+  async killAgent(agentId: string, operatorId: string, force = true): Promise<void> {
+    await this.killswitchService.killAgent(agentId);
+    await this.createOperatorAuditLog(agentId, operatorId, "kill", { force });
+  }
+}

apps/orchestrator/src/api/agents/agent-messages.service.spec.ts

@@ -0,0 +1,103 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { AgentMessagesService } from "./agent-messages.service";
+import { PrismaService } from "../../prisma/prisma.service";
+
+describe("AgentMessagesService", () => {
+  let service: AgentMessagesService;
+  let prisma: {
+    agentConversationMessage: {
+      findMany: ReturnType<typeof vi.fn>;
+      count: ReturnType<typeof vi.fn>;
+    };
+  };
+
+  beforeEach(() => {
+    prisma = {
+      agentConversationMessage: {
+        findMany: vi.fn(),
+        count: vi.fn(),
+      },
+    };
+
+    service = new AgentMessagesService(prisma as unknown as PrismaService);
+  });
+
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe("getMessages", () => {
+    it("returns paginated messages from Prisma", async () => {
+      const sessionId = "agent-123";
+      const messages = [
+        {
+          id: "msg-1",
+          sessionId,
+          provider: "internal",
+          role: "assistant",
+          content: "First message",
+          timestamp: new Date("2026-03-07T16:00:00.000Z"),
+          metadata: {},
+        },
+        {
+          id: "msg-2",
+          sessionId,
+          provider: "internal",
+          role: "user",
+          content: "Second message",
+          timestamp: new Date("2026-03-07T15:59:00.000Z"),
+          metadata: {},
+        },
+      ];
+
+      prisma.agentConversationMessage.findMany.mockResolvedValue(messages);
+      prisma.agentConversationMessage.count.mockResolvedValue(2);
+
+      const result = await service.getMessages(sessionId, 50, 0);
+
+      expect(prisma.agentConversationMessage.findMany).toHaveBeenCalledWith({
+        where: { sessionId },
+        orderBy: { timestamp: "desc" },
+        take: 50,
+        skip: 0,
+      });
+      expect(prisma.agentConversationMessage.count).toHaveBeenCalledWith({ where: { sessionId } });
+      expect(result).toEqual({
+        messages,
+        total: 2,
+      });
+    });
+
+    it("applies limit and cursor (skip) correctly", async () => {
+      const sessionId = "agent-456";
+      const limit = 10;
+      const cursor = 20;
+
+      prisma.agentConversationMessage.findMany.mockResolvedValue([]);
+      prisma.agentConversationMessage.count.mockResolvedValue(42);
+
+      await service.getMessages(sessionId, limit, cursor);
+
+      expect(prisma.agentConversationMessage.findMany).toHaveBeenCalledWith({
+        where: { sessionId },
+        orderBy: { timestamp: "desc" },
+        take: limit,
+        skip: cursor,
+      });
+    });
+
+    it("returns empty messages array when no messages exist", async () => {
+      const sessionId = "agent-empty";
+
+      prisma.agentConversationMessage.findMany.mockResolvedValue([]);
+      prisma.agentConversationMessage.count.mockResolvedValue(0);
+
+      const result = await service.getMessages(sessionId, 25, 0);
+
+      expect(result).toEqual({
+        messages: [],
+        total: 0,
+      });
+    });
+  });
+});

apps/orchestrator/src/api/agents/agent-messages.service.ts

@@ -0,0 +1,84 @@
+import { Injectable } from "@nestjs/common";
+import { type AgentConversationMessage, type Prisma } from "@prisma/client";
+import { PrismaService } from "../../prisma/prisma.service";
+
+@Injectable()
+export class AgentMessagesService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  async getMessages(
+    sessionId: string,
+    limit: number,
+    skip: number
+  ): Promise<{
+    messages: AgentConversationMessage[];
+    total: number;
+  }> {
+    const where = { sessionId };
+
+    const [messages, total] = await Promise.all([
+      this.prisma.agentConversationMessage.findMany({
+        where,
+        orderBy: {
+          timestamp: "desc",
+        },
+        take: limit,
+        skip,
+      }),
+      this.prisma.agentConversationMessage.count({ where }),
+    ]);
+
+    return {
+      messages,
+      total,
+    };
+  }
+
+  async getReplayMessages(sessionId: string, limit = 50): Promise<AgentConversationMessage[]> {
+    const messages = await this.prisma.agentConversationMessage.findMany({
+      where: { sessionId },
+      orderBy: {
+        timestamp: "desc",
+      },
+      take: limit,
+    });
+
+    return messages.reverse();
+  }
+
+  async getMessagesAfter(
+    sessionId: string,
+    lastSeenTimestamp: Date,
+    lastSeenMessageId: string | null
+  ): Promise<AgentConversationMessage[]> {
+    const where: Prisma.AgentConversationMessageWhereInput = {
+      sessionId,
+      ...(lastSeenMessageId
+        ? {
+            OR: [
+              {
+                timestamp: {
+                  gt: lastSeenTimestamp,
+                },
+              },
+              {
+                timestamp: lastSeenTimestamp,
+                id: {
+                  gt: lastSeenMessageId,
+                },
+              },
+            ],
+          }
+        : {
+            timestamp: {
+              gt: lastSeenTimestamp,
+            },
+          }),
+    };
+
+    return this.prisma.agentConversationMessage.findMany({
+      where,
+      orderBy: [{ timestamp: "asc" }, { id: "asc" }],
+    });
+  }
+}

apps/orchestrator/src/api/agents/agent-tree.service.spec.ts

@@ -0,0 +1,245 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { AgentTreeService } from "./agent-tree.service";
+import { PrismaService } from "../../prisma/prisma.service";
+
+describe("AgentTreeService", () => {
+  let service: AgentTreeService;
+  let prisma: {
+    agentSessionTree: {
+      findMany: ReturnType<typeof vi.fn>;
+      count: ReturnType<typeof vi.fn>;
+      findUnique: ReturnType<typeof vi.fn>;
+    };
+  };
+
+  beforeEach(() => {
+    prisma = {
+      agentSessionTree: {
+        findMany: vi.fn(),
+        count: vi.fn(),
+        findUnique: vi.fn(),
+      },
+    };
+
+    service = new AgentTreeService(prisma as unknown as PrismaService);
+  });
+
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe("listSessions", () => {
+    it("returns paginated sessions and cursor", async () => {
+      const sessions = [
+        {
+          id: "tree-2",
+          sessionId: "agent-2",
+          parentSessionId: null,
+          provider: "internal",
+          missionId: null,
+          taskId: "task-2",
+          taskSource: "queue",
+          agentType: "worker",
+          status: "running",
+          spawnedAt: new Date("2026-03-07T11:00:00.000Z"),
+          completedAt: null,
+          metadata: {},
+        },
+        {
+          id: "tree-1",
+          sessionId: "agent-1",
+          parentSessionId: null,
+          provider: "internal",
+          missionId: null,
+          taskId: "task-1",
+          taskSource: "queue",
+          agentType: "worker",
+          status: "running",
+          spawnedAt: new Date("2026-03-07T10:00:00.000Z"),
+          completedAt: null,
+          metadata: {},
+        },
+      ];
+
+      prisma.agentSessionTree.findMany.mockResolvedValue(sessions);
+      prisma.agentSessionTree.count.mockResolvedValue(7);
+
+      const result = await service.listSessions(undefined, 2);
+
+      expect(prisma.agentSessionTree.findMany).toHaveBeenCalledWith({
+        where: undefined,
+        orderBy: [{ spawnedAt: "desc" }, { sessionId: "desc" }],
+        take: 2,
+      });
+      expect(prisma.agentSessionTree.count).toHaveBeenCalledWith();
+      expect(result.sessions).toEqual(sessions);
+      expect(result.total).toBe(7);
+      expect(result.cursor).toBeTypeOf("string");
+    });
+
+    it("applies cursor filter when provided", async () => {
+      prisma.agentSessionTree.findMany.mockResolvedValue([]);
+      prisma.agentSessionTree.count.mockResolvedValue(0);
+
+      const cursorDate = "2026-03-07T10:00:00.000Z";
+      const cursorSessionId = "agent-5";
+      const cursor = Buffer.from(
+        JSON.stringify({
+          spawnedAt: cursorDate,
+          sessionId: cursorSessionId,
+        }),
+        "utf8"
+      ).toString("base64url");
+
+      await service.listSessions(cursor, 25);
+
+      expect(prisma.agentSessionTree.findMany).toHaveBeenCalledWith({
+        where: {
+          OR: [
+            {
+              spawnedAt: {
+                lt: new Date(cursorDate),
+              },
+            },
+            {
+              spawnedAt: new Date(cursorDate),
+              sessionId: {
+                lt: cursorSessionId,
+              },
+            },
+          ],
+        },
+        orderBy: [{ spawnedAt: "desc" }, { sessionId: "desc" }],
+        take: 25,
+      });
+    });
+
+    it("ignores invalid cursor values", async () => {
+      prisma.agentSessionTree.findMany.mockResolvedValue([]);
+      prisma.agentSessionTree.count.mockResolvedValue(0);
+
+      await service.listSessions("invalid-cursor", 10);
+
+      expect(prisma.agentSessionTree.findMany).toHaveBeenCalledWith({
+        where: undefined,
+        orderBy: [{ spawnedAt: "desc" }, { sessionId: "desc" }],
+        take: 10,
+      });
+    });
+  });
+
+  describe("getSession", () => {
+    it("returns matching session entry", async () => {
+      const session = {
+        id: "tree-1",
+        sessionId: "agent-123",
+        parentSessionId: null,
+        provider: "internal",
+        missionId: null,
+        taskId: "task-1",
+        taskSource: "queue",
+        agentType: "worker",
+        status: "running",
+        spawnedAt: new Date("2026-03-07T11:00:00.000Z"),
+        completedAt: null,
+        metadata: {},
+      };
+      prisma.agentSessionTree.findUnique.mockResolvedValue(session);
+
+      const result = await service.getSession("agent-123");
+
+      expect(prisma.agentSessionTree.findUnique).toHaveBeenCalledWith({
+        where: { sessionId: "agent-123" },
+      });
+      expect(result).toEqual(session);
+    });
+
+    it("returns null when session does not exist", async () => {
+      prisma.agentSessionTree.findUnique.mockResolvedValue(null);
+
+      const result = await service.getSession("agent-missing");
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("getTree", () => {
+    it("returns mapped entries from Prisma", async () => {
+      prisma.agentSessionTree.findMany.mockResolvedValue([
+        {
+          id: "tree-1",
+          sessionId: "agent-1",
+          parentSessionId: "agent-root",
+          provider: "internal",
+          missionId: "mission-1",
+          taskId: "task-1",
+          taskSource: "queue",
+          agentType: "worker",
+          status: "running",
+          spawnedAt: new Date("2026-03-07T10:00:00.000Z"),
+          completedAt: new Date("2026-03-07T11:00:00.000Z"),
+          metadata: {},
+        },
+      ]);
+
+      const result = await service.getTree();
+
+      expect(prisma.agentSessionTree.findMany).toHaveBeenCalledWith({
+        orderBy: { spawnedAt: "desc" },
+        take: 200,
+      });
+      expect(result).toEqual([
+        {
+          sessionId: "agent-1",
+          parentSessionId: "agent-root",
+          status: "running",
+          agentType: "worker",
+          taskSource: "queue",
+          spawnedAt: "2026-03-07T10:00:00.000Z",
+          completedAt: "2026-03-07T11:00:00.000Z",
+        },
+      ]);
+    });
+
+    it("returns empty array when no entries exist", async () => {
+      prisma.agentSessionTree.findMany.mockResolvedValue([]);
+
+      const result = await service.getTree();
+
+      expect(result).toEqual([]);
+    });
+
+    it("maps null parentSessionId and completedAt correctly", async () => {
+      prisma.agentSessionTree.findMany.mockResolvedValue([
+        {
+          id: "tree-2",
+          sessionId: "agent-root",
+          parentSessionId: null,
+          provider: "internal",
+          missionId: null,
+          taskId: null,
+          taskSource: null,
+          agentType: null,
+          status: "spawning",
+          spawnedAt: new Date("2026-03-07T09:00:00.000Z"),
+          completedAt: null,
+          metadata: {},
+        },
+      ]);
+
+      const result = await service.getTree();
+
+      expect(result).toEqual([
+        {
+          sessionId: "agent-root",
+          parentSessionId: null,
+          status: "spawning",
+          agentType: null,
+          taskSource: null,
+          spawnedAt: "2026-03-07T09:00:00.000Z",
+          completedAt: null,
+        },
+      ]);
+    });
+  });
+});

apps/orchestrator/src/api/agents/agent-tree.service.ts

@@ -0,0 +1,146 @@
+import { Injectable } from "@nestjs/common";
+import type { AgentSessionTree, Prisma } from "@prisma/client";
+import { AgentTreeResponseDto } from "./dto/agent-tree-response.dto";
+import { PrismaService } from "../../prisma/prisma.service";
+
+const DEFAULT_PAGE_LIMIT = 50;
+const MAX_PAGE_LIMIT = 200;
+
+interface SessionCursor {
+  spawnedAt: Date;
+  sessionId: string;
+}
+
+export interface AgentSessionTreeListResult {
+  sessions: AgentSessionTree[];
+  total: number;
+  cursor?: string;
+}
+
+@Injectable()
+export class AgentTreeService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  async listSessions(
+    cursor?: string,
+    limit = DEFAULT_PAGE_LIMIT
+  ): Promise<AgentSessionTreeListResult> {
+    const safeLimit = this.normalizeLimit(limit);
+    const parsedCursor = this.parseCursor(cursor);
+
+    const where: Prisma.AgentSessionTreeWhereInput | undefined = parsedCursor
+      ? {
+          OR: [
+            {
+              spawnedAt: {
+                lt: parsedCursor.spawnedAt,
+              },
+            },
+            {
+              spawnedAt: parsedCursor.spawnedAt,
+              sessionId: {
+                lt: parsedCursor.sessionId,
+              },
+            },
+          ],
+        }
+      : undefined;
+
+    const [sessions, total] = await Promise.all([
+      this.prisma.agentSessionTree.findMany({
+        where,
+        orderBy: [{ spawnedAt: "desc" }, { sessionId: "desc" }],
+        take: safeLimit,
+      }),
+      this.prisma.agentSessionTree.count(),
+    ]);
+
+    const nextCursor =
+      sessions.length === safeLimit
+        ? this.serializeCursor(sessions[sessions.length - 1])
+        : undefined;
+
+    return {
+      sessions,
+      total,
+      ...(nextCursor !== undefined ? { cursor: nextCursor } : {}),
+    };
+  }
+
+  async getSession(sessionId: string): Promise<AgentSessionTree | null> {
+    return this.prisma.agentSessionTree.findUnique({
+      where: { sessionId },
+    });
+  }
+
+  async getTree(): Promise<AgentTreeResponseDto[]> {
+    const entries = await this.prisma.agentSessionTree.findMany({
+      orderBy: { spawnedAt: "desc" },
+      take: 200,
+    });
+
+    const response: AgentTreeResponseDto[] = [];
+    for (const entry of entries) {
+      response.push({
+        sessionId: entry.sessionId,
+        parentSessionId: entry.parentSessionId ?? null,
+        status: entry.status,
+        agentType: entry.agentType ?? null,
+        taskSource: entry.taskSource ?? null,
+        spawnedAt: entry.spawnedAt.toISOString(),
+        completedAt: entry.completedAt?.toISOString() ?? null,
+      });
+    }
+
+    return response;
+  }
+
+  private normalizeLimit(limit: number): number {
+    const normalized = Number.isFinite(limit) ? Math.trunc(limit) : DEFAULT_PAGE_LIMIT;
+    if (normalized < 1) {
+      return 1;
+    }
+
+    return Math.min(normalized, MAX_PAGE_LIMIT);
+  }
+
+  private serializeCursor(entry: Pick<AgentSessionTree, "spawnedAt" | "sessionId">): string {
+    return Buffer.from(
+      JSON.stringify({
+        spawnedAt: entry.spawnedAt.toISOString(),
+        sessionId: entry.sessionId,
+      }),
+      "utf8"
+    ).toString("base64url");
+  }
+
+  private parseCursor(cursor?: string): SessionCursor | null {
+    if (!cursor) {
+      return null;
+    }
+
+    try {
+      const decoded = Buffer.from(cursor, "base64url").toString("utf8");
+      const parsed = JSON.parse(decoded) as {
+        spawnedAt?: string;
+        sessionId?: string;
+      };
+
+      if (typeof parsed.spawnedAt !== "string" || typeof parsed.sessionId !== "string") {
+        return null;
+      }
+
+      const spawnedAt = new Date(parsed.spawnedAt);
+      if (Number.isNaN(spawnedAt.getTime())) {
+        return null;
+      }
+
+      return {
+        spawnedAt,
+        sessionId: parsed.sessionId,
+      };
+    } catch {
+      return null;
+    }
+  }
+}

apps/orchestrator/src/api/agents/agents-killswitch.controller.spec.ts

@@ -5,6 +5,9 @@ import { AgentSpawnerService } from "../../spawner/agent-spawner.service";
 import { AgentLifecycleService } from "../../spawner/agent-lifecycle.service";
 import { KillswitchService } from "../../killswitch/killswitch.service";
 import { AgentEventsService } from "./agent-events.service";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentControlService } from "./agent-control.service";
+import { AgentTreeService } from "./agent-tree.service";
 import type { KillAllResult } from "../../killswitch/killswitch.service";
 
 describe("AgentsController - Killswitch Endpoints", () => {
@@ -27,6 +30,20 @@ describe("AgentsController - Killswitch Endpoints", () => {
     subscribe: ReturnType<typeof vi.fn>;
     getInitialSnapshot: ReturnType<typeof vi.fn>;
     createHeartbeat: ReturnType<typeof vi.fn>;
+    getRecentEvents: ReturnType<typeof vi.fn>;
+  };
+  let mockMessagesService: {
+    getMessages: ReturnType<typeof vi.fn>;
+    getReplayMessages: ReturnType<typeof vi.fn>;
+    getMessagesAfter: ReturnType<typeof vi.fn>;
+  };
+  let mockControlService: {
+    injectMessage: ReturnType<typeof vi.fn>;
+    pauseAgent: ReturnType<typeof vi.fn>;
+    resumeAgent: ReturnType<typeof vi.fn>;
+  };
+  let mockTreeService: {
+    getTree: ReturnType<typeof vi.fn>;
   };
 
   beforeEach(() => {
@@ -61,6 +78,23 @@ describe("AgentsController - Killswitch Endpoints", () => {
         timestamp: new Date().toISOString(),
         data: { heartbeat: true },
       }),
+      getRecentEvents: vi.fn().mockReturnValue([]),
+    };
+
+    mockMessagesService = {
+      getMessages: vi.fn(),
+      getReplayMessages: vi.fn().mockResolvedValue([]),
+      getMessagesAfter: vi.fn().mockResolvedValue([]),
+    };
+
+    mockControlService = {
+      injectMessage: vi.fn().mockResolvedValue(undefined),
+      pauseAgent: vi.fn().mockResolvedValue(undefined),
+      resumeAgent: vi.fn().mockResolvedValue(undefined),
+    };
+
+    mockTreeService = {
+      getTree: vi.fn().mockResolvedValue([]),
     };
 
     controller = new AgentsController(
@@ -68,7 +102,10 @@ describe("AgentsController - Killswitch Endpoints", () => {
       mockSpawnerService as unknown as AgentSpawnerService,
       mockLifecycleService as unknown as AgentLifecycleService,
       mockKillswitchService as unknown as KillswitchService,
-      mockEventsService as unknown as AgentEventsService
+      mockEventsService as unknown as AgentEventsService,
+      mockMessagesService as unknown as AgentMessagesService,
+      mockControlService as unknown as AgentControlService,
+      mockTreeService as unknown as AgentTreeService
     );
   });
 

apps/orchestrator/src/api/agents/agents.controller.spec.ts

@@ -4,6 +4,9 @@ import { AgentSpawnerService } from "../../spawner/agent-spawner.service";
 import { AgentLifecycleService } from "../../spawner/agent-lifecycle.service";
 import { KillswitchService } from "../../killswitch/killswitch.service";
 import { AgentEventsService } from "./agent-events.service";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentControlService } from "./agent-control.service";
+import { AgentTreeService } from "./agent-tree.service";
 import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
 
 describe("AgentsController", () => {
@@ -30,6 +33,19 @@ describe("AgentsController", () => {
     createHeartbeat: ReturnType<typeof vi.fn>;
     getRecentEvents: ReturnType<typeof vi.fn>;
   };
+  let messagesService: {
+    getMessages: ReturnType<typeof vi.fn>;
+    getReplayMessages: ReturnType<typeof vi.fn>;
+    getMessagesAfter: ReturnType<typeof vi.fn>;
+  };
+  let controlService: {
+    injectMessage: ReturnType<typeof vi.fn>;
+    pauseAgent: ReturnType<typeof vi.fn>;
+    resumeAgent: ReturnType<typeof vi.fn>;
+  };
+  let treeService: {
+    getTree: ReturnType<typeof vi.fn>;
+  };
 
   beforeEach(() => {
     // Create mock services
@@ -69,13 +85,32 @@ describe("AgentsController", () => {
       getRecentEvents: vi.fn().mockReturnValue([]),
     };
 
+    messagesService = {
+      getMessages: vi.fn(),
+      getReplayMessages: vi.fn().mockResolvedValue([]),
+      getMessagesAfter: vi.fn().mockResolvedValue([]),
+    };
+
+    controlService = {
+      injectMessage: vi.fn().mockResolvedValue(undefined),
+      pauseAgent: vi.fn().mockResolvedValue(undefined),
+      resumeAgent: vi.fn().mockResolvedValue(undefined),
+    };
+
+    treeService = {
+      getTree: vi.fn().mockResolvedValue([]),
+    };
+
     // Create controller with mocked services
     controller = new AgentsController(
       queueService as unknown as QueueService,
       spawnerService as unknown as AgentSpawnerService,
       lifecycleService as unknown as AgentLifecycleService,
       killswitchService as unknown as KillswitchService,
-      eventsService as unknown as AgentEventsService
+      eventsService as unknown as AgentEventsService,
+      messagesService as unknown as AgentMessagesService,
+      controlService as unknown as AgentControlService,
+      treeService as unknown as AgentTreeService
     );
   });
 
@@ -87,6 +122,27 @@ describe("AgentsController", () => {
     expect(controller).toBeDefined();
   });
 
+  describe("getAgentTree", () => {
+    it("should return tree entries", async () => {
+      const entries = [
+        {
+          sessionId: "agent-1",
+          parentSessionId: null,
+          status: "running",
+          agentType: "worker",
+          taskSource: "internal",
+          spawnedAt: "2026-03-07T00:00:00.000Z",
+          completedAt: null,
+        },
+      ];
+
+      treeService.getTree.mockResolvedValue(entries);
+
+      await expect(controller.getAgentTree()).resolves.toEqual(entries);
+      expect(treeService.getTree).toHaveBeenCalledTimes(1);
+    });
+  });
+
   describe("listAgents", () => {
     it("should return empty array when no agents exist", () => {
       // Arrange
@@ -365,6 +421,93 @@ describe("AgentsController", () => {
     });
   });
 
+  describe("agent control endpoints", () => {
+    const agentId = "0b64079f-4487-42b9-92eb-cf8ea0042a64";
+
+    it("should inject an operator message", async () => {
+      const req = { apiKey: "control-key" };
+
+      const result = await controller.injectAgentMessage(
+        agentId,
+        { message: "pause and summarize" },
+        req
+      );
+
+      expect(controlService.injectMessage).toHaveBeenCalledWith(
+        agentId,
+        "control-key",
+        "pause and summarize"
+      );
+      expect(result).toEqual({ message: `Message injected into agent ${agentId}` });
+    });
+
+    it("should default operator id when request api key is missing", async () => {
+      await controller.injectAgentMessage(agentId, { message: "continue" }, {});
+
+      expect(controlService.injectMessage).toHaveBeenCalledWith(agentId, "operator", "continue");
+    });
+
+    it("should pause an agent", async () => {
+      const result = await controller.pauseAgent(agentId, {}, { apiKey: "ops-user" });
+
+      expect(controlService.pauseAgent).toHaveBeenCalledWith(agentId, "ops-user");
+      expect(result).toEqual({ message: `Agent ${agentId} paused` });
+    });
+
+    it("should resume an agent", async () => {
+      const result = await controller.resumeAgent(agentId, {}, { apiKey: "ops-user" });
+
+      expect(controlService.resumeAgent).toHaveBeenCalledWith(agentId, "ops-user");
+      expect(result).toEqual({ message: `Agent ${agentId} resumed` });
+    });
+  });
+
+  describe("getAgentMessages", () => {
+    it("should return paginated message history", async () => {
+      const agentId = "0b64079f-4487-42b9-92eb-cf8ea0042a64";
+      const query = {
+        limit: 25,
+        skip: 10,
+      };
+
+      const response = {
+        messages: [
+          {
+            id: "msg-1",
+            sessionId: agentId,
+            role: "agent",
+            content: "hello",
+            provider: "internal",
+            timestamp: new Date("2026-03-07T03:00:00.000Z"),
+            metadata: {},
+          },
+        ],
+        total: 101,
+      };
+
+      messagesService.getMessages.mockResolvedValue(response);
+
+      const result = await controller.getAgentMessages(agentId, query);
+
+      expect(messagesService.getMessages).toHaveBeenCalledWith(agentId, 25, 10);
+      expect(result).toEqual(response);
+    });
+
+    it("should use default pagination values", async () => {
+      const agentId = "0b64079f-4487-42b9-92eb-cf8ea0042a64";
+      const query = {
+        limit: 50,
+        skip: 0,
+      };
+
+      messagesService.getMessages.mockResolvedValue({ messages: [], total: 0 });
+
+      await controller.getAgentMessages(agentId, query);
+
+      expect(messagesService.getMessages).toHaveBeenCalledWith(agentId, 50, 0);
+    });
+  });
+
   describe("getRecentEvents", () => {
     it("should return recent events with default limit", () => {
       eventsService.getRecentEvents.mockReturnValue([

apps/orchestrator/src/api/agents/agents.controller.ts

@@ -14,7 +14,9 @@ import {
   Sse,
   MessageEvent,
   Query,
+  Request,
 } from "@nestjs/common";
+import type { AgentConversationMessage } from "@prisma/client";
 import { Throttle } from "@nestjs/throttler";
 import { Observable } from "rxjs";
 import { QueueService } from "../../queue/queue.service";
@@ -25,6 +27,13 @@ import { SpawnAgentDto, SpawnAgentResponseDto } from "./dto/spawn-agent.dto";
 import { OrchestratorApiKeyGuard } from "../../common/guards/api-key.guard";
 import { OrchestratorThrottlerGuard } from "../../common/guards/throttler.guard";
 import { AgentEventsService } from "./agent-events.service";
+import { GetMessagesQueryDto } from "./dto/get-messages-query.dto";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentControlService } from "./agent-control.service";
+import { AgentTreeService } from "./agent-tree.service";
+import { AgentTreeResponseDto } from "./dto/agent-tree-response.dto";
+import { InjectAgentDto } from "./dto/inject-agent.dto";
+import { PauseAgentDto, ResumeAgentDto } from "./dto/control-agent.dto";
 
 /**
  * Controller for agent management endpoints
@@ -47,7 +56,10 @@ export class AgentsController {
     private readonly spawnerService: AgentSpawnerService,
     private readonly lifecycleService: AgentLifecycleService,
     private readonly killswitchService: KillswitchService,
-    private readonly eventsService: AgentEventsService
+    private readonly eventsService: AgentEventsService,
+    private readonly messagesService: AgentMessagesService,
+    private readonly agentControlService: AgentControlService,
+    private readonly agentTreeService: AgentTreeService
   ) {}
 
   /**
@@ -69,6 +81,7 @@ export class AgentsController {
       // Spawn agent using spawner service
       const spawnResponse = this.spawnerService.spawnAgent({
         taskId: dto.taskId,
+        ...(dto.parentAgentId !== undefined ? { parentAgentId: dto.parentAgentId } : {}),
         agentType: dto.agentType,
         context: dto.context,
       });
@@ -143,6 +156,13 @@ export class AgentsController {
     };
   }
 
+  @Get("tree")
+  @UseGuards(OrchestratorApiKeyGuard)
+  @Throttle({ default: { limit: 200, ttl: 60000 } })
+  async getAgentTree(): Promise<AgentTreeResponseDto[]> {
+    return this.agentTreeService.getTree();
+  }
+
   /**
    * List all agents
    * @returns Array of all agent sessions with their status
@@ -185,6 +205,107 @@ export class AgentsController {
     }
   }
 
+  /**
+   * Get paginated message history for an agent.
+   */
+  @Get(":agentId/messages")
+  @Throttle({ status: { limit: 200, ttl: 60000 } })
+  @UsePipes(new ValidationPipe({ transform: true, whitelist: true }))
+  async getAgentMessages(
+    @Param("agentId", ParseUUIDPipe) agentId: string,
+    @Query() query: GetMessagesQueryDto
+  ): Promise<{
+    messages: AgentConversationMessage[];
+    total: number;
+  }> {
+    return this.messagesService.getMessages(agentId, query.limit, query.skip);
+  }
+
+  /**
+   * Stream per-agent conversation messages as server-sent events (SSE).
+   */
+  @Sse(":agentId/messages/stream")
+  @Throttle({ status: { limit: 200, ttl: 60000 } })
+  streamAgentMessages(@Param("agentId", ParseUUIDPipe) agentId: string): Observable<MessageEvent> {
+    return new Observable<MessageEvent>((subscriber) => {
+      let isClosed = false;
+      let lastSeenTimestamp = new Date();
+      let lastSeenMessageId: string | null = null;
+
+      const emitMessage = (message: AgentConversationMessage): void => {
+        if (isClosed) {
+          return;
+        }
+
+        subscriber.next({
+          data: this.toMessageStreamPayload(message),
+        });
+
+        lastSeenTimestamp = message.timestamp;
+        lastSeenMessageId = message.id;
+      };
+
+      void this.messagesService
+        .getReplayMessages(agentId, 50)
+        .then((messages) => {
+          if (isClosed) {
+            return;
+          }
+
+          messages.forEach((message) => {
+            emitMessage(message);
+          });
+
+          if (messages.length === 0) {
+            lastSeenTimestamp = new Date();
+            lastSeenMessageId = null;
+          }
+        })
+        .catch((error: unknown) => {
+          this.logger.error(
+            `Failed to load replay messages for ${agentId}: ${error instanceof Error ? error.message : String(error)}`
+          );
+          lastSeenTimestamp = new Date();
+          lastSeenMessageId = null;
+        });
+
+      const pollInterval = setInterval(() => {
+        if (isClosed) {
+          return;
+        }
+
+        void this.messagesService
+          .getMessagesAfter(agentId, lastSeenTimestamp, lastSeenMessageId)
+          .then((messages) => {
+            if (isClosed || messages.length === 0) {
+              return;
+            }
+
+            messages.forEach((message) => {
+              emitMessage(message);
+            });
+          })
+          .catch((error: unknown) => {
+            this.logger.error(
+              `Failed to poll messages for ${agentId}: ${error instanceof Error ? error.message : String(error)}`
+            );
+          });
+      }, 1000);
+
+      const heartbeat = setInterval(() => {
+        if (!isClosed) {
+          subscriber.next({ data: { type: "heartbeat" } });
+        }
+      }, 15000);
+
+      return () => {
+        isClosed = true;
+        clearInterval(pollInterval);
+        clearInterval(heartbeat);
+      };
+    });
+  }
+
   /**
    * Get agent status
    * @param agentId Agent ID to query
@@ -269,6 +390,57 @@ export class AgentsController {
     }
   }
 
+  @Post(":agentId/inject")
+  @Throttle({ default: { limit: 10, ttl: 60000 } })
+  @HttpCode(200)
+  @UsePipes(new ValidationPipe({ transform: true, whitelist: true }))
+  async injectAgentMessage(
+    @Param("agentId", ParseUUIDPipe) agentId: string,
+    @Body() dto: InjectAgentDto,
+    @Request() req: { apiKey?: string }
+  ): Promise<{ message: string }> {
+    const operatorId = req.apiKey ?? "operator";
+    await this.agentControlService.injectMessage(agentId, operatorId, dto.message);
+
+    return {
+      message: `Message injected into agent ${agentId}`,
+    };
+  }
+
+  @Post(":agentId/pause")
+  @Throttle({ default: { limit: 10, ttl: 60000 } })
+  @HttpCode(200)
+  @UsePipes(new ValidationPipe({ transform: true, whitelist: true }))
+  async pauseAgent(
+    @Param("agentId", ParseUUIDPipe) agentId: string,
+    @Body() _dto: PauseAgentDto,
+    @Request() req: { apiKey?: string }
+  ): Promise<{ message: string }> {
+    const operatorId = req.apiKey ?? "operator";
+    await this.agentControlService.pauseAgent(agentId, operatorId);
+
+    return {
+      message: `Agent ${agentId} paused`,
+    };
+  }
+
+  @Post(":agentId/resume")
+  @Throttle({ default: { limit: 10, ttl: 60000 } })
+  @HttpCode(200)
+  @UsePipes(new ValidationPipe({ transform: true, whitelist: true }))
+  async resumeAgent(
+    @Param("agentId", ParseUUIDPipe) agentId: string,
+    @Body() _dto: ResumeAgentDto,
+    @Request() req: { apiKey?: string }
+  ): Promise<{ message: string }> {
+    const operatorId = req.apiKey ?? "operator";
+    await this.agentControlService.resumeAgent(agentId, operatorId);
+
+    return {
+      message: `Agent ${agentId} resumed`,
+    };
+  }
+
   /**
    * Kill all active agents
    * @returns Summary of kill operation
@@ -301,4 +473,24 @@ export class AgentsController {
       throw error;
     }
   }
+
+  private toMessageStreamPayload(message: AgentConversationMessage): {
+    messageId: string;
+    sessionId: string;
+    role: string;
+    content: string;
+    provider: string;
+    timestamp: string;
+    metadata: unknown;
+  } {
+    return {
+      messageId: message.id,
+      sessionId: message.sessionId,
+      role: message.role,
+      content: message.content,
+      provider: message.provider,
+      timestamp: message.timestamp.toISOString(),
+      metadata: message.metadata,
+    };
+  }
 }

apps/orchestrator/src/api/agents/agents.module.ts

@@ -6,10 +6,23 @@ import { KillswitchModule } from "../../killswitch/killswitch.module";
 import { ValkeyModule } from "../../valkey/valkey.module";
 import { OrchestratorApiKeyGuard } from "../../common/guards/api-key.guard";
 import { AgentEventsService } from "./agent-events.service";
+import { PrismaModule } from "../../prisma/prisma.module";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentControlService } from "./agent-control.service";
+import { AgentTreeService } from "./agent-tree.service";
+import { InternalAgentProvider } from "./internal-agent.provider";
 
 @Module({
-  imports: [QueueModule, SpawnerModule, KillswitchModule, ValkeyModule],
+  imports: [QueueModule, SpawnerModule, KillswitchModule, ValkeyModule, PrismaModule],
   controllers: [AgentsController],
-  providers: [OrchestratorApiKeyGuard, AgentEventsService],
+  providers: [
+    OrchestratorApiKeyGuard,
+    AgentEventsService,
+    AgentMessagesService,
+    AgentControlService,
+    AgentTreeService,
+    InternalAgentProvider,
+  ],
+  exports: [InternalAgentProvider],
 })
 export class AgentsModule {}

apps/orchestrator/src/api/agents/dto/agent-tree-response.dto.ts

@@ -0,0 +1,9 @@
+export class AgentTreeResponseDto {
+  sessionId!: string;
+  parentSessionId!: string | null;
+  status!: string;
+  agentType!: string | null;
+  taskSource!: string | null;
+  spawnedAt!: string;
+  completedAt!: string | null;
+}

apps/orchestrator/src/api/agents/dto/control-agent.dto.ts

@@ -0,0 +1,3 @@
+export class PauseAgentDto {}
+
+export class ResumeAgentDto {}

apps/orchestrator/src/api/agents/dto/get-messages-query.dto.spec.ts

@@ -0,0 +1,37 @@
+import { plainToInstance } from "class-transformer";
+import { validate } from "class-validator";
+import { describe, expect, it } from "vitest";
+import { GetMessagesQueryDto } from "./get-messages-query.dto";
+
+describe("GetMessagesQueryDto", () => {
+  it("should use defaults when empty", async () => {
+    const dto = plainToInstance(GetMessagesQueryDto, {});
+    const errors = await validate(dto);
+
+    expect(errors).toHaveLength(0);
+    expect(dto.limit).toBe(50);
+    expect(dto.skip).toBe(0);
+  });
+
+  it("should reject limit greater than 200", async () => {
+    const dto = plainToInstance(GetMessagesQueryDto, {
+      limit: 201,
+      skip: 0,
+    });
+    const errors = await validate(dto);
+
+    expect(errors.length).toBeGreaterThan(0);
+    expect(errors.some((error) => error.property === "limit")).toBe(true);
+  });
+
+  it("should reject negative skip", async () => {
+    const dto = plainToInstance(GetMessagesQueryDto, {
+      limit: 50,
+      skip: -1,
+    });
+    const errors = await validate(dto);
+
+    expect(errors.length).toBeGreaterThan(0);
+    expect(errors.some((error) => error.property === "skip")).toBe(true);
+  });
+});

apps/orchestrator/src/api/agents/dto/get-messages-query.dto.ts

@@ -0,0 +1,17 @@
+import { Type } from "class-transformer";
+import { IsInt, IsOptional, Max, Min } from "class-validator";
+
+export class GetMessagesQueryDto {
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  @Max(200)
+  limit = 50;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(0)
+  skip = 0;
+}

apps/orchestrator/src/api/agents/dto/inject-agent.dto.ts

@@ -0,0 +1,7 @@
+import { IsNotEmpty, IsString } from "class-validator";
+
+export class InjectAgentDto {
+  @IsString()
+  @IsNotEmpty()
+  message!: string;
+}

apps/orchestrator/src/api/agents/dto/spawn-agent.dto.ts

@@ -116,6 +116,10 @@ export class SpawnAgentDto {
   @IsOptional()
   @IsIn(["strict", "standard", "minimal", "custom"])
   gateProfile?: GateProfileType;
+
+  @IsOptional()
+  @IsString()
+  parentAgentId?: string;
 }
 
 /**

apps/orchestrator/src/api/agents/internal-agent.provider.spec.ts

@@ -0,0 +1,216 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { AgentConversationMessage, AgentSessionTree } from "@prisma/client";
+import { AgentControlService } from "./agent-control.service";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentTreeService } from "./agent-tree.service";
+import { InternalAgentProvider } from "./internal-agent.provider";
+
+describe("InternalAgentProvider", () => {
+  let provider: InternalAgentProvider;
+  let messagesService: {
+    getMessages: ReturnType<typeof vi.fn>;
+    getReplayMessages: ReturnType<typeof vi.fn>;
+    getMessagesAfter: ReturnType<typeof vi.fn>;
+  };
+  let controlService: {
+    injectMessage: ReturnType<typeof vi.fn>;
+    pauseAgent: ReturnType<typeof vi.fn>;
+    resumeAgent: ReturnType<typeof vi.fn>;
+    killAgent: ReturnType<typeof vi.fn>;
+  };
+  let treeService: {
+    listSessions: ReturnType<typeof vi.fn>;
+    getSession: ReturnType<typeof vi.fn>;
+  };
+
+  beforeEach(() => {
+    messagesService = {
+      getMessages: vi.fn(),
+      getReplayMessages: vi.fn(),
+      getMessagesAfter: vi.fn(),
+    };
+
+    controlService = {
+      injectMessage: vi.fn().mockResolvedValue(undefined),
+      pauseAgent: vi.fn().mockResolvedValue(undefined),
+      resumeAgent: vi.fn().mockResolvedValue(undefined),
+      killAgent: vi.fn().mockResolvedValue(undefined),
+    };
+
+    treeService = {
+      listSessions: vi.fn(),
+      getSession: vi.fn(),
+    };
+
+    provider = new InternalAgentProvider(
+      messagesService as unknown as AgentMessagesService,
+      controlService as unknown as AgentControlService,
+      treeService as unknown as AgentTreeService
+    );
+  });
+
+  it("maps paginated sessions", async () => {
+    const sessionEntry: AgentSessionTree = {
+      id: "tree-1",
+      sessionId: "session-1",
+      parentSessionId: "parent-1",
+      provider: "internal",
+      missionId: null,
+      taskId: "task-123",
+      taskSource: "queue",
+      agentType: "worker",
+      status: "running",
+      spawnedAt: new Date("2026-03-07T10:00:00.000Z"),
+      completedAt: null,
+      metadata: { branch: "feat/test" },
+    };
+
+    treeService.listSessions.mockResolvedValue({
+      sessions: [sessionEntry],
+      total: 1,
+      cursor: "next-cursor",
+    });
+
+    const result = await provider.listSessions("cursor-1", 25);
+
+    expect(treeService.listSessions).toHaveBeenCalledWith("cursor-1", 25);
+    expect(result).toEqual({
+      sessions: [
+        {
+          id: "session-1",
+          providerId: "internal",
+          providerType: "internal",
+          label: "task-123",
+          status: "active",
+          parentSessionId: "parent-1",
+          createdAt: new Date("2026-03-07T10:00:00.000Z"),
+          updatedAt: new Date("2026-03-07T10:00:00.000Z"),
+          metadata: { branch: "feat/test" },
+        },
+      ],
+      total: 1,
+      cursor: "next-cursor",
+    });
+  });
+
+  it("returns null for missing session", async () => {
+    treeService.getSession.mockResolvedValue(null);
+
+    const result = await provider.getSession("missing-session");
+
+    expect(treeService.getSession).toHaveBeenCalledWith("missing-session");
+    expect(result).toBeNull();
+  });
+
+  it("maps message history and parses skip cursor", async () => {
+    const message: AgentConversationMessage = {
+      id: "msg-1",
+      sessionId: "session-1",
+      provider: "internal",
+      role: "agent",
+      content: "hello",
+      timestamp: new Date("2026-03-07T10:05:00.000Z"),
+      metadata: { tokens: 42 },
+    };
+
+    messagesService.getMessages.mockResolvedValue({
+      messages: [message],
+      total: 10,
+    });
+
+    const result = await provider.getMessages("session-1", 30, "2");
+
+    expect(messagesService.getMessages).toHaveBeenCalledWith("session-1", 30, 2);
+    expect(result).toEqual([
+      {
+        id: "msg-1",
+        sessionId: "session-1",
+        role: "assistant",
+        content: "hello",
+        timestamp: new Date("2026-03-07T10:05:00.000Z"),
+        metadata: { tokens: 42 },
+      },
+    ]);
+  });
+
+  it("routes control operations through AgentControlService", async () => {
+    const injectResult = await provider.injectMessage("session-1", "new instruction");
+
+    await provider.pauseSession("session-1");
+    await provider.resumeSession("session-1");
+    await provider.killSession("session-1", false);
+
+    expect(controlService.injectMessage).toHaveBeenCalledWith(
+      "session-1",
+      "internal-provider",
+      "new instruction"
+    );
+    expect(injectResult).toEqual({ accepted: true });
+    expect(controlService.pauseAgent).toHaveBeenCalledWith("session-1", "internal-provider");
+    expect(controlService.resumeAgent).toHaveBeenCalledWith("session-1", "internal-provider");
+    expect(controlService.killAgent).toHaveBeenCalledWith("session-1", "internal-provider", false);
+  });
+
+  it("streams replay and incremental messages", async () => {
+    const replayMessage: AgentConversationMessage = {
+      id: "msg-replay",
+      sessionId: "session-1",
+      provider: "internal",
+      role: "agent",
+      content: "replay",
+      timestamp: new Date("2026-03-07T10:00:00.000Z"),
+      metadata: {},
+    };
+    const incrementalMessage: AgentConversationMessage = {
+      id: "msg-live",
+      sessionId: "session-1",
+      provider: "internal",
+      role: "operator",
+      content: "live",
+      timestamp: new Date("2026-03-07T10:00:01.000Z"),
+      metadata: {},
+    };
+
+    messagesService.getReplayMessages.mockResolvedValue([replayMessage]);
+    messagesService.getMessagesAfter
+      .mockResolvedValueOnce([incrementalMessage])
+      .mockResolvedValueOnce([]);
+
+    const iterator = provider.streamMessages("session-1")[Symbol.asyncIterator]();
+
+    const first = await iterator.next();
+    const second = await iterator.next();
+
+    expect(first.done).toBe(false);
+    expect(first.value).toEqual({
+      id: "msg-replay",
+      sessionId: "session-1",
+      role: "assistant",
+      content: "replay",
+      timestamp: new Date("2026-03-07T10:00:00.000Z"),
+      metadata: {},
+    });
+    expect(second.done).toBe(false);
+    expect(second.value).toEqual({
+      id: "msg-live",
+      sessionId: "session-1",
+      role: "user",
+      content: "live",
+      timestamp: new Date("2026-03-07T10:00:01.000Z"),
+      metadata: {},
+    });
+
+    await iterator.return?.();
+
+    expect(messagesService.getReplayMessages).toHaveBeenCalledWith("session-1", 50);
+    expect(messagesService.getMessagesAfter).toHaveBeenCalledWith(
+      "session-1",
+      new Date("2026-03-07T10:00:00.000Z"),
+      "msg-replay"
+    );
+  });
+
+  it("reports provider availability", async () => {
+    await expect(provider.isAvailable()).resolves.toBe(true);
+  });
+});

apps/orchestrator/src/api/agents/internal-agent.provider.ts

@@ -0,0 +1,218 @@
+import { Injectable } from "@nestjs/common";
+import type {
+  AgentMessage,
+  AgentMessageRole,
+  AgentSession,
+  AgentSessionList,
+  AgentSessionStatus,
+  IAgentProvider,
+  InjectResult,
+} from "@mosaic/shared";
+import type { AgentConversationMessage, AgentSessionTree } from "@prisma/client";
+import { AgentControlService } from "./agent-control.service";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentTreeService } from "./agent-tree.service";
+
+const DEFAULT_SESSION_LIMIT = 50;
+const DEFAULT_MESSAGE_LIMIT = 50;
+const MAX_MESSAGE_LIMIT = 200;
+const STREAM_POLL_INTERVAL_MS = 1000;
+const INTERNAL_OPERATOR_ID = "internal-provider";
+
+@Injectable()
+export class InternalAgentProvider implements IAgentProvider {
+  readonly providerId = "internal";
+  readonly providerType = "internal";
+  readonly displayName = "Internal Orchestrator";
+
+  constructor(
+    private readonly messagesService: AgentMessagesService,
+    private readonly controlService: AgentControlService,
+    private readonly treeService: AgentTreeService
+  ) {}
+
+  async listSessions(cursor?: string, limit = DEFAULT_SESSION_LIMIT): Promise<AgentSessionList> {
+    const {
+      sessions,
+      total,
+      cursor: nextCursor,
+    } = await this.treeService.listSessions(cursor, limit);
+
+    return {
+      sessions: sessions.map((session) => this.toAgentSession(session)),
+      total,
+      ...(nextCursor !== undefined ? { cursor: nextCursor } : {}),
+    };
+  }
+
+  async getSession(sessionId: string): Promise<AgentSession | null> {
+    const session = await this.treeService.getSession(sessionId);
+    return session ? this.toAgentSession(session) : null;
+  }
+
+  async getMessages(
+    sessionId: string,
+    limit = DEFAULT_MESSAGE_LIMIT,
+    before?: string
+  ): Promise<AgentMessage[]> {
+    const safeLimit = this.normalizeMessageLimit(limit);
+    const skip = this.parseSkip(before);
+
+    const result = await this.messagesService.getMessages(sessionId, safeLimit, skip);
+    return result.messages.map((message) => this.toAgentMessage(message));
+  }
+
+  async injectMessage(sessionId: string, content: string): Promise<InjectResult> {
+    await this.controlService.injectMessage(sessionId, INTERNAL_OPERATOR_ID, content);
+
+    return {
+      accepted: true,
+    };
+  }
+
+  async pauseSession(sessionId: string): Promise<void> {
+    await this.controlService.pauseAgent(sessionId, INTERNAL_OPERATOR_ID);
+  }
+
+  async resumeSession(sessionId: string): Promise<void> {
+    await this.controlService.resumeAgent(sessionId, INTERNAL_OPERATOR_ID);
+  }
+
+  async killSession(sessionId: string, force = true): Promise<void> {
+    await this.controlService.killAgent(sessionId, INTERNAL_OPERATOR_ID, force);
+  }
+
+  async *streamMessages(sessionId: string): AsyncIterable<AgentMessage> {
+    const replayMessages = await this.messagesService.getReplayMessages(
+      sessionId,
+      DEFAULT_MESSAGE_LIMIT
+    );
+
+    let lastSeenTimestamp = new Date();
+    let lastSeenMessageId: string | null = null;
+
+    for (const message of replayMessages) {
+      yield this.toAgentMessage(message);
+      lastSeenTimestamp = message.timestamp;
+      lastSeenMessageId = message.id;
+    }
+
+    for (;;) {
+      const newMessages = await this.messagesService.getMessagesAfter(
+        sessionId,
+        lastSeenTimestamp,
+        lastSeenMessageId
+      );
+
+      for (const message of newMessages) {
+        yield this.toAgentMessage(message);
+        lastSeenTimestamp = message.timestamp;
+        lastSeenMessageId = message.id;
+      }
+
+      await this.delay(STREAM_POLL_INTERVAL_MS);
+    }
+  }
+
+  isAvailable(): Promise<boolean> {
+    return Promise.resolve(true);
+  }
+
+  private toAgentSession(session: AgentSessionTree): AgentSession {
+    const metadata = this.toMetadata(session.metadata);
+
+    return {
+      id: session.sessionId,
+      providerId: this.providerId,
+      providerType: this.providerType,
+      ...(session.taskId !== null ? { label: session.taskId } : {}),
+      status: this.toSessionStatus(session.status),
+      ...(session.parentSessionId !== null ? { parentSessionId: session.parentSessionId } : {}),
+      createdAt: session.spawnedAt,
+      updatedAt: session.completedAt ?? session.spawnedAt,
+      ...(metadata !== undefined ? { metadata } : {}),
+    };
+  }
+
+  private toAgentMessage(message: AgentConversationMessage): AgentMessage {
+    const metadata = this.toMetadata(message.metadata);
+
+    return {
+      id: message.id,
+      sessionId: message.sessionId,
+      role: this.toMessageRole(message.role),
+      content: message.content,
+      timestamp: message.timestamp,
+      ...(metadata !== undefined ? { metadata } : {}),
+    };
+  }
+
+  private toSessionStatus(status: string): AgentSessionStatus {
+    switch (status) {
+      case "running":
+        return "active";
+      case "paused":
+        return "paused";
+      case "completed":
+        return "completed";
+      case "failed":
+      case "killed":
+        return "failed";
+      case "spawning":
+      default:
+        return "idle";
+    }
+  }
+
+  private toMessageRole(role: string): AgentMessageRole {
+    switch (role) {
+      case "agent":
+      case "assistant":
+        return "assistant";
+      case "system":
+        return "system";
+      case "tool":
+        return "tool";
+      case "operator":
+      case "user":
+      default:
+        return "user";
+    }
+  }
+
+  private normalizeMessageLimit(limit: number): number {
+    const normalized = Number.isFinite(limit) ? Math.trunc(limit) : DEFAULT_MESSAGE_LIMIT;
+    if (normalized < 1) {
+      return 1;
+    }
+
+    return Math.min(normalized, MAX_MESSAGE_LIMIT);
+  }
+
+  private parseSkip(before?: string): number {
+    if (!before) {
+      return 0;
+    }
+
+    const parsed = Number.parseInt(before, 10);
+    if (Number.isNaN(parsed) || parsed < 0) {
+      return 0;
+    }
+
+    return parsed;
+  }
+
+  private toMetadata(value: unknown): Record<string, unknown> | undefined {
+    if (value !== null && typeof value === "object" && !Array.isArray(value)) {
+      return value as Record<string, unknown>;
+    }
+
+    return undefined;
+  }
+
+  private async delay(ms: number): Promise<void> {
+    await new Promise((resolve) => {
+      setTimeout(resolve, ms);
+    });
+  }
+}

apps/orchestrator/src/spawner/agent-spawner.service.ts

@@ -115,7 +115,13 @@ export class AgentSpawnerService implements OnModuleDestroy {
     }
 
     void this.agentIngestionService
-      .recordAgentSpawned(agentId, undefined, undefined, request.taskId, request.agentType)
+      .recordAgentSpawned(
+        agentId,
+        request.parentAgentId,
+        undefined,
+        request.taskId,
+        request.agentType
+      )
       .catch((error: unknown) => {
         const errorMessage = error instanceof Error ? error.message : String(error);
         this.logger.error(`Failed to record spawned ingestion for ${agentId}: ${errorMessage}`);

apps/orchestrator/src/spawner/types/agent-spawner.types.ts

@@ -40,6 +40,8 @@ export interface SpawnAgentOptions {
 export interface SpawnAgentRequest {
   /** Unique task identifier */
   taskId: string;
+  /** Optional parent session identifier for subagent lineage */
+  parentAgentId?: string;
   /** Type of agent to spawn */
   agentType: AgentType;
   /** Context for task execution */

docs/TASKS.md

@@ -122,11 +122,11 @@ Target version: `v0.0.23`
 | id          | status      | milestone     | description                                                                                      | issue | repo         | branch                 | depends_on                                      | blocks                                                      | agent | started_at | completed_at | estimate | used | notes                                         |
 | ----------- | ----------- | ------------- | ------------------------------------------------------------------------------------------------ | ----- | ------------ | ---------------------- | ----------------------------------------------- | ----------------------------------------------------------- | ----- | ---------- | ------------ | -------- | ---- | --------------------------------------------- |
 | MS23-P0-001 | done        | p0-foundation | Prisma schema: AgentConversationMessage, AgentSessionTree, AgentProviderConfig, OperatorAuditLog | #693  | api          | feat/ms23-p0-schema    | —                                               | MS23-P0-002,MS23-P0-003,MS23-P0-004,MS23-P0-005,MS23-P1-001 | codex | 2026-03-06 | 2026-03-06   | 15K      | —    | taskSource field per mosaic-queue note in PRD |
-| MS23-P0-002 | in-progress | p0-foundation | Agent message ingestion: wire spawner/lifecycle to write messages to DB                          | #693  | orchestrator | feat/ms23-p0-ingestion | MS23-P0-001                                     | MS23-P0-006                                                 | codex | 2026-03-06 | —            | 20K      | —    |                                               |
-| MS23-P0-003 | not-started | p0-foundation | Orchestrator API: GET /agents/:id/messages + SSE stream endpoint                                 | #693  | orchestrator | feat/ms23-p0-stream    | MS23-P0-001                                     | MS23-P0-006                                                 | —     | —          | —            | 20K      | —    |                                               |
-| MS23-P0-004 | not-started | p0-foundation | Orchestrator API: POST /agents/:id/inject + pause/resume endpoints                               | #693  | orchestrator | feat/ms23-p0-controls  | MS23-P0-001                                     | MS23-P0-006                                                 | —     | —          | —            | 15K      | —    |                                               |
-| MS23-P0-005 | not-started | p0-foundation | Subagent tree: parentAgentId on spawn registration + GET /agents/tree                            | #693  | orchestrator | feat/ms23-p0-tree      | MS23-P0-001                                     | MS23-P0-006                                                 | —     | —          | —            | 15K      | —    |                                               |
-| MS23-P0-006 | not-started | p0-foundation | Unit + integration tests for all P0 orchestrator endpoints                                       | #693  | orchestrator | test/ms23-p0           | MS23-P0-002,MS23-P0-003,MS23-P0-004,MS23-P0-005 | MS23-P1-001                                                 | —     | —          | —            | 20K      | —    | Phase 0 gate: SSE stream verified via curl    |
+| MS23-P0-002 | done        | p0-foundation | Agent message ingestion: wire spawner/lifecycle to write messages to DB                          | #693  | orchestrator | feat/ms23-p0-ingestion | MS23-P0-001                                     | MS23-P0-006                                                 | codex | 2026-03-06 | 2026-03-07      | 20K      | —    |                                               |
+| MS23-P0-003 | done        | p0-foundation | Orchestrator API: GET /agents/:id/messages + SSE stream endpoint                                 | #693  | orchestrator | feat/ms23-p0-stream    | MS23-P0-001                                     | MS23-P0-006                                                 | codex | 2026-03-06 | 2026-03-07      | 20K      | —    |                                               |
+| MS23-P0-004 | done        | p0-foundation | Orchestrator API: POST /agents/:id/inject + pause/resume endpoints                               | #693  | orchestrator | feat/ms23-p0-controls  | MS23-P0-001                                     | MS23-P0-006                                                 | codex | 2026-03-07 | 2026-03-07 | 15K      | —    |                                               |
+| MS23-P0-005 | done        | p0-foundation | Subagent tree: parentAgentId on spawn registration + GET /agents/tree                            | #693  | orchestrator | feat/ms23-p0-tree      | MS23-P0-001                                     | MS23-P0-006                                                 | —     | —          | —            | 15K      | —    |                                               |
+| MS23-P0-006 | done        | p0-foundation | Unit + integration tests for all P0 orchestrator endpoints                                       | #693  | orchestrator | test/ms23-p0           | MS23-P0-002,MS23-P0-003,MS23-P0-004,MS23-P0-005 | MS23-P1-001                                                 | codex | 2026-03-07 | 2026-03-07 | 20K      | —    | Phase 0 gate: SSE stream verified via curl    |
 
 ### Phase 1 — Provider Interface (Plugin Architecture)
 

packages/shared/src/types/agent-provider.types.ts

@@ -0,0 +1,78 @@
+// Agent message roles
+export type AgentMessageRole = "user" | "assistant" | "system" | "tool";
+
+// A single message in an agent conversation
+export interface AgentMessage {
+  id: string;
+  sessionId: string;
+  role: AgentMessageRole;
+  content: string;
+  timestamp: Date;
+  metadata?: Record<string, unknown>;
+}
+
+// Session lifecycle status
+export type AgentSessionStatus = "active" | "paused" | "completed" | "failed" | "idle";
+
+// An agent session (conversation thread)
+export interface AgentSession {
+  id: string;
+  providerId: string; // which provider owns this session
+  providerType: string; // "internal" | "openclaw" | etc.
+  label?: string;
+  status: AgentSessionStatus;
+  parentSessionId?: string; // for subagent trees
+  createdAt: Date;
+  updatedAt: Date;
+  metadata?: Record<string, unknown>;
+}
+
+// Result of listing sessions
+export interface AgentSessionList {
+  sessions: AgentSession[];
+  total: number;
+  cursor?: string;
+}
+
+// Result of injecting a message
+export interface InjectResult {
+  accepted: boolean;
+  messageId?: string;
+}
+
+// The IAgentProvider interface — every provider (internal, OpenClaw, future) implements this
+export interface IAgentProvider {
+  readonly providerId: string;
+  readonly providerType: string;
+  readonly displayName: string;
+
+  // Session management
+  listSessions(cursor?: string, limit?: number): Promise<AgentSessionList>;
+  getSession(sessionId: string): Promise<AgentSession | null>;
+  getMessages(sessionId: string, limit?: number, before?: string): Promise<AgentMessage[]>;
+
+  // Control operations
+  injectMessage(sessionId: string, content: string): Promise<InjectResult>;
+  pauseSession(sessionId: string): Promise<void>;
+  resumeSession(sessionId: string): Promise<void>;
+  killSession(sessionId: string, force?: boolean): Promise<void>;
+
+  // SSE streaming — returns an AsyncIterable of AgentMessage events
+  streamMessages(sessionId: string): AsyncIterable<AgentMessage>;
+
+  // Health
+  isAvailable(): Promise<boolean>;
+}
+
+// Provider configuration stored in DB (AgentProviderConfig model from P0 schema)
+export interface AgentProviderConfig {
+  id: string;
+  providerId: string;
+  providerType: string;
+  displayName: string;
+  baseUrl?: string;
+  apiToken?: string;
+  enabled: boolean;
+  createdAt: Date;
+  updatedAt: Date;
+}

packages/shared/src/types/index.ts

@@ -134,3 +134,6 @@ export * from "./widget.types";
 
 // Export WebSocket types
 export * from "./websocket.types";
+
+// Export agent provider types
+export * from "./agent-provider.types";