diff --git a/packages/adapter-utils/src/types.ts b/packages/adapter-utils/src/types.ts
index 78bca57a..cd541036 100644
--- a/packages/adapter-utils/src/types.ts
+++ b/packages/adapter-utils/src/types.ts
@@ -179,6 +179,8 @@ export interface ServerAdapterModule {
   models?: AdapterModel[];
   listModels?: () => Promise<AdapterModel[]>;
   agentConfigurationDoc?: string;
+  /** Per D-04: If true, adapter manages its own context window (e.g. Claude, Codex). Session rotation is skipped but usage is still tracked. */
+  nativeContextManagement?: boolean;
   /**
    * Optional lifecycle hook when an agent is approved/hired (join-request or hire_agent approval).
    * adapterConfig is the agent's adapter config so the adapter can e.g. send a callback to a configured URL.
diff --git a/src/main/connectors.ts b/src/main/connectors.ts
index 27f782dc..96fb5030 100644
--- a/src/main/connectors.ts
+++ b/src/main/connectors.ts
@@ -57,6 +57,7 @@ const CONNECTORS: ConnectorDefinition[] = [
       execute: codexExecute,
       testEnvironment: codexTestEnvironment,
       sessionCodec: codexSessionCodec,
+      nativeContextManagement: true,
       models: codexModels,
     },
     listModels: async () => codexModels,
@@ -81,6 +82,7 @@ const CONNECTORS: ConnectorDefinition[] = [
       execute: claudeExecute,
       testEnvironment: claudeTestEnvironment,
       sessionCodec: claudeSessionCodec,
+      nativeContextManagement: true,
       models: claudeModels,
     },
     listModels: async () => claudeModels,
@@ -105,6 +107,7 @@ const CONNECTORS: ConnectorDefinition[] = [
       execute: geminiExecute,
       testEnvironment: geminiTestEnvironment,
       sessionCodec: geminiSessionCodec,
+      nativeContextManagement: false,
       models: geminiModels,
     },
     listModels: async () => geminiModels,
diff --git a/src/main/database.ts b/src/main/database.ts
index 221615ca..84a23e27 100644
--- a/src/main/database.ts
+++ b/src/main/database.ts
@@ -33,6 +33,7 @@ import type {
   SocialAccountRecord,
   StandupReport,
   TaskRecord,
+  TaskSessionRecord,
   WorkflowPipelineRecord,
   WorkspaceRecord,
 } from "@shared/types";
@@ -1429,6 +1430,99 @@ export class AppDatabase {
     };
   }
 
+  // ---------------------------------------------------------------------------
+  // task_sessions CRUD — session management (Plan 06-01)
+  // ---------------------------------------------------------------------------
+
+  getActiveTaskSession(taskId: string): TaskSessionRecord | null {
+    const task = this.db.prepare(
+      "SELECT active_session_id FROM tasks WHERE id = ?"
+    ).get(taskId) as { active_session_id: string | null } | undefined;
+    if (!task?.active_session_id) return null;
+    return this.db.prepare(
+      `SELECT id, company_id as companyId, task_id as taskId, agent_id as agentId,
+       adapter_type as adapterType, session_params_json as sessionParamsJson,
+       session_display_id as sessionDisplayId, last_run_id as lastRunId,
+       last_error as lastError, run_count as runCount,
+       total_input_tokens as totalInputTokens, total_output_tokens as totalOutputTokens,
+       rotated_at as rotatedAt, rotation_reason as rotationReason,
+       handoff_markdown as handoffMarkdown, created_at as createdAt, updated_at as updatedAt
+       FROM task_sessions WHERE id = ?`
+    ).get(task.active_session_id) as TaskSessionRecord | undefined ?? null;
+  }
+
+  incrementSessionUsage(sessionId: string, inputTokens: number, outputTokens: number, runId: string): void {
+    const ts = nowIso();
+    this.db.prepare(
+      `UPDATE task_sessions
+       SET run_count = run_count + 1,
+           total_input_tokens = total_input_tokens + ?,
+           total_output_tokens = total_output_tokens + ?,
+           last_run_id = ?,
+           updated_at = ?
+       WHERE id = ?`
+    ).run(inputTokens, outputTokens, runId, ts, sessionId);
+  }
+
+  archiveSession(sessionId: string, reason: string, handoffMarkdown: string): void {
+    const ts = nowIso();
+    this.db.prepare(
+      `UPDATE task_sessions SET rotated_at = ?, rotation_reason = ?, handoff_markdown = ?, updated_at = ? WHERE id = ?`
+    ).run(ts, reason, handoffMarkdown, ts, sessionId);
+  }
+
+  createNewSession(input: {
+    taskId: string;
+    companyId: string;
+    agentId: string;
+    adapterType: string;
+    sessionParamsJson: string | null;
+    sessionDisplayId: string | null;
+  }): string {
+    const sessionId = randomUUID();
+    const ts = nowIso();
+    this.db.prepare(
+      `INSERT INTO task_sessions (id, company_id, task_id, agent_id, adapter_type,
+       session_params_json, session_display_id, created_at, updated_at)
+       VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`
+    ).run(
+      sessionId, input.companyId, input.taskId, input.agentId, input.adapterType,
+      input.sessionParamsJson, input.sessionDisplayId, ts, ts
+    );
+    this.db.prepare("UPDATE tasks SET active_session_id = ?, updated_at = ? WHERE id = ?")
+      .run(sessionId, ts, input.taskId);
+    return sessionId;
+  }
+
+  getRecentRunsForTask(taskId: string, limit: number): Array<{
+    id: string;
+    status: string;
+    summary: string | null;
+    errorMessage: string | null;
+    finishedAt: string | null;
+    connectorId: string;
+  }> {
+    return this.readAll(
+      `SELECT id, status, summary, error_message as errorMessage,
+       finished_at as finishedAt, connector_id as connectorId
+       FROM runs WHERE task_id = ? ORDER BY finished_at DESC LIMIT ?`,
+      taskId, limit
+    );
+  }
+
+  getRecentActivityForTask(taskId: string, limit: number): Array<{
+    action: string;
+    detail: string;
+    createdAt: string;
+  }> {
+    return this.readAll(
+      `SELECT action, detail, created_at as createdAt
+       FROM activity WHERE entity_type = 'task' AND entity_id = ?
+       ORDER BY created_at DESC LIMIT ?`,
+      taskId, limit
+    );
+  }
+
   addActivity(input: { companyId: string; actor: string; action: string; entityType: string; entityId: string; detail: string }) {
     this.db
       .prepare("insert into activity (id, company_id, actor, action, entity_type, entity_id, detail, created_at) values (?, ?, ?, ?, ?, ?, ?, ?)")
diff --git a/src/shared/types.ts b/src/shared/types.ts
index 1792f6ad..299fdaba 100644
--- a/src/shared/types.ts
+++ b/src/shared/types.ts
@@ -317,6 +317,26 @@ export interface BudgetStatusSummary {
   }>;
 }
 
+export interface TaskSessionRecord {
+  id: string;
+  companyId: string;
+  taskId: string;
+  agentId: string;
+  adapterType: string;
+  sessionParamsJson: string | null;
+  sessionDisplayId: string | null;
+  lastRunId: string | null;
+  lastError: string | null;
+  runCount: number;
+  totalInputTokens: number;
+  totalOutputTokens: number;
+  rotatedAt: string | null;
+  rotationReason: string | null;
+  handoffMarkdown: string | null;
+  createdAt: string;
+  updatedAt: string;
+}
+
 export interface ActivityRecord {
   id: string;
   companyId: string;
diff --git a/tests/unit/session-management.test.ts b/tests/unit/session-management.test.ts
new file mode 100644
index 00000000..ab835479
--- /dev/null
+++ b/tests/unit/session-management.test.ts
@@ -0,0 +1,261 @@
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { mkdtemp, rm } from "node:fs/promises";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("electron", () => ({
+  safeStorage: {
+    isEncryptionAvailable: () => false,
+    getSelectedStorageBackend: () => "basic_text",
+    encryptString: (value: string) => Buffer.from(value, "utf8"),
+    decryptString: (value: Buffer) => value.toString("utf8"),
+  },
+}));
+
+import { AppDatabase } from "../../src/main/database";
+import { getConnectorDefinition } from "../../src/main/connectors";
+import type { ConnectorId } from "@shared/types";
+
+// ---------------------------------------------------------------------------
+// Helpers — create a minimal company + agent + task scaffold
+// ---------------------------------------------------------------------------
+function scaffold(db: AppDatabase) {
+  const companyId = db.saveCompany({
+    name: "Session Test Co",
+    description: "Testing session management",
+    status: "active",
+  });
+  const workspaceId = db.saveWorkspace({
+    companyId,
+    name: "Primary",
+    localPath: "/tmp/session-test",
+    repoUrl: "",
+    repoRef: "",
+    isPrimary: true,
+  });
+  const agentId = db.saveAgent({
+    companyId,
+    name: "Worker Agent",
+    role: "developer",
+    title: "Developer",
+    status: "active",
+    reportsTo: null,
+    connectorId: "claude_local",
+    workspaceId,
+    model: "claude-4-opus",
+    capabilities: "Writes code",
+    budgetMonthlyUsd: 100,
+  });
+  const goalId = db.saveGoal({
+    companyId,
+    title: "Ship feature",
+    description: "Build session management",
+    ownerAgentId: agentId,
+    status: "active",
+  });
+  const projectId = db.saveProject({
+    companyId,
+    goalId,
+    name: "Session Project",
+    description: "Session management work",
+    leadAgentId: agentId,
+    status: "in_progress",
+    targetDate: null,
+  });
+  const taskId = db.saveTask({
+    companyId,
+    projectId,
+    goalId,
+    title: "Implement session rotation",
+    description: "Build the session rotation logic for task execution.",
+    assigneeAgentId: agentId,
+    workspaceId,
+    priority: "high",
+    status: "in_progress",
+  });
+  return { companyId, workspaceId, agentId, goalId, projectId, taskId };
+}
+
+// ===========================================================================
+// task_sessions CRUD
+// ===========================================================================
+describe("task_sessions CRUD", () => {
+  let tempDir: string;
+  let db: AppDatabase;
+
+  beforeEach(async () => {
+    tempDir = await mkdtemp(join(tmpdir(), "agentcompany-session-"));
+    db = new AppDatabase(tempDir);
+    db.init();
+  });
+
+  afterEach(async () => {
+    db.close();
+    await rm(tempDir, { recursive: true, force: true });
+  });
+
+  it("getActiveTaskSession returns null when active_session_id is null", () => {
+    const { taskId } = scaffold(db);
+    const session = db.getActiveTaskSession(taskId);
+    expect(session).toBeNull();
+  });
+
+  it("getActiveTaskSession returns TaskSessionRecord when valid session exists", () => {
+    const { taskId, companyId, agentId } = scaffold(db);
+    const sessionId = db.createNewSession({
+      taskId,
+      companyId,
+      agentId,
+      adapterType: "claude_local",
+      sessionParamsJson: JSON.stringify({ sessionId: "abc123" }),
+      sessionDisplayId: "claude-abc123",
+    });
+
+    const session = db.getActiveTaskSession(taskId);
+    expect(session).not.toBeNull();
+    expect(session!.id).toBe(sessionId);
+    expect(session!.taskId).toBe(taskId);
+    expect(session!.companyId).toBe(companyId);
+    expect(session!.agentId).toBe(agentId);
+    expect(session!.adapterType).toBe("claude_local");
+    expect(session!.sessionParamsJson).toBe(JSON.stringify({ sessionId: "abc123" }));
+    expect(session!.sessionDisplayId).toBe("claude-abc123");
+    expect(session!.runCount).toBe(0);
+    expect(session!.totalInputTokens).toBe(0);
+    expect(session!.totalOutputTokens).toBe(0);
+    expect(session!.rotatedAt).toBeNull();
+    expect(session!.rotationReason).toBeNull();
+    expect(session!.handoffMarkdown).toBeNull();
+  });
+
+  it("incrementSessionUsage atomically updates counters", () => {
+    const { taskId, companyId, agentId } = scaffold(db);
+    const sessionId = db.createNewSession({
+      taskId,
+      companyId,
+      agentId,
+      adapterType: "claude_local",
+      sessionParamsJson: null,
+      sessionDisplayId: null,
+    });
+
+    db.incrementSessionUsage(sessionId, 1000, 500, "run-001");
+
+    const session = db.getActiveTaskSession(taskId);
+    expect(session!.runCount).toBe(1);
+    expect(session!.totalInputTokens).toBe(1000);
+    expect(session!.totalOutputTokens).toBe(500);
+    expect(session!.lastRunId).toBe("run-001");
+
+    // Second increment accumulates
+    db.incrementSessionUsage(sessionId, 2000, 800, "run-002");
+    const session2 = db.getActiveTaskSession(taskId);
+    expect(session2!.runCount).toBe(2);
+    expect(session2!.totalInputTokens).toBe(3000);
+    expect(session2!.totalOutputTokens).toBe(1300);
+    expect(session2!.lastRunId).toBe("run-002");
+  });
+
+  it("archiveSession sets rotated_at, rotation_reason, handoff_markdown", () => {
+    const { taskId, companyId, agentId } = scaffold(db);
+    const sessionId = db.createNewSession({
+      taskId,
+      companyId,
+      agentId,
+      adapterType: "claude_local",
+      sessionParamsJson: null,
+      sessionDisplayId: null,
+    });
+
+    db.archiveSession(sessionId, "max_runs", "# Handoff\nSession reached 20 runs.");
+
+    const session = db.getActiveTaskSession(taskId);
+    expect(session!.rotatedAt).toBeTruthy();
+    expect(session!.rotationReason).toBe("max_runs");
+    expect(session!.handoffMarkdown).toBe("# Handoff\nSession reached 20 runs.");
+  });
+
+  it("createNewSession creates session and updates tasks.active_session_id", () => {
+    const { taskId, companyId, agentId } = scaffold(db);
+
+    const sessionId = db.createNewSession({
+      taskId,
+      companyId,
+      agentId,
+      adapterType: "gemini_local",
+      sessionParamsJson: JSON.stringify({ key: "val" }),
+      sessionDisplayId: "gemini-session-1",
+    });
+
+    expect(typeof sessionId).toBe("string");
+    expect(sessionId.length).toBeGreaterThan(0);
+
+    // active_session_id should point to new session
+    const session = db.getActiveTaskSession(taskId);
+    expect(session).not.toBeNull();
+    expect(session!.id).toBe(sessionId);
+    expect(session!.adapterType).toBe("gemini_local");
+  });
+
+  it("getRecentRunsForTask returns last N runs ordered by finished_at DESC", () => {
+    const { taskId, companyId, agentId, workspaceId } = scaffold(db);
+
+    // Create some runs
+    const run1 = db.createRun({ companyId, taskId, agentId, workspaceId, connectorId: "claude_local" });
+    db.finishRun({
+      runId: run1.id,
+      status: "completed",
+      summary: "First run done",
+      errorMessage: null,
+      exitCode: 0,
+      signal: null,
+      model: "claude-4-opus",
+      sessionDisplayId: null,
+      costUsd: 0.01,
+      unattributedCost: false,
+    });
+
+    const run2 = db.createRun({ companyId, taskId, agentId, workspaceId, connectorId: "claude_local" });
+    db.finishRun({
+      runId: run2.id,
+      status: "failed",
+      summary: "Second run failed",
+      errorMessage: "Timeout",
+      exitCode: 1,
+      signal: null,
+      model: "claude-4-opus",
+      sessionDisplayId: null,
+      costUsd: 0.02,
+      unattributedCost: false,
+    });
+
+    const runs = db.getRecentRunsForTask(taskId, 5);
+    expect(runs.length).toBe(2);
+    // Most recent first
+    expect(runs[0].id).toBe(run2.id);
+    expect(runs[0].status).toBe("failed");
+    expect(runs[0].errorMessage).toBe("Timeout");
+    expect(runs[1].id).toBe(run1.id);
+    expect(runs[1].status).toBe("completed");
+  });
+});
+
+// ===========================================================================
+// adapter exemption
+// ===========================================================================
+describe("adapter exemption", () => {
+  it("claude_local connector has nativeContextManagement: true", () => {
+    const def = getConnectorDefinition("claude_local" as ConnectorId);
+    expect(def.module.nativeContextManagement).toBe(true);
+  });
+
+  it("codex_local connector has nativeContextManagement: true", () => {
+    const def = getConnectorDefinition("codex_local" as ConnectorId);
+    expect(def.module.nativeContextManagement).toBe(true);
+  });
+
+  it("gemini_local connector has nativeContextManagement: false", () => {
+    const def = getConnectorDefinition("gemini_local" as ConnectorId);
+    expect(def.module.nativeContextManagement).toBe(false);
+  });
+});