diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3c5321870..74fdca372 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ Docs: https://docs.molt.bot
 Status: beta.
 
 ### Changes
+- Security: add audit event logging for compliance and forensic analysis. (#3954)
 - Rebrand: rename the npm package/CLI to `moltbot`, add a `moltbot` compatibility shim, and move extensions to the `@moltbot/*` scope.
 - Commands: group /help and /commands output with Telegram paging. (#2504) Thanks @hougangdev.
 - macOS: limit project-local `node_modules/.bin` PATH preference to debug builds (reduce PATH hijacking risk).
diff --git a/src/config/types.gateway.ts b/src/config/types.gateway.ts
index a0d562f7b..0492fae4b 100644
--- a/src/config/types.gateway.ts
+++ b/src/config/types.gateway.ts
@@ -191,6 +191,33 @@ export type GatewayHttpConfig = {
   endpoints?: GatewayHttpEndpointsConfig;
 };
 
+/** Audit event categories for filtering. */
+export type GatewayAuditCategory =
+  | "auth"
+  | "authz"
+  | "admin"
+  | "config"
+  | "rate_limit"
+  | "channel"
+  | "session";
+
+/**
+ * Security audit logging configuration.
+ * Records security-relevant events for compliance and forensics.
+ */
+export type GatewayAuditLogConfig = {
+  /** Enable audit event logging (default: false). */
+  enabled?: boolean;
+  /** Output target: 'file' or 'stdout' (default: 'file'). */
+  target?: "file" | "stdout";
+  /** File path for file target (default: ~/.clawdbot/audit/audit.jsonl). */
+  filePath?: string;
+  /** Categories to log (default: all). */
+  categories?: GatewayAuditCategory[];
+  /** Include request IDs for correlation (default: true). */
+  includeRequestIds?: boolean;
+};
+
 export type GatewayNodesConfig = {
   /** Browser routing policy for node-hosted browser proxies. */
   browser?: {
@@ -233,6 +260,8 @@ export type GatewayConfig = {
   tls?: GatewayTlsConfig;
   http?: GatewayHttpConfig;
   nodes?: GatewayNodesConfig;
+  /** Security audit event logging configuration. */
+  auditLog?: GatewayAuditLogConfig;
   /**
    * IPs of trusted reverse proxies (e.g. Traefik, nginx). When a connection
    * arrives from one of these IPs, the Gateway trusts `x-forwarded-for` (or
diff --git a/src/security/audit-events.test.ts b/src/security/audit-events.test.ts
new file mode 100644
index 000000000..4b95ea51f
--- /dev/null
+++ b/src/security/audit-events.test.ts
@@ -0,0 +1,254 @@
+import { describe, expect, it, afterEach, vi, beforeEach } from "vitest";
+import { existsSync, readFileSync, rmSync, mkdirSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import {
+  AuditLogger,
+  resolveAuditLogConfig,
+  type AuditEvent,
+} from "./audit-events.js";
+
+describe("AuditLogger", () => {
+  let testDir: string;
+  let testLogPath: string;
+  let logger: AuditLogger | null = null;
+
+  beforeEach(() => {
+    testDir = join(tmpdir(), `audit-test-${Date.now()}`);
+    mkdirSync(testDir, { recursive: true });
+    testLogPath = join(testDir, "audit.jsonl");
+  });
+
+  afterEach(() => {
+    logger?.close();
+    logger = null;
+    if (existsSync(testDir)) {
+      rmSync(testDir, { recursive: true, force: true });
+    }
+  });
+
+  describe("basic logging", () => {
+    it("does not log when disabled", () => {
+      logger = new AuditLogger({ enabled: false, target: "file", filePath: testLogPath });
+      logger.logAuth({ action: "login", outcome: "success" });
+      logger.close();
+
+      expect(existsSync(testLogPath)).toBe(false);
+    });
+
+    it("logs to file when enabled", async () => {
+      logger = new AuditLogger({ enabled: true, target: "file", filePath: testLogPath });
+      logger.logAuth({ action: "login", outcome: "success", actorId: "user-123" });
+      logger.close();
+
+      // Wait for file write
+      await new Promise((resolve) => setTimeout(resolve, 50));
+
+      expect(existsSync(testLogPath)).toBe(true);
+      const content = readFileSync(testLogPath, "utf8");
+      const event = JSON.parse(content.trim());
+      expect(event.category).toBe("auth");
+      expect(event.action).toBe("login");
+      expect(event.outcome).toBe("success");
+      expect(event.actor.id).toBe("user-123");
+    });
+
+    it("logs to stdout when target is stdout", () => {
+      const writeSpy = vi.spyOn(process.stdout, "write").mockImplementation(() => true);
+
+      logger = new AuditLogger({ enabled: true, target: "stdout" });
+      logger.logAuth({ action: "login", outcome: "success" });
+      logger.close();
+
+      expect(writeSpy).toHaveBeenCalled();
+      const output = writeSpy.mock.calls[0]?.[0] as string;
+      expect(output).toContain("[audit]");
+      expect(output).toContain('"category":"auth"');
+
+      writeSpy.mockRestore();
+    });
+
+    it("calls custom handler when target is custom", () => {
+      const events: AuditEvent[] = [];
+      const customHandler = (event: AuditEvent) => events.push(event);
+
+      logger = new AuditLogger({
+        enabled: true,
+        target: "custom",
+        customHandler,
+      });
+
+      logger.logAuth({ action: "login", outcome: "success" });
+      logger.close();
+
+      expect(events).toHaveLength(1);
+      expect(events[0]?.category).toBe("auth");
+    });
+  });
+
+  describe("event types", () => {
+    let events: AuditEvent[];
+
+    beforeEach(() => {
+      events = [];
+      logger = new AuditLogger({
+        enabled: true,
+        target: "custom",
+        customHandler: (event) => events.push(event),
+      });
+    });
+
+    it("logs auth events correctly", () => {
+      logger!.logAuth({
+        action: "login",
+        outcome: "failure",
+        actorId: "user-123",
+        actorIp: "192.168.1.1",
+        method: "token",
+        error: "Invalid token",
+      });
+
+      expect(events[0]?.category).toBe("auth");
+      expect(events[0]?.action).toBe("login");
+      expect(events[0]?.outcome).toBe("failure");
+      expect(events[0]?.actor?.id).toBe("user-123");
+      expect(events[0]?.actor?.ip).toBe("192.168.1.1");
+      expect(events[0]?.details?.method).toBe("token");
+      expect(events[0]?.error).toBe("Invalid token");
+    });
+
+    it("logs authz events correctly", () => {
+      logger!.logAuthz({
+        action: "access_denied",
+        outcome: "denied",
+        actorId: "user-456",
+        resource: "/admin/settings",
+        permission: "admin:write",
+        reason: "Insufficient permissions",
+      });
+
+      expect(events[0]?.category).toBe("authz");
+      expect(events[0]?.action).toBe("access_denied");
+      expect(events[0]?.target?.name).toBe("/admin/settings");
+      expect(events[0]?.details?.permission).toBe("admin:write");
+      expect(events[0]?.details?.reason).toBe("Insufficient permissions");
+    });
+
+    it("logs admin events correctly", () => {
+      logger!.logAdmin({
+        action: "config_change",
+        outcome: "success",
+        actorId: "admin-1",
+        targetType: "gateway",
+        targetId: "config",
+        changes: { bind: "lan" },
+      });
+
+      expect(events[0]?.category).toBe("admin");
+      expect(events[0]?.action).toBe("config_change");
+      expect(events[0]?.target?.type).toBe("gateway");
+      expect(events[0]?.details?.changes).toEqual({ bind: "lan" });
+    });
+
+    it("logs rate limit events correctly", () => {
+      logger!.logRateLimit({
+        action: "request_limited",
+        outcome: "denied",
+        actorIp: "10.0.0.1",
+        retryAfterMs: 5000,
+      });
+
+      expect(events[0]?.category).toBe("rate_limit");
+      expect(events[0]?.action).toBe("request_limited");
+      expect(events[0]?.details?.retryAfterMs).toBe(5000);
+    });
+
+    it("logs session events correctly", () => {
+      logger!.logSession({
+        action: "session_end",
+        outcome: "success",
+        actorId: "user-789",
+        sessionId: "sess-abc",
+        channel: "telegram",
+        durationMs: 300000,
+      });
+
+      expect(events[0]?.category).toBe("session");
+      expect(events[0]?.action).toBe("session_end");
+      expect(events[0]?.target?.id).toBe("sess-abc");
+      expect(events[0]?.details?.durationMs).toBe(300000);
+    });
+  });
+
+  describe("filtering", () => {
+    it("filters by category", () => {
+      const events: AuditEvent[] = [];
+      logger = new AuditLogger({
+        enabled: true,
+        target: "custom",
+        categories: ["auth"], // Only auth events
+        customHandler: (event) => events.push(event),
+      });
+
+      logger.logAuth({ action: "login", outcome: "success" });
+      logger.logAdmin({ action: "config_change", outcome: "success" });
+      logger.close();
+
+      expect(events).toHaveLength(1);
+      expect(events[0]?.category).toBe("auth");
+    });
+
+    it("excludes requestId when disabled", () => {
+      const events: AuditEvent[] = [];
+      logger = new AuditLogger({
+        enabled: true,
+        target: "custom",
+        includeRequestIds: false,
+        customHandler: (event) => events.push(event),
+      });
+
+      logger.logAuth({ action: "login", outcome: "success", requestId: "req-123" });
+      logger.close();
+
+      expect(events[0]?.requestId).toBeUndefined();
+    });
+  });
+
+  describe("configuration", () => {
+    it("updates config at runtime", () => {
+      const events: AuditEvent[] = [];
+      logger = new AuditLogger({
+        enabled: false,
+        target: "custom",
+        customHandler: (event) => events.push(event),
+      });
+
+      logger.logAuth({ action: "login", outcome: "success" });
+      expect(events).toHaveLength(0);
+
+      logger.updateConfig({ enabled: true });
+      logger.logAuth({ action: "login", outcome: "success" });
+      expect(events).toHaveLength(1);
+    });
+  });
+});
+
+describe("resolveAuditLogConfig", () => {
+  it("returns defaults when no config provided", () => {
+    const config = resolveAuditLogConfig();
+    expect(config.enabled).toBe(false);
+    expect(config.target).toBe("file");
+    expect(config.categories).toContain("auth");
+    expect(config.includeRequestIds).toBe(true);
+  });
+
+  it("merges partial config with defaults", () => {
+    const config = resolveAuditLogConfig({
+      enabled: true,
+      target: "stdout",
+    });
+    expect(config.enabled).toBe(true);
+    expect(config.target).toBe("stdout");
+    expect(config.categories).toContain("auth"); // Default
+  });
+});
diff --git a/src/security/audit-events.ts b/src/security/audit-events.ts
new file mode 100644
index 000000000..f0d52a177
--- /dev/null
+++ b/src/security/audit-events.ts
@@ -0,0 +1,434 @@
+/**
+ * Security Audit Event Logging
+ *
+ * Records security-relevant events for compliance and forensic analysis:
+ * - Authentication attempts (success/failure)
+ * - Authorization decisions
+ * - Admin/elevated actions
+ * - Configuration changes
+ * - Rate limit violations
+ *
+ * Events are structured JSON for easy parsing by SIEM tools.
+ * Supports multiple output targets: file, stdout, or custom handler.
+ */
+
+import { createWriteStream, type WriteStream, existsSync, mkdirSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { resolveStateDir } from "../config/paths.js";
+
+// Event Categories
+export type AuditCategory =
+  | "auth" // Authentication events
+  | "authz" // Authorization events
+  | "admin" // Administrative actions
+  | "config" // Configuration changes
+  | "rate_limit" // Rate limiting events
+  | "channel" // Channel/messaging events
+  | "session"; // Session lifecycle events
+
+// Event outcomes
+export type AuditOutcome = "success" | "failure" | "denied" | "error";
+
+// Base audit event structure
+export type AuditEvent = {
+  /** ISO 8601 timestamp */
+  timestamp: string;
+  /** Event category */
+  category: AuditCategory;
+  /** Specific action within the category */
+  action: string;
+  /** Outcome of the action */
+  outcome: AuditOutcome;
+  /** Actor who initiated the action (user ID, IP, session ID, etc.) */
+  actor?: {
+    type: "user" | "system" | "api" | "channel";
+    id?: string;
+    ip?: string;
+    channel?: string;
+  };
+  /** Target of the action */
+  target?: {
+    type: string;
+    id?: string;
+    name?: string;
+  };
+  /** Additional context */
+  details?: Record<string, unknown>;
+  /** Error message if outcome is failure/error */
+  error?: string;
+  /** Request ID for correlation */
+  requestId?: string;
+};
+
+// Specific event builders for type safety
+export type AuthEventParams = {
+  action: "login" | "logout" | "token_refresh" | "password_change" | "api_key_use";
+  outcome: AuditOutcome;
+  actorId?: string;
+  actorIp?: string;
+  method?: "token" | "password" | "tailscale" | "device";
+  error?: string;
+  requestId?: string;
+};
+
+export type AuthzEventParams = {
+  action: "access_granted" | "access_denied" | "permission_check" | "role_assigned";
+  outcome: AuditOutcome;
+  actorId?: string;
+  actorIp?: string;
+  resource?: string;
+  permission?: string;
+  reason?: string;
+  requestId?: string;
+};
+
+export type AdminEventParams = {
+  action: "config_change" | "user_add" | "user_remove" | "channel_add" | "channel_remove" | "elevated_exec";
+  outcome: AuditOutcome;
+  actorId?: string;
+  actorIp?: string;
+  targetType?: string;
+  targetId?: string;
+  changes?: Record<string, unknown>;
+  command?: string;
+  error?: string;
+  requestId?: string;
+};
+
+export type RateLimitEventParams = {
+  action: "request_limited" | "channel_limited" | "auth_backoff";
+  outcome: "denied";
+  actorId?: string;
+  actorIp?: string;
+  channel?: string;
+  retryAfterMs?: number;
+  requestId?: string;
+};
+
+export type SessionEventParams = {
+  action: "session_start" | "session_end" | "session_timeout";
+  outcome: AuditOutcome;
+  actorId?: string;
+  sessionId?: string;
+  channel?: string;
+  durationMs?: number;
+  requestId?: string;
+};
+
+// Configuration
+export type AuditLogConfig = {
+  /** Enable audit logging (default: false) */
+  enabled?: boolean;
+  /** Output target: 'file', 'stdout', or 'custom' (default: 'file') */
+  target?: "file" | "stdout" | "custom";
+  /** File path for file target (default: ~/.clawdbot/audit/audit.jsonl) */
+  filePath?: string;
+  /** Categories to log (default: all) */
+  categories?: AuditCategory[];
+  /** Minimum outcome severity to log (default: all) */
+  minOutcome?: AuditOutcome;
+  /** Include request IDs for correlation (default: true) */
+  includeRequestIds?: boolean;
+  /** Custom handler for 'custom' target */
+  customHandler?: (event: AuditEvent) => void;
+};
+
+export type ResolvedAuditLogConfig = Required<Omit<AuditLogConfig, "customHandler">> & {
+  customHandler?: (event: AuditEvent) => void;
+};
+
+const DEFAULT_AUDIT_CONFIG: ResolvedAuditLogConfig = {
+  enabled: false,
+  target: "file",
+  filePath: "", // Resolved at runtime
+  categories: ["auth", "authz", "admin", "config", "rate_limit", "channel", "session"],
+  minOutcome: "success", // Log everything
+  includeRequestIds: true,
+};
+
+function resolveDefaultAuditPath(): string {
+  const stateDir = resolveStateDir();
+  return join(stateDir, "audit", "audit.jsonl");
+}
+
+export function resolveAuditLogConfig(config?: Partial<AuditLogConfig>): ResolvedAuditLogConfig {
+  const filePath = config?.filePath || resolveDefaultAuditPath();
+  return {
+    enabled: config?.enabled ?? DEFAULT_AUDIT_CONFIG.enabled,
+    target: config?.target ?? DEFAULT_AUDIT_CONFIG.target,
+    filePath,
+    categories: config?.categories ?? DEFAULT_AUDIT_CONFIG.categories,
+    minOutcome: config?.minOutcome ?? DEFAULT_AUDIT_CONFIG.minOutcome,
+    includeRequestIds: config?.includeRequestIds ?? DEFAULT_AUDIT_CONFIG.includeRequestIds,
+    customHandler: config?.customHandler,
+  };
+}
+
+/**
+ * Security audit logger for recording security-relevant events.
+ * Events are written as newline-delimited JSON (JSONL) for easy parsing.
+ */
+export class AuditLogger {
+  private config: ResolvedAuditLogConfig;
+  private fileStream: WriteStream | null = null;
+  private closed = false;
+
+  constructor(config?: Partial<AuditLogConfig>) {
+    this.config = resolveAuditLogConfig(config);
+
+    if (this.config.enabled && this.config.target === "file") {
+      this.initFileStream();
+    }
+  }
+
+  private initFileStream(): void {
+    const dir = dirname(this.config.filePath);
+    if (!existsSync(dir)) {
+      mkdirSync(dir, { recursive: true, mode: 0o700 });
+    }
+
+    this.fileStream = createWriteStream(this.config.filePath, {
+      flags: "a", // Append mode
+      mode: 0o600, // Owner read/write only
+      encoding: "utf8",
+    });
+
+    this.fileStream.on("error", (err) => {
+      console.error(`[audit] File write error: ${err.message}`);
+    });
+  }
+
+  /**
+   * Log a raw audit event.
+   */
+  log(event: Omit<AuditEvent, "timestamp">): void {
+    if (!this.config.enabled || this.closed) return;
+
+    // Check category filter
+    if (!this.config.categories.includes(event.category)) return;
+
+    const fullEvent: AuditEvent = {
+      ...event,
+      timestamp: new Date().toISOString(),
+    };
+
+    // Remove requestId if disabled
+    if (!this.config.includeRequestIds) {
+      delete fullEvent.requestId;
+    }
+
+    this.write(fullEvent);
+  }
+
+  /**
+   * Log an authentication event.
+   */
+  logAuth(params: AuthEventParams): void {
+    this.log({
+      category: "auth",
+      action: params.action,
+      outcome: params.outcome,
+      actor: params.actorId || params.actorIp
+        ? { type: "user", id: params.actorId, ip: params.actorIp }
+        : undefined,
+      details: params.method ? { method: params.method } : undefined,
+      error: params.error,
+      requestId: params.requestId,
+    });
+  }
+
+  /**
+   * Log an authorization event.
+   */
+  logAuthz(params: AuthzEventParams): void {
+    this.log({
+      category: "authz",
+      action: params.action,
+      outcome: params.outcome,
+      actor: params.actorId || params.actorIp
+        ? { type: "user", id: params.actorId, ip: params.actorIp }
+        : undefined,
+      target: params.resource
+        ? { type: "resource", name: params.resource }
+        : undefined,
+      details: {
+        ...(params.permission && { permission: params.permission }),
+        ...(params.reason && { reason: params.reason }),
+      },
+      requestId: params.requestId,
+    });
+  }
+
+  /**
+   * Log an administrative action.
+   */
+  logAdmin(params: AdminEventParams): void {
+    this.log({
+      category: "admin",
+      action: params.action,
+      outcome: params.outcome,
+      actor: params.actorId || params.actorIp
+        ? { type: "user", id: params.actorId, ip: params.actorIp }
+        : undefined,
+      target: params.targetType
+        ? { type: params.targetType, id: params.targetId }
+        : undefined,
+      details: {
+        ...(params.changes && { changes: params.changes }),
+        ...(params.command && { command: params.command }),
+      },
+      error: params.error,
+      requestId: params.requestId,
+    });
+  }
+
+  /**
+   * Log a rate limit event.
+   */
+  logRateLimit(params: RateLimitEventParams): void {
+    this.log({
+      category: "rate_limit",
+      action: params.action,
+      outcome: params.outcome,
+      actor: params.actorId || params.actorIp
+        ? { type: "user", id: params.actorId, ip: params.actorIp }
+        : undefined,
+      details: {
+        ...(params.channel && { channel: params.channel }),
+        ...(params.retryAfterMs && { retryAfterMs: params.retryAfterMs }),
+      },
+      requestId: params.requestId,
+    });
+  }
+
+  /**
+   * Log a session event.
+   */
+  logSession(params: SessionEventParams): void {
+    this.log({
+      category: "session",
+      action: params.action,
+      outcome: params.outcome,
+      actor: params.actorId
+        ? { type: "user", id: params.actorId }
+        : undefined,
+      target: params.sessionId
+        ? { type: "session", id: params.sessionId }
+        : undefined,
+      details: {
+        ...(params.channel && { channel: params.channel }),
+        ...(params.durationMs && { durationMs: params.durationMs }),
+      },
+      requestId: params.requestId,
+    });
+  }
+
+  /**
+   * Get current configuration.
+   */
+  getConfig(): ResolvedAuditLogConfig {
+    return { ...this.config };
+  }
+
+  /**
+   * Update configuration at runtime.
+   * Merges new config with existing config values.
+   */
+  updateConfig(config: Partial<AuditLogConfig>): void {
+    const wasEnabled = this.config.enabled;
+    const wasFile = this.config.target === "file";
+    const oldPath = this.config.filePath;
+
+    // Merge new config with existing config values
+    this.config = {
+      enabled: config.enabled ?? this.config.enabled,
+      target: config.target ?? this.config.target,
+      filePath: config.filePath ?? this.config.filePath,
+      categories: config.categories ?? this.config.categories,
+      minOutcome: config.minOutcome ?? this.config.minOutcome,
+      includeRequestIds: config.includeRequestIds ?? this.config.includeRequestIds,
+      customHandler: config.customHandler ?? this.config.customHandler,
+    };
+
+    // Handle file stream changes
+    if (this.config.enabled && this.config.target === "file") {
+      if (!wasEnabled || !wasFile || oldPath !== this.config.filePath) {
+        this.closeFileStream();
+        this.initFileStream();
+      }
+    } else {
+      this.closeFileStream();
+    }
+  }
+
+  /**
+   * Close the logger and release resources.
+   */
+  close(): void {
+    this.closed = true;
+    this.closeFileStream();
+  }
+
+  private closeFileStream(): void {
+    if (this.fileStream) {
+      this.fileStream.end();
+      this.fileStream = null;
+    }
+  }
+
+  private write(event: AuditEvent): void {
+    const line = JSON.stringify(event) + "\n";
+
+    switch (this.config.target) {
+      case "file":
+        if (this.fileStream) {
+          this.fileStream.write(line);
+        }
+        break;
+      case "stdout":
+        process.stdout.write(`[audit] ${line}`);
+        break;
+      case "custom":
+        if (this.config.customHandler) {
+          this.config.customHandler(event);
+        }
+        break;
+    }
+  }
+}
+
+// Singleton instance for global access
+let globalAuditLogger: AuditLogger | null = null;
+
+/**
+ * Get or create the global audit logger instance.
+ */
+export function getAuditLogger(config?: Partial<AuditLogConfig>): AuditLogger {
+  if (!globalAuditLogger) {
+    globalAuditLogger = new AuditLogger(config);
+  }
+  return globalAuditLogger;
+}
+
+/**
+ * Initialize the global audit logger with configuration.
+ * Call this early in application startup.
+ */
+export function initAuditLogger(config?: Partial<AuditLogConfig>): AuditLogger {
+  if (globalAuditLogger) {
+    globalAuditLogger.close();
+  }
+  globalAuditLogger = new AuditLogger(config);
+  return globalAuditLogger;
+}
+
+/**
+ * Close the global audit logger.
+ * Call this during application shutdown.
+ */
+export function closeAuditLogger(): void {
+  if (globalAuditLogger) {
+    globalAuditLogger.close();
+    globalAuditLogger = null;
+  }
+}