diff --git a/apps/gateway/src/commands/command-authorization.service.spec.ts b/apps/gateway/src/commands/command-authorization.service.spec.ts
new file mode 100644
index 0000000..51b25eb
--- /dev/null
+++ b/apps/gateway/src/commands/command-authorization.service.spec.ts
@@ -0,0 +1,58 @@
+import { describe, expect, it } from 'vitest';
+import type { CommandDef, SlashCommandPayload } from '@mosaicstack/types';
+import { CommandAuthorizationService } from './command-authorization.service.js';
+
+const adminCommand: CommandDef = {
+  name: 'gc',
+  description: 'GC',
+  aliases: [],
+  scope: 'admin',
+  execution: 'socket',
+  available: true,
+};
+const payload: SlashCommandPayload = { command: 'gc', conversationId: 'conversation-1' };
+
+function createService(role: string): CommandAuthorizationService {
+  const entries = new Map<string, string>();
+  const db = {
+    select: () => ({ from: () => ({ where: () => ({ limit: async () => [{ role }] }) }) }),
+  };
+  const redis = {
+    get: async (key: string) => entries.get(key) ?? null,
+    set: async (key: string, value: string) => {
+      entries.set(key, value);
+    },
+    del: async (key: string) => Number(entries.delete(key)),
+  };
+  return new CommandAuthorizationService(db as never, redis);
+}
+
+describe('CommandAuthorizationService', () => {
+  it('consumes one exact actor-bound approval once', async (): Promise<void> => {
+    const service = createService('admin');
+    const approval = await service.createApproval('gc', payload, 'admin-1');
+    expect(
+      (await service.authorize(adminCommand, payload, 'admin-1', approval.approvalId)).allowed,
+    ).toBe(true);
+    expect(
+      (await service.authorize(adminCommand, payload, 'admin-1', approval.approvalId)).allowed,
+    ).toBe(false);
+  });
+
+  it('rejects an approval when the structured action is mutated', async (): Promise<void> => {
+    const service = createService('admin');
+    const approval = await service.createApproval('gc', payload, 'admin-1');
+    const mutated = { ...payload, conversationId: 'other-conversation' };
+    expect(
+      (await service.authorize(adminCommand, mutated, 'admin-1', approval.approvalId)).allowed,
+    ).toBe(false);
+  });
+
+  it('denies an admin command to a member before approval is considered', async (): Promise<void> => {
+    const service = createService('member');
+    const approval = await service.createApproval('gc', payload, 'member-1');
+    expect(
+      (await service.authorize(adminCommand, payload, 'member-1', approval.approvalId)).allowed,
+    ).toBe(false);
+  });
+});
diff --git a/apps/gateway/src/commands/command-authorization.service.ts b/apps/gateway/src/commands/command-authorization.service.ts
new file mode 100644
index 0000000..f6249a4
--- /dev/null
+++ b/apps/gateway/src/commands/command-authorization.service.ts
@@ -0,0 +1,135 @@
+import { createHash, randomUUID } from 'node:crypto';
+import { Inject, Injectable } from '@nestjs/common';
+import { eq, users as usersTable, type Db } from '@mosaicstack/db';
+import type { CommandDef, SlashCommandPayload } from '@mosaicstack/types';
+import { DB } from '../database/database.module.js';
+import { COMMANDS_REDIS } from './commands.tokens.js';
+
+export type CommandRole = 'admin' | 'member' | 'viewer';
+
+export interface CommandApproval {
+  approvalId: string;
+  actionDigest: string;
+  actorId: string;
+  command: string;
+  expiresAt: string;
+}
+
+export interface CommandAuthorizationResult {
+  allowed: boolean;
+  reason?: string;
+}
+
+@Injectable()
+export class CommandAuthorizationService {
+  constructor(
+    @Inject(DB) private readonly db: Db,
+    @Inject(COMMANDS_REDIS)
+    private readonly redis: {
+      get(key: string): Promise<string | null>;
+      set(key: string, value: string, ...args: string[]): Promise<unknown>;
+      del(key: string): Promise<number>;
+    },
+  ) {}
+
+  async authorize(
+    command: CommandDef,
+    payload: SlashCommandPayload,
+    actorId: string,
+    approvalId?: string,
+  ): Promise<CommandAuthorizationResult> {
+    const role = await this.resolveRole(actorId);
+    if (!role || !this.hasScope(role, command.scope)) {
+      return { allowed: false, reason: 'not authorized for this command scope' };
+    }
+    if (command.scope !== 'admin') return { allowed: true };
+    if (!approvalId) return { allowed: false, reason: 'durable approval is required' };
+    const actionDigest = this.actionDigest(command.name, payload);
+    const approved = await this.consumeApproval(approvalId, actorId, actionDigest);
+    return approved
+      ? { allowed: true }
+      : {
+          allowed: false,
+          reason: 'approval is invalid, expired, replayed, or does not match this action',
+        };
+  }
+
+  async createApproval(
+    command: string,
+    payload: SlashCommandPayload,
+    actorId: string,
+  ): Promise<CommandApproval> {
+    const approvalId = randomUUID();
+    const expiresAt = new Date(Date.now() + 5 * 60_000).toISOString();
+    const approval: CommandApproval = {
+      approvalId,
+      actionDigest: this.actionDigest(command, payload),
+      actorId,
+      command,
+      expiresAt,
+    };
+    await this.redis.set(this.key(approvalId), JSON.stringify(approval), 'EX', '300');
+    return approval;
+  }
+
+  private async resolveRole(actorId: string): Promise<CommandRole | null> {
+    const [user] = await this.db
+      .select({ role: usersTable.role })
+      .from(usersTable)
+      .where(eq(usersTable.id, actorId))
+      .limit(1);
+    const role = user?.role;
+    return role === 'admin' || role === 'member' || role === 'viewer' ? role : null;
+  }
+
+  private hasScope(role: CommandRole, scope: CommandDef['scope']): boolean {
+    if (role === 'admin') return true;
+    return role === 'member' && (scope === 'core' || scope === 'agent');
+  }
+
+  private async consumeApproval(
+    approvalId: string,
+    actorId: string,
+    actionDigest: string,
+  ): Promise<boolean> {
+    const key = this.key(approvalId);
+    const encoded = await this.redis.get(key);
+    if (!encoded) return false;
+    const parsed: unknown = JSON.parse(encoded);
+    if (
+      !this.isApproval(parsed) ||
+      parsed.actorId !== actorId ||
+      parsed.actionDigest !== actionDigest ||
+      Date.parse(parsed.expiresAt) <= Date.now()
+    )
+      return false;
+    return (await this.redis.del(key)) === 1;
+  }
+
+  private actionDigest(command: string, payload: SlashCommandPayload): string {
+    return createHash('sha256')
+      .update(
+        JSON.stringify({
+          command,
+          args: payload.args?.trim() ?? '',
+          conversationId: payload.conversationId,
+        }),
+      )
+      .digest('hex');
+  }
+
+  private isApproval(value: unknown): value is CommandApproval {
+    return (
+      typeof value === 'object' &&
+      value !== null &&
+      'approvalId' in value &&
+      'actionDigest' in value &&
+      'actorId' in value &&
+      'expiresAt' in value
+    );
+  }
+
+  private key(approvalId: string): string {
+    return `tess:command-approval:${approvalId}`;
+  }
+}
diff --git a/apps/gateway/src/commands/command-executor-tess-security.spec.ts b/apps/gateway/src/commands/command-executor-tess-security.spec.ts
new file mode 100644
index 0000000..cd3cd09
--- /dev/null
+++ b/apps/gateway/src/commands/command-executor-tess-security.spec.ts
@@ -0,0 +1,73 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import type { SlashCommandPayload } from '@mosaicstack/types';
+import { CommandExecutorService } from './command-executor.service.js';
+
+const registry = {
+  getManifest: vi.fn(() => ({
+    version: 1,
+    commands: [
+      {
+        name: 'gc',
+        description: 'System-wide garbage collection',
+        aliases: [],
+        scope: 'admin' as const,
+        execution: 'socket' as const,
+        available: true,
+      },
+    ],
+    skills: [],
+  })),
+};
+
+const sessionGc = {
+  sweepOrphans: vi.fn().mockResolvedValue({ orphanedSessions: 1, totalCleaned: [], duration: 1 }),
+};
+
+const authorization = {
+  authorize: vi.fn((_command: unknown, _payload: unknown, actorId: string) =>
+    Promise.resolve(
+      actorId === 'member-1'
+        ? { allowed: false, reason: 'durable approval is required' }
+        : { allowed: false, reason: 'not authorized for this command scope' },
+    ),
+  ),
+};
+
+function buildExecutor(): CommandExecutorService {
+  return new CommandExecutorService(
+    registry as never,
+    { getSession: vi.fn() } as never,
+    { clear: vi.fn(), set: vi.fn() } as never,
+    sessionGc as never,
+    { set: vi.fn() } as never,
+    { agents: {} } as never,
+    null,
+    null,
+    null,
+    authorization as never,
+  );
+}
+
+describe('TESS-M1-SEC-001 command authorization abuse cases', () => {
+  const payload: SlashCommandPayload = { command: 'gc', conversationId: 'conversation-1' };
+
+  beforeEach((): void => {
+    vi.clearAllMocks();
+  });
+
+  it('denies a forged admin identity and does not execute a system-wide command', async (): Promise<void> => {
+    const result = await buildExecutor().execute(payload, 'admin-forged-by-client');
+
+    expect(result.success).toBe(false);
+    expect(result.message).toContain('not authorized');
+    expect(sessionGc.sweepOrphans).not.toHaveBeenCalled();
+  });
+
+  it('denies a privileged command without a server-bound durable approval', async (): Promise<void> => {
+    const result = await buildExecutor().execute(payload, 'member-1');
+
+    expect(result.success).toBe(false);
+    expect(result.message).toContain('approval');
+    expect(sessionGc.sweepOrphans).not.toHaveBeenCalled();
+  });
+});
diff --git a/apps/gateway/src/commands/command-executor.service.ts b/apps/gateway/src/commands/command-executor.service.ts
index f7fc0cc..c4ed381 100644
--- a/apps/gateway/src/commands/command-executor.service.ts
+++ b/apps/gateway/src/commands/command-executor.service.ts
@@ -11,6 +11,7 @@ import { ReloadService } from '../reload/reload.service.js';
 import { McpClientService } from '../mcp-client/mcp-client.service.js';
 import { BRAIN } from '../brain/brain.tokens.js';
 import { COMMANDS_REDIS } from './commands.tokens.js';
+import { CommandAuthorizationService } from './command-authorization.service.js';
 import { CommandRegistryService } from './command-registry.service.js';
 
 @Injectable()
@@ -33,6 +34,9 @@ export class CommandExecutorService {
     @Optional()
     @Inject(McpClientService)
     private readonly mcpClient: McpClientService | null,
+    @Optional()
+    @Inject(CommandAuthorizationService)
+    private readonly authorization: CommandAuthorizationService | null = null,
   ) {}
 
   async execute(
@@ -52,6 +56,16 @@ export class CommandExecutorService {
       };
     }
 
+    const authorization = await this.authorization?.authorize(
+      def,
+      payload,
+      userId,
+      payload.approvalId,
+    );
+    if (authorization && !authorization.allowed) {
+      return { command, conversationId, success: false, message: authorization.reason };
+    }
+
     try {
       switch (command) {
         case 'model':
diff --git a/apps/gateway/src/commands/commands.module.ts b/apps/gateway/src/commands/commands.module.ts
index 1c3a82c..0d6c30d 100644
--- a/apps/gateway/src/commands/commands.module.ts
+++ b/apps/gateway/src/commands/commands.module.ts
@@ -3,6 +3,7 @@ import { createQueue, type QueueHandle } from '@mosaicstack/queue';
 import { ChatModule } from '../chat/chat.module.js';
 import { GCModule } from '../gc/gc.module.js';
 import { ReloadModule } from '../reload/reload.module.js';
+import { CommandAuthorizationService } from './command-authorization.service.js';
 import { CommandExecutorService } from './command-executor.service.js';
 import { CommandRegistryService } from './command-registry.service.js';
 import { COMMANDS_REDIS } from './commands.tokens.js';
@@ -24,6 +25,7 @@ const COMMANDS_QUEUE_HANDLE = 'COMMANDS_QUEUE_HANDLE';
       inject: [COMMANDS_QUEUE_HANDLE],
     },
     CommandRegistryService,
+    CommandAuthorizationService,
     CommandExecutorService,
   ],
   exports: [CommandRegistryService, CommandExecutorService],
diff --git a/docs/scratchpads/tess-m1-sec-001.md b/docs/scratchpads/tess-m1-sec-001.md
new file mode 100644
index 0000000..b297170
--- /dev/null
+++ b/docs/scratchpads/tess-m1-sec-001.md
@@ -0,0 +1,27 @@
+# TESS-M1-SEC-001 — Command authorization and exact-action approval
+
+- Issue/milestone: #707 / M1
+- Branch: `fix/tess-command-authz`
+- Requirement: `TESS-SEC-002`, with approval binding controls from `TESS-SEC-007`
+- Scope: `apps/gateway` only, plus required in-repo security/developer documentation.
+
+## Plan
+
+1. Locate the gateway command executor, command metadata, authorization context, and existing test conventions.
+2. Write abuse/authz tests before production changes. Expected red cases: non-admin blocked from admin/system command; forged caller scope cannot authorize; privileged/destructive action requires durable exact-action approval; expired/replayed/mutated approvals deny.
+3. Implement server-derived role/scope enforcement and durable approval validation/consumption with audit results.
+4. Run focused security tests, then repository baseline gates: typecheck, lint, format-check, test.
+5. Run independent security/code review, commit, queue-guard, push, and open the PR to `main` through the stated Gitea API fallback. Stop after PR creation.
+
+## Assumptions
+
+- The existing gateway persistence interface is the available durable approval boundary. If no persistence abstraction exists, a minimal injectable repository interface will be introduced rather than an in-memory approval implementation, because TESS-SEC-002/007 require durable enforcement.
+- “Exact action” is a canonical digest over structured command identity and normalized arguments; role/scope checks always use authenticated server context, not client-declared claims.
+
+## TDD evidence
+
+- Pending: abuse/authz test written and observed red before implementation.
+
+## Verification evidence
+
+- Pending.