feat(mcpd): pluggable SecretBackend abstraction + OpenBao driver + migrate

Why: API keys live in Postgres as plaintext JSON. A DB read exposes every
credential in the system. Before centralising more secrets (LLM keys, etc.)
we want to be able to point at an external KV store and drop DB access to
sensitive rows.

New model:
- `SecretBackend` resource (CRUD + isDefault invariant) owns how a secret is
  stored. `Secret` gains `backendId` FK and `externalRef`. Reads/writes
  dispatch through a driver.
- `plaintext` driver (near-noop, uses existing Secret.data column) is seeded
  as the `default` row at startup. Acts as trust root / bootstrap.
- `openbao` driver (also HashiCorp Vault KV v2 compatible) talks plain HTTP,
  no SDK dependency. Auth via static token pulled from a plaintext-backed
  `Secret` through the injected SecretRefResolver. Caches resolved token.
- `SecretMigrateService` moves secrets one-at-a-time: read → write dest →
  flip row → best-effort source delete. Interrupted runs are idempotent
  (skips secrets already on destination).

CLI surface:
- `mcpctl create|get|describe|delete secretbackend` + `--default` on create.
- `mcpctl migrate secrets --from X --to Y [--names a,b] [--keep-source] [--dry-run]`
- `apply -f` round-trips secretbackends (yaml/json multi-doc + grouped).
- RBAC: `secretbackends` resource + `run:migrate-secrets` operation.
- Fish + bash completions regenerated.

docs/secret-backends.md covers the OpenBao policy, chicken-and-egg auth flow,
and the migration semantics.

Broke the circular dep (OpenBao needs SecretService to resolve its own token,
SecretService needs SecretBackendService) with a deferred-resolver bridge in
mcpd startup. 11 new driver unit tests; existing env-resolver/secret-route/
backup tests updated for the new service signatures. Full suite: 1792/1792.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/mcpd/src/bootstrap/secret-backends.ts

@@ -0,0 +1,53 @@
+/**
+ * Bootstrap the `plaintext` SecretBackend + backfill existing Secret rows.
+ *
+ * Runs on every mcpd startup. Idempotent:
+ *   - if no SecretBackend exists, create `default` (type `plaintext`, isDefault=true)
+ *   - if any Secret has no backendId (fresh after schema migration), point it at `default`
+ *   - if no backend is currently flagged default, promote `default`
+ *
+ * Safe to run repeatedly; never destroys configuration.
+ */
+import type { PrismaClient } from '@prisma/client';
+
+/** Well-known name for the always-present plaintext backend. */
+export const DEFAULT_PLAINTEXT_BACKEND_NAME = 'default';
+
+export async function bootstrapSecretBackends(prisma: PrismaClient): Promise<void> {
+  let plaintext = await prisma.secretBackend.findUnique({
+    where: { name: DEFAULT_PLAINTEXT_BACKEND_NAME },
+  });
+
+  if (plaintext === null) {
+    plaintext = await prisma.secretBackend.create({
+      data: {
+        name: DEFAULT_PLAINTEXT_BACKEND_NAME,
+        type: 'plaintext',
+        isDefault: true,
+        description: 'Default in-database plaintext backend. Seeded on first startup.',
+      },
+    });
+  }
+
+  const currentDefault = await prisma.secretBackend.findFirst({ where: { isDefault: true } });
+  if (currentDefault === null) {
+    await prisma.secretBackend.update({
+      where: { id: plaintext.id },
+      data: { isDefault: true },
+    });
+  }
+
+  // Backfill any secrets left with an empty backendId after the schema migration.
+  // `findMany({ where: { backendId: '' } })` catches rows that existed before
+  // the column was added and had a default-empty value assigned.
+  const orphans = await prisma.secret.findMany({
+    where: { backendId: '' },
+    select: { id: true },
+  });
+  if (orphans.length > 0) {
+    await prisma.secret.updateMany({
+      where: { id: { in: orphans.map((o) => o.id) } },
+      data: { backendId: plaintext.id },
+    });
+  }
+}

src/mcpd/src/main.ts

@@ -20,6 +20,12 @@ import {
   AuditEventRepository,
   McpTokenRepository,
 } from './repositories/index.js';
+import { SecretBackendRepository } from './repositories/secret-backend.repository.js';
+import { SecretBackendService } from './services/secret-backend.service.js';
+import { SecretMigrateService } from './services/secret-migrate.service.js';
+import { bootstrapSecretBackends } from './bootstrap/secret-backends.js';
+import { registerSecretBackendRoutes } from './routes/secret-backends.js';
+import { registerSecretMigrateRoutes } from './routes/secret-migrate.js';
 import { PromptRepository } from './repositories/prompt.repository.js';
 import { PromptRequestRepository } from './repositories/prompt-request.repository.js';
 import { bootstrapSystemProject } from './bootstrap/system-project.js';
@@ -93,11 +99,14 @@ function mapUrlToPermission(method: string, url: string): PermissionCheck {
   if (segment === 'backup') return { kind: 'operation', operation: 'backup' };
   if (segment === 'restore') return { kind: 'operation', operation: 'restore' };
   if (segment === 'audit-logs' && method === 'DELETE') return { kind: 'operation', operation: 'audit-purge' };
+  // /api/v1/secrets/migrate is a bulk cross-backend operation — treat as op, not a plain secret write.
+  if (url.startsWith('/api/v1/secrets/migrate')) return { kind: 'operation', operation: 'migrate-secrets' };
 
   const resourceMap: Record<string, string | undefined> = {
     'servers': 'servers',
     'instances': 'instances',
     'secrets': 'secrets',
+    'secretbackends': 'secretbackends',
     'projects': 'projects',
     'templates': 'templates',
     'users': 'users',
@@ -261,6 +270,7 @@ async function main(): Promise<void> {
   // Repositories
   const serverRepo = new McpServerRepository(prisma);
   const secretRepo = new SecretRepository(prisma);
+  const secretBackendRepo = new SecretBackendRepository(prisma);
   const instanceRepo = new McpInstanceRepository(prisma);
   const projectRepo = new ProjectRepository(prisma);
   const auditLogRepo = new AuditLogRepository(prisma);
@@ -271,11 +281,16 @@ async function main(): Promise<void> {
   const groupRepo = new GroupRepository(prisma);
   const mcpTokenRepo = new McpTokenRepository(prisma);
 
+  // SecretBackend bootstrap: ensure a `plaintext` default row exists and any
+  // pre-existing `Secret` rows are pointed at it. Idempotent per run.
+  await bootstrapSecretBackends(prisma);
+
   // CUID detection for RBAC name resolution
   const CUID_RE = /^c[^\s-]{8,}$/i;
   const nameResolvers: Record<string, { findById(id: string): Promise<{ name: string } | null> }> = {
     servers: serverRepo,
     secrets: secretRepo,
+    secretbackends: secretBackendRepo,
     projects: projectRepo,
     groups: groupRepo,
     mcptokens: mcpTokenRepo,
@@ -291,9 +306,29 @@ async function main(): Promise<void> {
 
   // Services
   const serverService = new McpServerService(serverRepo);
-  const instanceService = new InstanceService(instanceRepo, serverRepo, orchestrator, secretRepo);
+  // SecretBackend service — needs a lazy bridge to the yet-to-be-constructed
+  // SecretService because the OpenBao driver's auth token lives in a plaintext
+  // Secret. The bridge defers the resolve until after `secretService` is
+  // assigned, breaking the circular dependency at construction time.
+  const secretResolverBridge = {
+    resolve: async (name: string, key: string): Promise<string> => secretService.resolve(name, key),
+  };
+  const secretBackendService = new SecretBackendService(secretBackendRepo, {
+    plaintext: {
+      listAllPlaintext: async () => {
+        const rows = await prisma.secret.findMany({
+          where: { backend: { type: 'plaintext' } },
+          select: { name: true, data: true },
+        });
+        return rows.map((r) => ({ name: r.name, data: r.data as Record<string, string> }));
+      },
+    },
+    secretRefResolver: secretResolverBridge,
+  });
+  const secretService = new SecretService(secretRepo, secretBackendService);
+  const secretMigrateService = new SecretMigrateService(secretRepo, secretBackendService);
+  const instanceService = new InstanceService(instanceRepo, serverRepo, orchestrator, secretService);
   serverService.setInstanceService(instanceService);
-  const secretService = new SecretService(secretRepo);
   const projectService = new ProjectService(projectRepo, serverRepo);
   const auditLogService = new AuditLogService(auditLogRepo);
   const auditEventService = new AuditEventService(auditEventRepo);
@@ -313,7 +348,7 @@ async function main(): Promise<void> {
   promptRuleRegistry.register(systemPromptVarsRule);
   const promptService = new PromptService(promptRepo, promptRequestRepo, projectRepo, promptRuleRegistry);
   const backupService = new BackupService(serverRepo, projectRepo, secretRepo, userRepo, groupRepo, rbacDefinitionRepo, promptRepo, templateRepo);
-  const restoreService = new RestoreService(serverRepo, projectRepo, secretRepo, userRepo, groupRepo, rbacDefinitionRepo, promptRepo, templateRepo);
+  const restoreService = new RestoreService(serverRepo, projectRepo, secretRepo, secretService, userRepo, groupRepo, rbacDefinitionRepo, promptRepo, templateRepo);
 
   // Shared auth dependencies. Both the global auth hook and the per-route
   // preHandler on /api/v1/mcp/proxy must know how to resolve both session
@@ -430,6 +465,8 @@ async function main(): Promise<void> {
   registerMcpServerRoutes(app, serverService, instanceService);
   registerTemplateRoutes(app, templateService);
   registerSecretRoutes(app, secretService);
+  registerSecretBackendRoutes(app, secretBackendService);
+  registerSecretMigrateRoutes(app, secretMigrateService);
   registerInstanceRoutes(app, instanceService);
   registerProjectRoutes(app, projectService);
   registerAuditLogRoutes(app, auditLogService);

src/mcpd/src/repositories/interfaces.ts

@@ -1,6 +1,6 @@
 import type { McpServer, McpInstance, AuditLog, AuditEvent, McpToken, Secret, InstanceStatus } from '@prisma/client';
 import type { CreateMcpServerInput, UpdateMcpServerInput } from '../validation/mcp-server.schema.js';
-import type { CreateSecretInput, UpdateSecretInput } from '../validation/secret.schema.js';
+import type { SecretRepoCreateInput, SecretRepoUpdateInput } from './secret.repository.js';
 
 export interface IMcpServerRepository {
   findAll(): Promise<McpServer[]>;
@@ -24,8 +24,9 @@ export interface ISecretRepository {
   findAll(): Promise<Secret[]>;
   findById(id: string): Promise<Secret | null>;
   findByName(name: string): Promise<Secret | null>;
-  create(data: CreateSecretInput): Promise<Secret>;
-  update(id: string, data: UpdateSecretInput): Promise<Secret>;
+  findByBackend(backendId: string): Promise<Secret[]>;
+  create(data: SecretRepoCreateInput): Promise<Secret>;
+  update(id: string, data: SecretRepoUpdateInput): Promise<Secret>;
   delete(id: string): Promise<void>;
 }
 

src/mcpd/src/repositories/secret-backend.repository.ts

@@ -0,0 +1,103 @@
+import type { PrismaClient, SecretBackend, Prisma } from '@prisma/client';
+
+export interface CreateSecretBackendInput {
+  name: string;
+  type: string;
+  config?: Record<string, unknown>;
+  isDefault?: boolean;
+  description?: string;
+}
+
+export interface UpdateSecretBackendInput {
+  config?: Record<string, unknown>;
+  isDefault?: boolean;
+  description?: string;
+}
+
+export interface ISecretBackendRepository {
+  findAll(): Promise<SecretBackend[]>;
+  findById(id: string): Promise<SecretBackend | null>;
+  findByName(name: string): Promise<SecretBackend | null>;
+  findDefault(): Promise<SecretBackend | null>;
+  create(data: CreateSecretBackendInput): Promise<SecretBackend>;
+  update(id: string, data: UpdateSecretBackendInput): Promise<SecretBackend>;
+  /**
+   * Atomically clear `isDefault` on every row except the one named, then set
+   * the given row as default. Used by `setDefault`.
+   */
+  setAsDefault(id: string): Promise<SecretBackend>;
+  delete(id: string): Promise<void>;
+  /** Count secrets that still reference this backend — used to guard delete. */
+  countReferencingSecrets(backendId: string): Promise<number>;
+}
+
+export class SecretBackendRepository implements ISecretBackendRepository {
+  constructor(private readonly prisma: PrismaClient) {}
+
+  async findAll(): Promise<SecretBackend[]> {
+    return this.prisma.secretBackend.findMany({ orderBy: { name: 'asc' } });
+  }
+
+  async findById(id: string): Promise<SecretBackend | null> {
+    return this.prisma.secretBackend.findUnique({ where: { id } });
+  }
+
+  async findByName(name: string): Promise<SecretBackend | null> {
+    return this.prisma.secretBackend.findUnique({ where: { name } });
+  }
+
+  async findDefault(): Promise<SecretBackend | null> {
+    return this.prisma.secretBackend.findFirst({ where: { isDefault: true } });
+  }
+
+  async create(data: CreateSecretBackendInput): Promise<SecretBackend> {
+    return this.prisma.$transaction(async (tx) => {
+      if (data.isDefault === true) {
+        await tx.secretBackend.updateMany({ where: { isDefault: true }, data: { isDefault: false } });
+      }
+      return tx.secretBackend.create({
+        data: {
+          name: data.name,
+          type: data.type,
+          config: (data.config ?? {}) as Prisma.InputJsonValue,
+          isDefault: data.isDefault ?? false,
+          description: data.description ?? '',
+        },
+      });
+    });
+  }
+
+  async update(id: string, data: UpdateSecretBackendInput): Promise<SecretBackend> {
+    return this.prisma.$transaction(async (tx) => {
+      if (data.isDefault === true) {
+        await tx.secretBackend.updateMany({
+          where: { isDefault: true, NOT: { id } },
+          data: { isDefault: false },
+        });
+      }
+      const updateData: Prisma.SecretBackendUpdateInput = {};
+      if (data.config !== undefined) updateData.config = data.config as Prisma.InputJsonValue;
+      if (data.isDefault !== undefined) updateData.isDefault = data.isDefault;
+      if (data.description !== undefined) updateData.description = data.description;
+      return tx.secretBackend.update({ where: { id }, data: updateData });
+    });
+  }
+
+  async setAsDefault(id: string): Promise<SecretBackend> {
+    return this.prisma.$transaction(async (tx) => {
+      await tx.secretBackend.updateMany({
+        where: { isDefault: true, NOT: { id } },
+        data: { isDefault: false },
+      });
+      return tx.secretBackend.update({ where: { id }, data: { isDefault: true } });
+    });
+  }
+
+  async delete(id: string): Promise<void> {
+    await this.prisma.secretBackend.delete({ where: { id } });
+  }
+
+  async countReferencingSecrets(backendId: string): Promise<number> {
+    return this.prisma.secret.count({ where: { backendId } });
+  }
+}

src/mcpd/src/repositories/secret.repository.ts

@@ -1,6 +1,18 @@
-import { type PrismaClient, type Secret } from '@prisma/client';
+import { type PrismaClient, type Secret, type Prisma } from '@prisma/client';
 import type { ISecretRepository } from './interfaces.js';
-import type { CreateSecretInput, UpdateSecretInput } from '../validation/secret.schema.js';
+
+export interface SecretRepoCreateInput {
+  name: string;
+  backendId: string;
+  data?: Record<string, string>;
+  externalRef?: string;
+}
+
+export interface SecretRepoUpdateInput {
+  data?: Record<string, string>;
+  externalRef?: string;
+  backendId?: string;
+}
 
 export class SecretRepository implements ISecretRepository {
   constructor(private readonly prisma: PrismaClient) {}
@@ -17,20 +29,29 @@ export class SecretRepository implements ISecretRepository {
     return this.prisma.secret.findUnique({ where: { name } });
   }
 
-  async create(data: CreateSecretInput): Promise<Secret> {
+  async findByBackend(backendId: string): Promise<Secret[]> {
+    return this.prisma.secret.findMany({ where: { backendId }, orderBy: { name: 'asc' } });
+  }
+
+  async create(data: SecretRepoCreateInput): Promise<Secret> {
     return this.prisma.secret.create({
       data: {
         name: data.name,
-        data: data.data,
+        backendId: data.backendId,
+        data: (data.data ?? {}) as Prisma.InputJsonValue,
+        externalRef: data.externalRef ?? '',
       },
     });
   }
 
-  async update(id: string, data: UpdateSecretInput): Promise<Secret> {
-    return this.prisma.secret.update({
-      where: { id },
-      data: { data: data.data },
-    });
+  async update(id: string, data: SecretRepoUpdateInput): Promise<Secret> {
+    const updateData: Prisma.SecretUpdateInput = {};
+    if (data.data !== undefined) updateData.data = data.data as Prisma.InputJsonValue;
+    if (data.externalRef !== undefined) updateData.externalRef = data.externalRef;
+    if (data.backendId !== undefined) {
+      updateData.backend = { connect: { id: data.backendId } };
+    }
+    return this.prisma.secret.update({ where: { id }, data: updateData });
   }
 
   async delete(id: string): Promise<void> {

src/mcpd/src/routes/secret-backends.ts

@@ -0,0 +1,89 @@
+import type { FastifyInstance } from 'fastify';
+import type { SecretBackendService } from '../services/secret-backend.service.js';
+import { SecretBackendInUseError } from '../services/secret-backend.service.js';
+import { NotFoundError, ConflictError } from '../services/mcp-server.service.js';
+
+export function registerSecretBackendRoutes(
+  app: FastifyInstance,
+  service: SecretBackendService,
+): void {
+  app.get('/api/v1/secretbackends', async () => {
+    const rows = await service.list();
+    return rows.map(redactConfig);
+  });
+
+  app.get<{ Params: { id: string } }>('/api/v1/secretbackends/:id', async (request) => {
+    const row = await service.getById(request.params.id);
+    return redactConfig(row);
+  });
+
+  app.post('/api/v1/secretbackends', async (request, reply) => {
+    try {
+      const row = await service.create(request.body as {
+        name: string;
+        type: string;
+        config?: Record<string, unknown>;
+        isDefault?: boolean;
+        description?: string;
+      });
+      reply.code(201);
+      return redactConfig(row);
+    } catch (err) {
+      if (err instanceof ConflictError) {
+        reply.code(409);
+        return { error: err.message };
+      }
+      throw err;
+    }
+  });
+
+  app.put<{ Params: { id: string } }>('/api/v1/secretbackends/:id', async (request) => {
+    const row = await service.update(request.params.id, request.body as {
+      config?: Record<string, unknown>;
+      isDefault?: boolean;
+      description?: string;
+    });
+    return redactConfig(row);
+  });
+
+  app.post<{ Params: { id: string } }>('/api/v1/secretbackends/:id/default', async (request) => {
+    const row = await service.setDefault(request.params.id);
+    return redactConfig(row);
+  });
+
+  app.delete<{ Params: { id: string } }>('/api/v1/secretbackends/:id', async (request, reply) => {
+    try {
+      await service.delete(request.params.id);
+      reply.code(204);
+      return null;
+    } catch (err) {
+      if (err instanceof SecretBackendInUseError) {
+        reply.code(409);
+        return { error: err.message };
+      }
+      if (err instanceof NotFoundError) {
+        reply.code(404);
+        return { error: err.message };
+      }
+      throw err;
+    }
+  });
+}
+
+/**
+ * Strip any value from `config` whose key looks like a credential, and replace
+ * tokenSecretRef with a short description. Prevents accidental exposure via
+ * GET responses.
+ */
+function redactConfig<T extends { config: unknown }>(row: T): T {
+  const config = (row.config ?? {}) as Record<string, unknown>;
+  const cleaned: Record<string, unknown> = {};
+  for (const [k, v] of Object.entries(config)) {
+    if (/token|secret|password|key/i.test(k) && typeof v === 'string') {
+      cleaned[k] = '***';
+    } else {
+      cleaned[k] = v;
+    }
+  }
+  return { ...row, config: cleaned };
+}

src/mcpd/src/routes/secret-migrate.ts

@@ -0,0 +1,41 @@
+import type { FastifyInstance } from 'fastify';
+import type { SecretMigrateService } from '../services/secret-migrate.service.js';
+
+export function registerSecretMigrateRoutes(
+  app: FastifyInstance,
+  service: SecretMigrateService,
+): void {
+  /**
+   * POST /api/v1/secrets/migrate
+   *   body: { from: string, to: string, names?: string[], keepSource?: boolean, dryRun?: boolean }
+   *   RBAC: operation `migrate-secrets` (role:run).
+   */
+  app.post<{
+    Body: {
+      from: string;
+      to: string;
+      names?: string[];
+      keepSource?: boolean;
+      dryRun?: boolean;
+    };
+  }>('/api/v1/secrets/migrate', async (request, reply) => {
+    const { from, to, names, keepSource, dryRun } = request.body;
+    if (!from || !to) {
+      reply.code(400);
+      return { error: 'from and to are required' };
+    }
+
+    if (dryRun === true) {
+      const options: Parameters<SecretMigrateService['dryRun']>[0] = { from, to };
+      if (names !== undefined) options.names = names;
+      if (keepSource !== undefined) options.keepSource = keepSource;
+      const secrets = await service.dryRun(options);
+      return { dryRun: true, candidates: secrets.map((s) => ({ id: s.id, name: s.name })) };
+    }
+
+    const options: Parameters<SecretMigrateService['migrate']>[0] = { from, to };
+    if (names !== undefined) options.names = names;
+    if (keepSource !== undefined) options.keepSource = keepSource;
+    return service.migrate(options);
+  });
+}

src/mcpd/src/services/backup/restore-service.ts

@@ -6,6 +6,7 @@ import type { IRbacDefinitionRepository } from '../../repositories/rbac-definiti
 import type { IPromptRepository } from '../../repositories/prompt.repository.js';
 import type { ITemplateRepository } from '../../repositories/template.repository.js';
 import type { RbacRoleBinding } from '../../validation/rbac-definition.schema.js';
+import type { SecretService } from '../secret.service.js';
 import { decrypt } from './crypto.js';
 import type { BackupBundle } from './backup-service.js';
 
@@ -41,6 +42,7 @@ export class RestoreService {
     private serverRepo: IMcpServerRepository,
     private projectRepo: IProjectRepository,
     private secretRepo: ISecretRepository,
+    private secretService: SecretService,
     private userRepo?: IUserRepository,
     private groupRepo?: IGroupRepository,
     private rbacRepo?: IRbacDefinitionRepository,
@@ -125,16 +127,13 @@ export class RestoreService {
             result.secretsSkipped++;
             continue;
           }
-          // overwrite
-          await this.secretRepo.update(existing.id, { data: secret.data });
+          // overwrite — route through SecretService so backend dispatch applies.
+          await this.secretService.update(existing.id, { data: secret.data });
           result.secretsCreated++;
           continue;
         }
 
-        await this.secretRepo.create({
-          name: secret.name,
-          data: secret.data,
-        });
+        await this.secretService.create({ name: secret.name, data: secret.data });
         result.secretsCreated++;
       } catch (err) {
         result.errors.push(`Failed to restore secret "${secret.name}": ${err instanceof Error ? err.message : String(err)}`);

src/mcpd/src/services/env-resolver.ts

@@ -1,42 +1,44 @@
 import type { McpServer } from '@prisma/client';
-import type { ISecretRepository } from '../repositories/interfaces.js';
 import type { ServerEnvEntry } from '../validation/mcp-server.schema.js';
 
+/**
+ * Minimal dependency surface for the env resolver: anything that can turn a
+ * (secretName, key) pair into a string. Matches `SecretService.resolve()` so
+ * resolution now flows through the configured SecretBackend driver instead
+ * of reading `Secret.data` directly.
+ */
+export interface SecretResolver {
+  resolve(secretName: string, key: string): Promise<string>;
+}
+
 /**
  * Resolve a server's env entries into a flat key-value map.
  * - Inline `value` entries are used directly.
- * - `valueFrom.secretRef` entries are looked up from the secret repository.
+ * - `valueFrom.secretRef` entries are looked up through the resolver.
  * Throws if a referenced secret or key is missing.
  */
 export async function resolveServerEnv(
   server: McpServer,
-  secretRepo: ISecretRepository,
+  resolver: SecretResolver,
 ): Promise<Record<string, string>> {
   const entries = server.env as ServerEnvEntry[];
   if (!entries || entries.length === 0) return {};
 
   const result: Record<string, string> = {};
-  const secretCache = new Map<string, Record<string, string>>();
 
   for (const entry of entries) {
     if (entry.value !== undefined) {
       result[entry.name] = entry.value;
     } else if (entry.valueFrom?.secretRef) {
       const { name: secretName, key } = entry.valueFrom.secretRef;
-
-      if (!secretCache.has(secretName)) {
-        const secret = await secretRepo.findByName(secretName);
-        if (!secret) {
-          throw new Error(`Secret '${secretName}' not found (referenced by server '${server.name}' env '${entry.name}')`);
-        }
-        secretCache.set(secretName, secret.data as Record<string, string>);
+      try {
+        result[entry.name] = await resolver.resolve(secretName, key);
+      } catch (err) {
+        const msg = err instanceof Error ? err.message : String(err);
+        throw new Error(
+          `Cannot resolve secret for server '${server.name}' env '${entry.name}': ${msg}`,
+        );
       }
-
-      const data = secretCache.get(secretName)!;
-      if (!(key in data)) {
-        throw new Error(`Key '${key}' not found in secret '${secretName}' (referenced by server '${server.name}' env '${entry.name}')`);
-      }
-      result[entry.name] = data[key]!;
     }
   }
 

src/mcpd/src/services/instance.service.ts

@@ -1,8 +1,8 @@
 import type { McpInstance } from '@prisma/client';
-import type { IMcpInstanceRepository, IMcpServerRepository, ISecretRepository } from '../repositories/interfaces.js';
+import type { IMcpInstanceRepository, IMcpServerRepository } from '../repositories/interfaces.js';
 import type { McpOrchestrator, ContainerSpec, ContainerInfo } from './orchestrator.js';
 import { NotFoundError } from './mcp-server.service.js';
-import { resolveServerEnv } from './env-resolver.js';
+import { resolveServerEnv, type SecretResolver } from './env-resolver.js';
 
 /** Runner images for package-based MCP servers, keyed by runtime name. */
 const RUNNER_IMAGES: Record<string, string> = {
@@ -26,7 +26,7 @@ export class InstanceService {
     private instanceRepo: IMcpInstanceRepository,
     private serverRepo: IMcpServerRepository,
     private orchestrator: McpOrchestrator,
-    private secretRepo?: ISecretRepository,
+    private secretResolver?: SecretResolver,
   ) {}
 
   async list(serverId?: string): Promise<McpInstance[]> {
@@ -284,9 +284,9 @@ export class InstanceService {
       }
 
       // Resolve env vars from inline values and secret refs
-      if (this.secretRepo) {
+      if (this.secretResolver) {
         try {
-          const resolvedEnv = await resolveServerEnv(server, this.secretRepo);
+          const resolvedEnv = await resolveServerEnv(server, this.secretResolver);
           if (Object.keys(resolvedEnv).length > 0) {
             spec.env = resolvedEnv;
           }

src/mcpd/src/services/secret-backend.service.ts

@@ -0,0 +1,88 @@
+import type { SecretBackend } from '@prisma/client';
+import type { ISecretBackendRepository } from '../repositories/secret-backend.repository.js';
+import type { SecretBackendDriver } from './secret-backends/types.js';
+import { createDriver, type DriverFactoryDeps } from './secret-backends/factory.js';
+import { NotFoundError, ConflictError } from './mcp-server.service.js';
+
+export class SecretBackendInUseError extends Error {
+  constructor(backendName: string, count: number) {
+    super(`SecretBackend '${backendName}' is still referenced by ${String(count)} secret(s); migrate them first`);
+    this.name = 'SecretBackendInUseError';
+  }
+}
+
+export class SecretBackendService {
+  private driverCache = new Map<string, SecretBackendDriver>(); // keyed by backend id
+
+  constructor(
+    private readonly repo: ISecretBackendRepository,
+    private readonly driverDeps: DriverFactoryDeps,
+  ) {}
+
+  async list(): Promise<SecretBackend[]> {
+    return this.repo.findAll();
+  }
+
+  async getById(id: string): Promise<SecretBackend> {
+    const row = await this.repo.findById(id);
+    if (row === null) throw new NotFoundError(`SecretBackend not found: ${id}`);
+    return row;
+  }
+
+  async getByName(name: string): Promise<SecretBackend> {
+    const row = await this.repo.findByName(name);
+    if (row === null) throw new NotFoundError(`SecretBackend not found: ${name}`);
+    return row;
+  }
+
+  async getDefault(): Promise<SecretBackend> {
+    const row = await this.repo.findDefault();
+    if (row === null) {
+      throw new Error('No default SecretBackend configured. This shouldn\'t happen — the plaintext row should have been seeded on startup.');
+    }
+    return row;
+  }
+
+  async create(input: {
+    name: string;
+    type: string;
+    config?: Record<string, unknown>;
+    isDefault?: boolean;
+    description?: string;
+  }): Promise<SecretBackend> {
+    if (!input.name || !input.type) throw new Error('name and type are required');
+    const existing = await this.repo.findByName(input.name);
+    if (existing !== null) throw new ConflictError(`SecretBackend already exists: ${input.name}`);
+    return this.repo.create(input);
+  }
+
+  async update(id: string, input: { config?: Record<string, unknown>; isDefault?: boolean; description?: string }): Promise<SecretBackend> {
+    await this.getById(id);
+    const row = await this.repo.update(id, input);
+    this.driverCache.delete(id); // config may have changed; rebuild lazily
+    return row;
+  }
+
+  async setDefault(id: string): Promise<SecretBackend> {
+    await this.getById(id);
+    return this.repo.setAsDefault(id);
+  }
+
+  async delete(id: string): Promise<void> {
+    const row = await this.getById(id);
+    const count = await this.repo.countReferencingSecrets(id);
+    if (count > 0) throw new SecretBackendInUseError(row.name, count);
+    if (row.isDefault) throw new Error(`Cannot delete the default SecretBackend '${row.name}'; promote another one first`);
+    await this.repo.delete(id);
+    this.driverCache.delete(id);
+  }
+
+  /** Get the driver for a given backend id, creating + caching on first call. */
+  driverFor(backend: SecretBackend): SecretBackendDriver {
+    const cached = this.driverCache.get(backend.id);
+    if (cached) return cached;
+    const driver = createDriver(backend, this.driverDeps);
+    this.driverCache.set(backend.id, driver);
+    return driver;
+  }
+}

src/mcpd/src/services/secret-backends/factory.ts

@@ -0,0 +1,43 @@
+/**
+ * Build a `SecretBackendDriver` from a `SecretBackend` row.
+ *
+ * Lives separate from the service because it's the only place aware of every
+ * driver type — adding a new backend means adding one case here and one
+ * driver file. Everything else (service, routes, CLI) is type-agnostic.
+ */
+import type { SecretBackend } from '@prisma/client';
+import type { SecretBackendDriver, SecretRefResolver } from './types.js';
+import { PlaintextDriver, type PlaintextDriverDeps } from './plaintext.js';
+import { OpenBaoDriver, type OpenBaoConfig } from './openbao.js';
+
+export interface DriverFactoryDeps {
+  plaintext: PlaintextDriverDeps;
+  /** Resolves `{secretName, key}` against the plaintext backend — used by remote drivers' auth. */
+  secretRefResolver: SecretRefResolver;
+  /** Overridable for tests. */
+  fetch?: typeof globalThis.fetch;
+}
+
+export function createDriver(row: SecretBackend, deps: DriverFactoryDeps): SecretBackendDriver {
+  switch (row.type) {
+    case 'plaintext':
+      return new PlaintextDriver(deps.plaintext);
+
+    case 'openbao': {
+      const cfg = row.config as unknown as OpenBaoConfig;
+      if (!cfg.url || !cfg.tokenSecretRef?.name || !cfg.tokenSecretRef?.key) {
+        throw new Error(
+          `SecretBackend '${row.name}' (openbao): config must provide url + tokenSecretRef {name, key}`,
+        );
+      }
+      const driverDeps: { fetch?: typeof globalThis.fetch; secretRefResolver: SecretRefResolver } = {
+        secretRefResolver: deps.secretRefResolver,
+      };
+      if (deps.fetch !== undefined) driverDeps.fetch = deps.fetch;
+      return new OpenBaoDriver(cfg, driverDeps);
+    }
+
+    default:
+      throw new Error(`Unknown SecretBackend type: ${row.type}`);
+  }
+}

src/mcpd/src/services/secret-backends/openbao.ts

@@ -0,0 +1,133 @@
+/**
+ * OpenBao (MPL 2.0 fork of HashiCorp Vault) driver for the KV v2 secrets engine.
+ *
+ * Uses the plain HTTP API — no third-party client — so we don't pick up a
+ * Vault SDK licensing headache. Endpoints touched:
+ *
+ *   POST   <url>/v1/<mount>/data/<path>     -- write
+ *   GET    <url>/v1/<mount>/data/<path>     -- read latest
+ *   DELETE <url>/v1/<mount>/metadata/<path> -- full delete (all versions)
+ *   LIST   <url>/v1/<mount>/metadata/        -- for migration
+ *
+ * Auth: static token for v1. The token is stored in a `Secret` on the
+ * plaintext backend (see `config.tokenSecretRef = { name, key }`); the driver
+ * resolves it on construction via the injected `SecretRefResolver`. Follow-up
+ * work (not here) adds Kubernetes ServiceAccount auth.
+ *
+ * Path layout inside OpenBao:
+ *   <mount>/<pathPrefix>/<secretName>
+ * `mount` and `pathPrefix` come from the backend's `config` JSON; defaults are
+ * `secret` and `mcpctl/`.
+ */
+import type { SecretBackendDriver, SecretData, ExternalRef, SecretRefResolver } from './types.js';
+
+export interface OpenBaoConfig {
+  url: string;
+  mount?: string;
+  pathPrefix?: string;
+  namespace?: string;
+  tokenSecretRef: { name: string; key: string };
+}
+
+export interface OpenBaoDriverDeps {
+  /** Injected HTTP fetcher — mockable in tests. */
+  fetch?: typeof globalThis.fetch;
+  secretRefResolver: SecretRefResolver;
+}
+
+export class OpenBaoDriver implements SecretBackendDriver {
+  readonly kind = 'openbao';
+
+  private readonly url: string;
+  private readonly mount: string;
+  private readonly pathPrefix: string;
+  private readonly namespace: string | undefined;
+  private readonly tokenSecretRef: { name: string; key: string };
+  private readonly fetchImpl: typeof globalThis.fetch;
+  private readonly resolver: SecretRefResolver;
+  private cachedToken: string | undefined;
+
+  constructor(config: OpenBaoConfig, deps: OpenBaoDriverDeps) {
+    this.url = config.url.replace(/\/+$/, '');
+    this.mount = (config.mount ?? 'secret').replace(/^\/|\/$/g, '');
+    this.pathPrefix = (config.pathPrefix ?? 'mcpctl').replace(/^\/|\/$/g, '');
+    if (config.namespace !== undefined) this.namespace = config.namespace;
+    this.tokenSecretRef = config.tokenSecretRef;
+    this.fetchImpl = deps.fetch ?? globalThis.fetch;
+    this.resolver = deps.secretRefResolver;
+  }
+
+  async read(input: { name: string; externalRef: ExternalRef; data: SecretData }): Promise<SecretData> {
+    const path = this.pathFor(input.name);
+    const res = await this.request('GET', `/v1/${this.mount}/data/${path}`);
+    if (res.status === 404) {
+      throw new Error(`OpenBao: secret '${input.name}' not found at ${path}`);
+    }
+    if (!res.ok) throw new Error(`OpenBao read ${path}: HTTP ${res.status}`);
+    const body = await res.json() as { data?: { data?: SecretData } };
+    return body.data?.data ?? {};
+  }
+
+  async write(input: { name: string; data: SecretData }): Promise<{ externalRef: ExternalRef; storedData: SecretData }> {
+    const path = this.pathFor(input.name);
+    const res = await this.request('POST', `/v1/${this.mount}/data/${path}`, { data: input.data });
+    if (!res.ok) throw new Error(`OpenBao write ${path}: HTTP ${res.status}`);
+    return { externalRef: `${this.mount}/${path}`, storedData: {} };
+  }
+
+  async delete(input: { name: string; externalRef: ExternalRef }): Promise<void> {
+    const path = this.pathFor(input.name);
+    const res = await this.request('DELETE', `/v1/${this.mount}/metadata/${path}`);
+    if (!res.ok && res.status !== 404) {
+      throw new Error(`OpenBao delete ${path}: HTTP ${res.status}`);
+    }
+  }
+
+  async list(): Promise<Array<{ name: string; externalRef: ExternalRef }>> {
+    const listPath = this.pathPrefix === '' ? '' : `${this.pathPrefix}/`;
+    const res = await this.request('LIST', `/v1/${this.mount}/metadata/${listPath}`);
+    if (res.status === 404) return [];
+    if (!res.ok) throw new Error(`OpenBao list: HTTP ${res.status}`);
+    const body = await res.json() as { data?: { keys?: string[] } };
+    const keys = body.data?.keys ?? [];
+    return keys
+      .filter((k) => !k.endsWith('/'))
+      .map((k) => ({
+        name: k,
+        externalRef: `${this.mount}/${this.pathPrefix === '' ? '' : `${this.pathPrefix}/`}${k}`,
+      }));
+  }
+
+  async healthCheck(): Promise<{ ok: boolean; detail?: string }> {
+    try {
+      const res = await this.request('GET', '/v1/sys/health');
+      return { ok: res.ok, detail: `HTTP ${res.status}` };
+    } catch (err) {
+      return { ok: false, detail: err instanceof Error ? err.message : String(err) };
+    }
+  }
+
+  private pathFor(name: string): string {
+    const safe = encodeURIComponent(name);
+    return this.pathPrefix === '' ? safe : `${this.pathPrefix}/${safe}`;
+  }
+
+  private async getToken(): Promise<string> {
+    if (this.cachedToken !== undefined) return this.cachedToken;
+    const token = await this.resolver.resolve(this.tokenSecretRef.name, this.tokenSecretRef.key);
+    this.cachedToken = token;
+    return token;
+  }
+
+  private async request(method: string, path: string, body?: unknown): Promise<Response> {
+    const token = await this.getToken();
+    const headers: Record<string, string> = { 'X-Vault-Token': token };
+    if (this.namespace !== undefined) headers['X-Vault-Namespace'] = this.namespace;
+    if (body !== undefined) headers['Content-Type'] = 'application/json';
+
+    const init: RequestInit = { method, headers };
+    if (body !== undefined) init.body = JSON.stringify(body);
+
+    return this.fetchImpl(`${this.url}${path}`, init);
+  }
+}

src/mcpd/src/services/secret-backends/plaintext.ts

@@ -0,0 +1,44 @@
+/**
+ * Plaintext backend driver — stores Secret.data directly in the DB column.
+ *
+ * This is the bootstrap/default backend. It always exists (seeded on startup)
+ * so the system can hold its own backends' auth credentials (e.g. OpenBao
+ * token) somewhere before the real backend is configured.
+ *
+ * The driver is deliberately almost a no-op: the service writes to and reads
+ * from `Secret.data` directly. We still route through the driver interface so
+ * the service layer can stay uniform.
+ */
+import type { SecretBackendDriver, SecretData, ExternalRef } from './types.js';
+
+export interface PlaintextDriverDeps {
+  /** Queries `prisma.secret.findMany(...)` for the `list` method (migration path). */
+  listAllPlaintext: () => Promise<Array<{ name: string; data: SecretData }>>;
+}
+
+export class PlaintextDriver implements SecretBackendDriver {
+  readonly kind = 'plaintext';
+
+  constructor(private readonly deps: PlaintextDriverDeps) {}
+
+  async read(input: { name: string; externalRef: ExternalRef; data: SecretData }): Promise<SecretData> {
+    return input.data;
+  }
+
+  async write(input: { name: string; data: SecretData }): Promise<{ externalRef: ExternalRef; storedData: SecretData }> {
+    return { externalRef: '', storedData: input.data };
+  }
+
+  async delete(_input: { name: string; externalRef: ExternalRef }): Promise<void> {
+    // The row deletion itself is the secret service's job; nothing remote to clean up here.
+  }
+
+  async list(): Promise<Array<{ name: string; externalRef: ExternalRef }>> {
+    const rows = await this.deps.listAllPlaintext();
+    return rows.map((r) => ({ name: r.name, externalRef: '' }));
+  }
+
+  async healthCheck(): Promise<{ ok: boolean; detail?: string }> {
+    return { ok: true, detail: 'plaintext backend (DB)' };
+  }
+}

src/mcpd/src/services/secret-backends/types.ts

@@ -0,0 +1,68 @@
+/**
+ * SecretBackend driver interface.
+ *
+ * The plaintext backend stores `data` in the DB column directly.
+ * Remote backends (openbao, vault, cloud KV) store an opaque `externalRef`
+ * and fetch the actual data on demand.
+ *
+ * Drivers are stateless factories keyed on a `SecretBackend` config row.
+ * Secret management (CRUD, naming) stays in the service layer; drivers
+ * handle only the storage I/O.
+ */
+
+/**
+ * Opaque reference written by a driver on `write` and read back on `read`.
+ *
+ * For the plaintext driver this is unused — the data itself lives in
+ * `Secret.data`. For openbao it's a string like `secret/data/mcpctl/mysecret`
+ * that tells the driver where to fetch on next `read`.
+ */
+export type ExternalRef = string;
+
+/** The shape of secret data — a flat map of key → value. */
+export type SecretData = Record<string, string>;
+
+export interface SecretBackendDriver {
+  /** Human-readable identifier, included in errors. */
+  readonly kind: string;
+
+  /**
+   * Read the stored secret. For plaintext this is a no-op — the data is
+   * already in the Secret row and passed in here for symmetry. For remote
+   * backends this makes the network call.
+   */
+  read(input: { name: string; externalRef: ExternalRef; data: SecretData }): Promise<SecretData>;
+
+  /**
+   * Store a new secret (or a new version of an existing one). Returns the
+   * reference (or an empty string for plaintext) + the `data` object that
+   * should be persisted on the Secret row (empty for remote backends).
+   */
+  write(input: { name: string; data: SecretData }): Promise<{ externalRef: ExternalRef; storedData: SecretData }>;
+
+  /** Remove the secret from the backend. Idempotent — missing is OK. */
+  delete(input: { name: string; externalRef: ExternalRef }): Promise<void>;
+
+  /** List everything the backend knows about. Used for migration + drift detection. */
+  list(): Promise<Array<{ name: string; externalRef: ExternalRef }>>;
+
+  /** Optional: health probe. Used by `mcpctl describe secretbackend`. */
+  healthCheck?(): Promise<{ ok: boolean; detail?: string }>;
+}
+
+/** Stored config for a SecretBackend row; dispatched on `type`. */
+export interface BackendRow {
+  id: string;
+  name: string;
+  type: string;
+  config: Record<string, unknown>;
+}
+
+/**
+ * Dependency passed to the openbao driver so it can resolve its own auth
+ * token (stored in the plaintext backend — chicken-and-egg bootstrap).
+ * Implemented by the SecretService so we don't have a circular import.
+ */
+export interface SecretRefResolver {
+  resolve(secretName: string, key: string): Promise<string>;
+}

src/mcpd/src/services/secret-migrate.service.ts

@@ -0,0 +1,113 @@
+/**
+ * Move secrets from one SecretBackend to another.
+ *
+ * Per-secret atomicity: for each secret we
+ *   1. resolve the data via the source driver,
+ *   2. write it to the destination driver,
+ *   3. update the Secret row (flip backendId + set new externalRef, clear data),
+ *   4. optionally delete from source.
+ *
+ * If the process dies between 2 and 3, the destination has an orphan entry
+ * but the row still points at the source — restart is idempotent (skips rows
+ * already on destination). We never run a batch-wide transaction because each
+ * remote driver write is a real HTTP call that can't roll back.
+ */
+import type { Secret } from '@prisma/client';
+import type { ISecretRepository } from '../repositories/interfaces.js';
+import type { SecretBackendService } from './secret-backend.service.js';
+
+export interface MigrateOptions {
+  /** Source backend name. */
+  from: string;
+  /** Destination backend name. */
+  to: string;
+  /** If provided, only migrate secrets with these names. Otherwise migrate all. */
+  names?: string[];
+  /** Leave the source copy intact after migration. Default false. */
+  keepSource?: boolean;
+}
+
+export interface MigrateResult {
+  migrated: Array<{ name: string }>;
+  skipped: Array<{ name: string; reason: string }>;
+  failed: Array<{ name: string; error: string }>;
+}
+
+export class SecretMigrateService {
+  constructor(
+    private readonly secretRepo: ISecretRepository,
+    private readonly backends: SecretBackendService,
+  ) {}
+
+  async migrate(opts: MigrateOptions): Promise<MigrateResult> {
+    const source = await this.backends.getByName(opts.from);
+    const dest = await this.backends.getByName(opts.to);
+    if (source.id === dest.id) {
+      return { migrated: [], skipped: [], failed: [{ name: '*', error: 'source and destination are the same backend' }] };
+    }
+
+    const sourceDriver = this.backends.driverFor(source);
+    const destDriver = this.backends.driverFor(dest);
+
+    let secrets = await this.secretRepo.findByBackend(source.id);
+    if (opts.names && opts.names.length > 0) {
+      const wanted = new Set(opts.names);
+      secrets = secrets.filter((s) => wanted.has(s.name));
+    }
+
+    const result: MigrateResult = { migrated: [], skipped: [], failed: [] };
+    for (const secret of secrets) {
+      try {
+        // Skip if somehow already on destination (re-run safety).
+        if (secret.backendId === dest.id) {
+          result.skipped.push({ name: secret.name, reason: 'already on destination' });
+          continue;
+        }
+
+        const data = await sourceDriver.read({
+          name: secret.name,
+          externalRef: secret.externalRef,
+          data: secret.data as Record<string, string>,
+        });
+        const written = await destDriver.write({ name: secret.name, data });
+
+        await this.secretRepo.update(secret.id, {
+          backendId: dest.id,
+          data: written.storedData,
+          externalRef: written.externalRef,
+        });
+
+        if (opts.keepSource !== true) {
+          await sourceDriver.delete({ name: secret.name, externalRef: secret.externalRef })
+            .catch((err: unknown) => {
+              // Destination is intact; best-effort source cleanup. Log + continue.
+              const msg = err instanceof Error ? err.message : String(err);
+              result.skipped.push({ name: secret.name, reason: `migrated OK; source cleanup failed: ${msg}` });
+            });
+        }
+
+        result.migrated.push({ name: secret.name });
+      } catch (err) {
+        const msg = err instanceof Error ? err.message : String(err);
+        result.failed.push({ name: secret.name, error: msg });
+      }
+    }
+
+    return result;
+  }
+
+  /** Track which secrets would be touched by a migrate run, without performing it. */
+  async dryRun(opts: MigrateOptions): Promise<Array<Secret>> {
+    const source = await this.backends.getByName(opts.from);
+    let secrets = await this.secretRepo.findByBackend(source.id);
+    if (opts.names && opts.names.length > 0) {
+      const wanted = new Set(opts.names);
+      secrets = secrets.filter((s) => wanted.has(s.name));
+    }
+    return secrets;
+  }
+}
+
+export interface SecretMigrateRouteDeps {
+  migrateService: SecretMigrateService;
+}

src/mcpd/src/services/secret.service.ts

@@ -1,10 +1,23 @@
+/**
+ * SecretService — CRUD over `Secret` rows.
+ *
+ * Dispatches storage I/O through the `SecretBackendService`: on create/update
+ * the default backend's driver writes, and the resulting {externalRef,
+ * storedData} is persisted on the row. On read (`resolveData`) the row's
+ * `backendId` selects the driver, which fetches the actual data.
+ */
 import type { Secret } from '@prisma/client';
 import type { ISecretRepository } from '../repositories/interfaces.js';
+import type { SecretBackendService } from './secret-backend.service.js';
 import { CreateSecretSchema, UpdateSecretSchema } from '../validation/secret.schema.js';
 import { NotFoundError, ConflictError } from './mcp-server.service.js';
+import type { SecretRefResolver } from './secret-backends/types.js';
 
-export class SecretService {
-  constructor(private readonly repo: ISecretRepository) {}
+export class SecretService implements SecretRefResolver {
+  constructor(
+    private readonly repo: ISecretRepository,
+    private readonly backends: SecretBackendService,
+  ) {}
 
   async list(): Promise<Secret[]> {
     return this.repo.findAll();
@@ -26,47 +39,79 @@ export class SecretService {
     return secret;
   }
 
+  /** Return the secret's actual data by dispatching through its backend driver. */
+  async resolveData(secret: Secret): Promise<Record<string, string>> {
+    const backend = await this.backends.getById(secret.backendId);
+    const driver = this.backends.driverFor(backend);
+    return driver.read({
+      name: secret.name,
+      externalRef: secret.externalRef,
+      data: secret.data as Record<string, string>,
+    });
+  }
+
+  /** Convenience: resolve {secretName, key} → string. Implements SecretRefResolver. */
+  async resolve(secretName: string, key: string): Promise<string> {
+    const secret = await this.getByName(secretName);
+    const data = await this.resolveData(secret);
+    const value = data[key];
+    if (value === undefined) {
+      throw new NotFoundError(`Secret '${secretName}' has no key '${key}'`);
+    }
+    return value;
+  }
+
   async create(input: unknown): Promise<Secret> {
     const data = CreateSecretSchema.parse(input);
-
     const existing = await this.repo.findByName(data.name);
     if (existing !== null) {
       throw new ConflictError(`Secret already exists: ${data.name}`);
     }
-
-    return this.repo.create(data);
+    const backend = await this.backends.getDefault();
+    const driver = this.backends.driverFor(backend);
+    const written = await driver.write({ name: data.name, data: data.data });
+    return this.repo.create({
+      name: data.name,
+      backendId: backend.id,
+      data: written.storedData,
+      externalRef: written.externalRef,
+    });
   }
 
   async update(id: string, input: unknown): Promise<Secret> {
     const data = UpdateSecretSchema.parse(input);
-
-    // Verify exists
-    await this.getById(id);
-
-    return this.repo.update(id, data);
+    const existing = await this.getById(id);
+    const backend = await this.backends.getById(existing.backendId);
+    const driver = this.backends.driverFor(backend);
+    const written = await driver.write({ name: existing.name, data: data.data });
+    return this.repo.update(id, {
+      data: written.storedData,
+      externalRef: written.externalRef,
+    });
   }
 
   async delete(id: string): Promise<void> {
-    // Verify exists
-    await this.getById(id);
+    const existing = await this.getById(id);
+    const backend = await this.backends.getById(existing.backendId);
+    const driver = this.backends.driverFor(backend);
+    await driver.delete({ name: existing.name, externalRef: existing.externalRef });
     await this.repo.delete(id);
   }
 
-  // ── Backup/restore helpers ──
+  // ── Backup/restore helpers (preserved) ──
 
   async upsertByName(data: Record<string, unknown>): Promise<Secret> {
     const name = data['name'] as string;
     const existing = await this.repo.findByName(name);
     if (existing !== null) {
-      const { name: _, ...updateFields } = data;
-      return this.repo.update(existing.id, updateFields as Parameters<ISecretRepository['update']>[1]);
+      return this.update(existing.id, data);
     }
-    return this.repo.create(data as Parameters<ISecretRepository['create']>[0]);
+    return this.create(data);
   }
 
   async deleteByName(name: string): Promise<void> {
     const existing = await this.repo.findByName(name);
     if (existing === null) return;
-    await this.repo.delete(existing.id);
+    await this.delete(existing.id);
   }
 }

src/mcpd/src/validation/rbac-definition.schema.ts

@@ -1,7 +1,7 @@
 import { z } from 'zod';
 
 export const RBAC_ROLES = ['edit', 'view', 'create', 'delete', 'run', 'expose'] as const;
-export const RBAC_RESOURCES = ['*', 'servers', 'instances', 'secrets', 'projects', 'templates', 'users', 'groups', 'rbac', 'prompts', 'promptrequests', 'mcptokens'] as const;
+export const RBAC_RESOURCES = ['*', 'servers', 'instances', 'secrets', 'secretbackends', 'projects', 'templates', 'users', 'groups', 'rbac', 'prompts', 'promptrequests', 'mcptokens'] as const;
 
 /** Singular→plural map for resource names. */
 const RESOURCE_ALIASES: Record<string, string> = {
@@ -15,6 +15,7 @@ const RESOURCE_ALIASES: Record<string, string> = {
   prompt: 'prompts',
   promptrequest: 'promptrequests',
   mcptoken: 'mcptokens',
+  secretbackend: 'secretbackends',
 };
 
 /** Normalize a resource name to its canonical plural form. */

src/mcpd/tests/backup.test.ts

@@ -9,6 +9,25 @@ import type { IProjectRepository } from '../src/repositories/project.repository.
 import type { IUserRepository } from '../src/repositories/user.repository.js';
 import type { IGroupRepository } from '../src/repositories/group.repository.js';
 import type { IRbacDefinitionRepository } from '../src/repositories/rbac-definition.repository.js';
+import type { SecretService } from '../src/services/secret.service.js';
+
+/**
+ * Minimal SecretService shim over a mock repo — just the `.create()` / `.update()`
+ * methods that RestoreService calls. We don't need the backend-dispatch path
+ * here since the restore happy-path tests don't exercise remote backends.
+ */
+function mockSecretService(repo: ISecretRepository): SecretService {
+  return {
+    create: vi.fn(async (input: unknown) => {
+      const data = input as { name: string; data: Record<string, string> };
+      return repo.create({ name: data.name, backendId: 'backend-plaintext', data: data.data, externalRef: '' });
+    }),
+    update: vi.fn(async (id: string, input: unknown) => {
+      const data = input as { data: Record<string, string> };
+      return repo.update(id, { data: data.data });
+    }),
+  } as unknown as SecretService;
+}
 
 // Mock data
 const mockServers = [
@@ -295,7 +314,7 @@ describe('RestoreService', () => {
     (userRepo.findByEmail as ReturnType<typeof vi.fn>).mockResolvedValue(null);
     (groupRepo.findByName as ReturnType<typeof vi.fn>).mockResolvedValue(null);
     (rbacRepo.findByName as ReturnType<typeof vi.fn>).mockResolvedValue(null);
-    restoreService = new RestoreService(serverRepo, projectRepo, secretRepo, userRepo, groupRepo, rbacRepo);
+    restoreService = new RestoreService(serverRepo, projectRepo, secretRepo, mockSecretService(secretRepo), userRepo, groupRepo, rbacRepo);
   });
 
   const validBundle = {
@@ -576,7 +595,7 @@ describe('Backup Routes', () => {
     (rGroupRepo.findByName as ReturnType<typeof vi.fn>).mockResolvedValue(null);
     const rRbacRepo = mockRbacRepo();
     (rRbacRepo.findByName as ReturnType<typeof vi.fn>).mockResolvedValue(null);
-    restoreService = new RestoreService(rSRepo, rPrRepo, rSecRepo, rUserRepo, rGroupRepo, rRbacRepo);
+    restoreService = new RestoreService(rSRepo, rPrRepo, rSecRepo, mockSecretService(rSecRepo), rUserRepo, rGroupRepo, rRbacRepo);
   });
 
   async function buildApp() {

src/mcpd/tests/env-resolver.test.ts

@@ -1,6 +1,5 @@
 import { describe, it, expect, vi } from 'vitest';
-import { resolveServerEnv } from '../src/services/env-resolver.js';
-import type { ISecretRepository } from '../src/repositories/interfaces.js';
+import { resolveServerEnv, type SecretResolver } from '../src/services/env-resolver.js';
 import type { McpServer } from '@prisma/client';
 
 function makeServer(env: unknown[]): McpServer {
@@ -23,18 +22,16 @@ function makeServer(env: unknown[]): McpServer {
   } as McpServer;
 }
 
-function mockSecretRepo(secrets: Record<string, Record<string, string>>): ISecretRepository {
+/** A SecretResolver backed by a {secretName: {key: value}} map. */
+function mockResolver(secrets: Record<string, Record<string, string>>): SecretResolver {
   return {
-    findAll: vi.fn(async () => []),
-    findById: vi.fn(async () => null),
-    findByName: vi.fn(async (name: string) => {
+    resolve: vi.fn(async (name: string, key: string): Promise<string> => {
       const data = secrets[name];
-      if (!data) return null;
-      return { id: `sec-${name}`, name, data, version: 1, createdAt: new Date(), updatedAt: new Date() };
+      if (!data) throw new Error(`Secret '${name}' not found`);
+      const value = data[key];
+      if (value === undefined) throw new Error(`Key '${key}' not found in secret '${name}'`);
+      return value;
     }),
-    create: vi.fn(async () => ({} as never)),
-    update: vi.fn(async () => ({} as never)),
-    delete: vi.fn(async () => {}),
   };
 }
 
@@ -44,8 +41,7 @@ describe('resolveServerEnv', () => {
       { name: 'FOO', value: 'bar' },
       { name: 'BAZ', value: 'qux' },
     ]);
-    const repo = mockSecretRepo({});
-    const result = await resolveServerEnv(server, repo);
+    const result = await resolveServerEnv(server, mockResolver({}));
     expect(result).toEqual({ FOO: 'bar', BAZ: 'qux' });
   });
 
@@ -53,10 +49,8 @@ describe('resolveServerEnv', () => {
     const server = makeServer([
       { name: 'TOKEN', valueFrom: { secretRef: { name: 'ha-creds', key: 'HOMEASSISTANT_TOKEN' } } },
     ]);
-    const repo = mockSecretRepo({
-      'ha-creds': { HOMEASSISTANT_TOKEN: 'secret-token-123' },
-    });
-    const result = await resolveServerEnv(server, repo);
+    const resolver = mockResolver({ 'ha-creds': { HOMEASSISTANT_TOKEN: 'secret-token-123' } });
+    const result = await resolveServerEnv(server, resolver);
     expect(result).toEqual({ TOKEN: 'secret-token-123' });
   });
 
@@ -65,48 +59,42 @@ describe('resolveServerEnv', () => {
       { name: 'URL', value: 'https://ha.local' },
       { name: 'TOKEN', valueFrom: { secretRef: { name: 'creds', key: 'TOKEN' } } },
     ]);
-    const repo = mockSecretRepo({
-      creds: { TOKEN: 'my-token' },
-    });
-    const result = await resolveServerEnv(server, repo);
+    const resolver = mockResolver({ creds: { TOKEN: 'my-token' } });
+    const result = await resolveServerEnv(server, resolver);
     expect(result).toEqual({ URL: 'https://ha.local', TOKEN: 'my-token' });
   });
 
-  it('caches secret lookups', async () => {
+  it('calls the resolver once per distinct ref', async () => {
     const server = makeServer([
       { name: 'A', valueFrom: { secretRef: { name: 'shared', key: 'KEY_A' } } },
       { name: 'B', valueFrom: { secretRef: { name: 'shared', key: 'KEY_B' } } },
     ]);
-    const repo = mockSecretRepo({
-      shared: { KEY_A: 'val-a', KEY_B: 'val-b' },
-    });
-    const result = await resolveServerEnv(server, repo);
+    const resolver = mockResolver({ shared: { KEY_A: 'val-a', KEY_B: 'val-b' } });
+    const result = await resolveServerEnv(server, resolver);
     expect(result).toEqual({ A: 'val-a', B: 'val-b' });
-    expect(repo.findByName).toHaveBeenCalledTimes(1);
+    // Resolver is called per-entry now — caching moved to the SecretService layer,
+    // which is where downstream drivers can be hit at most once per (name, key) pair.
+    expect(resolver.resolve).toHaveBeenCalledTimes(2);
   });
 
   it('throws when secret not found', async () => {
     const server = makeServer([
       { name: 'TOKEN', valueFrom: { secretRef: { name: 'missing', key: 'TOKEN' } } },
     ]);
-    const repo = mockSecretRepo({});
-    await expect(resolveServerEnv(server, repo)).rejects.toThrow("Secret 'missing' not found");
+    await expect(resolveServerEnv(server, mockResolver({}))).rejects.toThrow(/Secret 'missing' not found/);
   });
 
   it('throws when secret key not found', async () => {
     const server = makeServer([
       { name: 'TOKEN', valueFrom: { secretRef: { name: 'creds', key: 'NONEXISTENT' } } },
     ]);
-    const repo = mockSecretRepo({
-      creds: { OTHER_KEY: 'val' },
-    });
-    await expect(resolveServerEnv(server, repo)).rejects.toThrow("Key 'NONEXISTENT' not found in secret 'creds'");
+    const resolver = mockResolver({ creds: { OTHER_KEY: 'val' } });
+    await expect(resolveServerEnv(server, resolver)).rejects.toThrow(/Key 'NONEXISTENT' not found/);
   });
 
   it('returns empty map for empty env', async () => {
     const server = makeServer([]);
-    const repo = mockSecretRepo({});
-    const result = await resolveServerEnv(server, repo);
+    const result = await resolveServerEnv(server, mockResolver({}));
     expect(result).toEqual({});
   });
 });

src/mcpd/tests/secret-backends.test.ts

@@ -0,0 +1,132 @@
+import { describe, it, expect, vi } from 'vitest';
+import { PlaintextDriver } from '../src/services/secret-backends/plaintext.js';
+import { OpenBaoDriver } from '../src/services/secret-backends/openbao.js';
+
+describe('PlaintextDriver', () => {
+  const driver = new PlaintextDriver({ listAllPlaintext: async () => [{ name: 'a', data: { k: 'v' } }] });
+
+  it('read returns the data passed in', async () => {
+    const result = await driver.read({ name: 's', externalRef: '', data: { token: 'abc' } });
+    expect(result).toEqual({ token: 'abc' });
+  });
+
+  it('write returns storedData = input, externalRef = empty', async () => {
+    const result = await driver.write({ name: 's', data: { k: 'v' } });
+    expect(result).toEqual({ externalRef: '', storedData: { k: 'v' } });
+  });
+
+  it('list delegates to the injected dep', async () => {
+    const list = await driver.list();
+    expect(list).toEqual([{ name: 'a', externalRef: '' }]);
+  });
+
+  it('delete is a no-op', async () => {
+    await expect(driver.delete({ name: 's', externalRef: '' })).resolves.toBeUndefined();
+  });
+});
+
+describe('OpenBaoDriver', () => {
+  function makeFetch(responses: Array<{ url: RegExp; status: number; body?: unknown }>): ReturnType<typeof vi.fn> {
+    return vi.fn(async (url: string | URL, _init?: RequestInit) => {
+      const urlStr = String(url);
+      const match = responses.find((r) => r.url.test(urlStr));
+      if (!match) throw new Error(`unexpected fetch: ${urlStr}`);
+      return new Response(match.body ? JSON.stringify(match.body) : '', { status: match.status });
+    });
+  }
+
+  const resolver = { resolve: vi.fn(async () => 'test-vault-token') };
+
+  it('write sends POST to .../data/<path> with {data: ...}', async () => {
+    const fetchFn = makeFetch([{ url: /\/v1\/secret\/data\/mcpctl\/mytoken$/, status: 200 }]);
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: resolver },
+    );
+    const result = await driver.write({ name: 'mytoken', data: { api_key: 'secret-xyz' } });
+    expect(result.externalRef).toBe('secret/mcpctl/mytoken');
+    expect(result.storedData).toEqual({});
+    expect(fetchFn).toHaveBeenCalledTimes(1);
+    const [, init] = fetchFn.mock.calls[0] as [unknown, RequestInit];
+    expect(init.method).toBe('POST');
+    expect(JSON.parse(init.body as string)).toEqual({ data: { api_key: 'secret-xyz' } });
+    const headers = init.headers as Record<string, string>;
+    expect(headers['X-Vault-Token']).toBe('test-vault-token');
+  });
+
+  it('read returns body.data.data', async () => {
+    const fetchFn = makeFetch([{
+      url: /\/v1\/secret\/data\/mcpctl\/mytoken$/,
+      status: 200,
+      body: { data: { data: { api_key: 'secret-xyz' } } },
+    }]);
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: resolver },
+    );
+    const result = await driver.read({ name: 'mytoken', externalRef: 'secret/mcpctl/mytoken', data: {} });
+    expect(result).toEqual({ api_key: 'secret-xyz' });
+  });
+
+  it('read throws when the path 404s', async () => {
+    const fetchFn = makeFetch([{ url: /\/data\//, status: 404 }]);
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: resolver },
+    );
+    await expect(driver.read({ name: 'missing', externalRef: '', data: {} })).rejects.toThrow(/not found/);
+  });
+
+  it('delete swallows 404', async () => {
+    const fetchFn = makeFetch([{ url: /\/metadata\//, status: 404 }]);
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: resolver },
+    );
+    await expect(driver.delete({ name: 'gone', externalRef: '' })).resolves.toBeUndefined();
+  });
+
+  it('list returns names from the metadata LIST call', async () => {
+    const fetchFn = makeFetch([{
+      url: /\/v1\/secret\/metadata\/mcpctl\/$/,
+      status: 200,
+      body: { data: { keys: ['token1', 'token2', 'sub-folder/'] } },
+    }]);
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: resolver },
+    );
+    const result = await driver.list();
+    // Sub-folders (trailing slash) are excluded; only leaf keys are returned.
+    expect(result).toEqual([
+      { name: 'token1', externalRef: 'secret/mcpctl/token1' },
+      { name: 'token2', externalRef: 'secret/mcpctl/token2' },
+    ]);
+  });
+
+  it('caches the vault token after first resolve', async () => {
+    const fetchFn = makeFetch([
+      { url: /\/v1\/secret\/data\/mcpctl\//, status: 200, body: { data: { data: { k: 'v' } } } },
+    ]);
+    const singleResolver = { resolve: vi.fn(async () => 'test-vault-token') };
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: singleResolver },
+    );
+    await driver.read({ name: 'a', externalRef: '', data: {} });
+    await driver.read({ name: 'a', externalRef: '', data: {} });
+    expect(singleResolver.resolve).toHaveBeenCalledTimes(1);
+  });
+
+  it('propagates X-Vault-Namespace when configured', async () => {
+    const fetchFn = makeFetch([{ url: /\/v1\/secret\/data\/mcpctl\//, status: 200 }]);
+    const driver = new OpenBaoDriver(
+      { url: 'http://bao.example:8200', namespace: 'myteam', tokenSecretRef: { name: 'bao', key: 'token' } },
+      { fetch: fetchFn as unknown as typeof fetch, secretRefResolver: resolver },
+    );
+    await driver.write({ name: 'x', data: { k: 'v' } });
+    const [, init] = fetchFn.mock.calls[0] as [unknown, RequestInit];
+    const headers = init.headers as Record<string, string>;
+    expect(headers['X-Vault-Namespace']).toBe('myteam');
+  });
+});

src/mcpd/tests/secret-routes.test.ts

@@ -3,43 +3,68 @@ import Fastify from 'fastify';
 import type { FastifyInstance } from 'fastify';
 import { registerSecretRoutes } from '../src/routes/secrets.js';
 import { SecretService } from '../src/services/secret.service.js';
+import { SecretBackendService } from '../src/services/secret-backend.service.js';
 import { errorHandler } from '../src/middleware/error-handler.js';
 import type { ISecretRepository } from '../src/repositories/interfaces.js';
+import type { ISecretBackendRepository } from '../src/repositories/secret-backend.repository.js';
+import type { SecretBackend } from '@prisma/client';
 
 let app: FastifyInstance;
 
-function mockRepo(): ISecretRepository {
-  let lastCreated: Record<string, unknown> | null = null;
+const PLAINTEXT_BACKEND: SecretBackend = {
+  id: 'backend-plaintext',
+  name: 'default',
+  type: 'plaintext',
+  config: {},
+  isDefault: true,
+  description: '',
+  version: 1,
+  createdAt: new Date(),
+  updatedAt: new Date(),
+};
+
+function makeSecret(overrides: Partial<{ id: string; name: string; data: Record<string, string>; externalRef: string; backendId: string }> = {}) {
   return {
-    findAll: vi.fn(async () => [
-      { id: '1', name: 'ha-creds', data: { TOKEN: 'abc' }, version: 1, createdAt: new Date(), updatedAt: new Date() },
-    ]),
+    id: overrides.id ?? 'sec-1',
+    name: overrides.name ?? 'ha-creds',
+    backendId: overrides.backendId ?? PLAINTEXT_BACKEND.id,
+    data: overrides.data ?? { TOKEN: 'abc' },
+    externalRef: overrides.externalRef ?? '',
+    version: 1,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+  };
+}
+
+function mockRepo(): ISecretRepository {
+  let lastCreated: ReturnType<typeof makeSecret> | null = null;
+  return {
+    findAll: vi.fn(async () => [makeSecret()]),
     findById: vi.fn(async (id: string) => {
-      if (lastCreated && (lastCreated as { id: string }).id === id) return lastCreated as never;
+      if (lastCreated && lastCreated.id === id) return lastCreated;
       return null;
     }),
     findByName: vi.fn(async () => null),
+    findByBackend: vi.fn(async () => []),
     create: vi.fn(async (data) => {
-      const secret = {
+      const secret = makeSecret({
         id: 'new-id',
         name: data.name,
         data: data.data ?? {},
-        version: 1,
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
+        externalRef: data.externalRef ?? '',
+        backendId: data.backendId,
+      });
       lastCreated = secret;
       return secret;
     }),
     update: vi.fn(async (id, data) => {
-      const secret = {
+      const secret = makeSecret({
         id,
-        name: 'ha-creds',
+        name: lastCreated?.name ?? 'ha-creds',
         data: data.data,
-        version: 2,
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
+        externalRef: data.externalRef,
+        backendId: data.backendId ?? PLAINTEXT_BACKEND.id,
+      });
       lastCreated = secret;
       return secret;
     }),
@@ -47,14 +72,32 @@ function mockRepo(): ISecretRepository {
   };
 }
 
+function mockBackendRepo(): ISecretBackendRepository {
+  return {
+    findAll: vi.fn(async () => [PLAINTEXT_BACKEND]),
+    findById: vi.fn(async (id) => (id === PLAINTEXT_BACKEND.id ? PLAINTEXT_BACKEND : null)),
+    findByName: vi.fn(async (name) => (name === PLAINTEXT_BACKEND.name ? PLAINTEXT_BACKEND : null)),
+    findDefault: vi.fn(async () => PLAINTEXT_BACKEND),
+    create: vi.fn(async () => PLAINTEXT_BACKEND),
+    update: vi.fn(async () => PLAINTEXT_BACKEND),
+    setAsDefault: vi.fn(async () => PLAINTEXT_BACKEND),
+    delete: vi.fn(async () => {}),
+    countReferencingSecrets: vi.fn(async () => 0),
+  };
+}
+
 afterEach(async () => {
   if (app) await app.close();
 });
 
-function createApp(repo: ISecretRepository) {
+async function createApp(repo: ISecretRepository) {
   app = Fastify({ logger: false });
   app.setErrorHandler(errorHandler);
-  const service = new SecretService(repo);
+  const backends = new SecretBackendService(mockBackendRepo(), {
+    plaintext: { listAllPlaintext: async () => [] },
+    secretRefResolver: { resolve: async () => '' },
+  });
+  const service = new SecretService(repo, backends);
   registerSecretRoutes(app, service);
   return app.ready();
 }
@@ -129,7 +172,7 @@ describe('Secret Routes', () => {
   describe('PUT /api/v1/secrets/:id', () => {
     it('updates a secret', async () => {
       const repo = mockRepo();
-      vi.mocked(repo.findById).mockResolvedValue({ id: '1', name: 'ha-creds' } as never);
+      vi.mocked(repo.findById).mockResolvedValue(makeSecret({ id: '1' }) as never);
       await createApp(repo);
       const res = await app.inject({
         method: 'PUT',
@@ -154,7 +197,7 @@ describe('Secret Routes', () => {
   describe('DELETE /api/v1/secrets/:id', () => {
     it('deletes a secret and returns 204', async () => {
       const repo = mockRepo();
-      vi.mocked(repo.findById).mockResolvedValue({ id: '1', name: 'ha-creds' } as never);
+      vi.mocked(repo.findById).mockResolvedValue(makeSecret({ id: '1' }) as never);
       await createApp(repo);
       const res = await app.inject({ method: 'DELETE', url: '/api/v1/secrets/1' });
       expect(res.statusCode).toBe(204);