diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f711436b..710e4d73d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,8 @@
 - Filter plugins by type, like layouts, themes or tabs, from a filter list beside the results
 - Browse shows plugins a page at a time
 - Plugins that need a newer Termix are hidden in Browse, with a toggle to show them
+- Hosts can be managed from a config file through a plugin. Managed hosts are read only for everyone, but pins and order still work
+- A plugin can block adding hosts by hand, so every host comes from one place
 
 ### Changed
 
diff --git a/packages/plugin-sdk/CHANGELOG.md b/packages/plugin-sdk/CHANGELOG.md
index da2b8f899..a2f5f82ed 100644
--- a/packages/plugin-sdk/CHANGELOG.md
+++ b/packages/plugin-sdk/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Changelog
 
+## 1.0.14
+
+Plugin API 1.6.0.
+
+### Added
+
+- `ctx.hosts.locks.provide` and the `hosts:lock` capability, so a plugin can manage hosts that stay read only for everyone else and block adding hosts by hand
+- `ctx.hosts.setShares` to replace every grant on a host in one call
+- `ctx.credentials.list` returns the acting user's credentials by name, without secrets
+- `ctx.hosts.create` and `update` take `password`, `key`, `keyPassword`, `keyType`, `sudoPassword`, `protocolAuth` and `pluginEnable`
+
 ## 1.0.13
 
 Plugin API 1.5.0.
diff --git a/packages/plugin-sdk/PLUGIN-GUIDE.md b/packages/plugin-sdk/PLUGIN-GUIDE.md
index 0d39d449b..ead6effbe 100644
--- a/packages/plugin-sdk/PLUGIN-GUIDE.md
+++ b/packages/plugin-sdk/PLUGIN-GUIDE.md
@@ -1,6 +1,6 @@
 # Termix plugin guide
 
-SDK 1.0.13 | Plugin API 1.5.0
+SDK 1.0.14 | Plugin API 1.6.0
 
 This guide is for anyone, person or AI coding tool, building a Termix plugin. It ships inside
 `@termix-ssh/plugin-sdk`, so the copy in your `node_modules` always matches the SDK you have installed.
@@ -300,6 +300,11 @@ router.post("/notes", async (req, res) => {
 - `ctx.rbac.require("manage")` on a single route, `await ctx.rbac.has("manage")` in code. A full id like
   `hosts.edit` checks a core permission.
 - Host access: `ctx.hosts.checkAccess(hostId, "connect" | "view" | "edit" | "manage")`.
+- Managed hosts: with `hosts:lock`, `ctx.hosts.locks.provide({ isLocked, note, allowManualCreate })` makes
+  the hosts you manage read only for the UI, the API and other plugins (pins and order still work), and
+  `allowManualCreate: () => false` blocks adding hosts by hand. Your own `ctx.hosts` writes still go
+  through. `ctx.hosts.setShares(hostId, grants)` replaces a host's whole grant list, and
+  `ctx.credentials.list()` finds the acting user's credentials by name.
 
 ### Errors
 
@@ -898,6 +903,7 @@ To run your own registry instead, see https://docs.termix.site/develop/registrie
 | `hosts:write`            | medium   | Add and edit hosts                                      |
 | `hosts:status-provide`   | medium   | Be the source of host status dots                       |
 | `hosts:activity-provide` | medium   | Be the source of the recent activity list               |
+| `hosts:lock`             | medium   | Make hosts it manages read only for everyone else       |
 | `network:probe`          | medium   | Check that a host answers on a TCP port                 |
 | `credentials:use`        | medium   | Connect with saved credentials without seeing them      |
 | `credentials:write`      | medium   | Save new credentials                                    |
diff --git a/packages/plugin-sdk/package.json b/packages/plugin-sdk/package.json
index 46a0afb1a..e217295f7 100644
--- a/packages/plugin-sdk/package.json
+++ b/packages/plugin-sdk/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@termix-ssh/plugin-sdk",
-  "version": "1.0.13",
+  "version": "1.0.14",
   "description": "The contract between Termix core and a plugin: types, the capability catalog and the manifest schema.",
   "license": "Apache-2.0",
   "repository": {
diff --git a/packages/plugin-sdk/schema/manifest.schema.json b/packages/plugin-sdk/schema/manifest.schema.json
index 1913584aa..8bc92658a 100644
--- a/packages/plugin-sdk/schema/manifest.schema.json
+++ b/packages/plugin-sdk/schema/manifest.schema.json
@@ -167,6 +167,7 @@
           "network:probe",
           "hosts:status-provide",
           "hosts:activity-provide",
+          "hosts:lock",
           "desktop:window",
           "desktop:local",
           "users:impersonate",
diff --git a/packages/plugin-sdk/src/backend.ts b/packages/plugin-sdk/src/backend.ts
index 66cf20a9e..e04e30761 100644
--- a/packages/plugin-sdk/src/backend.ts
+++ b/packages/plugin-sdk/src/backend.ts
@@ -698,6 +698,36 @@ export interface PluginHostCreateInput {
   sshOptions?: HostSshOptions | null;
   /** Host settings by plugin id, the shape a Termix export carries. */
   pluginSettings?: Record<string, Record<string, unknown>>;
+  /**
+   * Each plugin's own host switch (its manifest enableKey), by plugin id.
+   * A plugin that is not running is skipped and logged; one with no switch
+   * is refused.
+   */
+  pluginEnable?: Record<string, boolean>;
+  /**
+   * Secrets, stored encrypted with the owner's data key and never returned
+   * in a PluginHostRecord. An empty string or null clears the stored value.
+   */
+  password?: string | null;
+  key?: string | null;
+  keyPassword?: string | null;
+  keyType?: string | null;
+  sudoPassword?: string | null;
+  /**
+   * Logins for plugin protocols (contributes.protocols), keyed by protocol
+   * id. null removes that protocol's login. Unknown protocol ids are skipped.
+   */
+  protocolAuth?: Record<string, PluginHostProtocolAuthInput | null>;
+}
+
+/** One protocol login on a host write. Absent keys keep what is stored. */
+export interface PluginHostProtocolAuthInput {
+  authType?: "direct" | "credential" | "none";
+  credentialId?: number | null;
+  username?: string | null;
+  password?: string | null;
+  /** The protocol's declared credentialFields, secret ones included. */
+  fields?: Record<string, string>;
 }
 
 /** Fields a plugin may change on a host the acting user owns. */
@@ -725,6 +755,13 @@ export const PLUGIN_HOST_INPUT_KEYS = [
   "forceKeyboardInteractive",
   "sshOptions",
   "pluginSettings",
+  "pluginEnable",
+  "password",
+  "key",
+  "keyPassword",
+  "keyType",
+  "sudoPassword",
+  "protocolAuth",
 ] as const satisfies readonly (keyof PluginHostCreateInput)[];
 
 /** The same shape canAccessHost returns internally, without secrets. */
@@ -761,6 +798,34 @@ export interface PluginShareableRole {
   displayName: string | null;
 }
 
+/** One grant in ctx.hosts.setShares. */
+export interface PluginHostShareGrant {
+  target: PluginShareTarget;
+  permissionLevel: PluginHostShareLevel;
+  /** Omit for a grant that never expires. */
+  durationHours?: number;
+}
+
+/**
+ * Hosts a plugin manages itself, for example from a config file. Core refuses
+ * edits, deletes and share changes on a locked host from the UI, the API and
+ * other plugins, and marks it in host reads so a layout can show it read only.
+ * Pins and order stay with the user. Only the plugin that locks a host may
+ * still write it.
+ */
+export interface PluginHostLockProvider {
+  isLocked: (hostId: number) => boolean;
+  /** A short line shown under the managed note, or null. */
+  note: (hostId: number) => string | null;
+  /** False blocks adding hosts by hand (editor, import, other plugins). */
+  allowManualCreate: () => boolean;
+}
+
+export interface PluginHostLocksApi {
+  /** Registers this plugin's locks. Needs hosts:lock. Removed on deactivate. */
+  provide: (provider: PluginHostLockProvider) => () => void;
+}
+
 /**
  * Hosts the acting user can see, and the RBAC + sharing operations a plugin
  * needs to build a feature (like fleets) on top of hosts it does not own.
@@ -823,6 +888,15 @@ export interface PluginHosts {
     permissionLevel: PluginHostShareLevel,
     durationHours?: number,
   ) => Promise<PluginHostShareResult>;
+  /**
+   * Replaces every grant on a host the acting user owns with this list.
+   * Grants that stay keep their row and counters, missing ones are revoked.
+   * Needs hosts:write.
+   */
+  setShares: (
+    hostId: number,
+    grants: PluginHostShareGrant[],
+  ) => Promise<PluginHostShareResult>;
   /** Users the caller may pick as a share target, for building a picker UI. */
   listUsers: () => Promise<PluginShareableUser[]>;
   /** Non-system roles the caller may pick as a share target. */
@@ -896,6 +970,8 @@ export interface PluginHosts {
   ) => () => void;
   /** The recent activity list on the dashboard. */
   activity: PluginHostActivityApi;
+  /** Read only hosts this plugin manages. */
+  locks: PluginHostLocksApi;
 }
 
 export interface PluginHostImportOptions {
@@ -2011,6 +2087,15 @@ export interface PluginSshKeyCredential {
   publicKey: string | null;
 }
 
+/** A saved credential without its secrets. */
+export interface PluginCredentialSummary {
+  id: number;
+  name: string;
+  username: string | null;
+  authType: string;
+  folder: string | null;
+}
+
 /** A key pair to save as a new credential for the acting user. */
 export interface PluginSshKeyCredentialInput {
   name: string;
@@ -2032,6 +2117,12 @@ export interface PluginCredentials {
    * Needs credentials:use and the core credentials.view permission. Audited.
    */
   listSshKeys: () => Promise<PluginSshKeyCredential[]>;
+  /**
+   * The acting user's own credentials by name, with no secret material, so a
+   * plugin can point a host at one. Needs credentials:use and the core
+   * credentials.view permission. Audited.
+   */
+  list: () => Promise<PluginCredentialSummary[]>;
   /**
    * Saves a key pair as a new encrypted credential owned by the acting user
    * and returns its id. Needs credentials:write, the core credentials.create
diff --git a/packages/plugin-sdk/src/capabilities.ts b/packages/plugin-sdk/src/capabilities.ts
index e71cd39e2..1ca8eadbc 100644
--- a/packages/plugin-sdk/src/capabilities.ts
+++ b/packages/plugin-sdk/src/capabilities.ts
@@ -61,6 +61,7 @@ export const CAPABILITY_CATALOG: readonly CapabilityInfo[] = [
   entry("network:probe", "medium"),
   entry("hosts:status-provide", "medium"),
   entry("hosts:activity-provide", "medium"),
+  entry("hosts:lock", "medium"),
   entry("users:read", "medium"),
   entry("events:core", "medium"),
   entry("notify:send", "medium"),
diff --git a/packages/plugin-sdk/src/manifest.ts b/packages/plugin-sdk/src/manifest.ts
index b02ec8622..15a3a7533 100644
--- a/packages/plugin-sdk/src/manifest.ts
+++ b/packages/plugin-sdk/src/manifest.ts
@@ -37,7 +37,7 @@ export {
  * "^1.2" needs 1.2 or later). engine.termix is checked against the core
  * version by the server.
  */
-export const PLUGIN_API_VERSION = "1.5.0";
+export const PLUGIN_API_VERSION = "1.6.0";
 
 /** The API major, the default engine.api for a new plugin. */
 export const SUPPORTED_PLUGIN_API_VERSION = String(
diff --git a/packages/plugin-sdk/src/testing.ts b/packages/plugin-sdk/src/testing.ts
index 130d5b7cc..aaa8c2c28 100644
--- a/packages/plugin-sdk/src/testing.ts
+++ b/packages/plugin-sdk/src/testing.ts
@@ -76,6 +76,9 @@ import type {
   PluginHostProbeTarget,
   PluginHostStatusEntry,
   PluginActivityProvider,
+  PluginHostLockProvider,
+  PluginCredentialSummary,
+  PluginHostShareGrant,
   PluginHostStatusProvider,
   PluginNotification,
   PluginNotificationChannel,
@@ -140,6 +143,8 @@ export interface FakeContextOptions {
   protocolTargets?: Record<string, PluginProtocolTarget>;
   /** What ctx.credentials.listSshKeys answers. */
   sshKeyCredentials?: PluginSshKeyCredential[];
+  /** What ctx.credentials.list answers. */
+  credentialSummaries?: PluginCredentialSummary[];
   /** What ctx.desktop.available() answers. Defaults to false. */
   desktopAvailable?: boolean;
   /** What ctx.desktop.local is. Calls throw when this is not given. */
@@ -285,6 +290,8 @@ export interface FakePluginContext {
   hostStatusProviders: PluginHostStatusProvider[];
   /** Every provider passed to ctx.hosts.activity.provide that is still registered. */
   activityProviders: PluginActivityProvider[];
+  /** Every provider passed to ctx.hosts.locks.provide that is still registered. */
+  hostLockProviders: PluginHostLockProvider[];
   /** Topics emitted through ctx.events.emit, in order. */
   emitted: Array<{ topic: string; payload: unknown }>;
   /** Backing store behind ctx.kv. */
@@ -317,6 +324,8 @@ export interface FakePluginContext {
     permissionLevel: string;
     durationHours?: number;
   }>;
+  /** Every ctx.hosts.setShares call, in order. */
+  hostShareSets: Array<{ hostId: number; grants: PluginHostShareGrant[] }>;
   /** Everything registered through ctx.auth. */
   auth: FakeAuthRegistrations;
   /** Every ctx.desktop.openIsolatedWindow call, in order. */
@@ -488,7 +497,14 @@ function applyHostInput(
   const {
     tags,
     pluginSettings: _settings,
+    pluginEnable: _pluginEnable,
     forceKeyboardInteractive: _fki,
+    password: _password,
+    key: _key,
+    keyPassword: _keyPassword,
+    keyType: _keyType,
+    sudoPassword: _sudoPassword,
+    protocolAuth: _protocolAuth,
     ...rest
   } = input;
   const next: PluginHostRecord = { ...record };
@@ -517,6 +533,7 @@ export function createFakeContext(
   const emitted: Array<{ topic: string; payload: unknown }> = [];
   const hostStatusProviders: PluginHostStatusProvider[] = [];
   const activityProviders: PluginActivityProvider[] = [];
+  const hostLockProviders: PluginHostLockProvider[] = [];
   const kv = new Map<string, unknown>();
   const tables: PluginTableDefinition[] = [];
   const syncEntities: SyncEntityRegistration[] = [];
@@ -534,6 +551,7 @@ export function createFakeContext(
   }>();
   const sshConnections: FakePluginContext["sshConnections"] = [];
   const hostShares: FakePluginContext["hostShares"] = [];
+  const hostShareSets: FakePluginContext["hostShareSets"] = [];
   const desktopWindows: FakePluginContext["desktopWindows"] = [];
   const externalClientLaunches: FakePluginContext["externalClientLaunches"] =
     [];
@@ -1004,6 +1022,10 @@ export function createFakeContext(
         hostShares.push({ hostId, targets, permissionLevel, durationHours });
         return { hostId, shared: true };
       },
+      setShares: async (hostId, grants) => {
+        hostShareSets.push({ hostId, grants: [...grants] });
+        return { hostId, shared: true };
+      },
       listUsers: async () => options.shareableUsers ?? [],
       listRoles: async () => options.shareableRoles ?? [],
       trackSession: (hostId) => {
@@ -1034,6 +1056,15 @@ export function createFakeContext(
           };
         },
       },
+      locks: {
+        provide: (provider) => {
+          hostLockProviders.push(provider);
+          return () => {
+            const at = hostLockProviders.indexOf(provider);
+            if (at >= 0) hostLockProviders.splice(at, 1);
+          };
+        },
+      },
       status: {
         provide: (provider) => {
           hostStatusProviders.push(provider);
@@ -1286,6 +1317,7 @@ export function createFakeContext(
     },
 
     credentials: {
+      list: async () => [...(options.credentialSummaries ?? [])],
       listSshKeys: async () => [
         ...(options.sshKeyCredentials ?? []),
         ...createdSshKeys.map((key) => ({
@@ -1468,6 +1500,7 @@ export function createFakeContext(
     disposals,
     hostStatusProviders,
     activityProviders,
+    hostLockProviders,
     emitted,
     kv,
     tables,
@@ -1478,6 +1511,7 @@ export function createFakeContext(
     coreSettings,
     sshConnections,
     hostShares,
+    hostShareSets,
     auth,
     desktopWindows,
     externalClientLaunches,
@@ -1560,6 +1594,8 @@ export interface MockContextOptions {
   protocolTargets?: Record<string, PluginProtocolTarget>;
   /** What ctx.credentials.listSshKeys serves. */
   sshKeyCredentials?: PluginSshKeyCredential[];
+  /** What ctx.credentials.list serves. */
+  credentialSummaries?: PluginCredentialSummary[];
   /** What ctx.desktop.available() answers. */
   desktopAvailable?: boolean;
   /** What ctx.desktop.local is. See FakeContextOptions. */
@@ -1699,6 +1735,7 @@ export function createMockCtx(
     services: options.services,
     protocolTargets: options.protocolTargets,
     sshKeyCredentials: options.sshKeyCredentials,
+    credentialSummaries: options.credentialSummaries,
     desktopAvailable: options.desktopAvailable,
     desktopLocal: options.desktopLocal,
     auditEntries: options.auditEntries,
@@ -1900,6 +1937,10 @@ export function createMockCtx(
         require("hosts:write");
         return ctx.hosts.share(hostId, targets, permissionLevel, durationHours);
       },
+      setShares: async (hostId, grants) => {
+        require("hosts:write");
+        return ctx.hosts.setShares(hostId, grants);
+      },
       listUsers: async () => {
         require("hosts:write");
         return ctx.hosts.listUsers();
@@ -1930,6 +1971,12 @@ export function createMockCtx(
           return ctx.hosts.activity.provide(provider);
         },
       },
+      locks: {
+        provide: (provider) => {
+          require("hosts:lock");
+          return ctx.hosts.locks.provide(provider);
+        },
+      },
       status: {
         provide: (provider) => {
           require("hosts:read");
@@ -2098,6 +2145,10 @@ export function createMockCtx(
     },
 
     credentials: {
+      list: async () => {
+        require("credentials:use");
+        return ctx.credentials.list();
+      },
       listSshKeys: async () => {
         require("credentials:use");
         return ctx.credentials.listSshKeys();
diff --git a/packages/plugin-sdk/ui.api.txt b/packages/plugin-sdk/ui.api.txt
index 205f955d2..32801f057 100644
--- a/packages/plugin-sdk/ui.api.txt
+++ b/packages/plugin-sdk/ui.api.txt
@@ -151,7 +151,9 @@ HostFeatureFieldsProps (type): HostFeatureFieldsProps
 HostFolder (type): HostFolder
 HostGroupKey (type): HostGroupKey
 HostKeyVerificationDialog (value): ({ isOpen, scenario, ip, port, hostname, fingerprint, oldFingerprint, onAccept, onReject, backgroundColor, }: HostKeyVerificationDialogProps) => Element
+HostLock (type): HostLock
 HostOnly (value): ({ children }: { children: ReactNode; }) => Element
+HostPolicy (type): HostPolicy
 HostProtocolAuthInput (type): HostProtocolAuthInput
 HostProtocolDef (type): HostProtocolDef
 HostProtocols (type): HostProtocols
@@ -411,6 +413,7 @@ getHostAuthOverride (value): (hostId: number, protocol: string, sharedCopySyncId
 getHostDefaultsLevel (value): (target: HostDefaultsTarget) => Promise<HostDefaultsLevelData>
 getHostEditorSection (value): (id: string) => HostEditorSectionDef
 getHostPassword (value): (hostId: number, field?: "key" | "password" | "sudoPassword" | "keyPassword") => Promise<string>
+getHostPolicy (value): () => Promise<HostPolicy>
 getHostSidebarPreferences (value): () => Promise<HostSidebarPreferences>
 getHostTags (value): () => Promise<string[]>
 getLiveHostStatus (value): (hostId: number) => StatusValue
diff --git a/scripts/check-sdk-ui-exports.cjs b/scripts/check-sdk-ui-exports.cjs
index 6f60f4282..9f957824d 100644
--- a/scripts/check-sdk-ui-exports.cjs
+++ b/scripts/check-sdk-ui-exports.cjs
@@ -168,6 +168,8 @@ const ALLOWED = [
   "HostDefaultsTarget",
   "HostDensity",
   "HostFeatureFields",
+  "HostLock",
+  "HostPolicy",
   "HostFeatureFieldsProps",
   "HostFolder",
   "HostGroupKey",
@@ -432,6 +434,7 @@ const ALLOWED = [
   "getHostDefaultsLevel",
   "getHostEditorSection",
   "getHostPassword",
+  "getHostPolicy",
   "getHostSidebarPreferences",
   "getHostTags",
   "getLiveHostStatus",
diff --git a/src/backend/database/routes/host-bulk-routes.ts b/src/backend/database/routes/host-bulk-routes.ts
index c89df15f2..4055704b0 100644
--- a/src/backend/database/routes/host-bulk-routes.ts
+++ b/src/backend/database/routes/host-bulk-routes.ts
@@ -11,6 +11,7 @@ import { sshLogger } from "../../utils/logger.js";
 import { DatabaseSaveTrigger } from "../../utils/database-save-trigger.js";
 import { createCurrentHostRepository } from "../repositories/factory.js";
 import { validateParentHostId } from "./host-parent-validation.js";
+import { assertHostsUnlocked, sendHostLocked } from "../../hosts/locks.js";
 
 import { setHostPluginEnabled } from "./host-plugin-settings.js";
 
@@ -141,6 +142,15 @@ export function registerHostBulkRoutes(
         );
 
         const ownedIds = ownedHosts.map((h) => h.id);
+        // Pins stay the user's own on a managed host.
+        if (Object.keys(updates).some((key) => key !== "pin")) {
+          try {
+            assertHostsUnlocked(ownedIds);
+          } catch (error) {
+            if (sendHostLocked(res, error)) return;
+            throw error;
+          }
+        }
         const unauthorizedIds = hostIds.filter(
           (id: number) => !ownedIds.includes(id),
         );
diff --git a/src/backend/database/routes/host-defaults-routes.ts b/src/backend/database/routes/host-defaults-routes.ts
index 16d8358a9..fd8c57664 100644
--- a/src/backend/database/routes/host-defaults-routes.ts
+++ b/src/backend/database/routes/host-defaults-routes.ts
@@ -32,6 +32,7 @@ import {
 } from "../../hosts/defaults/service.js";
 import { changeHostOverrides } from "../../hosts/defaults/overrides.js";
 import { readDefaultsReset } from "./host-bulk-routes.js";
+import { assertHostsUnlocked, sendHostLocked } from "../../hosts/locks.js";
 
 type HostDefaultsRoutesDeps = {
   authenticateJWT: RequestHandler;
@@ -678,6 +679,7 @@ export function registerHostDefaultsRoutes(
       const reset = readDefaultsReset(req.body);
       if (!reset) return res.status(400).json({ error: "Nothing to reset" });
       try {
+        assertHostsUnlocked([hostId]);
         const access = await PermissionManager.getInstance().canAccessHost(
           userId,
           hostId,
@@ -700,6 +702,7 @@ export function registerHostDefaultsRoutes(
         await changeHostOverrides([hostId], reset);
         res.json({ message: "Host reset to its defaults" });
       } catch (error) {
+        if (sendHostLocked(res, error)) return;
         databaseLogger.error("Failed to reset host defaults", error);
         res.status(500).json({ error: "Failed to reset host defaults" });
       }
diff --git a/src/backend/database/routes/host-folder-routes.ts b/src/backend/database/routes/host-folder-routes.ts
index d0775f577..7da515c81 100644
--- a/src/backend/database/routes/host-folder-routes.ts
+++ b/src/backend/database/routes/host-folder-routes.ts
@@ -16,6 +16,31 @@ import {
   folderCredentialIds,
   setFolderCredentialDefault,
 } from "../../hosts/defaults/service.js";
+import {
+  assertHostsUnlocked,
+  hasHostLocks,
+  sendHostLocked,
+} from "../../hosts/locks.js";
+
+/** Refuses a folder change that would touch a locked host. */
+async function folderHostsUnlocked(
+  userId: string,
+  folderName: string,
+  res: Response,
+): Promise<boolean> {
+  if (!hasHostLocks()) return true;
+  const inFolder = await createCurrentHostFolderRepository().listHostsInFolder(
+    userId,
+    folderName,
+  );
+  try {
+    assertHostsUnlocked(inFolder.map((host) => host.id));
+    return true;
+  } catch (error) {
+    if (sendHostLocked(res, error)) return false;
+    throw error;
+  }
+}
 
 type HostFolderRoutesDeps = {
   authenticateJWT: RequestHandler;
@@ -86,6 +111,7 @@ export function registerHostFolderRoutes(
       }
 
       try {
+        if (!(await folderHostsUnlocked(userId, oldName, res))) return;
         const { updatedHosts, updatedCredentials } =
           await createCurrentHostFolderRepository().renameFolder(
             userId,
@@ -417,6 +443,7 @@ export function registerHostFolderRoutes(
       });
 
       try {
+        if (!(await folderHostsUnlocked(userId, folderName, res))) return;
         const hostFolderRepository = createCurrentHostFolderRepository();
         const hostsToDelete = await hostFolderRepository.listHostsInFolder(
           userId,
diff --git a/src/backend/database/routes/host-normalizers.ts b/src/backend/database/routes/host-normalizers.ts
index 54beeafbe..005ac2aaf 100644
--- a/src/backend/database/routes/host-normalizers.ts
+++ b/src/backend/database/routes/host-normalizers.ts
@@ -5,6 +5,7 @@ import {
 } from "../../hosts/ssh-options.js";
 import { listHostProtocols } from "../../hosts/protocol-auth/registry.js";
 import { sanitizeProtocolAuthForRecipient } from "../../hosts/protocol-auth/summary.js";
+import { hostLock } from "../../hosts/locks.js";
 
 export function isNonEmptyString(value: unknown): value is string {
   return typeof value === "string" && value.trim().length > 0;
@@ -337,6 +338,7 @@ const CONNECT_LEVEL_FIELDS = new Set([
   "sshPort",
   "protocolAuth",
   "jumpHosts",
+  "lock",
   "createdAt",
   "updatedAt",
 ]);
@@ -439,8 +441,10 @@ export function transformHostResponse(
   host: Record<string, unknown>,
 ): Record<string, unknown> {
   const shared = parseSharedSource(host.sharedSource);
+  const lock = typeof host.id === "number" ? hostLock(host.id) : null;
   return {
     ...host,
+    ...(lock ? { lock } : {}),
     sharedSource: undefined,
     localOnly: !!host.localOnly,
     sharedCopy: !!shared,
diff --git a/src/backend/database/routes/host.ts b/src/backend/database/routes/host.ts
index cd6114d7a..ca768aa6c 100644
--- a/src/backend/database/routes/host.ts
+++ b/src/backend/database/routes/host.ts
@@ -85,6 +85,11 @@ import {
   type PlannedProtocolAuth,
 } from "../../hosts/protocol-auth/protocol-auth.js";
 import { findHostProtocol } from "../../hosts/protocol-auth/registry.js";
+import {
+  manualCreateBlockedBy,
+  requireManualCreate,
+  requireUnlockedHost,
+} from "../../hosts/locks.js";
 import {
   mergeStoredSshOptions,
   parseTerminalConfig,
@@ -157,6 +162,7 @@ router.post(
   authenticateJWT,
   permissionManager.requirePermission("hosts.create"),
   requireDataAccess,
+  requireManualCreate,
   requireHostEnrollmentAccessForPath,
   upload.single("key"),
   async (req: Request, res: Response) => {
@@ -736,6 +742,7 @@ router.put(
   authenticateJWT,
   permissionManager.requirePermission("hosts.edit"),
   requireDataAccess,
+  requireUnlockedHost,
   upload.single("key"),
   async (req: Request, res: Response) => {
     const hostId = Array.isArray(req.params.id)
@@ -1205,6 +1212,27 @@ router.put(
   },
 );
 
+/**
+ * @openapi
+ * /host/policy:
+ *   get:
+ *     summary: Host creation policy
+ *     description: Whether hosts can be added by hand, or a plugin manages them all.
+ *     tags:
+ *       - SSH
+ *     responses:
+ *       200:
+ *         description: "{ manualCreate, blockedBy? } where blockedBy is the managing plugin's name."
+ */
+router.get("/policy", authenticateJWT, (_req: Request, res: Response) => {
+  const blocked = manualCreateBlockedBy();
+  res.json(
+    blocked
+      ? { manualCreate: false, blockedBy: blocked.pluginName }
+      : { manualCreate: true },
+  );
+});
+
 /**
  * @openapi
  * /host/db/host:
@@ -1702,6 +1730,7 @@ router.delete(
   authenticateJWT,
   permissionManager.requirePermission("hosts.delete"),
   requireDataAccess,
+  requireUnlockedHost,
   async (req: Request, res: Response) => {
     const userId = (req as AuthenticatedRequest).userId;
     const hostId = Array.isArray(req.params.id)
diff --git a/src/backend/database/routes/plugins.ts b/src/backend/database/routes/plugins.ts
index dcbf4415f..03702851f 100644
--- a/src/backend/database/routes/plugins.ts
+++ b/src/backend/database/routes/plugins.ts
@@ -44,6 +44,7 @@ import {
   validateSettingsSave,
   type PluginSettingsScope,
 } from "../../plugins/settings.js";
+import { assertHostsUnlocked, sendHostLocked } from "../../hosts/locks.js";
 import {
   getAuditUsername,
   getRequestMeta,
@@ -1878,6 +1879,18 @@ router.put(
       const inherit = Array.isArray(inheritRaw)
         ? inheritRaw.filter((key): key is string => typeof key === "string")
         : [];
+      // A managed host keeps its settings; only personal ones stay per user.
+      const changesShared = [...Object.keys(written), ...inherit].some(
+        (key) => !findField(manifest, "host", key)?.personal,
+      );
+      if (changesShared) {
+        try {
+          assertHostsUnlocked([hostId]);
+        } catch (error) {
+          if (sendHostLocked(res, error)) return;
+          throw error;
+        }
+      }
       const errors = await applySettings(
         userId,
         manifest,
diff --git a/src/backend/database/routes/rbac.ts b/src/backend/database/routes/rbac.ts
index f5b6c11a4..2f88ccc04 100644
--- a/src/backend/database/routes/rbac.ts
+++ b/src/backend/database/routes/rbac.ts
@@ -9,6 +9,12 @@ import {
   logAudit,
 } from "../../utils/audit-logger.js";
 import { isAuthOverrideProtocol } from "../../hosts/protocol-auth/registry.js";
+import {
+  assertHostsUnlocked,
+  hasHostLocks,
+  requireUnlockedHost,
+  sendHostLocked,
+} from "../../hosts/locks.js";
 import {
   SharedHostAuthOverrideService,
   SharedHostAuthOverrideServiceError,
@@ -229,6 +235,7 @@ router.post(
   "/host/:id/share",
   authenticateJWT,
   permissionManager.requirePermission("hosts.share"),
+  requireUnlockedHost,
   async (req: AuthenticatedRequest, res: Response) => {
     const id = Array.isArray(req.params.id) ? req.params.id[0] : req.params.id;
     const hostId = parseInt(id, 10);
@@ -451,6 +458,14 @@ router.post(
     }
 
     try {
+      if (hasHostLocks()) {
+        const inFolder =
+          await createCurrentHostFolderRepository().listHostsInFolder(
+            userId,
+            folder,
+          );
+        assertHostsUnlocked(inFolder.map((host) => host.id));
+      }
       const targets = parseShareTargets(req.body ?? {});
       if (!targets) {
         return res.status(400).json({
@@ -613,6 +628,7 @@ router.post(
         hostResults,
       });
     } catch (error) {
+      if (sendHostLocked(res, error)) return;
       databaseLogger.error("Failed to share folder", error, {
         operation: "share_folder",
         folder,
@@ -786,6 +802,7 @@ router.delete(
 router.patch(
   "/host/:id/access/:accessId",
   authenticateJWT,
+  requireUnlockedHost,
   async (req: AuthenticatedRequest, res: Response) => {
     const id = Array.isArray(req.params.id) ? req.params.id[0] : req.params.id;
     const accessIdParam = Array.isArray(req.params.accessId)
@@ -908,6 +925,7 @@ router.patch(
 router.delete(
   "/host/:id/access/:accessId",
   authenticateJWT,
+  requireUnlockedHost,
   async (req: AuthenticatedRequest, res: Response) => {
     const id = Array.isArray(req.params.id) ? req.params.id[0] : req.params.id;
     const accessIdParam = Array.isArray(req.params.accessId)
diff --git a/src/backend/hosts/import/host-import.ts b/src/backend/hosts/import/host-import.ts
index 340e43200..d9acb3b8c 100644
--- a/src/backend/hosts/import/host-import.ts
+++ b/src/backend/hosts/import/host-import.ts
@@ -30,6 +30,7 @@ import {
   isValidPort,
   normalizeImportedHost,
 } from "../../database/routes/host-normalizers.js";
+import { hasHostLocks, hostLock, manualCreateBlockedBy } from "../locks.js";
 
 /** A request the caller got wrong. Routes answer it with a 400. */
 export class ImportError extends Error {
@@ -263,6 +264,19 @@ export function importResponse(results: ImportResults) {
 
 export const MAX_IMPORT_HOSTS = 100;
 
+/** Why an import row can't be written while a plugin manages hosts, if it can't. */
+function importLockError(existingId: number | undefined): string | null {
+  if (!hasHostLocks()) return null;
+  if (existingId === undefined) {
+    const blocked = manualCreateBlockedBy();
+    return blocked
+      ? `Hosts are managed by ${blocked.pluginName}, so new hosts can't be added`
+      : null;
+  }
+  const lock = hostLock(existingId);
+  return lock ? `This host is managed by ${lock.pluginName}` : null;
+}
+
 /** Deletes what an atomic import created, newest first. */
 async function rollBackCreated(
   userId: string,
@@ -446,6 +460,12 @@ export async function runBulkImport(
         results.skipped++;
         continue;
       }
+      const locked = importLockError(existing?.id);
+      if (locked) {
+        results.failed++;
+        results.errors.push(`Host ${i + 1}: ${locked}`);
+        continue;
+      }
 
       if (
         effectiveConnectionType === "ssh" &&
@@ -745,6 +765,12 @@ export async function runSshConfigImport(
         results.skipped++;
         continue;
       }
+      const locked = importLockError(existing?.id);
+      if (locked) {
+        results.failed++;
+        results.errors.push(`Host "${parsed[i].name}": ${locked}`);
+        continue;
+      }
 
       const sshDataObj: Record<string, unknown> = {
         userId,
diff --git a/src/backend/hosts/locks.ts b/src/backend/hosts/locks.ts
new file mode 100644
index 000000000..8685a0c25
--- /dev/null
+++ b/src/backend/hosts/locks.ts
@@ -0,0 +1,173 @@
+/**
+ * Host locks: hosts a plugin manages itself (for example from a config file)
+ * through ctx.hosts.locks.provide. Core refuses edits, deletes and share
+ * changes on a locked host everywhere, except from the plugin that locks it,
+ * and a provider can block adding hosts by hand. Pins and order stay with the
+ * user.
+ */
+
+import type { PluginHostLockProvider } from "@termix-ssh/plugin-sdk/backend";
+import { pluginLogger } from "../utils/logger.js";
+
+export interface HostLockInfo {
+  pluginId: string;
+  pluginName: string;
+  note: string | null;
+}
+
+interface Entry {
+  pluginId: string;
+  pluginName: string;
+  provider: PluginHostLockProvider;
+}
+
+const providers = new Map<symbol, Entry>();
+
+export class HostLockedError extends Error {
+  readonly status = 403;
+  readonly code = "HOST_LOCKED";
+  constructor(
+    message: string,
+    readonly lock: { pluginId: string; pluginName: string },
+  ) {
+    super(message);
+    this.name = "HostLockedError";
+  }
+}
+
+export function provideHostLocks(
+  pluginId: string,
+  pluginName: string,
+  provider: PluginHostLockProvider,
+): () => void {
+  const key = Symbol(pluginId);
+  providers.set(key, { pluginId, pluginName, provider });
+  return () => {
+    providers.delete(key);
+  };
+}
+
+/** Test seam. */
+export function clearHostLocks(): void {
+  providers.clear();
+}
+
+// A provider that throws never locks: a broken plugin must not freeze hosts.
+function safely<T>(entry: Entry, fallback: T, read: () => T): T {
+  try {
+    return read();
+  } catch (error) {
+    pluginLogger.warn("Host lock provider failed", {
+      operation: "host_lock",
+      pluginId: entry.pluginId,
+      error: error instanceof Error ? error.message : String(error),
+    });
+    return fallback;
+  }
+}
+
+export function hostLock(
+  hostId: number,
+  exemptPluginId?: string,
+): HostLockInfo | null {
+  if (!Number.isInteger(hostId)) return null;
+  for (const entry of providers.values()) {
+    if (entry.pluginId === exemptPluginId) continue;
+    if (!safely(entry, false, () => entry.provider.isLocked(hostId))) continue;
+    return {
+      pluginId: entry.pluginId,
+      pluginName: entry.pluginName,
+      note: safely(entry, null, () => entry.provider.note(hostId) ?? null),
+    };
+  }
+  return null;
+}
+
+export function hasHostLocks(): boolean {
+  return providers.size > 0;
+}
+
+/** Throws HostLockedError for the first locked host. */
+export function assertHostsUnlocked(
+  hostIds: Iterable<number>,
+  exemptPluginId?: string,
+): void {
+  if (providers.size === 0) return;
+  for (const hostId of hostIds) {
+    const lock = hostLock(Number(hostId), exemptPluginId);
+    if (lock) {
+      throw new HostLockedError(
+        `This host is managed by ${lock.pluginName} and can't be changed here`,
+        lock,
+      );
+    }
+  }
+}
+
+/** The plugin that blocks adding hosts by hand, if any. */
+export function manualCreateBlockedBy(
+  exemptPluginId?: string,
+): { pluginId: string; pluginName: string } | null {
+  for (const entry of providers.values()) {
+    if (entry.pluginId === exemptPluginId) continue;
+    if (!safely(entry, true, () => entry.provider.allowManualCreate())) {
+      return { pluginId: entry.pluginId, pluginName: entry.pluginName };
+    }
+  }
+  return null;
+}
+
+export function assertManualCreateAllowed(exemptPluginId?: string): void {
+  const blocked = manualCreateBlockedBy(exemptPluginId);
+  if (blocked) {
+    throw new HostLockedError(
+      `Hosts are managed by ${blocked.pluginName}, so new hosts can't be added here`,
+      blocked,
+    );
+  }
+}
+
+type Res = { status: (code: number) => { json: (body: unknown) => unknown } };
+type Next = () => void;
+
+/** Route guard for creating hosts by hand. */
+export function requireManualCreate(_req: unknown, res: Res, next: Next) {
+  try {
+    assertManualCreateAllowed();
+  } catch (error) {
+    if (sendHostLocked(res, error)) return;
+    throw error;
+  }
+  next();
+}
+
+/** Route guard for routes that change the host named by :id. */
+export function requireUnlockedHost(
+  req: { params: Record<string, string | string[]> },
+  res: Res,
+  next: Next,
+) {
+  const raw = req.params.id;
+  const hostId = Number(Array.isArray(raw) ? raw[0] : raw);
+  try {
+    assertHostsUnlocked([hostId]);
+  } catch (error) {
+    if (sendHostLocked(res, error)) return;
+    throw error;
+  }
+  next();
+}
+
+/** Sends a HostLockedError as a 403. False when the error is something else. */
+export function sendHostLocked(
+  res: { status: (code: number) => { json: (body: unknown) => unknown } },
+  error: unknown,
+): boolean {
+  if (!(error instanceof HostLockedError)) return false;
+  res.status(403).json({
+    error: error.message,
+    code: error.code,
+    lockedBy: error.lock.pluginId,
+  });
+  return true;
+}
diff --git a/src/backend/plugins/ctx-credentials.ts b/src/backend/plugins/ctx-credentials.ts
index cfe5e1532..ed2fdd7a7 100644
--- a/src/backend/plugins/ctx-credentials.ts
+++ b/src/backend/plugins/ctx-credentials.ts
@@ -150,6 +150,37 @@ export function createPluginCredentials({
       }
     },
 
+    list: async () => {
+      try {
+        await assertCapability(pluginId, "credentials:use", declared);
+        const userId = actingUser();
+        await requireCorePermission(userId, "credentials.view");
+        const { createCurrentCredentialRepository } =
+          await import("../database/repositories/factory.js");
+        const rows =
+          await createCurrentCredentialRepository().listDecryptedByUserId(
+            userId,
+          );
+        const list = rows.map((row) => ({
+          id: row.id,
+          name: row.name,
+          username: row.username ?? null,
+          authType: String(row.authType ?? ""),
+          folder: row.folder ?? null,
+        }));
+        await audit("credentials_list", `${list.length} credentials`, {
+          success: true,
+        });
+        return list;
+      } catch (error) {
+        await audit("credentials_list", "saved credentials", {
+          success: false,
+          errorMessage: errorText(error),
+        });
+        throw error;
+      }
+    },
+
     createSshKey: async (input) => {
       const details = `SSH key "${input?.name ?? ""}"`;
       try {
diff --git a/src/backend/plugins/ctx-hosts.ts b/src/backend/plugins/ctx-hosts.ts
index 6b5c7f14a..c86b08669 100644
--- a/src/backend/plugins/ctx-hosts.ts
+++ b/src/backend/plugins/ctx-hosts.ts
@@ -20,6 +20,7 @@ import type {
   PluginShareableUser,
   PluginShareableRole,
   PluginHostJumpHost,
+  PluginHostShareGrant,
 } from "@termix-ssh/plugin-sdk/backend";
 import { PLUGIN_HOST_INPUT_KEYS } from "@termix-ssh/plugin-sdk/backend";
 import type { PluginManifest } from "@termix-ssh/plugin-sdk/manifest";
@@ -35,6 +36,11 @@ import { hostTerminalExport } from "../database/routes/host-normalizers.js";
 import type { DisposableBag } from "./disposables.js";
 import { pluginEvents, TOPICS } from "./events.js";
 import { pluginLogger } from "../utils/logger.js";
+import {
+  assertHostsUnlocked,
+  assertManualCreateAllowed,
+  provideHostLocks,
+} from "../hosts/locks.js";
 
 type AuditFn = (
   action: string,
@@ -207,6 +213,8 @@ void inputKeysComplete;
 export function toHostWrite(input: PluginHostUpdateInput): {
   row: Record<string, unknown>;
   settings: Record<string, Record<string, unknown>>;
+  protocolAuth: Record<string, unknown> | null;
+  pluginEnable: Record<string, boolean>;
 } {
   const unknown = Object.keys(input ?? {}).filter(
     (key) => !INPUT_KEYS.has(key),
@@ -268,6 +276,32 @@ export function toHostWrite(input: PluginHostUpdateInput): {
         ? null
         : JSON.stringify(parseSshOptions(input.sshOptions)),
   );
+  for (const key of [
+    "password",
+    "key",
+    "keyPassword",
+    "keyType",
+    "sudoPassword",
+  ] as const) {
+    const value = input[key];
+    if (value !== undefined && value !== null && typeof value !== "string") {
+      throw new PluginHostInputError(`${key} must be a string`);
+    }
+    set(key, value === undefined ? undefined : value || null);
+  }
+
+  let protocolAuth: Record<string, unknown> | null = null;
+  if (input.protocolAuth !== undefined && input.protocolAuth !== null) {
+    if (
+      typeof input.protocolAuth !== "object" ||
+      Array.isArray(input.protocolAuth)
+    ) {
+      throw new PluginHostInputError(
+        "protocolAuth must map protocol ids to their logins",
+      );
+    }
+    protocolAuth = input.protocolAuth as Record<string, unknown>;
+  }
 
   const settings: Record<string, Record<string, unknown>> = {};
   if (input.pluginSettings !== undefined && input.pluginSettings !== null) {
@@ -288,7 +322,136 @@ export function toHostWrite(input: PluginHostUpdateInput): {
       settings[pluginId] = values;
     }
   }
-  return { row, settings };
+  const pluginEnable: Record<string, boolean> = {};
+  if (input.pluginEnable !== undefined && input.pluginEnable !== null) {
+    if (
+      typeof input.pluginEnable !== "object" ||
+      Array.isArray(input.pluginEnable)
+    ) {
+      throw new PluginHostInputError(
+        "pluginEnable must map plugin ids to true or false",
+      );
+    }
+    for (const [pluginId, enabled] of Object.entries(input.pluginEnable)) {
+      if (typeof enabled !== "boolean") {
+        throw new PluginHostInputError(
+          `pluginEnable.${pluginId} must be true or false`,
+        );
+      }
+      pluginEnable[pluginId] = enabled;
+    }
+  }
+  return { row, settings, protocolAuth, pluginEnable };
+}
+
+/** Folds pluginEnable into each plugin's settings under its enableKey. */
+async function foldPluginEnable(
+  settings: Record<string, Record<string, unknown>>,
+  pluginEnable: Record<string, boolean>,
+): Promise<Record<string, Record<string, unknown>>> {
+  const ids = Object.keys(pluginEnable);
+  if (ids.length === 0) return settings;
+  const { hostSettingsPlugins } =
+    await import("../database/routes/host-plugin-settings.js");
+  const running = hostSettingsPlugins();
+  const out = { ...settings };
+  for (const pluginId of ids) {
+    const manifest = running.find((m) => m.id === pluginId);
+    if (!manifest) {
+      // checkHostPluginSettingsInput skips and logs a plugin that is not running.
+      out[pluginId] = { ...out[pluginId] };
+      continue;
+    }
+    const enableKey = manifest.contributes?.settings?.host?.enableKey;
+    if (!enableKey) {
+      throw new PluginHostInputError(`${pluginId} has no host switch`);
+    }
+    out[pluginId] = { ...out[pluginId], [enableKey]: pluginEnable[pluginId] };
+  }
+  return out;
+}
+
+/** Writes a host's protocol logins; a credential the owner can't use is refused. */
+async function writeHostProtocolAuth(
+  ownerId: string,
+  hostId: number,
+  protocolAuth: Record<string, unknown> | null,
+): Promise<void> {
+  if (!protocolAuth) return;
+  const { readProtocolAuthPayload, writeProtocolAuth } =
+    await import("../hosts/protocol-auth/protocol-auth.js");
+  const patch = readProtocolAuthPayload({ protocolAuth });
+  if (!patch) return;
+  const { findUsableCredential } =
+    await import("../hosts/usable-credential.js");
+  for (const [protocol, login] of patch) {
+    const credentialId = Number(login?.credentialId);
+    if (
+      Number.isInteger(credentialId) &&
+      credentialId > 0 &&
+      !(await findUsableCredential(credentialId, ownerId))
+    ) {
+      throw new PluginHostInputError(
+        `protocolAuth.${protocol}: credential ${credentialId} not found`,
+      );
+    }
+  }
+  await writeProtocolAuth(ownerId, hostId, patch, { isOwner: true });
+}
+
+const SHARE_LEVELS: readonly string[] = ["connect", "view", "edit", "manage"];
+
+/** Upserts one grant and snapshots the host's secrets for it. */
+async function grantHostShare(
+  hostId: number,
+  ownerId: string,
+  grantedBy: string,
+  target: PluginShareTarget,
+  permissionLevel: PluginHostShareLevel,
+  expiresAt: string | null,
+): Promise<number> {
+  const { createCurrentRbacAccessRepository } =
+    await import("../database/repositories/factory.js");
+  const grant = await createCurrentRbacAccessRepository().upsertHostAccess({
+    hostId,
+    grantedBy,
+    permissionLevel,
+    expiresAt,
+    ...(target.type === "user"
+      ? { targetType: "user" as const, targetUserId: target.id as string }
+      : { targetType: "role" as const, targetRoleId: target.id as number }),
+  });
+
+  const { SharedHostSecretsManager } =
+    await import("../utils/shared-host-secrets-manager.js");
+  const secretsManager = SharedHostSecretsManager.getInstance();
+  try {
+    if (target.type === "user") {
+      await secretsManager.snapshotForUser(
+        grant.id,
+        hostId,
+        target.id as string,
+        ownerId,
+      );
+    } else {
+      await secretsManager.snapshotForRole(
+        grant.id,
+        hostId,
+        target.id as number,
+        ownerId,
+      );
+    }
+  } catch {
+    // A snapshot failure never blocks the grant: the recipient can
+    // still be prompted, or the owner can retry sharing later.
+  }
+  return grant.id;
+}
+
+function hoursFromNow(durationHours: number | undefined): string | null {
+  return durationHours && durationHours > 0
+    ? new Date(Date.now() + durationHours * 60 * 60 * 1000).toISOString()
+    : null;
 }
 
 function actingUser(): string {
@@ -476,6 +639,7 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
     create: async (host: PluginHostCreateInput): Promise<PluginHostRecord> => {
       try {
         await requireWrite();
+        assertManualCreateAllowed(pluginId);
       } catch (error) {
         await audit("hosts_create", host?.name ?? host?.ip ?? "host", {
           success: false,
@@ -484,8 +648,10 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
         throw error;
       }
       const userId = actingUser();
-      const { row, settings } = toHostWrite(host);
-      const writes = await checkSettings(settings);
+      const { row, settings, protocolAuth, pluginEnable } = toHostWrite(host);
+      const writes = await checkSettings(
+        await foldPluginEnable(settings, pluginEnable),
+      );
       const { createCurrentHostRepository } =
         await import("../database/repositories/factory.js");
       const { applyHostDefaultsToWrite, applyDefaultsAfterHostWrite } =
@@ -504,6 +670,7 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
           userId,
           columns,
         );
+      await writeHostProtocolAuth(userId, created.id, protocolAuth);
       await applyDefaultsAfterHostWrite(created.id);
       await writeSettings(created.id, writes);
       await markSettingsOwn(created.id, writes);
@@ -520,6 +687,7 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
     ): Promise<PluginHostRecord | null> => {
       try {
         await requireWrite();
+        assertHostsUnlocked([hostId], pluginId);
       } catch (error) {
         await audit("hosts_update", `host ${hostId}`, {
           success: false,
@@ -528,8 +696,10 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
         throw error;
       }
       const userId = actingUser();
-      const { row, settings } = toHostWrite(patch);
-      const writes = await checkSettings(settings);
+      const { row, settings, protocolAuth, pluginEnable } = toHostWrite(patch);
+      const writes = await checkSettings(
+        await foldPluginEnable(settings, pluginEnable),
+      );
       const { createCurrentHostRepository } =
         await import("../database/repositories/factory.js");
       const { applyHostDefaultsToWrite, applyDefaultsAfterHostWrite } =
@@ -560,6 +730,7 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
           columns,
         );
       if (updated) {
+        await writeHostProtocolAuth(userId, hostId, protocolAuth);
         await writeSettings(hostId, writes);
         await markSettingsOwn(hostId, writes);
         await applyDefaultsAfterHostWrite(hostId, {
@@ -584,6 +755,7 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
     delete: async (hostId: number): Promise<boolean> => {
       try {
         await requireWrite();
+        assertHostsUnlocked([hostId], pluginId);
         const userId = actingUser();
         const { PermissionManager } =
           await import("../utils/permission-manager.js");
@@ -631,6 +803,7 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
     ): Promise<PluginHostShareResult> => {
       try {
         await requireWrite();
+        assertHostsUnlocked([hostId], pluginId);
       } catch (error) {
         await audit("hosts_share", `host ${hostId}`, {
           success: false,
@@ -660,10 +833,8 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
         return result;
       }
 
-      const {
-        createCurrentHostResolutionRepository,
-        createCurrentRbacAccessRepository,
-      } = await import("../database/repositories/factory.js");
+      const { createCurrentHostResolutionRepository } =
+        await import("../database/repositories/factory.js");
       const ownerId =
         (await createCurrentHostResolutionRepository().findHostOwnerId(
           hostId,
@@ -677,56 +848,95 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
         return { hostId, shared: false, reason: "owner" };
       }
 
-      const expiresAt =
-        durationHours && durationHours > 0
-          ? new Date(Date.now() + durationHours * 60 * 60 * 1000).toISOString()
-          : null;
-
-      const rbacAccessRepository = createCurrentRbacAccessRepository();
-      const { SharedHostSecretsManager } =
-        await import("../utils/shared-host-secrets-manager.js");
-      const secretsManager = SharedHostSecretsManager.getInstance();
-
+      const expiresAt = hoursFromNow(durationHours);
       for (const target of targets) {
-        const grant = await rbacAccessRepository.upsertHostAccess({
+        await grantHostShare(
           hostId,
-          grantedBy: userId,
+          ownerId,
+          userId,
+          target,
           permissionLevel,
           expiresAt,
-          ...(target.type === "user"
-            ? { targetType: "user" as const, targetUserId: target.id as string }
-            : {
-                targetType: "role" as const,
-                targetRoleId: target.id as number,
-              }),
-        });
-
-        try {
-          if (target.type === "user") {
-            await secretsManager.snapshotForUser(
-              grant.id,
-              hostId,
-              target.id as string,
-              ownerId,
-            );
-          } else {
-            await secretsManager.snapshotForRole(
-              grant.id,
-              hostId,
-              target.id as number,
-              ownerId,
-            );
-          }
-        } catch {
-          // A snapshot failure never blocks the grant: the recipient can
-          // still be prompted, or the owner can retry sharing later.
-        }
+        );
       }
 
       await audit("hosts_share", `host ${hostId}`, { success: true });
       return { hostId, shared: true };
     },
 
+    setShares: async (
+      hostId: number,
+      grants: PluginHostShareGrant[],
+    ): Promise<PluginHostShareResult> => {
+      const fail = async (reason: string): Promise<PluginHostShareResult> => {
+        await audit("hosts_set_shares", `host ${hostId}`, {
+          success: false,
+          errorMessage: reason,
+        });
+        return { hostId, shared: false, reason };
+      };
+      try {
+        await requireWrite();
+        assertHostsUnlocked([hostId], pluginId);
+      } catch (error) {
+        await fail(error instanceof Error ? error.message : String(error));
+        throw error;
+      }
+      if (!Array.isArray(grants)) {
+        throw new PluginHostInputError("grants must be a list");
+      }
+      for (const grant of grants) {
+        const type = grant?.target?.type;
+        if (
+          (type !== "user" && type !== "role") ||
+          !SHARE_LEVELS.includes(grant.permissionLevel)
+        ) {
+          throw new PluginHostInputError(
+            "Each grant needs a user or role target and a share level",
+          );
+        }
+      }
+
+      const userId = actingUser();
+      const {
+        createCurrentHostResolutionRepository,
+        createCurrentRbacAccessRepository,
+      } = await import("../database/repositories/factory.js");
+      const ownerId =
+        await createCurrentHostResolutionRepository().findHostOwnerId(hostId);
+      if (ownerId !== userId) return fail("forbidden");
+      if (
+        grants.some((g) => g.target.type === "user" && g.target.id === userId)
+      ) {
+        return fail("owner");
+      }
+
+      const kept = new Set<number>();
+      for (const grant of grants) {
+        kept.add(
+          await grantHostShare(
+            hostId,
+            ownerId,
+            userId,
+            grant.target,
+            grant.permissionLevel,
+            hoursFromNow(grant.durationHours),
+          ),
+        );
+      }
+      const repository = createCurrentRbacAccessRepository();
+      for (const existing of await repository.listHostAccess(hostId)) {
+        if (!kept.has(existing.id)) {
+          await repository.revokeHostAccess(existing.id, hostId);
+        }
+      }
+      const { pruneHostGrants } = await import("../database/routes/rbac.js");
+      await pruneHostGrants(hostId);
+
+      await audit("hosts_set_shares", `host ${hostId}`, { success: true });
+      return { hostId, shared: true };
+    },
+
     listUsers: async (): Promise<PluginShareableUser[]> => {
       try {
         await requireWrite();
@@ -810,6 +1020,27 @@ export function createPluginHosts({ manifest, bag, audit }: Deps): PluginHosts {
       return hostSessionStatus.hasActiveSession(hostId);
     },
 
+    locks: {
+      provide: (provider) => {
+        if (!declared.includes("hosts:lock")) {
+          throw capabilityRefused(pluginId, "hosts:lock");
+        }
+        const remove = provideHostLocks(
+          pluginId,
+          manifest.name || pluginId,
+          provider,
+        );
+        void audit("host_locks_provide", `${pluginId} manages hosts`, {
+          success: true,
+        });
+        const drop = bag?.add(remove, "host lock provider");
+        return () => {
+          drop?.();
+          remove();
+        };
+      },
+    },
+
     activity: {
       provide: (provider) => {
         if (!declared.includes("hosts:activity-provide")) {
diff --git a/src/backend/sync/server/push.ts b/src/backend/sync/server/push.ts
index d192e3dfc..4cfc19579 100644
--- a/src/backend/sync/server/push.ts
+++ b/src/backend/sync/server/push.ts
@@ -11,6 +11,12 @@ import type { SyncRow } from "@termix-ssh/plugin-sdk/backend";
 import { getEntity } from "../../plugins/sync-registry.js";
 import { PermissionManager } from "../../utils/permission-manager.js";
 import { syncLogger } from "../../utils/logger.js";
+import {
+  hasHostLocks,
+  hostLock,
+  manualCreateBlockedBy,
+} from "../../hosts/locks.js";
+import { createCurrentHostResolutionRepository } from "../../database/repositories/factory.js";
 import {
   createResolvers,
   deleteStoredRow,
@@ -48,6 +54,22 @@ export type PushResult =
 
 export const MAX_PUSH_OPS = 500;
 
+/** A host a plugin manages can't be changed from a desktop either. */
+async function hostPushLocked(
+  userId: string,
+  syncId: string,
+  exists: boolean,
+): Promise<boolean> {
+  if (!hasHostLocks()) return false;
+  if (!exists) return manualCreateBlockedBy() !== null;
+  const hostId =
+    await createCurrentHostResolutionRepository().findHostIdBySyncIdForUser(
+      syncId,
+      userId,
+    );
+  return hostId !== null && hostId !== undefined && hostLock(hostId) !== null;
+}
+
 function isPushOp(value: unknown): value is PushOp {
   if (!value || typeof value !== "object") return false;
   const op = value as Record<string, unknown>;
@@ -166,6 +188,13 @@ export async function applyPush(
       results.set(key, { ...base, status: "rejected", reason: "permission" });
       continue;
     }
+    if (
+      op.entityType === "hosts" &&
+      (await hostPushLocked(userId, op.syncId, exists))
+    ) {
+      results.set(key, { ...base, status: "rejected", reason: "locked" });
+      continue;
+    }
 
     try {
       if (op.op === "delete") {
diff --git a/src/backend/tests/database/routes/host-locked-routes.test.ts b/src/backend/tests/database/routes/host-locked-routes.test.ts
new file mode 100644
index 000000000..b1dcbf206
--- /dev/null
+++ b/src/backend/tests/database/routes/host-locked-routes.test.ts
@@ -0,0 +1,130 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import express, { type RequestHandler } from "express";
+import request from "supertest";
+
+const state = vi.hoisted(() => ({
+  updates: [] as Array<{ ids: number[]; update: Record<string, unknown> }>,
+  renamed: 0,
+  folderHosts: [] as Array<{ id: number }>,
+}));
+
+vi.mock("../../../utils/logger.js", () => ({
+  databaseLogger: { error: vi.fn(), warn: vi.fn(), info: vi.fn() },
+  sshLogger: { error: vi.fn(), warn: vi.fn(), info: vi.fn() },
+  pluginLogger: { warn: vi.fn() },
+}));
+vi.mock("../../../utils/database-save-trigger.js", () => ({
+  DatabaseSaveTrigger: { batched: (fn: RequestHandler) => fn },
+}));
+vi.mock("../../../hosts/defaults/overrides.js", () => ({
+  changeHostOverrides: async () => {},
+}));
+vi.mock("../../../hosts/defaults/recompute.js", () => ({
+  recompute: async () => ({ changedHostIds: [] }),
+}));
+vi.mock("../../../hosts/defaults/service.js", () => ({
+  folderCredentialIds: async () => [],
+  setFolderCredentialDefault: async () => {},
+}));
+vi.mock("../../../database/routes/host-plugin-settings.js", () => ({
+  setHostPluginEnabled: async () => true,
+}));
+vi.mock("../../../database/repositories/factory.js", () => ({
+  createCurrentHostRepository: () => ({
+    listBulkUpdateState: async (_userId: string, ids: number[]) =>
+      ids.map((id) => ({ id })),
+    updateManyForUser: async (
+      _userId: string,
+      ids: number[],
+      update: Record<string, unknown>,
+    ) => {
+      state.updates.push({ ids, update });
+    },
+  }),
+  createCurrentHostFolderRepository: () => ({
+    listHostsInFolder: async () => state.folderHosts,
+    renameFolder: async () => {
+      state.renamed++;
+      return { updatedHosts: 1, updatedCredentials: 0 };
+    },
+  }),
+  createCurrentFolderAccessRepository: () => ({
+    renameFolder: async () => {},
+  }),
+}));
+
+const { registerHostBulkRoutes } =
+  await import("../../../database/routes/host-bulk-routes.js");
+const { registerHostFolderRoutes } =
+  await import("../../../database/routes/host-folder-routes.js");
+const { clearHostLocks, provideHostLocks } =
+  await import("../../../hosts/locks.js");
+
+const pass: RequestHandler = (req, _res, next) => {
+  (req as unknown as { userId: string }).userId = "owner";
+  next();
+};
+
+function app() {
+  const router = express.Router();
+  registerHostBulkRoutes(router, pass, pass, pass);
+  registerHostFolderRoutes(router, {
+    authenticateJWT: pass,
+    requireViewPermission: pass,
+    requireEditPermission: pass,
+    requireDeletePermission: pass,
+    requireCredentialEditPermission: pass,
+    requireDataAccess: pass,
+  });
+  const server = express();
+  server.use(express.json());
+  server.use(router);
+  return server;
+}
+
+beforeEach(() => {
+  state.updates = [];
+  state.renamed = 0;
+  state.folderHosts = [];
+  provideHostLocks("cfg", "Config", {
+    isLocked: (hostId) => hostId === 2,
+    note: () => null,
+    allowManualCreate: () => true,
+  });
+});
+afterEach(() => clearHostLocks());
+
+describe("routes on locked hosts", () => {
+  it("still lets a user pin a locked host", async () => {
+    await request(app())
+      .patch("/bulk-update")
+      .send({ hostIds: [1, 2], updates: { pin: true } })
+      .expect(200);
+    expect(state.updates).toEqual([{ ids: [1, 2], update: { pin: true } }]);
+  });
+
+  it("refuses a bulk change that touches a locked host", async () => {
+    const res = await request(app())
+      .patch("/bulk-update")
+      .send({ hostIds: [1, 2], updates: { folder: "Moved" } })
+      .expect(403);
+    expect(res.body).toMatchObject({ code: "HOST_LOCKED" });
+    expect(state.updates).toEqual([]);
+  });
+
+  it("refuses renaming a folder that holds a locked host", async () => {
+    state.folderHosts = [{ id: 1 }, { id: 2 }];
+    await request(app())
+      .put("/folders/rename")
+      .send({ oldName: "Prod", newName: "Live" })
+      .expect(403);
+    expect(state.renamed).toBe(0);
+
+    state.folderHosts = [{ id: 1 }];
+    await request(app())
+      .put("/folders/rename")
+      .send({ oldName: "Prod", newName: "Live" })
+      .expect(200);
+    expect(state.renamed).toBe(1);
+  });
+});
diff --git a/src/backend/tests/hosts/locks.test.ts b/src/backend/tests/hosts/locks.test.ts
new file mode 100644
index 000000000..7efe6d1fb
--- /dev/null
+++ b/src/backend/tests/hosts/locks.test.ts
@@ -0,0 +1,113 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("../../utils/logger.js", () => ({
+  pluginLogger: { warn: vi.fn() },
+}));
+
+const {
+  assertHostsUnlocked,
+  assertManualCreateAllowed,
+  clearHostLocks,
+  hasHostLocks,
+  hostLock,
+  HostLockedError,
+  manualCreateBlockedBy,
+  provideHostLocks,
+  requireManualCreate,
+  requireUnlockedHost,
+} = await import("../../hosts/locks.js");
+
+const provider = (locked: number[], allowManualCreate = true) => ({
+  isLocked: (hostId: number) => locked.includes(hostId),
+  note: (hostId: number) => `id ${hostId}`,
+  allowManualCreate: () => allowManualCreate,
+});
+
+function fakeRes() {
+  const res = {
+    code: 0,
+    body: null as unknown,
+    status(code: number) {
+      res.code = code;
+      return { json: (body: unknown) => (res.body = body) };
+    },
+  };
+  return res;
+}
+
+afterEach(() => clearHostLocks());
+
+describe("host locks", () => {
+  it("reports nothing without providers", () => {
+    expect(hasHostLocks()).toBe(false);
+    expect(hostLock(1)).toBeNull();
+    expect(() => assertHostsUnlocked([1, 2])).not.toThrow();
+    expect(manualCreateBlockedBy()).toBeNull();
+  });
+
+  it("names the plugin and note for a locked host", () => {
+    provideHostLocks("cfg", "Config", provider([3]));
+    expect(hostLock(3)).toEqual({
+      pluginId: "cfg",
+      pluginName: "Config",
+      note: "id 3",
+    });
+    expect(hostLock(4)).toBeNull();
+    expect(() => assertHostsUnlocked([4, 3])).toThrow(HostLockedError);
+  });
+
+  it("lets the locking plugin through", () => {
+    provideHostLocks("cfg", "Config", provider([3], false));
+    expect(() => assertHostsUnlocked([3], "cfg")).not.toThrow();
+    expect(() => assertManualCreateAllowed("cfg")).not.toThrow();
+    expect(() => assertManualCreateAllowed()).toThrow(/managed by Config/);
+  });
+
+  it("drops a provider when removed", () => {
+    const remove = provideHostLocks("cfg", "Config", provider([3], false));
+    remove();
+    expect(hostLock(3)).toBeNull();
+    expect(manualCreateBlockedBy()).toBeNull();
+  });
+
+  it("never locks when a provider throws", () => {
+    provideHostLocks("cfg", "Config", {
+      isLocked: () => {
+        throw new Error("broken");
+      },
+      note: () => null,
+      allowManualCreate: () => {
+        throw new Error("broken");
+      },
+    });
+    expect(hostLock(1)).toBeNull();
+    expect(manualCreateBlockedBy()).toBeNull();
+  });
+});
+
+describe("lock route guards", () => {
+  it("answers 403 HOST_LOCKED for a locked :id", () => {
+    provideHostLocks("cfg", "Config", provider([7]));
+    const res = fakeRes();
+    const next = vi.fn();
+    requireUnlockedHost({ params: { id: "7" } }, res, next);
+    expect(next).not.toHaveBeenCalled();
+    expect(res.code).toBe(403);
+    expect(res.body).toMatchObject({ code: "HOST_LOCKED", lockedBy: "cfg" });
+
+    requireUnlockedHost({ params: { id: "8" } }, fakeRes(), next);
+    expect(next).toHaveBeenCalledTimes(1);
+  });
+
+  it("blocks manual creates only while a provider says so", () => {
+    const next = vi.fn();
+    requireManualCreate({}, fakeRes(), next);
+    expect(next).toHaveBeenCalledTimes(1);
+
+    provideHostLocks("cfg", "Config", provider([], false));
+    const res = fakeRes();
+    requireManualCreate({}, res, next);
+    expect(next).toHaveBeenCalledTimes(1);
+    expect(res.code).toBe(403);
+  });
+});
diff --git a/src/backend/tests/plugins/ctx-credentials.test.ts b/src/backend/tests/plugins/ctx-credentials.test.ts
index 3eb8bc505..2f07a00b3 100644
--- a/src/backend/tests/plugins/ctx-credentials.test.ts
+++ b/src/backend/tests/plugins/ctx-credentials.test.ts
@@ -461,6 +461,40 @@ describe("ctx.credentials.registerSecretResolver", () => {
   });
 });
 
+describe("ctx.credentials.list", () => {
+  beforeEach(() => {
+    state.userCredentials.set("owner", [
+      { id: 3, name: "pw", authType: "password", password: "secret" },
+      { id: 4, name: "key", authType: "key", privateKey: "PRIVATE KEY" },
+    ]);
+  });
+
+  it("refuses without credentials:use", async () => {
+    grants.set("demo", []);
+    const ctx = contextFor([]);
+    await expect(
+      runAsActor("owner", "request", () => ctx.credentials.list()),
+    ).rejects.toThrow(/credentials:use/);
+  });
+
+  it("lists the actor's credentials without secrets", async () => {
+    grants.set("demo", ["credentials:use"]);
+    const ctx = contextFor(["credentials:use"]);
+    const list = await runAsActor("owner", "request", () =>
+      ctx.credentials.list(),
+    );
+    expect(list).toEqual([
+      { id: 3, name: "pw", username: null, authType: "password", folder: null },
+      { id: 4, name: "key", username: null, authType: "key", folder: null },
+    ]);
+    expect(JSON.stringify(list)).not.toMatch(/secret|PRIVATE/);
+    expect(auditEntries.at(-1)).toMatchObject({
+      action: "plugin_credentials_list",
+      success: true,
+    });
+  });
+});
+
 describe("ctx.credentials.listSshKeys", () => {
   const pair = ssh2.utils.generateKeyPairSync("rsa", { bits: 2048 });
   const derived = (() => {
diff --git a/src/backend/tests/plugins/ctx-hosts.test.ts b/src/backend/tests/plugins/ctx-hosts.test.ts
index b5e8f4215..c572fdbb2 100644
--- a/src/backend/tests/plugins/ctx-hosts.test.ts
+++ b/src/backend/tests/plugins/ctx-hosts.test.ts
@@ -27,6 +27,9 @@ const h = vi.hoisted(() => ({
   statusPortsRemoved: [] as string[],
   userPermissions: new Set<string>(),
   deleted: [] as Array<{ userId: string; hostId: number }>,
+  existingAccess: [] as Array<{ id: number }>,
+  revoked: [] as number[],
+  protocolWrites: [] as Array<{ hostId: number; protocols: string[] }>,
   roles: [] as Array<{
     id: number;
     name: string;
@@ -85,6 +88,10 @@ vi.mock("../../database/repositories/factory.js", () => ({
       h.upserts.push(input);
       return { id: h.upserts.length, created: true };
     },
+    listHostAccess: async () => h.existingAccess,
+    revokeHostAccess: async (accessId: number) => {
+      h.revoked.push(accessId);
+    },
   }),
   createCurrentUserRepository: () => ({
     listAll: async () => h.users,
@@ -145,6 +152,13 @@ vi.mock("../../plugins/host-status-provider.js", () => ({
   },
 }));
 vi.mock("../../database/routes/host-plugin-settings.js", () => ({
+  hostSettingsPlugins: () => [
+    {
+      id: "metrics",
+      contributes: { settings: { host: { enableKey: "enableMetrics" } } },
+    },
+    { id: "noswitch", contributes: { settings: { host: { fields: [] } } } },
+  ],
   loadHostPluginSettings: async (hostIds: number[]) =>
     new Map(
       hostIds.map((id) => [
@@ -198,6 +212,25 @@ vi.mock("../../hosts/defaults/overrides.js", () => ({
   changeHostOverrides: async () => {},
 }));
 
+vi.mock("../../database/routes/rbac.js", () => ({
+  pruneHostGrants: async () => 0,
+}));
+vi.mock("../../hosts/usable-credential.js", () => ({
+  findUsableCredential: async (credentialId: number) =>
+    credentialId === 5 ? { id: 5 } : null,
+}));
+vi.mock("../../hosts/protocol-auth/protocol-auth.js", () => ({
+  readProtocolAuthPayload: (data: { protocolAuth: Record<string, unknown> }) =>
+    new Map(Object.entries(data.protocolAuth)),
+  writeProtocolAuth: async (
+    _ownerId: string,
+    hostId: number,
+    patch: Map<string, unknown>,
+  ) => {
+    h.protocolWrites.push({ hostId, protocols: [...patch.keys()] });
+  },
+}));
+
 vi.mock("../../hosts/delete-host.js", () => ({
   deleteOwnedHost: async (userId: string, hostId: number) => {
     h.deleted.push({ userId, hostId });
@@ -209,6 +242,8 @@ const { createPluginHosts } = await import("../../plugins/ctx-hosts.js");
 const { PluginCapabilityError } =
   await import("@termix-ssh/plugin-sdk/backend");
 const { pluginEvents, TOPICS } = await import("../../plugins/events.js");
+const { clearHostLocks, hostLock, provideHostLocks } =
+  await import("../../hosts/locks.js");
 
 function manifest(capabilities: string[]) {
   return {
@@ -236,6 +271,10 @@ beforeEach(() => {
   h.roles = [];
   h.userPermissions = new Set();
   h.deleted = [];
+  h.existingAccess = [];
+  h.revoked = [];
+  h.protocolWrites = [];
+  clearHostLocks();
 });
 
 describe("ctx.hosts", () => {
@@ -705,3 +744,220 @@ describe("ctx.hosts.status", () => {
     expect(h.statusPortsRemoved).toEqual(["rdp"]);
   });
 });
+
+describe("ctx.hosts secrets and protocol logins", () => {
+  it("stores secrets on create and writes protocol logins", async () => {
+    h.granted = new Set(["hosts:write"]);
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    const created = await hosts.create({
+      name: "rdp",
+      ip: "10.0.0.9",
+      port: 3389,
+      username: "",
+      authType: "password",
+      password: "s3cret",
+      sudoPassword: "",
+      protocolAuth: { rdp: { authType: "direct", username: "admin" } },
+    });
+    expect(h.created[0]).toMatchObject({
+      password: "s3cret",
+      sudoPassword: null,
+    });
+    expect(created).not.toHaveProperty("password");
+    expect(h.protocolWrites).toEqual([{ hostId: 99, protocols: ["rdp"] }]);
+  });
+
+  it("refuses a protocol credential the owner cannot use", async () => {
+    h.granted = new Set(["hosts:write"]);
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    await expect(
+      hosts.create({
+        name: "vnc",
+        ip: "10.0.0.9",
+        port: 5900,
+        username: "",
+        authType: "password",
+        protocolAuth: { vnc: { authType: "credential", credentialId: 6 } },
+      }),
+    ).rejects.toThrow(/credential 6/);
+  });
+
+  it("refuses a secret that is not a string", async () => {
+    h.granted = new Set(["hosts:write"]);
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    await expect(hosts.update(5, { password: 12 as never })).rejects.toThrow(
+      /password/,
+    );
+  });
+});
+
+describe("ctx.hosts pluginEnable", () => {
+  it("writes each plugin's switch under its enableKey", async () => {
+    h.granted = new Set(["hosts:write"]);
+    h.importRows = [];
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    await hosts.create({
+      name: "n",
+      ip: "10.0.0.1",
+      port: 22,
+      username: "root",
+      authType: "password",
+      pluginEnable: { metrics: false },
+    });
+    expect(h.importRows).toEqual([
+      { hostId: 99, row: { metrics: { enableMetrics: false } } },
+    ]);
+  });
+
+  it("refuses a plugin with no switch", async () => {
+    h.granted = new Set(["hosts:write"]);
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    await expect(
+      hosts.update(5, { pluginEnable: { noswitch: true } }),
+    ).rejects.toThrow(/no host switch/);
+    expect(h.updates).toHaveLength(0);
+  });
+});
+
+describe("ctx.hosts.setShares", () => {
+  it("upserts the listed grants and revokes the rest", async () => {
+    h.granted = new Set(["hosts:write"]);
+    h.existingAccess = [{ id: 1 }, { id: 7 }];
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    const result = await hosts.setShares(3, [
+      { target: { type: "role", id: 2 }, permissionLevel: "connect" },
+    ]);
+    expect(result).toEqual({ hostId: 3, shared: true });
+    expect(h.upserts).toEqual([
+      expect.objectContaining({
+        hostId: 3,
+        targetType: "role",
+        targetRoleId: 2,
+        permissionLevel: "connect",
+        expiresAt: null,
+      }),
+    ]);
+    expect(h.revoked).toEqual([7]);
+  });
+
+  it("only works for the host owner", async () => {
+    h.granted = new Set(["hosts:write"]);
+    h.ownerId = "someone-else";
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    expect(await hosts.setShares(3, [])).toEqual({
+      hostId: 3,
+      shared: false,
+      reason: "forbidden",
+    });
+    expect(h.revoked).toEqual([]);
+  });
+
+  it("refuses a bad level", async () => {
+    h.granted = new Set(["hosts:write"]);
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    await expect(
+      hosts.setShares(3, [
+        { target: { type: "user", id: "u2" }, permissionLevel: "own" as never },
+      ]),
+    ).rejects.toThrow(/share level/);
+  });
+});
+
+describe("ctx.hosts.locks", () => {
+  const provider = (locked: number[], allowManualCreate = true) => ({
+    isLocked: (hostId: number) => locked.includes(hostId),
+    note: () => "From hosts.yaml",
+    allowManualCreate: () => allowManualCreate,
+  });
+
+  it("needs hosts:lock", () => {
+    const hosts = createPluginHosts({
+      manifest: manifest([]),
+      audit: vi.fn(async () => {}),
+    });
+    expect(() => hosts.locks.provide(provider([1]))).toThrow(
+      PluginCapabilityError,
+    );
+  });
+
+  it("locks hosts until the plugin removes its provider", () => {
+    const hosts = createPluginHosts({
+      manifest: manifest(["hosts:lock"]),
+      audit: vi.fn(async () => {}),
+    });
+    const remove = hosts.locks.provide(provider([4]));
+    expect(hostLock(4)).toEqual({
+      pluginId: "fixture",
+      pluginName: "Fixture",
+      note: "From hosts.yaml",
+    });
+    expect(hostLock(5)).toBeNull();
+    remove();
+    expect(hostLock(4)).toBeNull();
+  });
+
+  it("blocks other plugins on a locked host but not the plugin that locks it", async () => {
+    h.granted = new Set(["hosts:write"]);
+    h.updateResult = { id: 4, name: "x" };
+    h.userPermissions = new Set(["hosts.delete"]);
+    provideHostLocks("hosts-file", "Hosts File", provider([4], false));
+    const other = createPluginHosts({
+      manifest: manifest(["hosts:write"]),
+      audit: vi.fn(async () => {}),
+    });
+    await expect(other.update(4, { name: "y" })).rejects.toThrow(
+      /managed by Hosts File/,
+    );
+    await expect(other.delete(4)).rejects.toThrow(/managed by Hosts File/);
+    await expect(
+      other.share(4, [{ type: "user", id: "u2" }], "view"),
+    ).rejects.toThrow(/managed by Hosts File/);
+    await expect(
+      other.create({
+        name: "n",
+        ip: "10.0.0.1",
+        port: 22,
+        username: "root",
+        authType: "password",
+      }),
+    ).rejects.toThrow(/new hosts can't be added/);
+    expect(h.updates).toHaveLength(0);
+    expect(h.deleted).toHaveLength(0);
+
+    const owner = createPluginHosts({
+      manifest: {
+        id: "hosts-file",
+        name: "Hosts File",
+        version: "1.0.0",
+        capabilities: ["hosts:write"],
+      } as never,
+      audit: vi.fn(async () => {}),
+    });
+    await owner.update(4, { name: "y" });
+    expect(h.updates).toHaveLength(1);
+  });
+});
diff --git a/src/types/index.ts b/src/types/index.ts
index 7606a6992..bc6f89fa4 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -37,6 +37,13 @@ export interface JumpHost {
   hostId: number;
 }
 
+/** The plugin that manages a host, from ctx.hosts.locks. */
+export interface HostLock {
+  pluginId: string;
+  pluginName: string;
+  note: string | null;
+}
+
 export type Host = {
   id: number;
   name: string;
@@ -116,6 +123,8 @@ export type Host = {
   ownerUsername?: string;
   /** A read-only copy of a host shared with the linked account. */
   sharedCopy?: boolean;
+  /** Set when a plugin manages this host: read only, pins and order still work. */
+  lock?: HostLock;
   /** Desktop only: kept on this device, never synced to the server. */
   localOnly?: boolean;
 
diff --git a/src/types/ui-types.ts b/src/types/ui-types.ts
index 84e0d52d3..cfb58ad81 100644
--- a/src/types/ui-types.ts
+++ b/src/types/ui-types.ts
@@ -1,4 +1,5 @@
 import type {
+  HostLock,
   HostProtocolAuthSummary,
   HostSshOptions,
   HostTerminalConfig,
@@ -104,6 +105,8 @@ export type Host = {
    * linked to. It arrives through sync and is managed on the server.
    */
   sharedCopy?: boolean;
+  /** Set when a plugin manages this host: read only, pins and order still work. */
+  lock?: HostLock;
   /** Desktop only: kept on this device, never synced to the server. */
   localOnly?: boolean;
 };
diff --git a/src/ui/api/ssh-host-management-api.ts b/src/ui/api/ssh-host-management-api.ts
index 7e3daf8ae..2ea8fda4f 100644
--- a/src/ui/api/ssh-host-management-api.ts
+++ b/src/ui/api/ssh-host-management-api.ts
@@ -86,6 +86,21 @@ export async function bulkUpdateSSHHosts(
   }
 }
 
+export interface HostPolicy {
+  manualCreate: boolean;
+  /** The plugin that manages hosts, when hosts can't be added by hand. */
+  blockedBy?: string;
+}
+
+export async function getHostPolicy(): Promise<HostPolicy> {
+  try {
+    const response = await sshHostApi.get("/policy");
+    return response.data;
+  } catch (error) {
+    handleApiError(error, "load host policy");
+  }
+}
+
 export async function reorderSSHHosts(
   positions: { id: number; sortOrder: number }[],
 ): Promise<{ updated: number }> {
diff --git a/src/ui/locales/en.json b/src/ui/locales/en.json
index 390501cf8..7bb9db0fa 100644
--- a/src/ui/locales/en.json
+++ b/src/ui/locales/en.json
@@ -548,6 +548,9 @@
     "deleteFolderConfirm_one": "Delete \"{{name}}\" and its {{count}} host? This cannot be undone.",
     "deleteFolderConfirm_other": "Delete \"{{name}}\" and its {{count}} hosts? This cannot be undone.",
     "failedToMoveHosts": "Failed to move hosts",
+    "managedBanner": "This host is managed by {{plugin}}. Change it there. You can still pin and reorder it.",
+    "managedTooltip": "Managed by {{plugin}}",
+    "addBlocked": "Hosts are managed by {{plugin}}, so new hosts can't be added here.",
     "failedToReorder": "Failed to reorder",
     "expandAll": "Expand all folders",
     "collapseAll": "Collapse all folders",
@@ -1212,6 +1215,10 @@
         "title": "Store recent activity",
         "consequence": "Becomes the store for the recent activity list of every user."
       },
+      "hosts:lock": {
+        "title": "Manage hosts as read only",
+        "consequence": "Hosts it manages can't be edited, deleted or reshared by anyone else."
+      },
       "desktop:window": {
         "title": "Open desktop windows",
         "consequence": "Only in the Termix desktop app."
diff --git a/src/ui/main-axios.ts b/src/ui/main-axios.ts
index 121e1b675..e5b27a720 100644
--- a/src/ui/main-axios.ts
+++ b/src/ui/main-axios.ts
@@ -879,6 +879,8 @@ export {
   updateSSHHost,
   bulkUpdateSSHHosts,
   reorderSSHHosts,
+  getHostPolicy,
+  type HostPolicy,
   deleteSSHHost,
   getSSHHostById,
   testProxyConnection,
diff --git a/src/ui/plugin-host/sdk-ui.ts b/src/ui/plugin-host/sdk-ui.ts
index 84e9f69dc..209504c2f 100644
--- a/src/ui/plugin-host/sdk-ui.ts
+++ b/src/ui/plugin-host/sdk-ui.ts
@@ -402,6 +402,7 @@ export {
 } from "@/types/host-sidebar-preferences";
 export type {
   HostData,
+  HostLock,
   HostProtocolAuthInput,
   ProxyNode,
   SSHHost,
@@ -656,6 +657,8 @@ export {
   getHostAccess,
   getHostAuthOverride,
   getHostPassword,
+  getHostPolicy,
+  type HostPolicy,
   getHostSidebarPreferences,
   getLogLevel,
   getPasswordLoginAllowed,
diff --git a/src/ui/sidebar/HostManagerData.ts b/src/ui/sidebar/HostManagerData.ts
index e4235f205..b6e6b42ed 100644
--- a/src/ui/sidebar/HostManagerData.ts
+++ b/src/ui/sidebar/HostManagerData.ts
@@ -74,6 +74,7 @@ export function sshHostToHost(h: SSHHostWithStatus): Host {
     connectionOrigin: h.connectionOrigin ?? null,
     localOnly: !!h.localOnly,
     sharedCopy: !!h.sharedCopy,
+    ...(h.lock ? { lock: h.lock } : {}),
     enableSsh: h.enableSsh != null ? h.enableSsh : isSshHost,
     sshPort:
       h.sshPort ??