diff --git a/src/agents/sandbox/backend.ts b/src/agents/sandbox/backend.ts
index 8dd97530c8f7..43f29a10723d 100644
--- a/src/agents/sandbox/backend.ts
+++ b/src/agents/sandbox/backend.ts
@@ -1,61 +1,28 @@
-import type { OpenClawConfig } from "../../config/config.js";
 import { normalizeOptionalLowercaseString } from "../../shared/string-coerce.js";
-import type { SandboxBackendHandle, SandboxBackendId } from "./backend-handle.types.js";
-import type { SandboxRegistryEntry } from "./registry.js";
-import type { SandboxConfig } from "./types.js";
+import type {
+  RegisteredSandboxBackend,
+  SandboxBackendFactory,
+  SandboxBackendId,
+  SandboxBackendManager,
+  SandboxBackendRegistration,
+} from "./backend.types.js";
 
+export type {
+  CreateSandboxBackendParams,
+  SandboxBackendFactory,
+  SandboxBackendId,
+  SandboxBackendManager,
+  SandboxBackendRegistration,
+  SandboxBackendRuntimeInfo,
+} from "./backend.types.js";
 export type {
   SandboxBackendCommandParams,
   SandboxBackendCommandResult,
   SandboxBackendExecSpec,
   SandboxBackendHandle,
-  SandboxBackendId,
   SandboxFsBridgeContext,
 } from "./backend-handle.types.js";
 
-export type SandboxBackendRuntimeInfo = {
-  running: boolean;
-  actualConfigLabel?: string;
-  configLabelMatch: boolean;
-};
-
-export type SandboxBackendManager = {
-  describeRuntime(params: {
-    entry: SandboxRegistryEntry;
-    config: OpenClawConfig;
-    agentId?: string;
-  }): Promise<SandboxBackendRuntimeInfo>;
-  removeRuntime(params: {
-    entry: SandboxRegistryEntry;
-    config: OpenClawConfig;
-    agentId?: string;
-  }): Promise<void>;
-};
-
-export type CreateSandboxBackendParams = {
-  sessionKey: string;
-  scopeKey: string;
-  workspaceDir: string;
-  agentWorkspaceDir: string;
-  cfg: SandboxConfig;
-};
-
-export type SandboxBackendFactory = (
-  params: CreateSandboxBackendParams,
-) => Promise<SandboxBackendHandle>;
-
-export type SandboxBackendRegistration =
-  | SandboxBackendFactory
-  | {
-      factory: SandboxBackendFactory;
-      manager?: SandboxBackendManager;
-    };
-
-type RegisteredSandboxBackend = {
-  factory: SandboxBackendFactory;
-  manager?: SandboxBackendManager;
-};
-
 const SANDBOX_BACKEND_FACTORIES = new Map<SandboxBackendId, RegisteredSandboxBackend>();
 
 function normalizeSandboxBackendId(id: string): SandboxBackendId {
diff --git a/src/agents/sandbox/docker-backend.ts b/src/agents/sandbox/docker-backend.ts
index cfc2c5b1196b..ccf4f7234a45 100644
--- a/src/agents/sandbox/docker-backend.ts
+++ b/src/agents/sandbox/docker-backend.ts
@@ -1,10 +1,10 @@
 import { buildDockerExecArgs } from "../bash-tools.shared.js";
+import type { SandboxBackendCommandParams } from "./backend-handle.types.js";
 import type {
   CreateSandboxBackendParams,
-  SandboxBackendManager,
-  SandboxBackendCommandParams,
   SandboxBackendHandle,
-} from "./backend.js";
+  SandboxBackendManager,
+} from "./backend.types.js";
 import { resolveSandboxConfigForAgent } from "./config.js";
 import {
   dockerContainerState,
diff --git a/src/plugins/types.ts b/src/plugins/types.ts
index 4cd56ea7a536..18fc72fa7829 100644
--- a/src/plugins/types.ts
+++ b/src/plugins/types.ts
@@ -12,7 +12,6 @@ import type {
 } from "../agents/auth-profiles/types.js";
 import type { AgentHarness } from "../agents/harness/types.js";
 import type { ModelCatalogEntry } from "../agents/model-catalog.types.js";
-import type { AgentHarness } from "../agents/harness/types.js";
 import type { FailoverReason } from "../agents/pi-embedded-helpers/types.js";
 import type { ModelProviderRequestTransportOverrides } from "../agents/provider-request-config.js";
 import type { ProviderSystemPromptContribution } from "../agents/system-prompt-contribution.js";
@@ -81,6 +80,18 @@ import type {
 import type { DeliveryContext } from "../utils/delivery-context.js";
 import type { VideoGenerationProvider } from "../video-generation/types.js";
 import type { WizardPrompter } from "../wizard/prompts.js";
+import {
+  PLUGIN_PROMPT_MUTATION_RESULT_FIELDS,
+  stripPromptMutationFieldsFromLegacyHookResult,
+} from "./hook-before-agent-start.types.js";
+import type {
+  PluginHookBeforeAgentStartEvent,
+  PluginHookBeforeAgentStartResult,
+  PluginHookBeforeModelResolveEvent,
+  PluginHookBeforeModelResolveResult,
+  PluginHookBeforePromptBuildEvent,
+  PluginHookBeforePromptBuildResult,
+} from "./hook-before-agent-start.types.js";
 import type { PluginKind } from "./plugin-kind.types.js";
 import type { SecretInputMode } from "./provider-auth-types.js";
 import type { createVpsAwareOAuthHandlers } from "./provider-oauth-flow.js";
@@ -93,6 +104,19 @@ import type { PluginRuntime } from "./runtime/types.js";
 export type { PluginRuntime } from "./runtime/types.js";
 export type { AnyAgentTool } from "../agents/tools/common.js";
 export type { AgentHarness } from "../agents/harness/types.js";
+export type {
+  PluginHookBeforeAgentStartEvent,
+  PluginHookBeforeAgentStartOverrideResult,
+  PluginHookBeforeAgentStartResult,
+  PluginHookBeforeModelResolveEvent,
+  PluginHookBeforeModelResolveResult,
+  PluginHookBeforePromptBuildEvent,
+  PluginHookBeforePromptBuildResult,
+} from "./hook-before-agent-start.types.js";
+export {
+  PLUGIN_PROMPT_MUTATION_RESULT_FIELDS,
+  stripPromptMutationFieldsFromLegacyHookResult,
+} from "./hook-before-agent-start.types.js";
 
 export type ProviderAuthOptionBag = {
   token?: string;
@@ -2453,87 +2477,6 @@ export type PluginHookAgentContext = {
   channelId?: string;
 };
 
-// before_model_resolve hook
-export type PluginHookBeforeModelResolveEvent = {
-  /** User prompt for this run. No session messages are available yet in this phase. */
-  prompt: string;
-};
-
-export type PluginHookBeforeModelResolveResult = {
-  /** Override the model for this agent run. E.g. "llama3.3:8b" */
-  modelOverride?: string;
-  /** Override the provider for this agent run. E.g. "ollama" */
-  providerOverride?: string;
-};
-
-// before_prompt_build hook
-export type PluginHookBeforePromptBuildEvent = {
-  prompt: string;
-  /** Session messages prepared for this run. */
-  messages: unknown[];
-};
-
-export type PluginHookBeforePromptBuildResult = {
-  systemPrompt?: string;
-  prependContext?: string;
-  /**
-   * Prepended to the agent system prompt so providers can cache it (e.g. prompt caching).
-   * Use for static plugin guidance instead of prependContext to avoid per-turn token cost.
-   */
-  prependSystemContext?: string;
-  /**
-   * Appended to the agent system prompt so providers can cache it (e.g. prompt caching).
-   * Use for static plugin guidance instead of prependContext to avoid per-turn token cost.
-   */
-  appendSystemContext?: string;
-};
-
-export const PLUGIN_PROMPT_MUTATION_RESULT_FIELDS = [
-  "systemPrompt",
-  "prependContext",
-  "prependSystemContext",
-  "appendSystemContext",
-] as const satisfies readonly (keyof PluginHookBeforePromptBuildResult)[];
-
-type MissingPluginPromptMutationResultFields = Exclude<
-  keyof PluginHookBeforePromptBuildResult,
-  (typeof PLUGIN_PROMPT_MUTATION_RESULT_FIELDS)[number]
->;
-type AssertAllPluginPromptMutationResultFieldsListed =
-  MissingPluginPromptMutationResultFields extends never ? true : never;
-const assertAllPluginPromptMutationResultFieldsListed: AssertAllPluginPromptMutationResultFieldsListed = true;
-void assertAllPluginPromptMutationResultFieldsListed;
-
-// before_agent_start hook (legacy compatibility: combines both phases)
-export type PluginHookBeforeAgentStartEvent = {
-  prompt: string;
-  /** Optional because legacy hook can run in pre-session phase. */
-  messages?: unknown[];
-};
-
-export type PluginHookBeforeAgentStartResult = PluginHookBeforePromptBuildResult &
-  PluginHookBeforeModelResolveResult;
-
-export type PluginHookBeforeAgentStartOverrideResult = Omit<
-  PluginHookBeforeAgentStartResult,
-  keyof PluginHookBeforePromptBuildResult
->;
-
-export const stripPromptMutationFieldsFromLegacyHookResult = (
-  result: PluginHookBeforeAgentStartResult | void,
-): PluginHookBeforeAgentStartOverrideResult | void => {
-  if (!result || typeof result !== "object") {
-    return result;
-  }
-  const remaining: Partial<PluginHookBeforeAgentStartResult> = { ...result };
-  for (const field of PLUGIN_PROMPT_MUTATION_RESULT_FIELDS) {
-    delete remaining[field];
-  }
-  return Object.keys(remaining).length > 0
-    ? (remaining as PluginHookBeforeAgentStartOverrideResult)
-    : undefined;
-};
-
 // before_agent_reply hook
 export type PluginHookBeforeAgentReplyEvent = {
   /** The final user message text heading to the LLM (after commands/directives). */