diff --git a/src/auto-reply/reply/session-delivery.ts b/src/auto-reply/reply/session-delivery.ts
new file mode 100644
index 00000000000..f49ab9b0182
--- /dev/null
+++ b/src/auto-reply/reply/session-delivery.ts
@@ -0,0 +1,145 @@
+import type { SessionEntry } from "../../config/sessions.js";
+import { buildAgentMainSessionKey } from "../../routing/session-key.js";
+import { parseAgentSessionKey } from "../../sessions/session-key-utils.js";
+import {
+  deliveryContextFromSession,
+  deliveryContextKey,
+  normalizeDeliveryContext,
+} from "../../utils/delivery-context.js";
+import {
+  INTERNAL_MESSAGE_CHANNEL,
+  isDeliverableMessageChannel,
+  normalizeMessageChannel,
+} from "../../utils/message-channel.js";
+import type { MsgContext } from "../templating.js";
+
+export type LegacyMainDeliveryRetirement = {
+  key: string;
+  entry: SessionEntry;
+};
+
+function resolveSessionKeyChannelHint(sessionKey?: string): string | undefined {
+  const parsed = parseAgentSessionKey(sessionKey);
+  if (!parsed?.rest) {
+    return undefined;
+  }
+  const head = parsed.rest.split(":")[0]?.trim().toLowerCase();
+  if (!head || head === "main" || head === "cron" || head === "subagent" || head === "acp") {
+    return undefined;
+  }
+  return normalizeMessageChannel(head);
+}
+
+function isExternalRoutingChannel(channel?: string): channel is string {
+  return Boolean(
+    channel && channel !== INTERNAL_MESSAGE_CHANNEL && isDeliverableMessageChannel(channel),
+  );
+}
+
+export function resolveLastChannelRaw(params: {
+  originatingChannelRaw?: string;
+  persistedLastChannel?: string;
+  sessionKey?: string;
+}): string | undefined {
+  const originatingChannel = normalizeMessageChannel(params.originatingChannelRaw);
+  const persistedChannel = normalizeMessageChannel(params.persistedLastChannel);
+  const sessionKeyChannelHint = resolveSessionKeyChannelHint(params.sessionKey);
+  let resolved = params.originatingChannelRaw || params.persistedLastChannel;
+  // Internal/non-deliverable sources should not overwrite previously known
+  // external delivery routes (or explicit channel hints from the session key).
+  if (!isExternalRoutingChannel(originatingChannel)) {
+    if (isExternalRoutingChannel(persistedChannel)) {
+      resolved = persistedChannel;
+    } else if (isExternalRoutingChannel(sessionKeyChannelHint)) {
+      resolved = sessionKeyChannelHint;
+    }
+  }
+  return resolved;
+}
+
+export function resolveLastToRaw(params: {
+  originatingChannelRaw?: string;
+  originatingToRaw?: string;
+  toRaw?: string;
+  persistedLastTo?: string;
+  persistedLastChannel?: string;
+  sessionKey?: string;
+}): string | undefined {
+  const originatingChannel = normalizeMessageChannel(params.originatingChannelRaw);
+  const persistedChannel = normalizeMessageChannel(params.persistedLastChannel);
+  const sessionKeyChannelHint = resolveSessionKeyChannelHint(params.sessionKey);
+
+  // When the turn originates from an internal/non-deliverable source, do not
+  // replace an established external destination with internal routing ids
+  // (e.g., session/webchat ids).
+  if (!isExternalRoutingChannel(originatingChannel)) {
+    const hasExternalFallback =
+      isExternalRoutingChannel(persistedChannel) || isExternalRoutingChannel(sessionKeyChannelHint);
+    if (hasExternalFallback && params.persistedLastTo) {
+      return params.persistedLastTo;
+    }
+  }
+
+  return params.originatingToRaw || params.toRaw || params.persistedLastTo;
+}
+
+export function maybeRetireLegacyMainDeliveryRoute(params: {
+  sessionCfg: { dmScope?: string } | undefined;
+  sessionKey: string;
+  sessionStore: Record<string, SessionEntry>;
+  agentId: string;
+  mainKey: string;
+  isGroup: boolean;
+  ctx: MsgContext;
+}): LegacyMainDeliveryRetirement | undefined {
+  const dmScope = params.sessionCfg?.dmScope ?? "main";
+  if (dmScope === "main" || params.isGroup) {
+    return undefined;
+  }
+  const canonicalMainSessionKey = buildAgentMainSessionKey({
+    agentId: params.agentId,
+    mainKey: params.mainKey,
+  }).toLowerCase();
+  if (params.sessionKey === canonicalMainSessionKey) {
+    return undefined;
+  }
+  const legacyMain = params.sessionStore[canonicalMainSessionKey];
+  if (!legacyMain) {
+    return undefined;
+  }
+  const legacyRouteKey = deliveryContextKey(deliveryContextFromSession(legacyMain));
+  if (!legacyRouteKey) {
+    return undefined;
+  }
+  const activeDirectRouteKey = deliveryContextKey(
+    normalizeDeliveryContext({
+      channel: params.ctx.OriginatingChannel as string | undefined,
+      to: params.ctx.OriginatingTo || params.ctx.To,
+      accountId: params.ctx.AccountId,
+      threadId: params.ctx.MessageThreadId,
+    }),
+  );
+  if (!activeDirectRouteKey || activeDirectRouteKey !== legacyRouteKey) {
+    return undefined;
+  }
+  if (
+    legacyMain.deliveryContext === undefined &&
+    legacyMain.lastChannel === undefined &&
+    legacyMain.lastTo === undefined &&
+    legacyMain.lastAccountId === undefined &&
+    legacyMain.lastThreadId === undefined
+  ) {
+    return undefined;
+  }
+  return {
+    key: canonicalMainSessionKey,
+    entry: {
+      ...legacyMain,
+      deliveryContext: undefined,
+      lastChannel: undefined,
+      lastTo: undefined,
+      lastAccountId: undefined,
+      lastThreadId: undefined,
+    },
+  };
+}
diff --git a/src/auto-reply/reply/session-fork.ts b/src/auto-reply/reply/session-fork.ts
new file mode 100644
index 00000000000..84c5eb0079d
--- /dev/null
+++ b/src/auto-reply/reply/session-fork.ts
@@ -0,0 +1,63 @@
+import crypto from "node:crypto";
+import fs from "node:fs";
+import path from "node:path";
+import { CURRENT_SESSION_VERSION, SessionManager } from "@mariozechner/pi-coding-agent";
+import type { OpenClawConfig } from "../../config/config.js";
+import { resolveSessionFilePath, type SessionEntry } from "../../config/sessions.js";
+
+/**
+ * Default max parent token count beyond which thread/session parent forking is skipped.
+ * This prevents new thread sessions from inheriting near-full parent context.
+ * See #26905.
+ */
+const DEFAULT_PARENT_FORK_MAX_TOKENS = 100_000;
+
+export function resolveParentForkMaxTokens(cfg: OpenClawConfig): number {
+  const configured = cfg.session?.parentForkMaxTokens;
+  if (typeof configured === "number" && Number.isFinite(configured) && configured >= 0) {
+    return Math.floor(configured);
+  }
+  return DEFAULT_PARENT_FORK_MAX_TOKENS;
+}
+
+export function forkSessionFromParent(params: {
+  parentEntry: SessionEntry;
+  agentId: string;
+  sessionsDir: string;
+}): { sessionId: string; sessionFile: string } | null {
+  const parentSessionFile = resolveSessionFilePath(
+    params.parentEntry.sessionId,
+    params.parentEntry,
+    { agentId: params.agentId, sessionsDir: params.sessionsDir },
+  );
+  if (!parentSessionFile || !fs.existsSync(parentSessionFile)) {
+    return null;
+  }
+  try {
+    const manager = SessionManager.open(parentSessionFile);
+    const leafId = manager.getLeafId();
+    if (leafId) {
+      const sessionFile = manager.createBranchedSession(leafId) ?? manager.getSessionFile();
+      const sessionId = manager.getSessionId();
+      if (sessionFile && sessionId) {
+        return { sessionId, sessionFile };
+      }
+    }
+    const sessionId = crypto.randomUUID();
+    const timestamp = new Date().toISOString();
+    const fileTimestamp = timestamp.replace(/[:.]/g, "-");
+    const sessionFile = path.join(manager.getSessionDir(), `${fileTimestamp}_${sessionId}.jsonl`);
+    const header = {
+      type: "session",
+      version: CURRENT_SESSION_VERSION,
+      id: sessionId,
+      timestamp,
+      cwd: manager.getCwd(),
+      parentSession: parentSessionFile,
+    };
+    fs.writeFileSync(sessionFile, `${JSON.stringify(header)}\n`, "utf-8");
+    return { sessionId, sessionFile };
+  } catch {
+    return null;
+  }
+}
diff --git a/src/auto-reply/reply/session-hooks.ts b/src/auto-reply/reply/session-hooks.ts
new file mode 100644
index 00000000000..8e22dc247bc
--- /dev/null
+++ b/src/auto-reply/reply/session-hooks.ts
@@ -0,0 +1,66 @@
+import { resolveSessionAgentId } from "../../agents/agent-scope.js";
+import type { OpenClawConfig } from "../../config/config.js";
+
+export type SessionHookContext = {
+  sessionId: string;
+  sessionKey: string;
+  agentId: string;
+};
+
+function buildSessionHookContext(params: {
+  sessionId: string;
+  sessionKey: string;
+  cfg: OpenClawConfig;
+}): SessionHookContext {
+  return {
+    sessionId: params.sessionId,
+    sessionKey: params.sessionKey,
+    agentId: resolveSessionAgentId({ sessionKey: params.sessionKey, config: params.cfg }),
+  };
+}
+
+export function buildSessionStartHookPayload(params: {
+  sessionId: string;
+  sessionKey: string;
+  cfg: OpenClawConfig;
+  resumedFrom?: string;
+}): {
+  event: { sessionId: string; sessionKey: string; resumedFrom?: string };
+  context: SessionHookContext;
+} {
+  return {
+    event: {
+      sessionId: params.sessionId,
+      sessionKey: params.sessionKey,
+      resumedFrom: params.resumedFrom,
+    },
+    context: buildSessionHookContext({
+      sessionId: params.sessionId,
+      sessionKey: params.sessionKey,
+      cfg: params.cfg,
+    }),
+  };
+}
+
+export function buildSessionEndHookPayload(params: {
+  sessionId: string;
+  sessionKey: string;
+  cfg: OpenClawConfig;
+  messageCount?: number;
+}): {
+  event: { sessionId: string; sessionKey: string; messageCount: number };
+  context: SessionHookContext;
+} {
+  return {
+    event: {
+      sessionId: params.sessionId,
+      sessionKey: params.sessionKey,
+      messageCount: params.messageCount ?? 0,
+    },
+    context: buildSessionHookContext({
+      sessionId: params.sessionId,
+      sessionKey: params.sessionKey,
+      cfg: params.cfg,
+    }),
+  };
+}
diff --git a/src/auto-reply/reply/session.ts b/src/auto-reply/reply/session.ts
index 0af56ec6118..4cb4b986e72 100644
--- a/src/auto-reply/reply/session.ts
+++ b/src/auto-reply/reply/session.ts
@@ -1,7 +1,5 @@
 import crypto from "node:crypto";
-import fs from "node:fs";
 import path from "node:path";
-import { CURRENT_SESSION_VERSION, SessionManager } from "@mariozechner/pi-coding-agent";
 import { resolveSessionAgentId } from "../../agents/agent-scope.js";
 import { normalizeChatType } from "../../channels/chat-type.js";
 import type { OpenClawConfig } from "../../config/config.js";
@@ -17,7 +15,6 @@ import {
   resolveSessionResetPolicy,
   resolveSessionResetType,
   resolveGroupSessionKey,
-  resolveSessionFilePath,
   resolveSessionKey,
   resolveSessionTranscriptPath,
   resolveStorePath,
@@ -30,91 +27,22 @@ import { archiveSessionTranscripts } from "../../gateway/session-utils.fs.js";
 import { deliverSessionMaintenanceWarning } from "../../infra/session-maintenance-warning.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
 import { getGlobalHookRunner } from "../../plugins/hook-runner-global.js";
-import { buildAgentMainSessionKey, normalizeMainKey } from "../../routing/session-key.js";
-import { parseAgentSessionKey } from "../../sessions/session-key-utils.js";
-import {
-  deliveryContextFromSession,
-  deliveryContextKey,
-  normalizeDeliveryContext,
-  normalizeSessionDeliveryFields,
-} from "../../utils/delivery-context.js";
-import {
-  INTERNAL_MESSAGE_CHANNEL,
-  isDeliverableMessageChannel,
-  normalizeMessageChannel,
-} from "../../utils/message-channel.js";
+import { normalizeMainKey } from "../../routing/session-key.js";
+import { normalizeSessionDeliveryFields } from "../../utils/delivery-context.js";
 import { resolveCommandAuthorization } from "../command-auth.js";
-import type { MsgContext, TemplateContext } from "../templating.js";
+import type { TemplateContext } from "../templating.js";
 import { normalizeInboundTextNewlines } from "./inbound-text.js";
 import { stripMentions, stripStructuralPrefixes } from "./mentions.js";
+import {
+  maybeRetireLegacyMainDeliveryRoute,
+  resolveLastChannelRaw,
+  resolveLastToRaw,
+} from "./session-delivery.js";
+import { forkSessionFromParent, resolveParentForkMaxTokens } from "./session-fork.js";
+import { buildSessionEndHookPayload, buildSessionStartHookPayload } from "./session-hooks.js";
 
 const log = createSubsystemLogger("session-init");
 
-function resolveSessionKeyChannelHint(sessionKey?: string): string | undefined {
-  const parsed = parseAgentSessionKey(sessionKey);
-  if (!parsed?.rest) {
-    return undefined;
-  }
-  const head = parsed.rest.split(":")[0]?.trim().toLowerCase();
-  if (!head || head === "main" || head === "cron" || head === "subagent" || head === "acp") {
-    return undefined;
-  }
-  return normalizeMessageChannel(head);
-}
-
-function isExternalRoutingChannel(channel?: string): channel is string {
-  return Boolean(
-    channel && channel !== INTERNAL_MESSAGE_CHANNEL && isDeliverableMessageChannel(channel),
-  );
-}
-
-function resolveLastChannelRaw(params: {
-  originatingChannelRaw?: string;
-  persistedLastChannel?: string;
-  sessionKey?: string;
-}): string | undefined {
-  const originatingChannel = normalizeMessageChannel(params.originatingChannelRaw);
-  const persistedChannel = normalizeMessageChannel(params.persistedLastChannel);
-  const sessionKeyChannelHint = resolveSessionKeyChannelHint(params.sessionKey);
-  let resolved = params.originatingChannelRaw || params.persistedLastChannel;
-  // Internal/non-deliverable sources should not overwrite previously known
-  // external delivery routes (or explicit channel hints from the session key).
-  if (!isExternalRoutingChannel(originatingChannel)) {
-    if (isExternalRoutingChannel(persistedChannel)) {
-      resolved = persistedChannel;
-    } else if (isExternalRoutingChannel(sessionKeyChannelHint)) {
-      resolved = sessionKeyChannelHint;
-    }
-  }
-  return resolved;
-}
-
-function resolveLastToRaw(params: {
-  originatingChannelRaw?: string;
-  originatingToRaw?: string;
-  toRaw?: string;
-  persistedLastTo?: string;
-  persistedLastChannel?: string;
-  sessionKey?: string;
-}): string | undefined {
-  const originatingChannel = normalizeMessageChannel(params.originatingChannelRaw);
-  const persistedChannel = normalizeMessageChannel(params.persistedLastChannel);
-  const sessionKeyChannelHint = resolveSessionKeyChannelHint(params.sessionKey);
-
-  // When the turn originates from an internal/non-deliverable source, do not
-  // replace an established external destination with internal routing ids
-  // (e.g., session/webchat ids).
-  if (!isExternalRoutingChannel(originatingChannel)) {
-    const hasExternalFallback =
-      isExternalRoutingChannel(persistedChannel) || isExternalRoutingChannel(sessionKeyChannelHint);
-    if (hasExternalFallback && params.persistedLastTo) {
-      return params.persistedLastTo;
-    }
-  }
-
-  return params.originatingToRaw || params.toRaw || params.persistedLastTo;
-}
-
 export type SessionInitResult = {
   sessionCtx: TemplateContext;
   sessionEntry: SessionEntry;
@@ -134,193 +62,6 @@ export type SessionInitResult = {
   triggerBodyNormalized: string;
 };
 
-/**
- * Default max parent token count beyond which thread/session parent forking is skipped.
- * This prevents new thread sessions from inheriting near-full parent context.
- * See #26905.
- */
-const DEFAULT_PARENT_FORK_MAX_TOKENS = 100_000;
-
-type LegacyMainDeliveryRetirement = {
-  key: string;
-  entry: SessionEntry;
-};
-
-type SessionHookContext = {
-  sessionId: string;
-  sessionKey: string;
-  agentId: string;
-};
-
-function buildSessionHookContext(params: {
-  sessionId: string;
-  sessionKey: string;
-  cfg: OpenClawConfig;
-}): SessionHookContext {
-  return {
-    sessionId: params.sessionId,
-    sessionKey: params.sessionKey,
-    agentId: resolveSessionAgentId({ sessionKey: params.sessionKey, config: params.cfg }),
-  };
-}
-
-function buildSessionStartHookPayload(params: {
-  sessionId: string;
-  sessionKey: string;
-  cfg: OpenClawConfig;
-  resumedFrom?: string;
-}): {
-  event: { sessionId: string; sessionKey: string; resumedFrom?: string };
-  context: SessionHookContext;
-} {
-  return {
-    event: {
-      sessionId: params.sessionId,
-      sessionKey: params.sessionKey,
-      resumedFrom: params.resumedFrom,
-    },
-    context: buildSessionHookContext({
-      sessionId: params.sessionId,
-      sessionKey: params.sessionKey,
-      cfg: params.cfg,
-    }),
-  };
-}
-
-function buildSessionEndHookPayload(params: {
-  sessionId: string;
-  sessionKey: string;
-  cfg: OpenClawConfig;
-  messageCount?: number;
-}): {
-  event: { sessionId: string; sessionKey: string; messageCount: number };
-  context: SessionHookContext;
-} {
-  return {
-    event: {
-      sessionId: params.sessionId,
-      sessionKey: params.sessionKey,
-      messageCount: params.messageCount ?? 0,
-    },
-    context: buildSessionHookContext({
-      sessionId: params.sessionId,
-      sessionKey: params.sessionKey,
-      cfg: params.cfg,
-    }),
-  };
-}
-
-function resolveParentForkMaxTokens(cfg: OpenClawConfig): number {
-  const configured = cfg.session?.parentForkMaxTokens;
-  if (typeof configured === "number" && Number.isFinite(configured) && configured >= 0) {
-    return Math.floor(configured);
-  }
-  return DEFAULT_PARENT_FORK_MAX_TOKENS;
-}
-
-function maybeRetireLegacyMainDeliveryRoute(params: {
-  sessionCfg: OpenClawConfig["session"] | undefined;
-  sessionKey: string;
-  sessionStore: Record<string, SessionEntry>;
-  agentId: string;
-  mainKey: string;
-  isGroup: boolean;
-  ctx: MsgContext;
-}): LegacyMainDeliveryRetirement | undefined {
-  const dmScope = params.sessionCfg?.dmScope ?? "main";
-  if (dmScope === "main" || params.isGroup) {
-    return undefined;
-  }
-  const canonicalMainSessionKey = buildAgentMainSessionKey({
-    agentId: params.agentId,
-    mainKey: params.mainKey,
-  }).toLowerCase();
-  if (params.sessionKey === canonicalMainSessionKey) {
-    return undefined;
-  }
-  const legacyMain = params.sessionStore[canonicalMainSessionKey];
-  if (!legacyMain) {
-    return undefined;
-  }
-  const legacyRouteKey = deliveryContextKey(deliveryContextFromSession(legacyMain));
-  if (!legacyRouteKey) {
-    return undefined;
-  }
-  const activeDirectRouteKey = deliveryContextKey(
-    normalizeDeliveryContext({
-      channel: params.ctx.OriginatingChannel as string | undefined,
-      to: params.ctx.OriginatingTo || params.ctx.To,
-      accountId: params.ctx.AccountId,
-      threadId: params.ctx.MessageThreadId,
-    }),
-  );
-  if (!activeDirectRouteKey || activeDirectRouteKey !== legacyRouteKey) {
-    return undefined;
-  }
-  if (
-    legacyMain.deliveryContext === undefined &&
-    legacyMain.lastChannel === undefined &&
-    legacyMain.lastTo === undefined &&
-    legacyMain.lastAccountId === undefined &&
-    legacyMain.lastThreadId === undefined
-  ) {
-    return undefined;
-  }
-  return {
-    key: canonicalMainSessionKey,
-    entry: {
-      ...legacyMain,
-      deliveryContext: undefined,
-      lastChannel: undefined,
-      lastTo: undefined,
-      lastAccountId: undefined,
-      lastThreadId: undefined,
-    },
-  };
-}
-
-function forkSessionFromParent(params: {
-  parentEntry: SessionEntry;
-  agentId: string;
-  sessionsDir: string;
-}): { sessionId: string; sessionFile: string } | null {
-  const parentSessionFile = resolveSessionFilePath(
-    params.parentEntry.sessionId,
-    params.parentEntry,
-    { agentId: params.agentId, sessionsDir: params.sessionsDir },
-  );
-  if (!parentSessionFile || !fs.existsSync(parentSessionFile)) {
-    return null;
-  }
-  try {
-    const manager = SessionManager.open(parentSessionFile);
-    const leafId = manager.getLeafId();
-    if (leafId) {
-      const sessionFile = manager.createBranchedSession(leafId) ?? manager.getSessionFile();
-      const sessionId = manager.getSessionId();
-      if (sessionFile && sessionId) {
-        return { sessionId, sessionFile };
-      }
-    }
-    const sessionId = crypto.randomUUID();
-    const timestamp = new Date().toISOString();
-    const fileTimestamp = timestamp.replace(/[:.]/g, "-");
-    const sessionFile = path.join(manager.getSessionDir(), `${fileTimestamp}_${sessionId}.jsonl`);
-    const header = {
-      type: "session",
-      version: CURRENT_SESSION_VERSION,
-      id: sessionId,
-      timestamp,
-      cwd: manager.getCwd(),
-      parentSession: parentSessionFile,
-    };
-    fs.writeFileSync(sessionFile, `${JSON.stringify(header)}\n`, "utf-8");
-    return { sessionId, sessionFile };
-  } catch {
-    return null;
-  }
-}
-
 export async function initSessionState(params: {
   ctx: MsgContext;
   cfg: OpenClawConfig;