diff --git a/extensions/discord/contract-api.ts b/extensions/discord/contract-api.ts
index 8659ae168fd..ddaace1ca57 100644
--- a/extensions/discord/contract-api.ts
+++ b/extensions/discord/contract-api.ts
@@ -13,7 +13,6 @@ export {
   unsupportedSecretRefSurfacePatterns,
   collectUnsupportedSecretRefConfigCandidates,
 } from "./src/security-contract.js";
-export { deriveLegacySessionChatType } from "./src/session-contract.js";
 export type {
   DiscordInteractiveHandlerContext,
   DiscordInteractiveHandlerRegistration,
diff --git a/extensions/discord/src/session-contract.ts b/extensions/discord/src/session-contract.ts
deleted file mode 100644
index 00b66226902..00000000000
--- a/extensions/discord/src/session-contract.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export function deriveLegacySessionChatType(sessionKey: string): "channel" | undefined {
-  return /^discord:(?:[^:]+:)?guild-[^:]+:channel-[^:]+$/.test(sessionKey) ? "channel" : undefined;
-}
diff --git a/extensions/discord/src/shared.ts b/extensions/discord/src/shared.ts
index acdb136137f..2f7860dae5d 100644
--- a/extensions/discord/src/shared.ts
+++ b/extensions/discord/src/shared.ts
@@ -29,7 +29,6 @@ import {
   unsupportedSecretRefSurfacePatterns,
 } from "./security-contract.js";
 import { discordSecurityAdapter } from "./security.js";
-import { deriveLegacySessionChatType } from "./session-contract.js";
 
 const DISCORD_CHANNEL = "discord" as const;
 
@@ -160,9 +159,6 @@ export function createDiscordPluginBase(params: {
           },
         }),
     },
-    messaging: {
-      deriveLegacySessionChatType,
-    },
     security: discordSecurityAdapter,
     secrets: {
       secretTargetRegistryEntries,
diff --git a/extensions/whatsapp/contract-api.ts b/extensions/whatsapp/contract-api.ts
index 7ba0e12d044..66859646afe 100644
--- a/extensions/whatsapp/contract-api.ts
+++ b/extensions/whatsapp/contract-api.ts
@@ -1,5 +1,5 @@
 import { whatsappCommandPolicy as whatsappCommandPolicyImpl } from "./src/command-policy.js";
-import { resolveLegacyGroupSessionKey as resolveLegacyGroupSessionKeyImpl } from "./src/group-session-contract.js";
+import { resolveGroupSessionKey as resolveGroupSessionKeyImpl } from "./src/group-session-contract.js";
 import { __testing as whatsappAccessControlTestingImpl } from "./src/inbound/access-control.js";
 import {
   isWhatsAppGroupJid as isWhatsAppGroupJidImpl,
@@ -10,20 +10,14 @@ export {
   listWhatsAppDirectoryPeersFromConfig,
 } from "./src/directory-config.js";
 import { resolveWhatsAppRuntimeGroupPolicy as resolveWhatsAppRuntimeGroupPolicyImpl } from "./src/runtime-group-policy.js";
-import {
-  canonicalizeLegacySessionKey as canonicalizeLegacySessionKeyImpl,
-  isLegacyGroupSessionKey as isLegacyGroupSessionKeyImpl,
-} from "./src/session-contract.js";
 export {
   collectUnsupportedSecretRefConfigCandidates,
   unsupportedSecretRefSurfacePatterns,
 } from "./src/security-contract.js";
 
-export const canonicalizeLegacySessionKey = canonicalizeLegacySessionKeyImpl;
-export const isLegacyGroupSessionKey = isLegacyGroupSessionKeyImpl;
 export const isWhatsAppGroupJid = isWhatsAppGroupJidImpl;
 export const normalizeWhatsAppTarget = normalizeWhatsAppTargetImpl;
-export const resolveLegacyGroupSessionKey = resolveLegacyGroupSessionKeyImpl;
+export const resolveGroupSessionKey = resolveGroupSessionKeyImpl;
 export const resolveWhatsAppRuntimeGroupPolicy = resolveWhatsAppRuntimeGroupPolicyImpl;
 export const whatsappAccessControlTesting = whatsappAccessControlTestingImpl;
 export const whatsappCommandPolicy = whatsappCommandPolicyImpl;
diff --git a/extensions/whatsapp/src/group-session-contract.ts b/extensions/whatsapp/src/group-session-contract.ts
index 00c9cf5f5f0..d24a3e4fab0 100644
--- a/extensions/whatsapp/src/group-session-contract.ts
+++ b/extensions/whatsapp/src/group-session-contract.ts
@@ -1,6 +1,6 @@
 import { normalizeLowercaseStringOrEmpty } from "openclaw/plugin-sdk/string-coerce-runtime";
 
-export function resolveLegacyGroupSessionKey(ctx: { From?: string }): {
+export function resolveGroupSessionKey(ctx: { From?: string }): {
   key: string;
   channel: string;
   id: string;
diff --git a/extensions/whatsapp/src/session-contract.test.ts b/extensions/whatsapp/src/session-contract.test.ts
index 03fe2be8675..f600a7c18cb 100644
--- a/extensions/whatsapp/src/session-contract.test.ts
+++ b/extensions/whatsapp/src/session-contract.test.ts
@@ -1,9 +1,5 @@
 import { describe, expect, it } from "vitest";
-import {
-  canonicalizeLegacySessionKey,
-  deriveLegacySessionChatType,
-  isLegacyGroupSessionKey,
-} from "./session-contract.js";
+import { canonicalizeLegacySessionKey, isLegacyGroupSessionKey } from "./session-contract.js";
 
 describe("whatsapp legacy session contract", () => {
   it("canonicalizes legacy WhatsApp group keys to channel-qualified agent keys", () => {
@@ -20,12 +16,11 @@ describe("whatsapp legacy session contract", () => {
 
   it("does not claim generic non-WhatsApp group keys", () => {
     expect(isLegacyGroupSessionKey("group:abc")).toBe(false);
-    expect(deriveLegacySessionChatType("group:abc")).toBeUndefined();
     expect(canonicalizeLegacySessionKey({ key: "group:abc", agentId: "main" })).toBeNull();
   });
 
-  it("derives chat type for legacy WhatsApp group keys", () => {
-    expect(deriveLegacySessionChatType("123@g.us")).toBe("group");
-    expect(deriveLegacySessionChatType("whatsapp:123@g.us")).toBe("group");
+  it("identifies legacy WhatsApp group keys for doctor migration", () => {
+    expect(isLegacyGroupSessionKey("123@g.us")).toBe(true);
+    expect(isLegacyGroupSessionKey("whatsapp:123@g.us")).toBe(true);
   });
 });
diff --git a/extensions/whatsapp/src/session-contract.ts b/extensions/whatsapp/src/session-contract.ts
index e5c3d4fc751..5e7f456f33f 100644
--- a/extensions/whatsapp/src/session-contract.ts
+++ b/extensions/whatsapp/src/session-contract.ts
@@ -28,10 +28,6 @@ export function isLegacyGroupSessionKey(key: string): boolean {
   return extractLegacyWhatsAppGroupId(key) !== null;
 }
 
-export function deriveLegacySessionChatType(key: string): "group" | undefined {
-  return isLegacyGroupSessionKey(key) ? "group" : undefined;
-}
-
 export function canonicalizeLegacySessionKey(params: {
   key: string;
   agentId: string;
diff --git a/extensions/whatsapp/src/shared.ts b/extensions/whatsapp/src/shared.ts
index b3ff58ddbc1..556423b9e1d 100644
--- a/extensions/whatsapp/src/shared.ts
+++ b/extensions/whatsapp/src/shared.ts
@@ -26,17 +26,12 @@ import {
 import { formatWhatsAppConfigAllowFromEntries } from "./config-accessors.js";
 import { WhatsAppChannelConfigSchema } from "./config-schema.js";
 import { whatsappDoctor } from "./doctor.js";
-import { resolveLegacyGroupSessionKey } from "./group-session-contract.js";
+import { resolveGroupSessionKey } from "./group-session-contract.js";
 import {
   collectUnsupportedSecretRefConfigCandidates,
   unsupportedSecretRefSurfacePatterns,
 } from "./security-contract.js";
 import { applyWhatsAppSecurityConfigFixes } from "./security-fix.js";
-import {
-  canonicalizeLegacySessionKey,
-  deriveLegacySessionChatType,
-  isLegacyGroupSessionKey,
-} from "./session-contract.js";
 
 const WHATSAPP_CHANNEL = "whatsapp" as const;
 
@@ -259,11 +254,7 @@ export function createWhatsAppPluginBase(params: {
     config: base.config!,
     messaging: {
       defaultMarkdownTableMode: "bullets",
-      deriveLegacySessionChatType,
-      resolveLegacyGroupSessionKey,
-      isLegacyGroupSessionKey,
-      canonicalizeLegacySessionKey: (params) =>
-        canonicalizeLegacySessionKey({ key: params.key, agentId: params.agentId }),
+      resolveGroupSessionKey,
     },
     secrets: {
       unsupportedSecretRefSurfacePatterns,
diff --git a/src/channels/plugins/bundled.ts b/src/channels/plugins/bundled.ts
index 4d7f3a10447..8fa8e613524 100644
--- a/src/channels/plugins/bundled.ts
+++ b/src/channels/plugins/bundled.ts
@@ -729,11 +729,7 @@ export function listBundledChannelLegacySessionSurfaces(
     if (surface) {
       return [surface];
     }
-    if (!hasSetupEntryFeature(setupEntry, "legacySessionSurfaces")) {
-      return [];
-    }
-    const plugin = getBundledChannelSetupPluginForRoot(id, rootScope, loadContext);
-    return plugin?.messaging ? [plugin.messaging] : [];
+    return [];
   });
 }
 
diff --git a/src/channels/plugins/types.core.ts b/src/channels/plugins/types.core.ts
index 30631d2729d..b5851f22c96 100644
--- a/src/channels/plugins/types.core.ts
+++ b/src/channels/plugins/types.core.ts
@@ -515,13 +515,7 @@ export type ChannelMessagingAdapter = {
     sessionKey: string;
     ctx: MsgContext;
   }) => string | undefined;
-  deriveLegacySessionChatType?: (sessionKey: string) => "direct" | "group" | "channel" | undefined;
-  isLegacyGroupSessionKey?: (key: string) => boolean;
-  canonicalizeLegacySessionKey?: (params: {
-    key: string;
-    agentId: string;
-  }) => string | null | undefined;
-  resolveLegacyGroupSessionKey?: (ctx: MsgContext) => {
+  resolveGroupSessionKey?: (ctx: MsgContext) => {
     key: string;
     channel: string;
     id: string;
diff --git a/src/config/sessions/group.ts b/src/config/sessions/group.ts
index d8d52c0fd86..b3091e96f32 100644
--- a/src/config/sessions/group.ts
+++ b/src/config/sessions/group.ts
@@ -11,15 +11,15 @@ import type { GroupKeyResolution } from "./types.js";
 
 const getGroupSurfaces = () => new Set<string>([...listDeliverableMessageChannels(), "webchat"]);
 
-type LegacyGroupSessionSurface = {
-  resolveLegacyGroupSessionKey?: (ctx: MsgContext) => GroupKeyResolution | null;
+type GroupSessionSurface = {
+  resolveGroupSessionKey?: (ctx: MsgContext) => GroupKeyResolution | null;
 };
 
-function resolveLegacyGroupSessionKey(ctx: MsgContext): GroupKeyResolution | null {
+function resolvePluginGroupSessionKey(ctx: MsgContext): GroupKeyResolution | null {
   for (const plugin of listChannelPlugins()) {
     const resolved = (
-      plugin.messaging as LegacyGroupSessionSurface | undefined
-    )?.resolveLegacyGroupSessionKey?.(ctx);
+      plugin.messaging as GroupSessionSurface | undefined
+    )?.resolveGroupSessionKey?.(ctx);
     if (resolved) {
       return resolved;
     }
@@ -107,13 +107,13 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
   const normalizedChatType =
     chatType === "channel" ? "channel" : chatType === "group" ? "group" : undefined;
 
-  const legacyResolution = resolveLegacyGroupSessionKey(ctx);
+  const pluginResolution = resolvePluginGroupSessionKey(ctx);
   const looksLikeGroup =
     normalizedChatType === "group" ||
     normalizedChatType === "channel" ||
     from.includes(":group:") ||
     from.includes(":channel:") ||
-    legacyResolution !== null;
+    pluginResolution !== null;
   if (!looksLikeGroup) {
     return null;
   }
@@ -124,11 +124,11 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
   const head = normalizeLowercaseStringOrEmpty(parts[0]);
   const headIsSurface = head ? getGroupSurfaces().has(head) : false;
 
-  if (!headIsSurface && !providerHint && legacyResolution) {
-    return legacyResolution;
+  if (!headIsSurface && !providerHint && pluginResolution) {
+    return pluginResolution;
   }
 
-  const provider = headIsSurface ? head : (providerHint ?? legacyResolution?.channel);
+  const provider = headIsSurface ? head : (providerHint ?? pluginResolution?.channel);
   if (!provider) {
     return null;
   }
diff --git a/src/sessions/session-chat-type-shared.ts b/src/sessions/session-chat-type-shared.ts
index 8c232f1f516..81e20725373 100644
--- a/src/sessions/session-chat-type-shared.ts
+++ b/src/sessions/session-chat-type-shared.ts
@@ -3,21 +3,7 @@ import { parseAgentSessionKey } from "./session-key-utils.js";
 
 export type SessionKeyChatType = "direct" | "group" | "channel" | "unknown";
 
-function deriveBuiltInLegacySessionChatType(
-  scopedSessionKey: string,
-): SessionKeyChatType | undefined {
-  if (/^group:[^:]+$/.test(scopedSessionKey)) {
-    return "group";
-  }
-  return undefined;
-}
-
-export function deriveSessionChatTypeFromScopedKey(
-  scopedSessionKey: string,
-  deriveLegacySessionChatTypes: Array<
-    (scopedSessionKey: string) => SessionKeyChatType | undefined
-  > = [],
-): SessionKeyChatType {
+export function deriveSessionChatTypeFromScopedKey(scopedSessionKey: string): SessionKeyChatType {
   const tokens = new Set(scopedSessionKey.split(":").filter(Boolean));
   if (tokens.has("group")) {
     return "group";
@@ -28,32 +14,17 @@ export function deriveSessionChatTypeFromScopedKey(
   if (tokens.has("direct") || tokens.has("dm")) {
     return "direct";
   }
-  const builtInLegacy = deriveBuiltInLegacySessionChatType(scopedSessionKey);
-  if (builtInLegacy) {
-    return builtInLegacy;
-  }
-  for (const deriveLegacySessionChatType of deriveLegacySessionChatTypes) {
-    const derived = deriveLegacySessionChatType(scopedSessionKey);
-    if (derived) {
-      return derived;
-    }
-  }
   return "unknown";
 }
 
-/**
- * Best-effort chat-type extraction from session keys across canonical and legacy formats.
- */
+/** Best-effort chat-type extraction from canonical session keys. */
 export function deriveSessionChatTypeFromKey(
   sessionKey: string | undefined | null,
-  deriveLegacySessionChatTypes: Array<
-    (scopedSessionKey: string) => SessionKeyChatType | undefined
-  > = [],
 ): SessionKeyChatType {
   const raw = normalizeLowercaseStringOrEmpty(sessionKey);
   if (!raw) {
     return "unknown";
   }
   const scoped = parseAgentSessionKey(raw)?.rest ?? raw;
-  return deriveSessionChatTypeFromScopedKey(scoped, deriveLegacySessionChatTypes);
+  return deriveSessionChatTypeFromScopedKey(scoped);
 }
diff --git a/src/sessions/session-chat-type.ts b/src/sessions/session-chat-type.ts
index a90ed8ab01d..2cd987cbcfa 100644
--- a/src/sessions/session-chat-type.ts
+++ b/src/sessions/session-chat-type.ts
@@ -1,65 +1,13 @@
-import { getBootstrapChannelPlugin } from "../channels/plugins/bootstrap-registry.js";
-import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
 import {
   deriveSessionChatTypeFromKey,
   type SessionKeyChatType,
 } from "./session-chat-type-shared.js";
-import { parseAgentSessionKey } from "./session-key-utils.js";
 
 export {
   deriveSessionChatTypeFromKey,
   type SessionKeyChatType,
 } from "./session-chat-type-shared.js";
 
-type LegacySessionChatTypeDeriver = NonNullable<
-  NonNullable<ReturnType<typeof getBootstrapChannelPlugin>>["messaging"]
->["deriveLegacySessionChatType"];
-
-function resolveScopedSessionKey(sessionKey: string | undefined | null): string {
-  const raw = normalizeLowercaseStringOrEmpty(sessionKey);
-  if (!raw) {
-    return "";
-  }
-  return parseAgentSessionKey(raw)?.rest ?? raw;
-}
-
-function collectLegacyChatTypeCandidatePluginIds(scopedSessionKey: string): string[] {
-  const ids = new Set<string>();
-  const firstToken = scopedSessionKey.split(":").find(Boolean);
-  if (firstToken) {
-    ids.add(firstToken);
-  }
-  if (scopedSessionKey.includes("@g.us")) {
-    ids.add("whatsapp");
-  }
-  return Array.from(ids);
-}
-
-function derivePluginLegacySessionChatType(
-  scopedSessionKey: string,
-  deriveLegacySessionChatType: LegacySessionChatTypeDeriver,
-): SessionKeyChatType | undefined {
-  if (!deriveLegacySessionChatType) {
-    return undefined;
-  }
-  return deriveLegacySessionChatType(scopedSessionKey);
-}
-
 export function deriveSessionChatType(sessionKey: string | undefined | null): SessionKeyChatType {
-  const builtInType = deriveSessionChatTypeFromKey(sessionKey);
-  if (builtInType !== "unknown") {
-    return builtInType;
-  }
-
-  const scopedSessionKey = resolveScopedSessionKey(sessionKey);
-  for (const pluginId of collectLegacyChatTypeCandidatePluginIds(scopedSessionKey)) {
-    const derived = derivePluginLegacySessionChatType(
-      scopedSessionKey,
-      getBootstrapChannelPlugin(pluginId)?.messaging?.deriveLegacySessionChatType,
-    );
-    if (derived) {
-      return derived;
-    }
-  }
-  return "unknown";
+  return deriveSessionChatTypeFromKey(sessionKey);
 }