diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6acb2fd82fb..b03cd7108e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ Docs: https://docs.openclaw.ai
 
 ### Changes
 
+- Sessions/named DM: add `buildNamedDmSessionKey`, `parseNamedDmSessionKey`, and `isNamedDmSessionKey` key-format helpers, an `activeNamedSession` field on `SessionEntry`, and `setActiveNamedSession`/`getActiveNamedSessionKey` store helpers as infrastructure for named DM session switching.
+
 - Android/mobile: add a system-aware dark theme across onboarding and post-onboarding screens so the app follows the device theme through setup, chat, and voice flows. (#46249) Thanks @sibbl.
 - Commands/btw: add `/btw` side questions for quick tool-less answers about the current session without changing future session context, with dismissible in-session TUI answers and explicit BTW replies on external channels. (#45444) Thanks @ngutman.
 - Gateway/health monitor: add configurable stale-event thresholds and restart limits, plus per-channel and per-account `healthMonitor.enabled` overrides, while keeping the existing global disable path on `gateway.channelHealthCheckMinutes=0`. (#42107) Thanks @rstar327.
diff --git a/src/config/sessions/types.ts b/src/config/sessions/types.ts
index 4ba9b336127..4efa4578156 100644
--- a/src/config/sessions/types.ts
+++ b/src/config/sessions/types.ts
@@ -76,6 +76,12 @@ export type SessionEntry = {
   sessionId: string;
   updatedAt: number;
   sessionFile?: string;
+  /**
+   * Active named session for DM routing (ETH-608).
+   * When set, DM messages from this peer route to the named session instead of main.
+   * Format: "valorant", "work", etc. (session name only, not full key).
+   */
+  activeNamedSession?: string;
   /** Parent session key that spawned this session (used for sandbox session-tool scoping). */
   spawnedBy?: string;
   /** Workspace inherited by spawned sessions and reused on later turns for the same child session. */
diff --git a/src/gateway/session-utils.ts b/src/gateway/session-utils.ts
index 00a2cb7747e..5e2a22e08f9 100644
--- a/src/gateway/session-utils.ts
+++ b/src/gateway/session-utils.ts
@@ -30,7 +30,7 @@ import {
   normalizeMainKey,
   parseAgentSessionKey,
 } from "../routing/session-key.js";
-import { isCronRunSessionKey } from "../sessions/session-key-utils.js";
+import { buildNamedDmSessionKey, isCronRunSessionKey } from "../sessions/session-key-utils.js";
 import {
   AVATAR_MAX_BYTES,
   isAvatarDataUrl,
@@ -843,6 +843,57 @@ export function resolveSessionModelIdentityRef(
   return { provider: resolved.provider, model: resolved.model };
 }
 
+/**
+ * Get the active named session key for a DM peer, if one is set.
+ * Returns the full named session key if active, or null otherwise.
+ */
+export function getActiveNamedSessionKey(params: {
+  mainEntry: SessionEntry | undefined;
+  agentId: string;
+  peerId: string;
+}): string | null {
+  if (!params.mainEntry || !params.mainEntry.activeNamedSession) {
+    return null;
+  }
+  const name = params.mainEntry.activeNamedSession.trim();
+  if (!name) {
+    return null;
+  }
+  return buildNamedDmSessionKey({
+    agentId: params.agentId,
+    peerId: params.peerId,
+    name,
+  });
+}
+
+/**
+ * Set or clear the active named session for a DM peer on the main session entry.
+ * If name is null/empty, clears the active named session (returns to main).
+ * Returns true if the update was applied.
+ */
+export function setActiveNamedSession(params: {
+  mainEntry: SessionEntry;
+  name: string | null | undefined;
+}): boolean {
+  const trimmed = params.name?.trim();
+  if (!trimmed) {
+    if (params.mainEntry.activeNamedSession !== undefined) {
+      delete params.mainEntry.activeNamedSession;
+      return true;
+    }
+    return false;
+  }
+  const normalized = trimmed.toLowerCase();
+  if (normalized.includes(":")) {
+    throw new Error(`setActiveNamedSession: name must not contain ":" (got: "${normalized}")`);
+  }
+  if (params.mainEntry.activeNamedSession !== normalized) {
+    params.mainEntry.activeNamedSession = normalized;
+    return true;
+  }
+  return false;
+}
+
 export function listSessionsFromStore(params: {
   cfg: OpenClawConfig;
   storePath: string;
diff --git a/src/sessions/session-key-utils.test.ts b/src/sessions/session-key-utils.test.ts
new file mode 100644
index 00000000000..9e55bd5312b
--- /dev/null
+++ b/src/sessions/session-key-utils.test.ts
@@ -0,0 +1,278 @@
+import { describe, expect, it } from "vitest";
+import type { SessionEntry } from "../config/sessions.js";
+import { getActiveNamedSessionKey, setActiveNamedSession } from "../gateway/session-utils.js";
+import {
+  buildNamedDmSessionKey,
+  isNamedDmSessionKey,
+  parseNamedDmSessionKey,
+} from "./session-key-utils.js";
+
+describe("Named DM Session Keys (ETH-608)", () => {
+  describe("buildNamedDmSessionKey", () => {
+    it("builds a valid named DM session key", () => {
+      const key = buildNamedDmSessionKey({
+        agentId: "main",
+        peerId: "123456789",
+        name: "valorant",
+      });
+      expect(key).toBe("agent:main:dm-named:123456789:valorant");
+    });
+
+    it("normalizes inputs to lowercase", () => {
+      const key = buildNamedDmSessionKey({
+        agentId: "MAIN",
+        peerId: "USER123",
+        name: "MySession",
+      });
+      expect(key).toBe("agent:main:dm-named:user123:mysession");
+    });
+
+    it("throws on empty agentId", () => {
+      expect(() =>
+        buildNamedDmSessionKey({
+          agentId: "",
+          peerId: "123",
+          name: "work",
+        }),
+      ).toThrow("agentId, peerId, and name are required");
+    });
+
+    it("throws on empty peerId", () => {
+      expect(() =>
+        buildNamedDmSessionKey({
+          agentId: "main",
+          peerId: "",
+          name: "work",
+        }),
+      ).toThrow("agentId, peerId, and name are required");
+    });
+
+    it("throws on empty name", () => {
+      expect(() =>
+        buildNamedDmSessionKey({
+          agentId: "main",
+          peerId: "123",
+          name: "",
+        }),
+      ).toThrow("agentId, peerId, and name are required");
+    });
+
+    it("throws when agentId contains a colon", () => {
+      expect(() =>
+        buildNamedDmSessionKey({
+          agentId: "ma:in",
+          peerId: "123",
+          name: "work",
+        }),
+      ).toThrow();
+    });
+
+    it("throws when peerId contains a colon", () => {
+      expect(() =>
+        buildNamedDmSessionKey({
+          agentId: "main",
+          peerId: "123:456",
+          name: "work",
+        }),
+      ).toThrow();
+    });
+
+    it("trims whitespace", () => {
+      const key = buildNamedDmSessionKey({
+        agentId: "  main  ",
+        peerId: "  123  ",
+        name: "  work  ",
+      });
+      expect(key).toBe("agent:main:dm-named:123:work");
+    });
+  });
+
+  describe("isNamedDmSessionKey", () => {
+    it("returns true for valid named DM session keys", () => {
+      expect(isNamedDmSessionKey("agent:main:dm-named:123456789:valorant")).toBe(true);
+      expect(isNamedDmSessionKey("agent:ops:dm-named:999:work")).toBe(true);
+    });
+
+    it("returns false for non-agent keys", () => {
+      expect(isNamedDmSessionKey("main")).toBe(false);
+      expect(isNamedDmSessionKey("discord:direct:123")).toBe(false);
+    });
+
+    it("returns false for agent keys that are not named DM keys", () => {
+      expect(isNamedDmSessionKey("agent:main:main")).toBe(false);
+      expect(isNamedDmSessionKey("agent:main:direct:123")).toBe(false);
+      expect(isNamedDmSessionKey("agent:main:group:456")).toBe(false);
+    });
+
+    it("returns false for malformed named DM keys", () => {
+      expect(isNamedDmSessionKey("agent:main:dm-named")).toBe(false);
+      expect(isNamedDmSessionKey("agent:main:dm-named:123")).toBe(false);
+      expect(isNamedDmSessionKey("agent:main:dm-named:123:work:extra")).toBe(false);
+    });
+
+    it("returns false for null/undefined/empty", () => {
+      expect(isNamedDmSessionKey(null)).toBe(false);
+      expect(isNamedDmSessionKey(undefined)).toBe(false);
+      expect(isNamedDmSessionKey("")).toBe(false);
+    });
+  });
+
+  describe("parseNamedDmSessionKey", () => {
+    it("parses valid named DM session keys", () => {
+      const result = parseNamedDmSessionKey("agent:main:dm-named:123456789:valorant");
+      expect(result).toEqual({
+        agentId: "main",
+        peerId: "123456789",
+        name: "valorant",
+      });
+    });
+
+    it("normalizes to lowercase", () => {
+      const result = parseNamedDmSessionKey("AGENT:MAIN:DM-NAMED:USER123:WORK");
+      expect(result).toEqual({
+        agentId: "main",
+        peerId: "user123",
+        name: "work",
+      });
+    });
+
+    it("returns null for non-agent keys", () => {
+      expect(parseNamedDmSessionKey("main")).toBe(null);
+      expect(parseNamedDmSessionKey("discord:direct:123")).toBe(null);
+    });
+
+    it("returns null for non-named-DM agent keys", () => {
+      expect(parseNamedDmSessionKey("agent:main:main")).toBe(null);
+      expect(parseNamedDmSessionKey("agent:main:direct:123")).toBe(null);
+    });
+
+    it("returns null for malformed named DM keys", () => {
+      expect(parseNamedDmSessionKey("agent:main:dm-named")).toBe(null);
+      expect(parseNamedDmSessionKey("agent:main:dm-named:123")).toBe(null);
+    });
+
+    it("returns null for null/undefined/empty", () => {
+      expect(parseNamedDmSessionKey(null)).toBe(null);
+      expect(parseNamedDmSessionKey(undefined)).toBe(null);
+      expect(parseNamedDmSessionKey("")).toBe(null);
+    });
+
+    it("handles multiple agents", () => {
+      const result1 = parseNamedDmSessionKey("agent:ops:dm-named:456:project-x");
+      expect(result1).toEqual({
+        agentId: "ops",
+        peerId: "456",
+        name: "project-x",
+      });
+
+      const result2 = parseNamedDmSessionKey("agent:dev:dm-named:789:testing");
+      expect(result2).toEqual({
+        agentId: "dev",
+        peerId: "789",
+        name: "testing",
+      });
+    });
+  });
+
+  describe("round-trip", () => {
+    it("build and parse round-trip correctly", () => {
+      const original = {
+        agentId: "main",
+        peerId: "123456789",
+        name: "valorant",
+      };
+
+      const key = buildNamedDmSessionKey(original);
+      const parsed = parseNamedDmSessionKey(key);
+
+      expect(parsed).toEqual(original);
+    });
+
+    it("round-trip with normalization", () => {
+      const key = buildNamedDmSessionKey({
+        agentId: "MAIN",
+        peerId: "USER123",
+        name: "MySession",
+      });
+
+      const parsed = parseNamedDmSessionKey(key);
+
+      expect(parsed).toEqual({
+        agentId: "main",
+        peerId: "user123",
+        name: "mysession",
+      });
+    });
+  });
+
+  describe("setActiveNamedSession", () => {
+    it("sets activeNamedSession on the entry and returns true", () => {
+      const entry = {} as SessionEntry;
+      const result = setActiveNamedSession({ mainEntry: entry, name: "work" });
+      expect(result).toBe(true);
+      expect(entry.activeNamedSession).toBe("work");
+    });
+
+    it("is idempotent — returns false when called twice with same name", () => {
+      const entry = {} as SessionEntry;
+      setActiveNamedSession({ mainEntry: entry, name: "work" });
+      const result = setActiveNamedSession({ mainEntry: entry, name: "work" });
+      expect(result).toBe(false);
+    });
+
+    it("clears activeNamedSession when name is null and returns true", () => {
+      const entry = { activeNamedSession: "work" } as SessionEntry;
+      const result = setActiveNamedSession({ mainEntry: entry, name: null });
+      expect(result).toBe(true);
+      expect(entry.activeNamedSession).toBeUndefined();
+    });
+
+    it("returns false when clearing an already-cleared entry", () => {
+      const entry = {} as SessionEntry;
+      const result = setActiveNamedSession({ mainEntry: entry, name: null });
+      expect(result).toBe(false);
+    });
+
+    it("throws when name contains a colon", () => {
+      const entry = {} as SessionEntry;
+      expect(() => setActiveNamedSession({ mainEntry: entry, name: "foo:bar" })).toThrow();
+      expect(entry.activeNamedSession).toBeUndefined();
+    });
+
+    it("normalizes name to lowercase", () => {
+      const entry = {} as SessionEntry;
+      setActiveNamedSession({ mainEntry: entry, name: "Work" });
+      expect(entry.activeNamedSession).toBe("work");
+    });
+  });
+
+  describe("getActiveNamedSessionKey", () => {
+    it("returns null when mainEntry is undefined", () => {
+      const result = getActiveNamedSessionKey({
+        mainEntry: undefined,
+        agentId: "main",
+        peerId: "123",
+      });
+      expect(result).toBeNull();
+    });
+
+    it("returns null when activeNamedSession is not set", () => {
+      const entry = {} as SessionEntry;
+      const result = getActiveNamedSessionKey({ mainEntry: entry, agentId: "main", peerId: "123" });
+      expect(result).toBeNull();
+    });
+
+    it("returns null when activeNamedSession is whitespace-only", () => {
+      const entry = { activeNamedSession: "   " } as SessionEntry;
+      const result = getActiveNamedSessionKey({ mainEntry: entry, agentId: "main", peerId: "123" });
+      expect(result).toBeNull();
+    });
+
+    it("returns the correct named session key on round-trip", () => {
+      const entry = {} as SessionEntry;
+      setActiveNamedSession({ mainEntry: entry, name: "work" });
+      const result = getActiveNamedSessionKey({ mainEntry: entry, agentId: "main", peerId: "123" });
+      expect(result).toBe("agent:main:dm-named:123:work");
+    });
+  });
+});
diff --git a/src/sessions/session-key-utils.ts b/src/sessions/session-key-utils.ts
index c405df3a5ff..e8a6bfab72b 100644
--- a/src/sessions/session-key-utils.ts
+++ b/src/sessions/session-key-utils.ts
@@ -47,7 +47,7 @@ export function deriveSessionChatType(sessionKey: string | undefined | null): Se
   if (tokens.has("channel")) {
     return "channel";
   }
-  if (tokens.has("direct") || tokens.has("dm")) {
+  if (tokens.has("direct") || tokens.has("dm") || tokens.has("dm-named")) {
     return "direct";
   }
   // Legacy Discord keys can be shaped like:
@@ -130,3 +130,72 @@ export function resolveThreadParentSessionKey(
   const parent = raw.slice(0, idx).trim();
   return parent ? parent : null;
 }
+
+/**
+ * Check if a session key is a named DM session key.
+ * Format: agent:main:dm-named:<peerId>:<name>
+ */
+export function isNamedDmSessionKey(sessionKey: string | undefined | null): boolean {
+  const parsed = parseAgentSessionKey(sessionKey);
+  if (!parsed) {
+    return false;
+  }
+  return /^dm-named:[^:]+:[^:]+$/.test(parsed.rest);
+}
+
+/**
+ * Build a named DM session key.
+ * Format: agent:<agentId>:dm-named:<peerId>:<name>
+ */
+export function buildNamedDmSessionKey(params: {
+  agentId: string;
+  peerId: string;
+  name: string;
+}): string {
+  const agentId = params.agentId.trim().toLowerCase();
+  const peerId = params.peerId.trim().toLowerCase();
+  const name = params.name.trim().toLowerCase();
+  if (!agentId || !peerId || !name) {
+    throw new Error("buildNamedDmSessionKey: agentId, peerId, and name are required");
+  }
+  if (agentId.includes(":")) {
+    throw new Error(`buildNamedDmSessionKey: agentId must not contain ":" (got: "${agentId}")`);
+  }
+  if (peerId.includes(":")) {
+    throw new Error(`buildNamedDmSessionKey: peerId must not contain ":" (got: "${peerId}")`);
+  }
+  if (name.includes(":")) {
+    throw new Error(`buildNamedDmSessionKey: name must not contain ":" (got: "${name}")`);
+  }
+  return `agent:${agentId}:dm-named:${peerId}:${name}`;
+}
+
+/**
+ * Parse a named DM session key.
+ * Returns { agentId, peerId, name } or null if not a named DM key.
+ */
+export function parseNamedDmSessionKey(
+  sessionKey: string | undefined | null,
+): { agentId: string; peerId: string; name: string } | null {
+  const parsed = parseAgentSessionKey(sessionKey);
+  if (!parsed) {
+    return null;
+  }
+  const parts = parsed.rest.split(":");
+  if (parts.length !== 3) {
+    return null;
+  }
+  if (parts[0] !== "dm-named") {
+    return null;
+  }
+  const peerId = parts[1]?.trim();
+  const name = parts[2]?.trim();
+  if (!peerId || !name) {
+    return null;
+  }
+  return {
+    agentId: parsed.agentId,
+    peerId,
+    name,
+  };
+}