diff --git a/src/discord/accounts.ts b/src/discord/accounts.ts
index 7964a2a4e..a503631c9 100644
--- a/src/discord/accounts.ts
+++ b/src/discord/accounts.ts
@@ -20,6 +20,15 @@ function listConfiguredAccountIds(cfg: MoltbotConfig): string[] {
 
 export function listDiscordAccountIds(cfg: MoltbotConfig): string[] {
   const ids = listConfiguredAccountIds(cfg);
+  const explicitDefault = ids.includes(DEFAULT_ACCOUNT_ID);
+
+  if (!explicitDefault) {
+    const defaultResolution = resolveDiscordToken(cfg, { accountId: DEFAULT_ACCOUNT_ID });
+    if (defaultResolution.source !== "none") {
+      ids.push(DEFAULT_ACCOUNT_ID);
+    }
+  }
+
   if (ids.length === 0) return [DEFAULT_ACCOUNT_ID];
   return ids.sort((a, b) => a.localeCompare(b));
 }
diff --git a/src/discord/monitor/message-handler.process.ts b/src/discord/monitor/message-handler.process.ts
index 6d502be21..8baa44870 100644
--- a/src/discord/monitor/message-handler.process.ts
+++ b/src/discord/monitor/message-handler.process.ts
@@ -284,6 +284,7 @@ export async function processDiscordMessage(ctx: DiscordMessagePreflightContext)
     Surface: "discord" as const,
     WasMentioned: effectiveWasMentioned,
     MessageSid: message.id,
+    RpcId: `discord:${route.accountId}:${message.id}`,
     ParentSessionKey: autoThreadContext?.ParentSessionKey ?? threadKeys.parentSessionKey,
     ThreadStarterBody: threadStarterBody,
     ThreadLabel: threadLabel,
diff --git a/src/discord/multi-account.test.ts b/src/discord/multi-account.test.ts
new file mode 100644
index 000000000..4020e072c
--- /dev/null
+++ b/src/discord/multi-account.test.ts
@@ -0,0 +1,99 @@
+import { describe, expect, it } from "vitest";
+import { type MoltbotConfig } from "../config/config.js";
+import { listDiscordAccountIds } from "./accounts.js";
+import { resolveDiscordToken } from "./token.js";
+
+describe("discord multi-account logic", () => {
+  it("should list all configured accounts", () => {
+    const config = {
+      channels: {
+        discord: {
+          accounts: {
+            bot_a: { token: "token_a", enabled: true },
+            bot_b: { token: "token_b", enabled: true },
+            bot_c: { token: "token_c", enabled: false },
+          },
+        },
+      },
+    } as unknown as MoltbotConfig;
+
+    const ids = listDiscordAccountIds(config);
+    expect(ids).toEqual(["bot_a", "bot_b", "bot_c"]);
+  });
+
+  it("should resolve specific account tokens", () => {
+    const config = {
+      channels: {
+        discord: {
+          accounts: {
+            bot_a: { token: "token_a" },
+            bot_b: { token: "token_b" },
+          },
+        },
+      },
+    } as unknown as MoltbotConfig;
+
+    const tokenA = resolveDiscordToken(config, { accountId: "bot_a" });
+    const tokenB = resolveDiscordToken(config, { accountId: "bot_b" });
+    const tokenUnknown = resolveDiscordToken(config, { accountId: "bot_unknown" });
+
+    expect(tokenA.token).toBe("token_a");
+    expect(tokenB.token).toBe("token_b");
+    expect(tokenUnknown.token).toBe("");
+  });
+
+  it("should fall back to default token if no account token specified", () => {
+    const config = {
+      channels: {
+        discord: {
+          token: "default_token",
+          accounts: {
+            bot_a: {}, // no token
+          },
+        },
+      },
+    } as unknown as MoltbotConfig;
+
+    const tokenA = resolveDiscordToken(config, { accountId: "bot_a" });
+    // Current implementation might strictly require per-account token if it's not the default account.
+    // Let's verify behavior.
+    // Actually, looking at token.ts:
+    // const accountToken = ...
+    // if (accountToken) return ...
+    // const allowEnv = accountId === DEFAULT_ACCOUNT_ID;
+    // const configToken = allowEnv ? ... : undefined;
+
+    // So valid behavior: non-default accounts MUST have a specific token.
+    expect(tokenA.token).toBe("");
+  });
+
+  it("should include default account if top-level token is present", () => {
+    const config = {
+      channels: {
+        discord: {
+          token: "default_token",
+          accounts: {
+            bot_a: { token: "token_a" },
+          },
+        },
+      },
+    } as unknown as MoltbotConfig;
+
+    const ids = listDiscordAccountIds(config);
+    expect(ids).toContain("default");
+    expect(ids).toContain("bot_a");
+  });
+
+  it("should resolve default account correctly", () => {
+    const config = {
+      channels: {
+        discord: {
+          token: "default_token",
+        },
+      },
+    } as unknown as MoltbotConfig;
+
+    const token = resolveDiscordToken(config, { accountId: "default" });
+    expect(token.token).toBe("default_token");
+  });
+});
diff --git a/src/routing/session-key.ts b/src/routing/session-key.ts
index 320ffeb83..9f6fa0295 100644
--- a/src/routing/session-key.ts
+++ b/src/routing/session-key.ts
@@ -139,11 +139,22 @@ export function buildAgentPeerSessionKey(params: {
     }
     if (dmScope === "per-channel-peer" && peerId) {
       const channel = (params.channel ?? "").trim().toLowerCase() || "unknown";
+      const accountId = normalizeAccountId(params.accountId);
+      if (accountId !== DEFAULT_ACCOUNT_ID) {
+        return `agent:${normalizeAgentId(params.agentId)}:${channel}:${accountId}:dm:${peerId}`;
+      }
       return `agent:${normalizeAgentId(params.agentId)}:${channel}:dm:${peerId}`;
     }
     if (dmScope === "per-peer" && peerId) {
       return `agent:${normalizeAgentId(params.agentId)}:dm:${peerId}`;
     }
+    const accountId = normalizeAccountId(params.accountId);
+    if (accountId && accountId !== DEFAULT_ACCOUNT_ID) {
+      if (dmScope === "main") {
+        return `agent:${normalizeAgentId(params.agentId)}:dm:${peerId}:${accountId}`;
+      }
+      return `agent:${normalizeAgentId(params.agentId)}:dm:${peerId}:${accountId}`;
+    }
     return buildAgentMainSessionKey({
       agentId: params.agentId,
       mainKey: params.mainKey,
@@ -151,7 +162,13 @@ export function buildAgentPeerSessionKey(params: {
   }
   const channel = (params.channel ?? "").trim().toLowerCase() || "unknown";
   const peerId = ((params.peerId ?? "").trim() || "unknown").toLowerCase();
-  return `agent:${normalizeAgentId(params.agentId)}:${channel}:${peerKind}:${peerId}`;
+  const accountId = normalizeAccountId(params.accountId);
+  const baseKey = `agent:${normalizeAgentId(params.agentId)}:${channel}:${peerKind}:${peerId}`;
+
+  if (accountId && accountId !== DEFAULT_ACCOUNT_ID) {
+    return `${baseKey}:${accountId}`;
+  }
+  return baseKey;
 }
 
 function resolveLinkedPeerId(params: {
diff --git a/src/routing/shared-channel.test.ts b/src/routing/shared-channel.test.ts
new file mode 100644
index 000000000..d94b5da09
--- /dev/null
+++ b/src/routing/shared-channel.test.ts
@@ -0,0 +1,59 @@
+import { describe, it, expect } from "vitest";
+import { resolveAgentRoute, type ResolveAgentRouteInput } from "./resolve-route.js";
+import type { MoltbotConfig } from "../config/config.js";
+
+const mockConfig: MoltbotConfig = {
+  agents: { list: [{ id: "main" }] },
+  channels: {
+    discord: {
+      enabled: true,
+      accounts: {
+        bot_a: { token: "taken_a" },
+        bot_b: { token: "token_b" },
+      },
+    },
+  },
+};
+
+describe("resolveAgentRoute - Shared Channel", () => {
+  it("should generate distinct keys for SAME channel on DIFFERENT bots", () => {
+    const inputA: ResolveAgentRouteInput = {
+      cfg: mockConfig,
+      channel: "discord",
+      accountId: "bot_a",
+      peer: { kind: "channel", id: "channel_123" },
+    };
+
+    const inputB: ResolveAgentRouteInput = {
+      cfg: mockConfig,
+      channel: "discord",
+      accountId: "bot_b",
+      peer: { kind: "channel", id: "channel_123" },
+    };
+
+    const routeA = resolveAgentRoute(inputA);
+    const routeB = resolveAgentRoute(inputB);
+
+    console.log("Channel RouteA:", routeA.sessionKey);
+    console.log("Channel RouteB:", routeB.sessionKey);
+
+    expect(routeA.sessionKey).not.toEqual(routeB.sessionKey);
+    expect(routeA.sessionKey).toContain(":bot_a");
+    expect(routeB.sessionKey).toContain(":bot_b");
+  });
+
+  it("should preserve backward compatibility for default bot in channel", () => {
+    const input: ResolveAgentRouteInput = {
+      cfg: mockConfig,
+      channel: "discord",
+      accountId: "default",
+      peer: { kind: "channel", id: "channel_123" },
+    };
+
+    const route = resolveAgentRoute(input);
+    console.log("Channel Default:", route.sessionKey);
+
+    // Should NOT have :default
+    expect(route.sessionKey).toBe("agent:main:discord:channel:channel_123");
+  });
+});