diff --git a/packages/chat/src/chat.ts b/packages/chat/src/chat.ts
index cf9c281f..f2b36610 100644
--- a/packages/chat/src/chat.ts
+++ b/packages/chat/src/chat.ts
@@ -1707,10 +1707,8 @@ export class Chat<
     initialMessage: Message,
     isSubscribedContext = false
   ): Thread<TState> {
-    // Parse thread ID to get channel info
-    // Format: "adapter:channel:thread"
-    const parts = threadId.split(":");
-    const channelId = parts[1] || "";
+    // Parse thread ID to get channel ID with adapter
+    const channelId = adapter.channelIdFromThreadId(threadId);
 
     // Check if this is a DM
     const isDM = adapter.isDM?.(threadId) ?? false;
diff --git a/packages/integration-tests/src/replay-actions-reactions.test.ts b/packages/integration-tests/src/replay-actions-reactions.test.ts
index 628f9283..bdb38195 100644
--- a/packages/integration-tests/src/replay-actions-reactions.test.ts
+++ b/packages/integration-tests/src/replay-actions-reactions.test.ts
@@ -70,7 +70,7 @@ describe("Replay Tests - Actions & Reactions", () => {
         userId: "U00FAKEUSER1",
         userName: "testuser",
         adapterName: "slack",
-        channelId: "C00FAKECHAN1",
+        channelId: "slack:C00FAKECHAN1",
         isDM: false,
       });
 
@@ -91,7 +91,7 @@ describe("Replay Tests - Actions & Reactions", () => {
         added: true,
         userId: "U00FAKEUSER1",
         adapterName: "slack",
-        channelId: "C00FAKECHAN1",
+        channelId: "slack:C00FAKECHAN1",
         messageId: "1767326126.896109",
         isDM: false,
       });
@@ -110,7 +110,7 @@ describe("Replay Tests - Actions & Reactions", () => {
         userId: "U00FAKEUSER1",
         userName: "testuser",
         adapterName: "slack",
-        channelId: "C00FAKECHAN1",
+        channelId: "slack:C00FAKECHAN1",
         isDM: false,
       });
 
@@ -129,7 +129,7 @@ describe("Replay Tests - Actions & Reactions", () => {
         userId: "U00FAKEUSER1",
         userName: "testuser",
         adapterName: "slack",
-        channelId: "C00FAKECHAN1",
+        channelId: "slack:C00FAKECHAN1",
         isDM: false,
       });
 
diff --git a/packages/integration-tests/src/replay-channel.test.ts b/packages/integration-tests/src/replay-channel.test.ts
index 71b413c0..50443c82 100644
--- a/packages/integration-tests/src/replay-channel.test.ts
+++ b/packages/integration-tests/src/replay-channel.test.ts
@@ -116,7 +116,7 @@ describe("Replay Tests - Channel", () => {
         userId: "U00FAKEUSER1",
         userName: "testuser",
         adapterName: "slack",
-        channelId: "C00FAKECHAN1",
+        channelId: "slack:C00FAKECHAN1",
         isDM: false,
       });
     });
diff --git a/packages/integration-tests/src/replay-modal-private-metadata.test.ts b/packages/integration-tests/src/replay-modal-private-metadata.test.ts
index 91e71488..d84cbb57 100644
--- a/packages/integration-tests/src/replay-modal-private-metadata.test.ts
+++ b/packages/integration-tests/src/replay-modal-private-metadata.test.ts
@@ -64,7 +64,7 @@ describe("Replay Tests - Modal privateMetadata", () => {
         userId: "U0A8WUV28QM",
         userName: "sd0a90bkva4s_user",
         adapterName: "slack",
-        channelId: "C0A9D9RTBMF",
+        channelId: "slack:C0A9D9RTBMF",
         isDM: false,
       });
 
diff --git a/packages/integration-tests/src/replay-modals.test.ts b/packages/integration-tests/src/replay-modals.test.ts
index 6cc6dea0..822364bd 100644
--- a/packages/integration-tests/src/replay-modals.test.ts
+++ b/packages/integration-tests/src/replay-modals.test.ts
@@ -80,7 +80,7 @@ describe("Replay Tests - Modals", () => {
         userId: "U00FAKEUSER2",
         userName: "jane.smith",
         adapterName: "slack",
-        channelId: "C00FAKECHAN2",
+        channelId: "slack:C00FAKECHAN2",
         isDM: false,
       });
 
@@ -254,7 +254,7 @@ describe("Replay Tests - Modals", () => {
       expect(capturedAction?.threadId).toBe(
         "slack:C00FAKECHAN3:1771126602.612659"
       );
-      expect(capturedAction?.thread?.channelId).toBe("C00FAKECHAN3");
+      expect(capturedAction?.thread?.channelId).toBe("slack:C00FAKECHAN3");
     });
 
     it("should allow editing relatedMessage from ephemeral modal submission", async () => {