Chat trigger not pass message to next node

[Hassan_Zakria]

Problem:
chat triggger node not gives msg to the next node
but when i gives direct message to the Q&A chain then ans retrive
i use latest version of n8n self hosted on railway.pp by docker image

code :
{
“nodes”: [
{
“parameters”: {
“authentication”: “chromaCloudApi”,
“chromaCollection”: {
“__rl”: true,
“value”: “diabetes_care_2026_pdf”,
“mode”: “list”,
“cachedResultName”: “diabetes_care_2026_pdf”
},
“options”: {}
},
“type”: “@n8n/n8n-nodes-langchain.vectorStoreChromaDB”,
“typeVersion”: 1.3,
“position”: [
640,
-96
],
“id”: “6bcbcabb-1628-4705-acc1-ec69e9cdd2ea”,
“name”: “Chroma Vector Store”,
“notesInFlow”: true,
“credentials”: {
“chromaCloudApi”: {
“id”: “GJVxnKM6boNKGDcQ”,
“name”: “ChromaDB Cloud”
}
}
},
{
“parameters”: {
“options”: {}
},
“type”: “@n8n/n8n-nodes-langchain.embeddingsOpenAi”,
“typeVersion”: 1.2,
“position”: [
512,
-32
],
“id”: “53369344-d75a-4e1b-8cbe-7e330ada84e7”,
“name”: “Embeddings OpenAI”,
“credentials”: {
“openAiApi”: {
“id”: “U8c47VlPDVe4QvHM”,
“name”: “OpenAI account”
}
}
},
{
“parameters”: {
“model”: {
“__rl”: true,
“value”: “gpt-4o-mini”,
“mode”: “list”,
“cachedResultName”: “gpt-4o-mini”
},
“builtInTools”: {},
“options”: {
“textFormat”: {
“textOptions”: {
“type”: “text”
}
}
}
},
“type”: “@n8n/n8n-nodes-langchain.lmChatOpenAi”,
“typeVersion”: 1.3,
“position”: [
368,
-144
],
“id”: “85a2a69d-b7f5-43a0-9761-94f58981658e”,
“name”: “OpenAI Chat Model”,
“credentials”: {
“openAiApi”: {
“id”: “U8c47VlPDVe4QvHM”,
“name”: “OpenAI account”
}
}
},
{
“parameters”: {
“options”: {
“responseMode”: “lastNode”
}
},
“type”: “@n8n/n8n-nodes-langchain.chatTrigger”,
“typeVersion”: 1.4,
“position”: [
176,
-384
],
“id”: “2a23a459-2e0a-41e2-b42f-3f7dc8e457ce”,
“name”: “When chat message received”,
“webhookId”: “fb089fe6-d959-4530-8e15-b76291e07d0f”,
“alwaysOutputData”: false
},
{
“parameters”: {},
“type”: “@n8n/n8n-nodes-langchain.retrieverVectorStore”,
“typeVersion”: 1,
“position”: [
560,
-256
],
“id”: “8f040c30-62c4-4655-aec0-dd8db30f5575”,
“name”: “Vector Store Retriever”
},
{
“parameters”: {
“options”: {}
},
“type”: “@n8n/n8n-nodes-langchain.chainRetrievalQa”,
“typeVersion”: 1.7,
“position”: [
400,
-384
],
“id”: “5abff650-028a-4dae-8859-00b3fc45f1ea”,
“name”: “Question and Answer Chain”
}
],
“connections”: {
“Chroma Vector Store”: {
“ai_tool”: [

],
“ai_vectorStore”: [
[
{
“node”: “Vector Store Retriever”,
“type”: “ai_vectorStore”,
“index”: 0
}
]
]
},
“Embeddings OpenAI”: {
“ai_embedding”: [
[
{
“node”: “Chroma Vector Store”,
“type”: “ai_embedding”,
“index”: 0
}
]
]
},
“OpenAI Chat Model”: {
“ai_languageModel”: [
[
{
“node”: “Question and Answer Chain”,
“type”: “ai_languageModel”,
“index”: 0
}
]
]
},
“When chat message received”: {
“main”: [
[
{
“node”: “Question and Answer Chain”,
“type”: “main”,
“index”: 0
}
]
]
},
“Vector Store Retriever”: {
“ai_retriever”: [
[
{
“node”: “Question and Answer Chain”,
“type”: “ai_retriever”,
“index”: 0
}
]
]
},
“Question and Answer Chain”: {
“main”: [

]
}
},
“pinData”: {},
“meta”: {
“templateCredsSetupCompleted”: true,
“instanceId”: “e80c933fa7f4d5967cc2a038c97a89862a2e4ccb4b18372a6ce2a883e1398a68”
}
}

[oimrqs_ops]

The first split is whether the Chat Trigger is producing a different field name than the Q&A chain expects. Open one execution from the Chat Trigger path and look at the item just before the Q&A/agent node: is the user text under chatInput, message, or somewhere else?

Post only that redacted item shape and the first node after Chat Trigger. If direct Q&A works but the Chat Trigger path is blank, the useful check is the mapping between the trigger’s text field and the field the chain reads, not Chroma.

[Hassan_Zakria]

chat trigger not work also with the agent
its a bug ?
The “When chat message received” atach with any node gives the same answer “Failed to receive response”
not data pass to the other node why ??

[oimrqs_ops]

Not enough to call it a bug yet. Failed to receive response is the chat page saying it did not get a workflow response back; it does not prove the Chat Trigger output is empty.

Check the Chat Trigger Response Mode before changing the agent. If it is Using Response Nodes, the flow needs to reach a Chat node or Respond to Webhook node. If it is When Last Node Finishes, one chat message should create an execution and the last node must finish with output. Post only the response mode, n8n version, and whether a new execution appears when you send one chat message.

[Hassan_Zakria]

without chat trigger :
it gives the response

but with the chat trigger :
the chat trigger not pass input to the next node how to debug or error track ?

[oimrqs_ops]

Debug it from the execution, not from the chat panel. Send one chat message, then open that new execution and click the Chat Trigger node first. If its output contains the text under chatInput, the trigger did its part and the next node is reading the wrong field; map {{$json.chatInput}} into the field the agent/QA node reads.

If no execution appears, or the Chat Trigger output has no text at all, that is the useful evidence. Post only the response mode, n8n version, and the redacted Chat Trigger output from that execution.

[nguyenthieutoan]

One more thing to check while you’re debugging: the “Nothing to display yet” log panel means no execution was recorded at all, which usually points to the workflow not being active. The built-in chat widget only works with an activated workflow - make sure you’ve toggled the workflow ON (the switch in the top-right of the editor). In test mode, the trigger only fires once per manual test run, so the embedded chat widget won’t stay connected to it.

[kjooleng]

Hi @Hassan_Zakria

The Chat Trigger relies on a webhook. If n8n doesn’t know its own external URL, the chat window cannot “find” your workflow to send the message.

• The Problem: If WEBHOOK_URL is not set in your Railway environment variables, n8n uses localhost, but the chat interface is trying to reach your railway.app domain.
• The Fix:
  1. Go to your Railway Project Settings → Variables.
  2. Add a new variable: WEBHOOK_URL.
  3. Set the value to your full n8n instance URL (e.g., https://n8n-production-xxxx.up.railway.app/). Make sure it includes the https:// and ends with a trailing slash /.
  4. Redeploy/Restart the service.

[Hassan_Zakria]

Thansks alot