Describe the problem/error/question
Hello,
I have workflow which including 1 MCP Sever trigger and several MCP clients. Around 2 hours ago, suddenly the client can not access the MCP server anymore (workflow in active mode).
I try to check the connection and was told to set up credential?!
I started a new workflow and create very simple MCP server - client and hit the same error.
Please help, which kill my whole week’s work. here is a simple example
{
“nodes”: [
{
“parameters”: {
“path”: “469b4516-9d56-4049-8800-282da4d8faa7”
},
“type”: “@n8n/n8n-nodes-langchain.mcpTrigger”,
“typeVersion”: 1,
“position”: [
860,
-240
],
“id”: “9bfce68f-a463-424b-ab1e-8844ae7b59b9”,
“name”: “MCP Server Trigger”,
“webhookId”: “469b4516-9d56-4049-8800-282da4d8faa7”
},
{
“parameters”: {
“sseEndpoint”: “https://tradelyai.app.n8n.cloud/mcp/469b4516-9d56-4049-8800-282da4d8faa7/sse”,
“include”: “selected”
},
“type”: “@n8n/n8n-nodes-langchain.mcpClientTool”,
“typeVersion”: 1,
“position”: [
340,
80
],
“id”: “31ff919e-0b7d-40e5-96fe-3ad4c522af2e”,
“name”: “MCP Client”
},
{
“parameters”: {
“promptType”: “define”,
“text”: “search reddit "how about stock price today"\n”,
“options”: {}
},
“type”: “@n8n/n8n-nodes-langchain.agent”,
“typeVersion”: 2,
“position”: [
80,
-240
],
“id”: “d09ee864-6bd1-49fc-8408-47d98d384880”,
“name”: “AI Agent”
},
{
“parameters”: {
“model”: “anthropic/claude-sonnet-4”,
“options”: {}
},
“type”: “@n8n/n8n-nodes-langchain.lmChatOpenRouter”,
“typeVersion”: 1,
“position”: [
0,
60
],
“id”: “167355be-9ae8-4d8d-b4fa-6698d0806a3c”,
“name”: “OpenRouter Chat Model”,
“credentials”: {
“openRouterApi”: {
“id”: “JJI0mg40T4SNQNO5”,
“name”: “OpenRouter account”
}
}
},
{
“parameters”: {},
“type”: “n8n-nodes-base.manualTrigger”,
“typeVersion”: 1,
“position”: [
-180,
-240
],
“id”: “5f14a57b-0e47-4d6d-a2f8-1e297429aff3”,
“name”: “When clicking ‘Execute workflow’”
},
{
“parameters”: {
“operation”: “search”,
“subreddit”: “={{ /n8n-auto-generated-fromAI-override/ $fromAI(‘Subreddit’, ``, ‘string’) }}”,
“keyword”: “={{ /n8n-auto-generated-fromAI-override/ $fromAI(‘Keyword’, ``, ‘string’) }}”,
“limit”: “={{ /n8n-auto-generated-fromAI-override/ $fromAI(‘Limit’, ``, ‘number’) }}”,
“additionalFields”: {}
},
“type”: “n8n-nodes-base.redditTool”,
“typeVersion”: 1,
“position”: [
1060,
20
],
“id”: “f2d02296-c02b-4cb5-9dbf-c1025c88067b”,
“name”: “Reddit”,
“credentials”: {
“redditOAuth2Api”: {
“id”: “Jv0p0S0tQFYUPxC8”,
“name”: “Reddit account”
}
}
}
],
“connections”: {
“MCP Client”: {
“ai_tool”: [
[
{
“node”: “AI Agent”,
“type”: “ai_tool”,
“index”: 0
}
]
]
},
“OpenRouter Chat Model”: {
“ai_languageModel”: [
[
{
“node”: “AI Agent”,
“type”: “ai_languageModel”,
“index”: 0
}
]
]
},
“When clicking ‘Execute workflow’”: {
“main”: [
[
{
“node”: “AI Agent”,
“type”: “main”,
“index”: 0
}
]
]
},
“Reddit”: {
“ai_tool”: [
[
{
“node”: “MCP Server Trigger”,
“type”: “ai_tool”,
“index”: 0
}
]
]
}
},
“pinData”: {},
“meta”: {
“templateCredsSetupCompleted”: true,
“instanceId”: “bca2e2865f2a489a09ebfc27bc2cef70bbb94badc96bd6aaf3a5276e0c6aef21”
}
}
What is the error message (if any)?
Please share your workflow
(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)
Share the output returned by the last node
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