Describe the problem/error/question
I have a self-hosted queue deployed on AKS.
I’m looking to use MCP Trigger and MCP Tools to unify the functions. However, I’m getting this error:
There was a problem loading the parameter options from the server: "Could not connect to your MCP server"
I created the nodes and a simple trigger to validate:
Trigger:
{
“nodes”: [
{
“parameters”: {
“description”: “Use this tool by passing the subject to receive a sample message for the user”,
“jsCode”: “let subject = query.toLowerCase();\n\nconst result = {\n"supplier": "Access our quero_ser_fornecedor platform; there we have a specific chat for you, or send your question to the ‘support’ email address",\n"resume": "Access https://informacoes-processos-selecao",\n"rh": "PPP request, send an email to recipient ‘[email protected]’. Agreement: Abertta Saúde Contacts: Email: [email protected] Phone: 0800 721 4015”,\n "ecommerce": "You can access the online store here: https://loja.com.br.",\n "patrocinio": "To learn more about sponsorships, just visit: https://www.org.br/\“,\n "juridico": "You can send your request directly to our legal department at: [email protected]",\n "golpe": "If you wish to file a complaint, you can send it to: [email protected] or visit https://golpe.com/fraude.\”\n };\n\nreturn result[subject];",
“specifyInputSchema”: true,
“schemaType”: “manual”,
“inputSchema”: “{\n"type": "string",\n"properties": {\n\t"subject": {\n\t\t"type": "string",\n\t\t"description": "subject of interest"\n\t\t}\n\t}\n}”
},
“type”: “@n8n/n8n-nodes-langchain.toolCode”,
“typeVersion”: 1.3,
“position”: [
-16,
-48
],
“id”: “c9abfaf8-4188-423a-b39a-5547e47e1ce1”,
“name”: “OtherSubjects”
},
{
“parameters”: {
“path”: “9f4eeb61-9a15-4914-99a1x”
},
“type”: “@n8n/n8n-nodes-langchain.mcpTrigger”,
“typeVersion”: 2,
“position”: [
-112,
-240
],
“id”: “1358492d-3e2f-4531-9076-a099f633f8f8”,
“name”: “MCP Server Trigger”,
“webhookId”: “9f4eeb61-9a15-4914-99a1-afe8092b6eb8”
}
],
“connections”: {
“OtherSubjects”: {
“ai_tool”: [
[
{
“node”: “MCP Server Trigger”,
“type”: “ai_tool”,
“index”: 0
}
]
]
}
},
“pinData”: {},
“goal”: {
“templateCredsSetupCompleted”: true,
“instanceId”: “747a2ae747b59a835be6bc798c57338406970668b8646e25cb3886941ea338a2”
}
}
then I call the tool:
{
“nodes”: [
{
“parameters”: {
“endpointUrl”: “https://n8n-url/mcp/9f4eeb61-9a15-4914-99a1x”,
“serverTransport”: “httpStreamable”,
“include”: “selected”
},
“type”: “@n8n/n8n-nodes-langchain.mcpClientTool”,
“typeVersion”: 1.1,
“position”: [
896,
-256
],
“id”: “d3dfcf9b-841d-4217-9f6d-313352202fff”,
“name”: “MCP”
}
],
“connections”: {
“MCP”: {
“ai_tool”: [
]
}
},
“pinData”: {},
“goal”: {
“templateCredsSetupCompleted”: true,
“instanceId”: “747a2ae747b59a835be6bc798c57338406970668b8646e25cb3886941ea338a2”
}
}
Below is the complete log:
With HTTPS:
06/08/2025 18:00:42
Pod: n8n-editor-56f48d7bc9-kppsp
Container ID: 0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
File: error-reporter.js
Function: defaultReport
Error:
Could not connect to your MCP server
With HTTP:
06/08/2025 18:00:55
Pod: n8n-editor-56f48d7bc9-kppsp
Container ID: 0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
File: error-reporter.js
Function: defaultReport
Schema validation error (Zod):[
{
“received”: “string”,
“code”: “invalid_literal”,
“expected”: “object”,
“path”: [“tools”, 0, “inputSchema”, “type”],
“message”: “Invalid literal value, expected "object"”
}
]
or:
06/08/2025, 18:00:42
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
2025-08-06T21:00:42.703Z | [31merror[39m | [31mCould not connect to your MCP server[39m {“file”:“error-reporter.js”,“function”:“defaultReport”}
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
2025-08-06T21:00:55.340Z | [31merror[39m | [31m[[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m {[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “received”: “string”,[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “code”: “invalid_literal”,[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “expected”: “object”,[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “path”: [[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “tools”,[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m 0,[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “inputSchema”,[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “type”[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m ],[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m “message”: “Invalid literal value, expected "object"”[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m }[39m
06/08/2025, 18:00:55
n8n-editor-56f48d7bc9-kppsp
0f0edc5c1bebe2f5dac794be25f8660938bab3d6c3cf4d1e93232981392856dc
[31m][39m {“file”:“error-reporter.js”,“function”:“defaultReport”}