N8N + Line messaging setup

N8N Startup Script

docker volume create n8n_data

docker run -it --name n8n -p 5678:5678 -v n8n_data:/home/node/.n8n docker.n8n.io/n8nio/n8n

---

ngrok http --url=teal-awaited-gorilla.ngrok-free.app 80

workflow.json

{
  "name": "Gemini and Line Assitance",
  "nodes": [
    {
      "parameters": {
        "httpMethod": "POST",
        "path": "0692e7e5-0b00-465f-8e97-ed3f9698ac9e",
        "options": {}
      },
      "type": "n8n-nodes-base.webhook",
      "typeVersion": 2,
      "position": [
        0,
        0
      ],
      "id": "11004452-b2a1-403b-aed2-ba2227bdd5c1",
      "name": "Webhook",
      "webhookId": "0692e7e5-0b00-465f-8e97-ed3f9698ac9e"
    },
    {
      "parameters": {
        "assignments": {
          "assignments": [
            {
              "id": "7b11e548-b804-449c-bc92-524080bfd9fc",
              "name": "body.events[0].message.text",
              "value": "={{ $json.body.events[0].message.text }}",
              "type": "string"
            },
            {
              "id": "5a96e6e8-0fee-4573-9a30-5deff0f3c8ed",
              "name": "body.events[0].replyToken",
              "value": "={{ $json.body.events[0].replyToken }}",
              "type": "string"
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.set",
      "typeVersion": 3.4,
      "position": [
        220,
        0
      ],
      "id": "fc96e52c-25f0-43db-89c0-7a7dcfe09fa3",
      "name": "Edit Fields"
    },
    {
      "parameters": {
        "promptType": "define",
        "text": "=Guess why they're typing this  {{ $json.body.events[0].message.text }}",
        "options": {
          "systemMessage": "You are a helpful assistant"
        }
      },
      "type": "@n8n/n8n-nodes-langchain.agent",
      "typeVersion": 1.9,
      "position": [
        440,
        0
      ],
      "id": "c9f5ee0d-2202-41bb-b1a6-f404ed9907f2",
      "name": "AI Agent"
    },
    {
      "parameters": {
        "modelName": "models/gemini-2.5-flash-preview-04-17",
        "options": {}
      },
      "type": "@n8n/n8n-nodes-langchain.lmChatGoogleGemini",
      "typeVersion": 1,
      "position": [
        340,
        240
      ],
      "id": "e77f6487-08f3-424a-84e2-59eedfce182b",
      "name": "Google Gemini Chat Model",
      "credentials": {
        "googlePalmApi": {
          "id": "RtUQQhjbMarTERDf",
          "name": "Google Gemini(PaLM) Api account"
        }
      }
    },
    {
      "parameters": {
        "method": "POST",
        "url": "https://api.line.me/v2/bot/message/reply",
        "authentication": "genericCredentialType",
        "genericAuthType": "httpHeaderAuth",
        "sendBody": true,
        "specifyBody": "json",
        "jsonBody": "={\n    \"replyToken\":\"{{$('Edit Fields').first().json.body.events[0].replyToken}}\",\n    \"messages\":[\n        {\n            \"type\":\"text\",\n            \"text\":{{ JSON.stringify($json['output'])}}\n        }\n    ]\n}",
        "options": {}
      },
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "position": [
        800,
        0
      ],
      "id": "d8a6e3cb-ccff-4486-b68d-469ad865818b",
      "name": "HTTP Request",
      "credentials": {
        "httpHeaderAuth": {
          "id": "quSOjfhybYgdtknE",
          "name": "Header Auth account"
        }
      }
    }
  ],
  "pinData": {},
  "connections": {
    "Webhook": {
      "main": [
        [
          {
            "node": "Edit Fields",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Edit Fields": {
      "main": [
        [
          {
            "node": "AI Agent",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Google Gemini Chat Model": {
      "ai_languageModel": [
        [
          {
            "node": "AI Agent",
            "type": "ai_languageModel",
            "index": 0
          }
        ]
      ]
    },
    "AI Agent": {
      "main": [
        [
          {
            "node": "HTTP Request",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "active": false,
  "settings": {
    "executionOrder": "v1"
  },
  "versionId": "83403144-38ed-494e-839d-5c309213e406",
  "meta": {
    "templateCredsSetupCompleted": true,
    "instanceId": "6ea6758a8a88c864c0b1af9f886503bb67c3e3a2a99bef4c32284ecbf88285c2"
  },
  "id": "3h51xndHkzOG1MwG",
  "tags": []
}