Extract text from PDF and image using Vertex AI (Gemini) into CSV
工作流概述
这是一个包含16个节点的复杂工作流,主要用于自动化处理各种任务。
工作流源代码
{
"id": "sUIPemKdKqmUQFt6",
"meta": {
"instanceId": "558d88703fb65b2d0e44613bc35916258b0f0bf983c5d4730c00c424b77ca36a",
"templateCredsSetupCompleted": true
},
"name": "Extract text from PDF and image using Vertex AI (Gemini) into CSV",
"tags": [],
"nodes": [
{
"id": "f60ef5f9-bc08-4cc9-804e-697ae6f88b9b",
"name": "Google Gemini Chat Model",
"type": "@n8n/n8n-nodes-langchain.lmChatGoogleGemini",
"position": [
980,
920
],
"parameters": {
"options": {},
"modelName": "models/gemini-1.5-pro-latest"
},
"credentials": {
"googlePalmApi": {
"id": "hmNTKSKfppgtDbM5",
"name": "Google Gemini(PaLM) Api account"
}
},
"typeVersion": 1
},
{
"id": "81d3f7b8-20cb-4aac-82a9-d4e8e6581105",
"name": "Get PDF or Images",
"type": "n8n-nodes-base.googleDriveTrigger",
"position": [
220,
420
],
"parameters": {
"event": "fileCreated",
"options": {},
"pollTimes": {
"item": [
{
"mode": "everyMinute"
}
]
},
"triggerOn": "specificFolder",
"folderToWatch": {
"__rl": true,
"mode": "list",
"value": "1HOeRP5iwccg93UPUYmWYD7DyDmRREkhj",
"cachedResultUrl": "https://drive.google.com/drive/folders/1HOeRP5iwccg93UPUYmWYD7DyDmRREkhj",
"cachedResultName": "Actual Budget"
},
"authentication": "serviceAccount"
},
"credentials": {
"googleApi": {
"id": "axkK6IN61bEAT6GM",
"name": "Google Service Account account"
}
},
"typeVersion": 1
},
{
"id": "fe9a8228-7950-4e2c-8982-328e03725782",
"name": "Route based on PDF or Image",
"type": "n8n-nodes-base.switch",
"position": [
480,
420
],
"parameters": {
"rules": {
"rules": [
{
"value2": "application/pdf",
"outputKey": "pdf"
},
{
"value2": "image/",
"operation": "contains",
"outputKey": "image"
}
]
},
"value1": "={{$json.mimeType}}",
"dataType": "string"
},
"typeVersion": 2
},
{
"id": "f62b71e5-af17-4f85-abff-7cee5100affc",
"name": "Download PDF",
"type": "n8n-nodes-base.googleDrive",
"position": [
740,
320
],
"parameters": {
"fileId": {
"__rl": true,
"mode": "id",
"value": "={{ $('Get PDF or Images').item.json.id }}"
},
"options": {},
"operation": "download",
"authentication": "serviceAccount"
},
"credentials": {
"googleApi": {
"id": "axkK6IN61bEAT6GM",
"name": "Google Service Account account"
}
},
"executeOnce": true,
"typeVersion": 3
},
{
"id": "fa99fbcf-1353-410d-a0db-48cea1178a76",
"name": "Download Image",
"type": "n8n-nodes-base.googleDrive",
"position": [
740,
740
],
"parameters": {
"fileId": {
"__rl": true,
"mode": "id",
"value": "={{ $('Get PDF or Images').item.json.id }}"
},
"options": {},
"operation": "download",
"authentication": "serviceAccount"
},
"credentials": {
"googleApi": {
"id": "axkK6IN61bEAT6GM",
"name": "Google Service Account account"
}
},
"executeOnce": true,
"retryOnFail": false,
"typeVersion": 3,
"alwaysOutputData": true
},
{
"id": "e4979746-44bb-493e-b5eb-f9646b510888",
"name": "Extract data from PDF",
"type": "n8n-nodes-base.extractFromFile",
"position": [
980,
320
],
"parameters": {
"options": {},
"operation": "pdf"
},
"typeVersion": 1
},
{
"id": "6549c335-e749-4b95-b77d-096a5e77af5e",
"name": "Send data to A.I.",
"type": "n8n-nodes-base.httpRequest",
"position": [
1180,
320
],
"parameters": {
"url": "https://openrouter.ai/api/v1/chat/completions",
"method": "POST",
"options": {},
"jsonBody": "={
\"model\": \"meta-llama/llama-3.1-70b-instruct:free\",
\"messages\": [
{
\"role\": \"user\",
\"content\": \"You are given a bank statement.{{encodeURIComponent($json.text)}}. Read the PDF and export all the transactions as CSV. Add a column called category and based on the information assign a category name. Return only the CSV data starting with the header row.\"
}
]
}",
"sendBody": true,
"specifyBody": "json",
"authentication": "genericCredentialType",
"genericAuthType": "httpHeaderAuth"
},
"credentials": {
"httpHeaderAuth": {
"id": "WY7UkF14ksPKq3S8",
"name": "Header Auth account 2"
}
},
"typeVersion": 4.2,
"alwaysOutputData": false
},
{
"id": "42341f03-c9fc-4290-963e-1a723202a739",
"name": "Convert to CSV",
"type": "n8n-nodes-base.convertToFile",
"position": [
1400,
320
],
"parameters": {
"options": {}
},
"typeVersion": 1.1
},
{
"id": "bb446447-3f46-47e7-96a2-3fc720715828",
"name": "Upload to Google Drive",
"type": "n8n-nodes-base.googleDrive",
"position": [
1640,
320
],
"parameters": {
"name": "={{$today}}",
"driveId": {
"__rl": true,
"mode": "list",
"value": "My Drive",
"cachedResultUrl": "https://drive.google.com/drive/my-drive",
"cachedResultName": "My Drive"
},
"options": {},
"folderId": {
"__rl": true,
"mode": "list",
"value": "1Zo4OFCv1qWRX1jo0VL_iqUBf4v0fZEXe",
"cachedResultUrl": "https://drive.google.com/drive/folders/1Zo4OFCv1qWRX1jo0VL_iqUBf4v0fZEXe",
"cachedResultName": "CSV Exports"
},
"authentication": "serviceAccount"
},
"credentials": {
"googleApi": {
"id": "axkK6IN61bEAT6GM",
"name": "Google Service Account account"
}
},
"typeVersion": 3
},
{
"id": "843bc9c1-79a6-4f42-b9ee-fbec5f30b18d",
"name": "Convert to CSV2",
"type": "n8n-nodes-base.convertToFile",
"position": [
1360,
740
],
"parameters": {
"options": {}
},
"typeVersion": 1.1
},
{
"id": "6404bf65-3a7e-4be9-9b7f-98a23dca2ffd",
"name": "Upload to Google Drive1",
"type": "n8n-nodes-base.googleDrive",
"position": [
1640,
740
],
"parameters": {
"name": "={{$today}}",
"driveId": {
"__rl": true,
"mode": "list",
"value": "My Drive",
"cachedResultUrl": "https://drive.google.com/drive/my-drive",
"cachedResultName": "My Drive"
},
"options": {},
"folderId": {
"__rl": true,
"mode": "list",
"value": "1Zo4OFCv1qWRX1jo0VL_iqUBf4v0fZEXe",
"cachedResultUrl": "https://drive.google.com/drive/folders/1Zo4OFCv1qWRX1jo0VL_iqUBf4v0fZEXe",
"cachedResultName": "CSV Exports"
},
"authentication": "serviceAccount"
},
"credentials": {
"googleApi": {
"id": "axkK6IN61bEAT6GM",
"name": "Google Service Account account"
}
},
"typeVersion": 3
},
{
"id": "5dd5771f-6ccb-47ab-acbb-d6cbec60d22b",
"name": "Sticky Note",
"type": "n8n-nodes-base.stickyNote",
"position": [
220,
-40
],
"parameters": {
"width": 589.0376569037658,
"height": 163.2468619246862,
"content": "## How to extract PDF and image text into CSV using n8n (without manual data entry)
This workflow will extract text data from PDF and images, then store it as CSV.
[💡 You can read more about this workflow here](https://rumjahn.com/how-to-create-an-a-i-agent-to-analyze-matomo-analytics-using-n8n-for-free/)"
},
"typeVersion": 1
},
{
"id": "37416630-9b52-4ce6-98d0-1bdd39ff0d6b",
"name": "Sticky Note1",
"type": "n8n-nodes-base.stickyNote",
"position": [
160,
160
],
"parameters": {
"color": 4,
"width": 248.11715481171547,
"height": 432.7364016736402,
"content": "## Get PDF or image
You need to create a new folder inside Google Drive for uploading your PDF and images.
Once you create a folder, you need to add your Google cloud user by going to Share -> Add user. The user email should be like: n8n-server@n8n-server-435232.iam.gserviceaccount.com"
},
"typeVersion": 1
},
{
"id": "3ab10f17-de8f-4263-aef8-cc2fb090ffe5",
"name": "Sticky Note2",
"type": "n8n-nodes-base.stickyNote",
"position": [
1120,
52.864368048917754
],
"parameters": {
"color": 5,
"height": 446.3929762816575,
"content": "## Send to Openrouter
You need to set up an Openrouter account to use this. It sends the data to openrouter to extract text.
Use Header Auth. Name is \"Authorization\" and value is \"Bearer {API token}\"."
},
"typeVersion": 1
},
{
"id": "e966f95c-c54e-4d11-895d-d5f75c53aca5",
"name": "Sticky Note3",
"type": "n8n-nodes-base.stickyNote",
"position": [
920,
540
],
"parameters": {
"color": 6,
"width": 399.0962343096232,
"height": 517.154811715481,
"content": "## Vertex AI for image recogniztion
We send the photo to Vertex AI to extract text. You'll need to activate Vertex AI and add the correct rights to your Google cloud credentials.
- Enable Vertex API
- Add vertex to user account"
},
"typeVersion": 1
},
{
"id": "daa3ab66-fa14-4792-96d0-3bcbeffd5d60",
"name": "Vertex A.I. extract text",
"type": "@n8n/n8n-nodes-langchain.chainLlm",
"position": [
980,
740
],
"parameters": {
"text": "=Extract the transactions from the image",
"messages": {
"messageValues": [
{
"message": "=You are given a screenshot of payment transactions. Read the image and export all the transactions as CSV. Add a column called category and based on the information assign a category name. Return only the CSV data starting with the header row."
},
{
"type": "HumanMessagePromptTemplate",
"messageType": "imageBinary"
}
]
},
"promptType": "define",
"hasOutputParser": true
},
"typeVersion": 1.4
}
],
"active": false,
"pinData": {},
"settings": {
"executionOrder": "v1"
},
"versionId": "80635382-3d1c-4e46-a753-84b033cfc3a7",
"connections": {
"Download PDF": {
"main": [
[
{
"node": "Extract data from PDF",
"type": "main",
"index": 0
}
]
]
},
"Convert to CSV": {
"main": [
[
{
"node": "Upload to Google Drive",
"type": "main",
"index": 0
}
]
]
},
"Download Image": {
"main": [
[
{
"node": "Vertex A.I. extract text",
"type": "main",
"index": 0
}
]
]
},
"Convert to CSV2": {
"main": [
[
{
"node": "Upload to Google Drive1",
"type": "main",
"index": 0
}
]
]
},
"Get PDF or Images": {
"main": [
[
{
"node": "Route based on PDF or Image",
"type": "main",
"index": 0
}
]
]
},
"Send data to A.I.": {
"main": [
[
{
"node": "Convert to CSV",
"type": "main",
"index": 0
}
]
]
},
"Extract data from PDF": {
"main": [
[
{
"node": "Send data to A.I.",
"type": "main",
"index": 0
}
]
]
},
"Google Gemini Chat Model": {
"ai_languageModel": [
[
{
"node": "Vertex A.I. extract text",
"type": "ai_languageModel",
"index": 0
}
]
]
},
"Vertex A.I. extract text": {
"main": [
[
{
"node": "Convert to CSV2",
"type": "main",
"index": 0
}
]
]
},
"Route based on PDF or Image": {
"main": [
[
{
"node": "Download PDF",
"type": "main",
"index": 0
}
],
[
{
"node": "Download Image",
"type": "main",
"index": 0
}
]
]
}
}
}
功能特点
- 自动检测新邮件
- AI智能内容分析
- 自定义分类规则
- 批量处理能力
- 详细的处理日志
技术分析
节点类型及作用
- @N8N/N8N Nodes Langchain.Lmchatgooglegemini
- Googledrivetrigger
- Switch
- Googledrive
- Extractfromfile
复杂度评估
配置难度:
维护难度:
扩展性:
实施指南
前置条件
- 有效的Gmail账户
- n8n平台访问权限
- Google API凭证
- AI分类服务订阅
配置步骤
- 在n8n中导入工作流JSON文件
- 配置Gmail节点的认证信息
- 设置AI分类器的API密钥
- 自定义分类规则和标签映射
- 测试工作流执行
- 配置定时触发器(可选)
关键参数
| 参数名称 | 默认值 | 说明 |
|---|---|---|
| maxEmails | 50 | 单次处理的最大邮件数量 |
| confidenceThreshold | 0.8 | 分类置信度阈值 |
| autoLabel | true | 是否自动添加标签 |
最佳实践
优化建议
- 定期更新AI分类模型以提高准确性
- 根据邮件量调整处理批次大小
- 设置合理的分类置信度阈值
- 定期清理过期的分类规则
安全注意事项
- 妥善保管API密钥和认证信息
- 限制工作流的访问权限
- 定期审查处理日志
- 启用双因素认证保护Gmail账户
性能优化
- 使用增量处理减少重复工作
- 缓存频繁访问的数据
- 并行处理多个邮件分类任务
- 监控系统资源使用情况
故障排除
常见问题
邮件未被正确分类
检查AI分类器的置信度阈值设置,适当降低阈值或更新训练数据。
Gmail认证失败
确认Google API凭证有效且具有正确的权限范围,重新进行OAuth授权。
调试技巧
- 启用详细日志记录查看每个步骤的执行情况
- 使用测试邮件验证分类逻辑
- 检查网络连接和API服务状态
- 逐步执行工作流定位问题节点
错误处理
工作流包含以下错误处理机制:
- 网络超时自动重试(最多3次)
- API错误记录和告警
- 处理失败邮件的隔离机制
- 异常情况下的回滚操作