Conversational PostgreSQL Agent with Visuals, Multi-KPI, and Data Editing (MCP)

Description

Ask your PostgreSQL database complex questions and receive clear summaries, charts, and even update or insert data — all through one smart agent powered by n8n’s Model Context Protocol (MCP).

Supports:
Multi-KPI insights in one prompt
Auto-generated QuickChart bar/pie charts
Natural-language inserts and updates
Markdown-friendly output for dashboards

🚀 Why This Version Stands Out

This version goes beyond reporting:
📈 Auto-generates charts (QuickChart)
🧮 Answers multiple KPIs in one message
✍️ Add and update records securely
🧠 Uses up to 30 planned steps for smart reasoning

💰 Estimated cost per run: ~$0.02

💬 Example Output

🧰 Key Components

MCP Server Trigger → Receives natural queries
Claude 3.5 Haiku → Plans, reasons, splits tasks
DeepSeek → SQL and QuickChart generation
checkdatabase subflow → Validates SQL
Plot Tool → Converts data to QuickChart URLs
Insert/Update nodes → Edits PostgreSQL records
Markdown Formatter → Combines output into readable message

🤖 Model Configuration Notes

This workflow uses two models:

Claude 3.5 Haiku (Anthropic)
Used as the MCP agent for reasoning, planning, and tool calling. Claude is the native model for MCP and delivers reliable results in fewer steps.

DeepSeek
Used in:
checkdatabase for SQL generation
Plot Tool for QuickChart JSON generation

🧠 All models are modular — you can plug in OpenAI, Gemini, or Mistral if desired.

🔐 Security by Design

No raw SQL from user input
Fully parameterized queries
Structured tool calling with validation
Safe output format (text + chart links)

🧪 Try This Prompt

> “Show me top 5 products by revenue, revenue per month chart, and best customers.”

Expected output:
3 KPIs
Multiple SQL queries
2–3 QuickChart links
Markdown summary for dashboard/Slack

🛠 How to Use

Import:
Build_your_own_PostgreSQL_MCP_server__visuals_capable_.json
checkdatabase.json
Plot_tool.json

Create your PostgreSQL credential under “Credentials” in n8n:
Must match the name used in the workflow (e.g., Postgres account 3)

Assign AI models:
Claude 3.5 Haiku → MCP agent (Claude 3.5 MCP Agent)
DeepSeek → LLM nodes inside checkdatabase and Plot Tool

Trigger the workflow using the URL from the MCP Server Trigger node
(e.g., in a chatbot, HTTP request, or Webhook UI)

📦 End-User Setup Guide

If you're using this template for the first time, follow these exact steps:

Go to your n8n dashboard and import all three workflows (main + subflows)
Create a PostgreSQL credential using your host, database, user, and password
Go to the Claude and DeepSeek nodes, and connect them to your account(s)
Use the Webhook URL in the MCP Server Trigger to connect your chatbot or frontend
Send a prompt like:
“Show me revenue per month, top 5 products, and a chart of best customers.”

Optional:
You can increase the MCP Agent’s MaxIterations to go deeper (default is 30)
You can use Switch nodes to limit access to certain tables or actions
Insert/Update nodes are already included and can be safely enabled

✅ Once this is done, your AI assistant will:
Read from your database
Visualize data via QuickChart
Insert or update rows
Respond in clear, markdown-formatted summaries

🔗 More Templates by the Same Creator

PostgreSQL Conversational Agent with Claude & DeepSeek (Multi-KPI, Secure)

Conversing with Data: Transforming Text into SQL Queries and Visual Curves

Customer Feedback Analysis with AI, QuickChart & HTML Report Generator