---

name: Add Evidence Page description: Create new Evidence.dev dashboard page with charts and tables

Add Evidence Page

When to Use

• Adding new visualization/dashboard
• Creating charts for existing DLT data

File Structure

├── pages/<category>/<page>.md    # Page with charts
└── sources/nfcore_db/<query>.sql # SQL data source

Page Template

---
title: Page Title
sidebar_position: 1
---

Brief description of what this page shows.

```sql summary_query
SELECT COUNT(*) as total FROM nfcore_db.<table_name>
```

SELECT
  date_trunc('week', created_at) as week,
  COUNT(*) as count
FROM nfcore_db.<table_name>
GROUP BY 1
ORDER BY 1

SQL Source Template

File: sources/nfcore_db/<query>.sql

SELECT
  column1,
  column2,
  COUNT(*) as count
FROM <table_name>
GROUP BY 1, 2
ORDER BY count DESC

Component Reference

Component	Use Case	Key Props
BigValue	KPI cards	data, value, title, sparkline, fmt
LineChart	Time series	data, x, y, title, yAxisTitle
AreaChart	Stacked trends	data, x, y, series, seriesColors
BarChart	Comparisons	data, x, y, type=grouped, yFmt
DataTable	Tabular data	data, search, totalRow, <Column>
CalendarHeatmap	Daily heatmap	data, date, value
Tabs/Tab	Tabbed views	<Tab label="Name">
DateRange	Date filter	name, data, dates, defaultValue

DataTable with Columns

<DataTable data={query} search=true totalRow=true>
  <Column id="name" title="Name"/>
  <Column id="count" title="Count" align="right"/>
  <Column id="url" contentType=link linkLabel="View"/>
  <Column id="score" contentType=colorscale colorScale=negative/>
</DataTable>

Stacked AreaChart with Colors

<AreaChart
  data={query}
  x=date
  y={["category_a", "category_b", "category_c"]}
  seriesColors={['#2ecc71', '#f39c12', '#e74c3c']}
  title="Distribution Over Time"
/>

Date Filtering Pattern

<DateRange name="date_range" data={base_query} dates=timestamp defaultValue="Last 90 Days"/>

```sql filtered_query
SELECT * FROM nfcore_db.<table>
WHERE timestamp >= '${inputs.date_range.start}'
  AND timestamp <= '${inputs.date_range.end}'
```

Testing

npm run dev
# Open http://localhost:3000/path/to/page

Checklist

1. Create SQL source in sources/nfcore_db/
2. Create page in pages/<category>/
3. Add frontmatter (title, sidebar_position)
4. Add summary metrics (BigValue)
5. Add time series chart (LineChart/AreaChart)
6. Add detail table (DataTable)
7. Test with npm run dev