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The evidence dev command starts a local development server with hot module reloading for building Evidence projects.

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Syntax

evidence dev [options]

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Description

This command launches the Evidence development environment, which:
  • Starts a Vite development server on port 3000
  • Watches for file changes in your project
  • Provides hot module reloading for instant updates
  • Syncs files from your project to the .evidence/template directory
  • Loads environment variables from .env files
  • Automatically increases Node.js memory limit to 4096MB

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Options

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--debug
boolean
default:"false"
Enables verbose console logs for debugging. When enabled, detailed logging information is printed to the console.

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File Watching

The dev server automatically watches and syncs the following directories:
  • pages/ - Markdown pages
  • static/ - Static files (images, etc.)
  • sources/ - Source configuration files
  • queries/ - SQL query files
  • components/ - Custom Svelte components
  • partials/ - Reusable content partials
  • app.css - Custom theme file

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Usage Examples

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Start the development server

evidence dev
The server will be available at http://localhost:3000.

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Start with debug logging

evidence dev --debug

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Environment Variables

The dev command respects the following environment variables:
  • EVIDENCE_DATA_DIR - Directory for data files (default: ./static/data)
  • EVIDENCE_DATA_URL_PREFIX - URL prefix for data files (default: static/data)
  • NODE_OPTIONS - Node.js options (automatically set if not present)
See Environment Variables for a complete list.

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Exit Codes

  • 0 - Server started successfully
  • Non-zero - Error occurred during startup

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Warnings

If no source manifest is found at .evidence/template/static/data/manifest.json, you’ll see: 
[!] Unable to load source manifest
This likely means you have no source data, and need to generate it.
Running npm run sources will generate the needed data.
Run evidence sources to generate the required data files.

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