Development Server

/**
 * Start development server with hot reloading and file watching
 * @param options - Development server configuration
 */
gatsby develop [options]

interface DevelopOptions {
  host?: string;                    // -H, --host (default: localhost)
  port?: string;                    // -p, --port (default: 8000 or env.PORT)  
  open?: boolean;                   // -o, --open browser automatically
  https?: boolean;                  // -S, --https enable HTTPS
  certFile?: string;               // -c, --cert-file custom HTTPS certificate
  keyFile?: string;                // -k, --key-file custom HTTPS private key
  caFile?: string;                 // --ca-file custom CA certificate
  graphqlTracing?: boolean;        // --graphql-tracing trace GraphQL resolvers
  openTracingConfigFile?: string;  // --open-tracing-config-file OpenTracing config
  inspect?: number;                // --inspect Node.js debugging port (default: 9229)
  inspectBrk?: number;             // --inspect-brk debugging with breakpoint
}

# Standard development server
gatsby develop

# Custom host and port
gatsby develop --host 0.0.0.0 --port 3000
gatsby develop -H localhost -p 8080

# Network access for testing on other devices
gatsby develop -H 0.0.0.0

# Auto-open browser
gatsby develop --open

# Enable HTTPS
gatsby develop --https

# HTTPS with custom certificates
gatsby develop --https --cert-file ./certificates/cert.pem --key-file ./certificates/key.pem

# Enable Node.js debugging
gatsby develop --inspect
gatsby develop --inspect-brk 9229

/**
 * HTTPS development server configuration
 * Supports custom certificates or automatic generation
 */
interface HttpsConfig {
  https: boolean;           // Enable HTTPS
  certFile?: string;        // Path to certificate file (.crt/.pem)
  keyFile?: string;         // Path to private key file (.key/.pem)  
  caFile?: string;          // Path to CA certificate file
}

# Basic HTTPS (uses generated certificates)
gatsby develop --https

# Custom certificate files
gatsby develop --https \
  --cert-file ./certs/localhost.crt \
  --key-file ./certs/localhost.key

# With CA certificate
gatsby develop --https \
  --cert-file ./certs/cert.pem \
  --key-file ./certs/key.pem \
  --ca-file ./certs/ca.pem

/**
 * Network access configuration for development server
 * Enables access from other devices on the same network
 */
interface NetworkConfig {
  host: string;    // Bind address (0.0.0.0 for network access)
  port: string;    // Port number
}

# Enable network access
gatsby develop --host 0.0.0.0

# Custom network configuration
gatsby develop --host 0.0.0.0 --port 3000

You can now view your site in the browser.

  Local:            http://localhost:8000/
  On Your Network:  http://192.168.1.100:8000/

/**
 * Node.js debugging configuration
 * Enables Chrome DevTools debugging for server-side code
 */
interface DebuggingConfig {
  inspect?: number;     // Enable debugging on port (default: 9229)
  inspectBrk?: number;  // Enable debugging with breakpoint on port
}

# Enable debugging on default port (9229)
gatsby develop --inspect

# Custom debugging port
gatsby develop --inspect 9230

# Start with breakpoint (waits for debugger)
gatsby develop --inspect-brk

# Debugging with custom port and breakpoint
gatsby develop --inspect-brk 9230

/**
 * GraphQL tracing configuration
 * Enables detailed performance analysis of GraphQL operations
 */
interface GraphQLTracingConfig {
  graphqlTracing: boolean;          // Enable GraphQL resolver tracing
  openTracingConfigFile?: string;   // OpenTracing configuration file
}

# Enable GraphQL tracing
gatsby develop --graphql-tracing

# With OpenTracing configuration
gatsby develop --graphql-tracing --open-tracing-config-file ./tracing.json

interface EnvironmentVariables {
  GATSBY_HOST?: string;     // Default host (overrides localhost)
  PORT?: string;            // Default port (overrides 8000)
  HTTPS?: string;           // Enable HTTPS if "true"
  NODE_ENV?: string;        // Set to "development" automatically
}

# Set via environment
export GATSBY_HOST=0.0.0.0
export PORT=3000
gatsby develop

# Inline environment variables
GATSBY_HOST=0.0.0.0 PORT=3000 gatsby develop