jwt-gen

Generate and decode JWT tokens from the command line. Supports HS256 and RS256 signing, custom claims, and configurable expiry. Zero external dependencies.

Install

npm install -g @lxgicstudios/jwt-gen

Or run directly:

npx @lxgicstudios/jwt-gen --secret "my-key" --sub "user123"

Features

• Generate JWT tokens with HS256 or RS256 signing
• Decode and inspect any JWT token
• Verify token signatures
• Custom claims with --claim key=value
• Configurable expiry (30m, 1h, 7d, 365d)
• Standard claims support (iss, sub, aud)
• JSON output for scripting
• Zero external dependencies (uses Node's built-in crypto)

Usage

Generate a token

jwt-gen --secret "my-secret-key" --sub "user123" --exp 24h

Add custom claims

jwt-gen -s "secret" --claim "role=admin" --claim "tier=pro" --claim "active=true"

Generate with RS256

jwt-gen --algo RS256 --key private.pem --sub "my-service"

Decode a token

jwt-gen --decode "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."

Decode and verify

jwt-gen --decode "eyJhbG..." --secret "my-secret" --verify

Options

| Option | Alias | Default | Description | |--------|-------|---------|-------------| | --help | -h | | Show help message | | --json | | | Output as JSON | | --secret | -s | | HMAC secret key (for HS256) | | --key | -k | | Private key file path (for RS256) | | --pub | | | Public key file path (for verification) | | --algo | -a | HS256 | Algorithm: HS256 or RS256 | | --exp | -e | 1h | Expiry duration (30m, 1h, 7d, etc.) | | --iss | | | Issuer claim | | --sub | | | Subject claim | | --aud | | | Audience claim | | --claim | | | Custom claim as key=value (repeatable) | | --decode | -d | | Decode a JWT token | | --verify | | | Verify signature when decoding |

Duration Formats

| Format | Meaning | |--------|---------| | 30s | 30 seconds | | 30m | 30 minutes | | 1h | 1 hour | | 24h | 24 hours | | 7d | 7 days | | 52w | 52 weeks |

License

MIT - LXGIC Studios