Jwt Toolkit

Decode, inspect, and validate JWT (JSON Web Token) tokens from the command line. Shows header, payload, algorithm, expiry status, and known claim labels. Use when debugging auth tokens, checking if a JWT is expired, inspecting JWT claims, decoding Bearer tokens, or analyzing token structure. Triggers on "decode JWT", "inspect token", "JWT expired", "parse JWT", "check Bearer token", "token claims".

Zero-dependency JWT decoder and inspector. Decodes any JWT token and shows header, payload claims, algorithm info, expiry status, and signature details.

Quick Start

# Decode a JWT token
python3 scripts/jwt_decode.py eyJhbGciOiJIUzI1NiIs...

# Read token from file
python3 scripts/jwt_decode.py --file token.txt

# Read from stdin (pipe from curl, etc.)
echo "eyJ..." | python3 scripts/jwt_decode.py --stdin

# JSON output for scripting
python3 scripts/jwt_decode.py eyJ... --format json

# Also handles "Bearer " prefix automatically
python3 scripts/jwt_decode.py "Bearer eyJhbGciOiJIUzI1NiIs..."

Features

• Decodes header and payload with human-readable claim labels
• Shows algorithm details and security warnings (e.g., none algorithm)
• Checks token expiry with remaining time or time-since-expired
• Recognizes 20+ standard and common claims (iss, sub, aud, roles, scope, etc.)
• Strips "Bearer " prefix automatically
• JSON and text output formats
• No external dependencies — pure Python stdlib