auth

A FastAPI authentication and authorization setup for verifying users and controlling what they can access. It uses signed JWT tokens, OAuth2, password hashing, and user roles.

In plain words
What is it for?
Use it to add login security, access tokens, refresh tokens, password verification, OAuth2 flows, and role-based access control.
Why use it?
It removes much of the repeated work involved in safely handling passwords, login tokens, token expiry, and permission checks.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/justdvp/claude-code-templates/auth
Clone the repo
git clone --depth 1 https://github.com/Justdvp/claude-code-templates

Made for: Claude Code.

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 5,021 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.05021
Opus 5 $0.00000 $0.02511
Sonnet 5 $0.00000 $0.01004
Haiku 4.5 $0.00000 $0.00502

Measured 2d ago against content hash 66b7265094e9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

auth scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

cli-tool/templates/python/examples/fastapi-app/.claude/commands/auth.md · 776 lines

How it starts

The opening of the file, as written. The whole thing — 776 lines — stays where its author put it; the contents beside it link to each section on GitHub.

FastAPI Authentication & Authorization

Complete authentication system with JWT tokens, OAuth2, and role-based access control.

Usage

# Install auth dependencies
pip install python-jose[cryptography] passlib[bcrypt] python-multipart

# Generate secret key
openssl rand -hex 32

JWT Configuration

# app/core/security.py
from datetime import datetime, timedelta
from typing import Optional, Union, Any
from jose import JWTError, jwt
from passlib.context import CryptContext
from app.core.config import settings

# Password hashing
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

# JWT settings
SECRET_KEY = settings.SECRET_KEY
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30
REFRESH_TOKEN_EXPIRE_DAYS = 7

def create_access_token(
    subject: Union[str, Any], 
    expires_delta: Optional[timedelta] = None
) -> str:
    """Create JWT access token."""
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    
    to_encode = {"exp": expire, "sub": str(subject), "type": "access"}
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def create_refresh_token(subject: Union[str, Any]) -> str:
    """Create JWT refresh token."""
    expire = datetime.utcnow() + timedelta(days=REFRESH_TOKEN_EXPIRE_DAYS)
    to_encode = {"exp": expire, "sub": str(subject), "type": "refresh"}
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verify password against hash."""
    return pwd_context.verify(plain_password, hashed_password)

def get_password_hash(password: str) -> str:
    """Generate password hash."""
    return pwd_context.hash(password)

def decode_token(token: str) -> Optional[dict]:
    """Decode and verify JWT token."""
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        return payload
    except JWTError:
        return None

Read the full file on GitHub · 776 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 776 lines · 0 tokens per session scan A 66b7265094e9

Subscribe to this mod's changes

auth is a command published in the GitHub repository Justdvp/claude-code-templates (7 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 5,021 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.