# Epic: Redis Authentication

**Author:** TextIQ
**Date:** 2025-12-04
**Epic Type:** Security Enhancement
**Story Count:** 1 (Simple change)

---

## Overview

Add password authentication and database selection to Redis configuration to close security gap and prepare for production deployment.

**Current State:** Redis running without authentication (`redis://localhost:6379`)
**Target State:** Redis with password authentication (`redis://:password@host:port/db`)

---

## User Value

**For DevOps/Security:** Redis is secured with authentication, preventing unauthorized access and aligning with security best practices.

**For Developers:** Clear configuration pattern for local vs production Redis, backward compatible with existing setup.

**For Production:** Production-ready Redis configuration that meets security requirements (NFR11, NFR12).

---

## Epic Goal

Enable Redis authentication while maintaining backward compatibility and requiring zero changes to consuming code.

---

## Stories in This Epic

### Story 1: Add Redis Authentication Configuration

**Status:** Ready for implementation
**Estimated Effort:** 1-2 hours
**Files Changed:** 4 (config, env, docker, docs)
**Breaking Changes:** None (backward compatible)

See: `docs/sprint-artifacts/story-redis-auth-1.md`

---

## Technical Context

**Architecture Decision:** Use environment-based configuration with Pydantic Settings to build authenticated Redis URL dynamically.

**Integration Points:**
- Celery broker/backend
- Rate limiting service
- Progress tracking service
- Health checks
- All API routes using Redis

**Testing Scope:**
- Unit tests for URL building
- Integration tests for authenticated connections
- Manual verification of Docker Compose setup

---

## Success Criteria

✅ Redis requires password authentication
✅ All services connect successfully with password
✅ Backward compatible with empty password (local dev)
✅ Health check reports Redis as healthy
✅ Celery workers connect and process tasks
✅ Documentation updated with setup instructions

---

## Dependencies

**Blocks:** None
**Blocked By:** None
**Related:** Epic 1 (Foundation) - follows existing configuration patterns

---

## Risk Assessment

**Risk Level:** Low
**Rollback Strategy:** Remove `--requirepass` from Redis config, restart services

**Risks:**
- Configuration mismatch between .env and Docker Compose → Mitigation: Clear documentation, test locally first
- Existing Redis data becomes inaccessible → Mitigation: Redis data is ephemeral (task queue, cache), can be cleared

---

_This epic enhances security posture without disrupting existing functionality._
