# ADR-019 Implementation Summary

**Quick Reference for Developer**
**Date**: 2025-11-19
**Version Target**: 0.8.0

## What You Need to Know

This is a **critical bug fix** that implements IndieAuth authentication correctly by following the IndieLogin.com API specification. The previous attempts (v0.7.0 OAuth metadata, v0.7.1 h-app visibility) were based on misunderstanding the requirements.

## Documentation Structure

All documentation has been separated into proper categories:

### 1. **Architecture Decision Record** (ADR-019)
**File**: `/home/phil/Projects/starpunk/docs/decisions/ADR-019-indieauth-pkce-authentication.md`

**What it contains**:
- Context: Why we need this change
- Decision: What we're doing (PKCE implementation)
- Rationale: Why this approach is correct
- Consequences: Benefits and trade-offs
- **NO implementation details** (those are in the design doc)

### 2. **Design Document** (Complete Technical Specifications)
**File**: `/home/phil/Projects/starpunk/docs/designs/indieauth-pkce-authentication.md`

**What it contains**:
- Complete authentication flow diagrams
- PKCE implementation specifications
- Database schema changes
- Exact code changes with line numbers
- Code to remove with line numbers
- Testing strategy and test code
- Error handling specifications
- Security considerations
- **Complete implementation guide with step-by-step instructions**

This is your **primary implementation reference**.

### 3. **Versioning Guidance**
**File**: `/home/phil/Projects/starpunk/docs/reports/ADR-019-versioning-guidance.md`

**What it contains**:
- Version number decision: **0.8.0**
- Git tag handling (keep all existing tags)
- CHANGELOG update instructions
- Rationale for versioning choice
- What to do with v0.7.0 and v0.7.1 tags

## Quick Implementation Checklist

Follow the design document for detailed steps. This is just a high-level checklist:

### Pre-Implementation
- [ ] Read ADR-019 (architectural decision)
- [ ] Read full design document
- [ ] Review versioning guidance
- [ ] Understand PKCE flow

### Database
- [ ] Add `code_verifier` column to `auth_state` table
- [ ] Test migration

### Code Changes
- [ ] Add PKCE functions to `starpunk/auth.py`
- [ ] Update `_verify_state_token()` to return verifier
- [ ] Update `initiate_login()` with PKCE
- [ ] Update `handle_callback()` with PKCE and iss validation
- [ ] Update callback route to extract and pass `iss`
- [ ] Update logging to redact `code_verifier`

### Code Removal
- [ ] Remove OAuth metadata endpoint from `starpunk/routes/public.py`
- [ ] Remove h-app microformats from `templates/base.html`
- [ ] Remove indieauth-metadata link from `templates/base.html`

### Testing
- [ ] Run unit tests for PKCE functions
- [ ] Run integration tests for auth flow
- [ ] Manual testing with IndieLogin.com
- [ ] Verify logs show PKCE parameters (redacted)
- [ ] Check database for code_verifier storage

### Versioning
- [ ] Update `__version__` to "0.8.0" in `starpunk/__init__.py`
- [ ] Update `__version_info__` to (0, 8, 0)
- [ ] Update CHANGELOG.md with v0.8.0 entry
- [ ] Add notes to v0.7.0 and v0.7.1 CHANGELOG entries
- [ ] Create git tag v0.8.0
- [ ] **Do NOT delete v0.7.0 or v0.7.1 tags**

### Documentation
- [ ] Update ADR-016 status to "Superseded by ADR-019"
- [ ] Update ADR-017 status to "Superseded by ADR-019"
- [ ] Add implementation note to ADR-005

## Key Points

### What's Wrong Now
1. **Missing PKCE** - IndieLogin.com requires it, we don't have it
2. **Wrong endpoints** - Using `/auth` instead of `/authorize` and `/token`
3. **Unnecessary features** - OAuth metadata and h-app not needed

### What We're Fixing
1. **Add PKCE** - Generate verifier/challenge, store, validate
2. **Correct endpoints** - Use `/authorize` and `/token`
3. **Remove cruft** - Delete OAuth metadata and h-app
4. **Add iss validation** - Security best practice

### Why v0.8.0?
- **Not v0.7.2**: Too substantial for PATCH (database change, PKCE implementation, removals)
- **Not v1.0.0**: Not ready for stable (V1 features not complete)
- **Yes v0.8.0**: Appropriate MINOR increment for significant change during 0.x phase

### Why Keep v0.7.0 and v0.7.1 Tags?
- Git history integrity
- Can't "un-release" versions
- CHANGELOG explains what didn't work
- Shows progression of understanding

## File Reference

**Read in this order**:
1. This file (you are here) - Overview
2. `/home/phil/Projects/starpunk/docs/decisions/ADR-019-indieauth-pkce-authentication.md` - Architectural decision
3. `/home/phil/Projects/starpunk/docs/designs/indieauth-pkce-authentication.md` - **Full implementation guide**
4. `/home/phil/Projects/starpunk/docs/reports/ADR-019-versioning-guidance.md` - Versioning details

**Standards Reference**:
- `/home/phil/Projects/starpunk/docs/standards/versioning-strategy.md` - Semantic versioning rules
- `/home/phil/Projects/starpunk/docs/standards/git-branching-strategy.md` - Git workflow

## Critical Files to Modify

### Python Code
```
/home/phil/Projects/starpunk/starpunk/auth.py
/home/phil/Projects/starpunk/starpunk/routes/auth.py
/home/phil/Projects/starpunk/starpunk/routes/public.py (deletions)
/home/phil/Projects/starpunk/starpunk/__init__.py (version)
```

### Templates
```
/home/phil/Projects/starpunk/templates/base.html (deletions)
```

### Database
```
Schema: auth_state table (add code_verifier column)
```

### Documentation
```
/home/phil/Projects/starpunk/CHANGELOG.md (updates)
/home/phil/Projects/starpunk/docs/decisions/ADR-016-indieauth-client-discovery.md (status)
/home/phil/Projects/starpunk/docs/decisions/ADR-017-oauth-client-metadata-document.md (status)
/home/phil/Projects/starpunk/docs/decisions/ADR-005-indielogin-authentication.md (note)
```

## Success Criteria

You're done when:
1. User can log in via IndieLogin.com
2. PKCE parameters visible in authorization URL
3. code_verifier stored in database
4. Token exchange succeeds with code_verifier
5. All tests pass
6. Version is 0.8.0
7. CHANGELOG updated
8. ADR statuses updated

## Getting Help

**If authentication still fails**:
1. Check logs for PKCE parameters (should be redacted but visible)
2. Verify database has code_verifier column
3. Check authorization URL has `code_challenge` and `code_challenge_method=S256`
4. Verify token exchange POST includes `code_verifier`
5. Check IndieLogin.com response in logs

**Key debugging points**:
- `initiate_login()`: Should generate verifier and challenge
- Database: Should store verifier with state
- Authorization URL: Should include challenge
- `handle_callback()`: Should retrieve verifier
- Token exchange: Should send verifier
- IndieLogin.com: Should return `{"me": "url"}`

## Questions?

Refer to:
- Design document for "how"
- ADR-019 for "why"
- Versioning guidance for "what version"

All documentation follows the project principle: **Every line must justify its existence.**

---

**Author**: StarPunk Architect
**Status**: Ready for Implementation
**Priority**: Critical (authentication broken in production)