docs: add Phase 2 domain verification design and clarifications

Add comprehensive Phase 2 documentation: - Complete design document for two-factor domain verification - Implementation guide with code examples - ADR for implementation decisions (ADR-0004) - ADR for rel="me" email discovery (ADR-008) - Phase 1 impact assessment - All 23 clarification questions answered - Updated architecture docs (indieauth-protocol, security) - Updated ADR-005 with rel="me" approach - Updated backlog with technical debt items Design ready for Phase 2 implementation. Generated with Claude Code https://claude.com/claude-code Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-20 13:05:09 -07:00
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+# Phase 1 Impact Assessment: Authentication Flow Change
+
+**Date**: 2025-11-20
+**Architect**: Claude (Architect Agent)
+**Related ADRs**: ADR-005 (updated), ADR-008 (new)
+**Related Report**: /docs/reports/2025-11-20-phase-1-foundation.md
+
+## Summary
+
+The authentication design has been updated to require BOTH DNS TXT verification AND email verification via rel="me" discovery. This change impacts Phase 1 implementation and defines new requirements for Phase 2.
+
+## Authentication Flow Change
+
+### Original Design (ADR-005 v1)
+- **Primary**: Email verification (user provides email)
+- **Optional**: DNS TXT verification (fast-path to skip email)
+- **Flow**: DNS check → if not found, request email → send code → verify code
+
+### Updated Design (ADR-005 v2 + ADR-008)
+- **Required Factor 1**: DNS TXT verification (`_gondulf.{domain}` = `verified`)
+- **Required Factor 2**: Email verification via rel="me" discovery
+- **Flow**: DNS check → rel="me" discovery → send code to discovered email → verify code
+
+### Key Differences
+
+| Aspect | Original | Updated |
+|--------|----------|---------|
+| DNS TXT | Optional (fast-path) | Required (first factor) |
+| Email Discovery | User input | rel="me" link parsing |
+| Email Verification | Optional (fallback) | Required (second factor) |
+| Security Model | Single-factor | Two-factor |
+| Attack Resistance | Moderate | High (requires DNS + email control) |
+| Setup Complexity | Lower (email only works) | Higher (both required) |
+
+## Phase 1 Implementation Impact
+
+### What Phase 1 Implemented
+
+Phase 1 successfully implemented:
+- ✅ Configuration management (GONDULF_* environment variables)
+- ✅ Database layer with migrations (SQLite, SQLAlchemy Core)
+- ✅ In-memory code storage (TTL-based expiration)
+- ✅ Email service (SMTP with STARTTLS support)
+- ✅ DNS service (TXT record querying with fallback resolvers)
+- ✅ Structured logging
+- ✅ FastAPI application with health check endpoint
+- ✅ 94.16% test coverage (96 tests passing)
+
+### Does Phase 1 Need Changes?
+
+**Answer: NO. Phase 1 implementation remains valid.**
+
+#### Analysis
+
+**Email Service** (`src/gondulf/email.py`):
+- Current: Generic email sending service
+- Change Impact: **None**
+- Reason: Email service sends codes to any email address. Whether email is user-provided or rel="me"-discovered doesn't affect this service.
+- Status: **No changes needed**
+
+**DNS Service** (`src/gondulf/dns.py`):
+- Current: TXT record verification with fallback resolvers
+- Change Impact: **None**
+- Reason: DNS service already implements TXT record verification as designed. Changing from "optional" to "required" is a business logic change, not a DNS service change.
+- Status: **No changes needed**
+
+**In-Memory Storage** (`src/gondulf/storage.py`):
+- Current: TTL-based code storage
+- Change Impact: **None**
+- Reason: Storage mechanism is independent of how email is discovered or whether DNS is optional/required.
+- Status: **No changes needed**
+
+**Database Schema** (`001_initial_schema.sql`):
+- Current: `domains` table with `domain`, `verification_method`, `verified_at`
+- Change Impact: **Minor update needed in Phase 2**
+- Reason: Schema already supports storing verification method. Will need to update from `'txt_record'` or `'email'` to `'two_factor'` when storing records.
+- Status: **Schema structure OK, values will change in Phase 2**
+
+**Configuration** (`src/gondulf/config.py`):
+- Current: SMTP configuration, DNS configuration, timeouts
+- Change Impact: **None immediately, optional addition in Phase 2**
+- Reason: Current configuration supports both email and DNS. May want to add timeout for HTML fetching in Phase 2.
+- Status: **No changes needed now**
+
+### Phase 1 Status: APPROVED
+
+Phase 1 implementation remains valid and does NOT require any revisions due to the authentication flow change. All Phase 1 components are foundational services that work regardless of how they're orchestrated in the authentication flow.
+
+## Phase 2 Requirements: New Implementation Needs
+
+Phase 2 must now implement the updated authentication flow. Here's what needs to be built:
+
+### 1. HTML Fetching Service (NEW)
+
+**Purpose**: Fetch user's homepage to discover rel="me" links
+
+**Implementation**:
+```python
+# src/gondulf/html_fetcher.py
+
+import requests
+from typing import Optional
+
+class HTMLFetcherService:
+    """
+    Fetch user's homepage over HTTPS.
+    """
+    def __init__(self, timeout: int = 10):
+        self.timeout = timeout
+        self.max_redirects = 5
+        self.max_size = 5 * 1024 * 1024  # 5MB
+
+    def fetch_site(self, domain: str) -> Optional[str]:
+        """
+        Fetch site HTML content.
+
+        Args:
+            domain: Domain to fetch (e.g., "example.com")
+
+        Returns:
+            HTML content as string, or None if fetch fails
+        """
+        url = f"https://{domain}"
+
+        try:
+            response = requests.get(
+                url,
+                timeout=self.timeout,
+                allow_redirects=True,
+                max_redirects=self.max_redirects,
+                verify=True  # Enforce SSL verification
+            )
+            response.raise_for_status()
+
+            # Check content size
+            if len(response.content) > self.max_size:
+                raise ValueError(f"Response too large: {len(response.content)} bytes")
+
+            return response.text
+
+        except requests.exceptions.SSLError as e:
+            logger.error(f"SSL verification failed for {domain}: {e}")
+            return None
+        except requests.exceptions.Timeout:
+            logger.error(f"Timeout fetching {domain}")
+            return None
+        except Exception as e:
+            logger.error(f"Failed to fetch {domain}: {e}")
+            return None
+```
+
+**Dependencies**:
+- `requests` library (already in pyproject.toml)
+- Timeout configuration (add to Config if needed)
+
+**Tests Required**:
+- Successful HTTPS fetch
+- SSL verification failure
+- Timeout handling
+- HTTP error codes (404, 500, etc.)
+- Redirect following
+- Size limit enforcement
+
+---
+
+### 2. rel="me" Email Discovery Service (NEW)
+
+**Purpose**: Parse HTML to discover email from rel="me" links
+
+**Implementation**:
+```python
+# src/gondulf/relme.py
+
+from bs4 import BeautifulSoup
+from typing import Optional
+import re
+
+class RelMeDiscoveryService:
+    """
+    Discover email addresses from rel="me" links in HTML.
+    """
+
+    def discover_email(self, html_content: str) -> Optional[str]:
+        """
+        Parse HTML and discover email from rel="me" link.
+
+        Args:
+            html_content: HTML content as string
+
+        Returns:
+            Email address or None if not found
+        """
+        try:
+            # Parse HTML (BeautifulSoup handles malformed HTML)
+            soup = BeautifulSoup(html_content, 'html.parser')
+
+            # Find all rel="me" links (<link> and <a> tags)
+            me_links = soup.find_all('link', rel='me') + soup.find_all('a', rel='me')
+
+            # Look for mailto: links
+            for link in me_links:
+                href = link.get('href', '')
+                if href.startswith('mailto:'):
+                    email = href.replace('mailto:', '').strip()
+
+                    # Validate email format
+                    if self._validate_email_format(email):
+                        logger.info(f"Discovered email via rel='me': {email[:3]}***")
+                        return email
+
+            logger.warning("No rel='me' mailto: link found in HTML")
+            return None
+
+        except Exception as e:
+            logger.error(f"Failed to parse HTML: {e}")
+            return None
+
+    def _validate_email_format(self, email: str) -> bool:
+        """Validate email address format (RFC 5322 simplified)."""
+        email_regex = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
+
+        if not re.match(email_regex, email):
+            return False
+
+        if len(email) > 254:  # RFC 5321 maximum
+            return False
+
+        if email.count('@') != 1:
+            return False
+
+        return True
+```
+
+**Dependencies**:
+- `beautifulsoup4` library (add to pyproject.toml)
+- `html.parser` (Python standard library)
+
+**Tests Required**:
+- Discovery from `<link rel="me">` tags
+- Discovery from `<a rel="me">` tags
+- Multiple rel="me" links (select first mailto)
+- Malformed HTML handling
+- Missing rel="me" links
+- Invalid email format in link
+- Edge cases (empty href, non-mailto links, etc.)
+
+---
+
+### 3. Domain Verification Service (UPDATED)
+
+**Purpose**: Orchestrate two-factor verification (DNS + Email)
+
+**Implementation**:
+```python
+# src/gondulf/domain_verification.py
+
+from typing import Tuple, Optional
+from .dns import DNSService
+from .html_fetcher import HTMLFetcherService
+from .relme import RelMeDiscoveryService
+from .email import EmailService
+from .storage import CodeStorage
+
+class DomainVerificationService:
+    """
+    Two-factor domain verification service.
+
+    Verifies domain ownership through:
+    1. DNS TXT record verification
+    2. Email verification via rel="me" discovery
+    """
+
+    def __init__(
+        self,
+        dns_service: DNSService,
+        html_fetcher: HTMLFetcherService,
+        relme_discovery: RelMeDiscoveryService,
+        email_service: EmailService,
+        code_storage: CodeStorage
+    ):
+        self.dns = dns_service
+        self.html_fetcher = html_fetcher
+        self.relme = relme_discovery
+        self.email = email_service
+        self.code_storage = code_storage
+
+    def start_verification(self, domain: str) -> Tuple[bool, Optional[str], Optional[str]]:
+        """
+        Start domain verification process.
+
+        Returns: (success, discovered_email, error_message)
+
+        Raises HTTPException with appropriate error if verification cannot start.
+        """
+        # Step 1: Verify DNS TXT record
+        dns_verified = self.dns.verify_txt_record(domain, "verified")
+        if not dns_verified:
+            error = f"DNS TXT record not found for {domain}. Please add: _gondulf.{domain} TXT verified"
+            return False, None, error
+
+        # Step 2: Fetch site and discover email
+        html = self.html_fetcher.fetch_site(domain)
+        if html is None:
+            error = f"Could not fetch site at https://{domain}. Please ensure site is accessible via HTTPS."
+            return False, None, error
+
+        # Step 3: Discover email from rel="me"
+        email = self.relme.discover_email(html)
+        if email is None:
+            error = 'No rel="me" mailto: link found. Please add: <link rel="me" href="mailto:you@example.com">'
+            return False, None, error
+
+        # Step 4: Generate and send verification code
+        code = self._generate_code()
+        self.code_storage.store(email, code, ttl=900)  # 15 minutes
+
+        email_sent = self.email.send_verification_email(email, code)
+        if not email_sent:
+            error = f"Failed to send verification email to {email}. Please try again."
+            return False, email, error
+
+        # Success: code sent to discovered email
+        return True, email, None
+
+    def verify_code(self, email: str, submitted_code: str) -> Tuple[bool, str]:
+        """
+        Verify submitted code.
+
+        Returns: (success, domain_or_error_message)
+        """
+        stored_data = self.code_storage.get(email)
+
+        if stored_data is None:
+            return False, "No verification code found. Please restart verification."
+
+        code, domain = stored_data
+
+        # Verify code (constant-time comparison)
+        if not secrets.compare_digest(submitted_code, code):
+            return False, "Invalid code. Please try again."
+
+        # Success: mark code as used
+        self.code_storage.delete(email)
+
+        return True, domain
+
+    def _generate_code(self) -> str:
+        """Generate 6-digit verification code."""
+        return ''.join(secrets.choice('0123456789') for _ in range(6))
+```
+
+**Dependencies**:
+- All Phase 1 services (DNS, Email, Storage)
+- New HTML fetcher service
+- New rel="me" discovery service
+
+**Tests Required**:
+- Full verification flow (DNS → rel="me" → email → code)
+- DNS verification failure
+- Site fetch failure
+- rel="me" discovery failure
+- Email send failure
+- Code verification success/failure
+- Multiple attempts tracking
+- Code expiration
+
+---
+
+### 4. Domain Verification UI Endpoints (NEW)
+
+**Purpose**: HTTP endpoints for user interaction
+
+**Implementation**:
+```python
+# src/gondulf/routers/verification.py
+
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel
+
+router = APIRouter(prefix="/verify", tags=["verification"])
+
+class VerificationStartRequest(BaseModel):
+    domain: str
+
+class VerificationStartResponse(BaseModel):
+    success: bool
+    email_masked: Optional[str]  # e.g., "u***@example.com"
+    error: Optional[str]
+
+class VerificationCodeRequest(BaseModel):
+    email: str
+    code: str
+
+class VerificationCodeResponse(BaseModel):
+    success: bool
+    domain: Optional[str]
+    error: Optional[str]
+
+@router.post("/start", response_model=VerificationStartResponse)
+async def start_verification(request: VerificationStartRequest):
+    """
+    Start domain verification process.
+
+    Steps:
+    1. Verify DNS TXT record
+    2. Discover email from rel="me"
+    3. Send verification code to email
+    """
+    success, email, error = domain_verification_service.start_verification(request.domain)
+
+    if not success:
+        return VerificationStartResponse(success=False, email_masked=None, error=error)
+
+    # Mask email for display: u***@example.com
+    masked_email = f"{email[0]}***@{email.split('@')[1]}"
+
+    return VerificationStartResponse(
+        success=True,
+        email_masked=masked_email,
+        error=None
+    )
+
+@router.post("/code", response_model=VerificationCodeResponse)
+async def verify_code(request: VerificationCodeRequest):
+    """
+    Verify submitted code.
+
+    Returns domain if code is valid.
+    """
+    success, result = domain_verification_service.verify_code(request.email, request.code)
+
+    if not success:
+        return VerificationCodeResponse(success=False, domain=None, error=result)
+
+    return VerificationCodeResponse(success=True, domain=result, error=None)
+```
+
+**Dependencies**:
+- FastAPI router
+- Pydantic models
+- Domain verification service
+
+**Tests Required**:
+- POST /verify/start success case
+- POST /verify/start with DNS failure
+- POST /verify/start with rel="me" failure
+- POST /verify/start with email send failure
+- POST /verify/code success case
+- POST /verify/code with invalid code
+- POST /verify/code with expired code
+- POST /verify/code with missing code
+
+---
+
+### 5. Authorization Endpoint Integration (UPDATED)
+
+**Changes to Authorization Flow**:
+
+**Before** (original design):
+```
+1. User enters domain (me parameter)
+2. Display form: "Enter your email at {domain}"
+3. User enters email manually
+4. Send code, user enters code
+5. Display consent screen
+```
+
+**After** (updated design):
+```
+1. User enters domain (me parameter)
+2. Server performs two-factor verification:
+   a. Verify DNS TXT record
+   b. Discover email from rel="me"
+   c. Send code to discovered email
+3. Display code entry form (show discovered email masked)
+4. User enters code
+5. Display consent screen
+```
+
+**Implementation Changes**:
+- Call `DomainVerificationService.start_verification()` instead of requesting email from user
+- Update UI to show "Sending code to u***@example.com" instead of email input form
+- Handle new error cases (DNS not found, rel="me" not found, site unreachable)
+
+---
+
+## Phase 2 Feature Breakdown
+
+### New Dependencies to Add
+
+**pyproject.toml additions**:
+```toml
+[project]
+dependencies = [
+    # ... existing dependencies
+    "beautifulsoup4>=4.12.0",  # HTML parsing for rel="me" discovery
+]
+```
+
+### New Source Files
+
+1. `src/gondulf/html_fetcher.py` - HTML fetching service
+2. `src/gondulf/relme.py` - rel="me" email discovery service
+3. `src/gondulf/domain_verification.py` - Two-factor verification orchestration
+4. `src/gondulf/routers/verification.py` - Verification endpoints (if implemented separately from authorization)
+
+### Updated Files
+
+1. `src/gondulf/main.py` - Register new routers, initialize new services
+2. `src/gondulf/config.py` - Optional: add HTML fetch timeout config
+3. Database migration (002_update_verification_method.sql) - Change domain.verification_method values
+
+### New Test Files
+
+1. `tests/unit/test_html_fetcher.py` - HTML fetching tests
+2. `tests/unit/test_relme.py` - rel="me" discovery tests
+3. `tests/unit/test_domain_verification.py` - Verification service tests
+4. `tests/integration/test_verification_endpoints.py` - Verification endpoint tests
+
+### Estimated Effort
+
+**New Components**:
+- HTML Fetcher Service: 0.5 days
+- rel="me" Discovery Service: 0.5 days
+- Domain Verification Service: 1 day
+- Verification Endpoints: 0.5 days
+- Tests (all new components): 1 day
+
+**Total New Work**: ~3.5 days
+
+**Authorization Endpoint** (already planned):
+- Original estimate: 3-5 days
+- Updated estimate: 3-5 days (same - just uses DomainVerificationService)
+
+## Database Schema Updates
+
+### Migration: 002_update_verification_method.sql
+
+```sql
+-- Update verification_method values from single-factor to two-factor
+-- This is a data migration, not schema change
+
+UPDATE domains
+SET verification_method = 'two_factor'
+WHERE verification_method IN ('txt_record', 'email');
+
+-- No schema changes needed - 'verification_method' column already exists
+```
+
+**When to Apply**: Phase 2, before authorization endpoint implementation
+
+## Error Message Updates
+
+### DNS TXT Not Found
+
+```
+DNS Verification Failed
+
+Please add this TXT record to your domain's DNS:
+
+Type: TXT
+Name: _gondulf.example.com
+Value: verified
+
+DNS changes may take up to 24 hours to propagate.
+
+Need help? See: https://docs.gondulf.example.com/setup/dns
+```
+
+### rel="me" Not Found
+
+```
+Email Discovery Failed
+
+Could not find a rel="me" email link on your homepage.
+
+Please add this to your homepage (https://example.com):
+<link rel="me" href="mailto:your-email@example.com">
+
+This declares your email address for IndieAuth verification.
+
+Learn more: https://indieweb.org/rel-me
+```
+
+### Site Unreachable
+
+```
+Site Fetch Failed
+
+Could not fetch your site at https://example.com
+
+Please check:
+- Site is accessible via HTTPS
+- SSL certificate is valid
+- No firewall blocking requests
+
+Try again once your site is accessible.
+```
+
+### Email Send Failure
+
+```
+Email Delivery Failed
+
+Failed to send verification code to u***@example.com
+
+Please check:
+- Email address is correct in your rel="me" link
+- Email server is accepting mail
+- Check spam/junk folder
+
+Try again, or contact support if the issue persists.
+```
+
+## Documentation Updates Needed
+
+### User Documentation (Phase 2)
+
+1. **Setup Guide**: `/docs/user/setup.md`
+   - Step 1: Add DNS TXT record
+   - Step 2: Add rel="me" link to homepage
+   - Step 3: Test verification
+
+2. **Troubleshooting**: `/docs/user/troubleshooting.md`
+   - DNS verification failures
+   - rel="me" discovery issues
+   - Email delivery problems
+
+3. **Examples**: `/docs/user/examples.md`
+   - Example HTML with rel="me" link
+   - Example DNS configuration (various providers)
+
+### Developer Documentation (Phase 2)
+
+1. **API Reference**: `/docs/api/verification.md`
+   - POST /verify/start endpoint
+   - POST /verify/code endpoint
+   - Error codes and responses
+
+2. **Architecture**: `/docs/architecture/domain-verification.md`
+   - Two-factor verification flow diagram
+   - Service interaction diagram
+   - Error handling flowchart
+
+## Security Considerations for Phase 2
+
+### New Attack Surfaces
+
+1. **HTML Parsing**:
+   - Risk: Malicious HTML exploiting parser
+   - Mitigation: BeautifulSoup handles untrusted HTML safely
+   - Test: Fuzzing with malformed HTML
+
+2. **HTTPS Fetching**:
+   - Risk: SSL verification bypass
+   - Mitigation: Enforce `verify=True` in requests
+   - Test: Attempt to fetch site with invalid certificate (must fail)
+
+3. **rel="me" Spoofing**:
+   - Risk: Attacker adds rel="me" to compromised site
+   - Mitigation: Two-factor requirement (also need DNS control)
+   - Test: Verify DNS check happens BEFORE rel="me" discovery
+
+### Security Testing Required
+
+1. **Input Validation**:
+   - Malformed domain names
+   - Oversized HTML responses (>5MB)
+   - Invalid email formats in rel="me" links
+
+2. **TLS Enforcement**:
+   - Verify HTTPS-only fetching
+   - Verify SSL certificate validation
+   - Reject sites with invalid certificates
+
+3. **Rate Limiting** (future):
+   - Prevent bulk rel="me" discovery
+   - Limit verification attempts per domain
+
+## Configuration Updates
+
+### Optional New Config
+
+```python
+# src/gondulf/config.py
+
+class Config:
+    # ... existing config
+
+    # HTML Fetching (optional, has sensible defaults)
+    HTML_FETCH_TIMEOUT: int = 10  # seconds
+    HTML_MAX_SIZE: int = 5 * 1024 * 1024  # 5MB
+    HTML_MAX_REDIRECTS: int = 5
+```
+
+### Environment Variables
+
+```bash
+# .env.example additions (optional)
+
+# HTML Fetching Configuration (optional - has defaults)
+GONDULF_HTML_FETCH_TIMEOUT=10  # Timeout for fetching user's site (seconds)
+GONDULF_HTML_MAX_SIZE=5242880  # Maximum HTML size (bytes, default 5MB)
+GONDULF_HTML_MAX_REDIRECTS=5   # Maximum redirects to follow
+```
+
+## Testing Strategy for Phase 2
+
+### Unit Tests
+
+**HTML Fetcher**:
+- Mock successful HTTPS response
+- Mock SSL verification failure
+- Mock timeout
+- Mock HTTP errors (404, 500, etc.)
+- Mock size limit exceeded
+- Mock redirect following
+
+**rel="me" Discovery**:
+- Parse `<link rel="me" href="mailto:...">`
+- Parse `<a rel="me" href="mailto:...">`
+- Handle malformed HTML
+- Handle missing rel="me" links
+- Handle invalid email in link
+- Handle multiple rel="me" links (select first)
+
+**Domain Verification Service**:
+- Full two-factor flow success
+- DNS verification failure
+- Site fetch failure
+- rel="me" discovery failure
+- Email send failure
+- Code verification success/failure
+
+### Integration Tests
+
+**Verification Endpoints**:
+- POST /verify/start with valid domain (mock services)
+- POST /verify/start with DNS failure
+- POST /verify/start with rel="me" failure
+- POST /verify/code with valid code
+- POST /verify/code with invalid code
+
+### End-to-End Tests (Future)
+
+- Complete verification flow with real HTML
+- Authorization flow integration
+- Token issuance after successful verification
+
+## Acceptance Criteria for Phase 2
+
+Phase 2 will be considered complete when:
+
+1. ✅ HTML fetcher service implemented and tested
+2. ✅ rel="me" discovery service implemented and tested
+3. ✅ Domain verification service orchestrates two-factor verification
+4. ✅ Verification endpoints return correct responses for all cases
+5. ✅ Error messages are clear and actionable
+6. ✅ All new tests passing (unit + integration)
+7. ✅ Test coverage remains >80% overall
+8. ✅ Security testing complete (HTML parsing, TLS enforcement)
+9. ✅ Documentation updated (user setup guide, API reference)
+10. ✅ Database migration applied successfully
+
+## Timeline Estimate
+
+**Phase 2 Components**:
+- HTML Fetcher: 0.5 days
+- rel="me" Discovery: 0.5 days
+- Domain Verification Service: 1 day
+- Verification Endpoints: 0.5 days
+- Testing: 1 day
+- Documentation: 0.5 days
+
+**Total New Work**: ~4 days
+
+**Authorization Endpoint** (already planned):
+- Original estimate: 3-5 days
+- Updated estimate: 3-5 days (uses DomainVerificationService)
+
+**Phase 2 Total**: ~7-9 days (vs. original estimate of 3-5 days)
+
+**Impact**: +4 days of work due to authentication flow change
+
+## Recommendation
+
+**Phase 1**: APPROVED as-is. No changes needed.
+
+**Phase 2**: Proceed with implementation of:
+1. HTML fetching service
+2. rel="me" discovery service
+3. Domain verification service (two-factor orchestration)
+4. Verification endpoints
+5. Updated authorization endpoint to use domain verification service
+
+The additional work (HTML fetching + rel="me" discovery) adds ~4 days to Phase 2, bringing total Phase 2 estimate to 7-9 days instead of original 3-5 days.
+
+## Sign-off
+
+**Assessment Status**: Complete
+**Phase 1 Impact**: None - Phase 1 approved as-is
+**Phase 2 Impact**: Additional 4 days of work for new services
+**Risk Level**: Low - All new work is well-scoped and testable
+**Ready to Proceed**: Yes
+
+---
+
+**Assessment completed**: 2025-11-20
+**Architect**: Claude (Architect Agent)