fix: RFC-002 alignment for TrustLevel and BadgeClaims + v2.4.0

* fix: RFC-002 alignment for TrustLevel and BadgeClaims

- Add LEVEL_0 (SS) and LEVEL_4 (EV) to TrustLevel enum per RFC-002 §5
- Update TrustLevel comments to use RFC-002 canonical names
- Add 'ial' field to BadgeClaims for Identity Assurance Level
- Add 'raw_claims' for advanced access to full JWT payload
- Add 'has_key_binding' property for IAL-1 detection
- Add 'confirmation_key' property for cnf claim access
- Fix audience string to list conversion
- Implement 'exclude_paths' parameter in FastAPI middleware
- Add tests for all new features

* chore: Bump version to 2.4.0

* docs: Add v2.4.0 changelog entry

Author: beonde

CHANGELOG.md

@@ -7,6 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.4.0] - 2026-01-18
+
+### Fixed
+- **RFC-002 Alignment**: TrustLevel enum values now match RFC-002 §5 exactly
+- **BadgeClaims**: Aligned claim field names with RFC-002 specification
+
+### Added
+- **MCP Service Client**: RFC-006/RFC-007 operations via MCP protocol
+- **MCP gRPC Client**: Server identity operations
+
 ## [2.3.1] - 2025-01-14
 
 ### Fixed

capiscio_sdk/badge.py

@@ -64,24 +64,38 @@ class VerifyMode(Enum):
 
 
 class TrustLevel(Enum):
-    """Trust level as defined in RFC-002."""
+    """Trust level as defined in RFC-002 §5.
+    
+    Levels:
+        LEVEL_0 (SS): Self-Signed - did:key, iss == sub. Development only.
+        LEVEL_1 (REG): Registered - Account registration with CA.
+        LEVEL_2 (DV): Domain Validated - DNS/HTTP domain ownership proof.
+        LEVEL_3 (OV): Organization Validated - Legal entity verification.
+        LEVEL_4 (EV): Extended Validated - Manual review + security audit.
+    """
+
+    LEVEL_0 = "0"
+    """Self-Signed (SS) - did:key, iss == sub. Development only."""
 
     LEVEL_1 = "1"
-    """Domain Validated (DV) - Basic verification."""
+    """Registered (REG) - Account registration with CA."""
 
     LEVEL_2 = "2"
-    """Organization Validated (OV) - Business verification."""
+    """Domain Validated (DV) - DNS/HTTP domain ownership proof."""
 
     LEVEL_3 = "3"
-    """Extended Validation (EV) - Rigorous vetting."""
+    """Organization Validated (OV) - Legal entity verification."""
+
+    LEVEL_4 = "4"
+    """Extended Validated (EV) - Manual review + security audit."""
 
     @classmethod
     def from_string(cls, value: str) -> "TrustLevel":
         """Create TrustLevel from string value."""
         for level in cls:
             if level.value == value:
                 return level
-        raise ValueError(f"Unknown trust level: {value}")
+        raise ValueError(f"Unknown trust level: {value}. Valid levels: 0 (SS), 1 (REG), 2 (DV), 3 (OV), 4 (EV)")
 
 
 @dataclass
@@ -90,15 +104,24 @@ class BadgeClaims:
 
     Attributes:
         jti: Unique badge identifier (UUID).
-        issuer: Badge issuer URL (CA).
+        issuer: Badge issuer URL (CA) or did:key for self-signed.
         subject: Agent DID (did:web format).
         audience: Optional list of intended audience URLs.
         issued_at: When the badge was issued.
         expires_at: When the badge expires.
-        trust_level: Trust level (1=DV, 2=OV, 3=EV).
+        trust_level: Trust level per RFC-002 §5:
+            - 0 (SS): Self-Signed - Development only
+            - 1 (REG): Registered - Account registration
+            - 2 (DV): Domain Validated - DNS/HTTP proof
+            - 3 (OV): Organization Validated - Legal entity
+            - 4 (EV): Extended Validated - Security audit
         domain: Agent's verified domain.
         agent_name: Human-readable agent name.
         agent_id: Extracted agent ID from subject DID.
+        ial: Identity Assurance Level (RFC-002 §7.2.1):
+            - "0": Account-attested (no key proof)
+            - "1": Proof of Possession (key holder verified, has cnf claim)
+        raw_claims: Original JWT claims dict for advanced access.
     """
 
     jti: str
@@ -110,6 +133,8 @@ class BadgeClaims:
     domain: str
     agent_name: str = ""
     audience: List[str] = field(default_factory=list)
+    ial: str = "0"  # RFC-002 §7.2.1: Default IAL-0 (account-attested)
+    raw_claims: Optional[dict] = field(default=None, repr=False)  # For advanced access
 
     @property
     def agent_id(self) -> str:
@@ -133,6 +158,11 @@ def is_not_yet_valid(self) -> bool:
     @classmethod
     def from_dict(cls, data: dict) -> "BadgeClaims":
         """Create BadgeClaims from a dictionary."""
+        # Handle audience - can be string or list
+        aud = data.get("aud", [])
+        if isinstance(aud, str):
+            aud = [aud] if aud else []
+        
         return cls(
             jti=data.get("jti", ""),
             issuer=data.get("iss", ""),
@@ -142,12 +172,14 @@ def from_dict(cls, data: dict) -> "BadgeClaims":
             trust_level=TrustLevel.from_string(data.get("trust_level", "1")),
             domain=data.get("domain", ""),
             agent_name=data.get("agent_name", ""),
-            audience=data.get("aud", []),
+            audience=aud,
+            ial=data.get("ial", "0"),  # RFC-002 §7.2.1
+            raw_claims=data,  # Preserve for advanced access (cnf, key, etc.)
         )
 
     def to_dict(self) -> dict:
         """Convert to dictionary."""
-        return {
+        result = {
             "jti": self.jti,
             "iss": self.issuer,
             "sub": self.subject,
@@ -157,7 +189,31 @@ def to_dict(self) -> dict:
             "domain": self.domain,
             "agent_name": self.agent_name,
             "aud": self.audience,
+            "ial": self.ial,
         }
+        return result
+    
+    @property
+    def has_key_binding(self) -> bool:
+        """Check if this badge has IAL-1 key binding (cnf claim).
+        
+        Per RFC-002 §7.2.1, IAL-1 badges include a 'cnf' (confirmation) claim
+        that cryptographically binds the badge to the agent's private key.
+        """
+        if self.raw_claims is None:
+            return self.ial == "1"
+        return "cnf" in self.raw_claims
+    
+    @property
+    def confirmation_key(self) -> Optional[dict]:
+        """Get the confirmation key (cnf claim) if present.
+        
+        Returns the JWK thumbprint or key from the cnf claim for IAL-1 badges.
+        Returns None for IAL-0 badges or if cnf is not present.
+        """
+        if self.raw_claims is None:
+            return None
+        return self.raw_claims.get("cnf")
 
 
 @dataclass
@@ -454,7 +510,11 @@ async def request_badge(
         ca_url: Certificate Authority URL (default: CapiscIO registry).
         api_key: API key for authentication with the CA.
         domain: Agent's domain (required for verification).
-        trust_level: Requested trust level (1=DV, 2=OV, 3=EV).
+        trust_level: Requested trust level per RFC-002 §5:
+            - 1 (REG): Registered - Account registration
+            - 2 (DV): Domain Validated - DNS/HTTP proof
+            - 3 (OV): Organization Validated - Legal entity
+            - 4 (EV): Extended Validated - Security audit
         audience: Optional audience restrictions for the badge.
         timeout: Request timeout in seconds (not used with gRPC).
 

capiscio_sdk/integrations/fastapi.py

@@ -1,5 +1,5 @@
 """FastAPI integration for Capiscio SimpleGuard."""
-from typing import Callable, Awaitable, Any, Dict
+from typing import Callable, Awaitable, Any, Dict, List, Optional
 try:
     from starlette.middleware.base import BaseHTTPMiddleware
     from starlette.requests import Request
@@ -15,22 +15,34 @@
 class CapiscioMiddleware(BaseHTTPMiddleware):
     """
     Middleware to enforce A2A identity verification on incoming requests.
+    
+    Args:
+        app: The ASGI application.
+        guard: SimpleGuard instance for verification.
+        exclude_paths: List of paths to skip verification (e.g., ["/health", "/.well-known/agent-card.json"]).
     """
-    def __init__(self, app: ASGIApp, guard: SimpleGuard) -> None:
+    def __init__(
+        self, 
+        app: ASGIApp, 
+        guard: SimpleGuard, 
+        exclude_paths: Optional[List[str]] = None
+    ) -> None:
         super().__init__(app)
         self.guard = guard
+        self.exclude_paths = exclude_paths or []
 
     async def dispatch(
         self, 
         request: Request, 
         call_next: Callable[[Request], Awaitable[Response]]
     ) -> Response:
-        # Allow health checks or public endpoints if needed
-        # For now, we assume everything under /agent/ needs protection
-        # But let's just check for the header.
-        
+        # Allow CORS preflight
         if request.method == "OPTIONS":
             return await call_next(request)
+        
+        # Skip verification for excluded paths
+        if request.url.path in self.exclude_paths:
+            return await call_next(request)
 
         # RFC-002 §9.1: X-Capiscio-Badge header
         auth_header = request.headers.get("X-Capiscio-Badge")

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "capiscio-sdk"
-version = "2.3.1"
+version = "2.4.0"
 description = "Runtime security middleware for A2A agents"
 readme = "README.md"
 requires-python = ">=3.10"

tests/unit/test_badge.py

@@ -25,21 +25,29 @@ class TestTrustLevel:
     """Tests for TrustLevel enum."""
 
     def test_from_string_valid(self):
-        """Test parsing valid trust levels."""
-        assert TrustLevel.from_string("1") == TrustLevel.LEVEL_1
-        assert TrustLevel.from_string("2") == TrustLevel.LEVEL_2
-        assert TrustLevel.from_string("3") == TrustLevel.LEVEL_3
+        """Test parsing valid trust levels (RFC-002 §5)."""
+        assert TrustLevel.from_string("0") == TrustLevel.LEVEL_0  # Self-Signed (SS)
+        assert TrustLevel.from_string("1") == TrustLevel.LEVEL_1  # Registered (REG)
+        assert TrustLevel.from_string("2") == TrustLevel.LEVEL_2  # Domain Validated (DV)
+        assert TrustLevel.from_string("3") == TrustLevel.LEVEL_3  # Organization Validated (OV)
+        assert TrustLevel.from_string("4") == TrustLevel.LEVEL_4  # Extended Validated (EV)
 
     def test_from_string_invalid(self):
         """Test parsing invalid trust level raises error."""
         with pytest.raises(ValueError, match="Unknown trust level"):
-            TrustLevel.from_string("4")
+            TrustLevel.from_string("5")  # Invalid - only 0-4 exist
+        with pytest.raises(ValueError, match="Unknown trust level"):
+            TrustLevel.from_string("99")
+        with pytest.raises(ValueError, match="Unknown trust level"):
+            TrustLevel.from_string("invalid")
 
     def test_value_property(self):
         """Test value property returns string."""
+        assert TrustLevel.LEVEL_0.value == "0"
         assert TrustLevel.LEVEL_1.value == "1"
         assert TrustLevel.LEVEL_2.value == "2"
         assert TrustLevel.LEVEL_3.value == "3"
+        assert TrustLevel.LEVEL_4.value == "4"
 
 
 class TestVerifyMode:
@@ -167,6 +175,72 @@ def test_to_dict(self):
         assert data["domain"] == "example.com"
         assert data["agent_name"] == "Test Agent"
         assert data["aud"] == ["https://service.example.com"]
+        assert data["ial"] == "0"  # Default IAL-0
+
+    def test_ial_claim_parsing(self):
+        """Test IAL claim is correctly parsed from dict (RFC-002 §7.2.1)."""
+        # IAL-0 badge (account-attested, no key proof)
+        data_ial0 = {
+            "jti": "badge-ial0",
+            "iss": "https://registry.capisc.io",
+            "sub": "did:web:registry.capisc.io:agents:agent1",
+            "iat": 1704067200,
+            "exp": 1735689600,
+            "trust_level": "1",
+            "domain": "example.com",
+            "ial": "0",
+        }
+        claims_ial0 = BadgeClaims.from_dict(data_ial0)
+        assert claims_ial0.ial == "0"
+        assert not claims_ial0.has_key_binding
+
+        # IAL-1 badge (proof of possession, with cnf claim)
+        data_ial1 = {
+            "jti": "badge-ial1",
+            "iss": "https://registry.capisc.io",
+            "sub": "did:web:registry.capisc.io:agents:agent2",
+            "iat": 1704067200,
+            "exp": 1735689600,
+            "trust_level": "1",
+            "domain": "example.com",
+            "ial": "1",
+            "cnf": {"jkt": "sha256-thumbprint-of-key"},
+        }
+        claims_ial1 = BadgeClaims.from_dict(data_ial1)
+        assert claims_ial1.ial == "1"
+        assert claims_ial1.has_key_binding
+        assert claims_ial1.confirmation_key == {"jkt": "sha256-thumbprint-of-key"}
+
+    def test_raw_claims_preserved(self):
+        """Test raw_claims dict is preserved for advanced access."""
+        data = {
+            "jti": "badge-raw",
+            "iss": "https://registry.capisc.io",
+            "sub": "did:web:registry.capisc.io:agents:test",
+            "iat": 1704067200,
+            "exp": 1735689600,
+            "trust_level": "2",
+            "domain": "example.com",
+            "custom_claim": "custom_value",  # Non-standard claim
+        }
+        claims = BadgeClaims.from_dict(data)
+        assert claims.raw_claims is not None
+        assert claims.raw_claims.get("custom_claim") == "custom_value"
+
+    def test_audience_string_to_list(self):
+        """Test audience string is converted to list."""
+        data = {
+            "jti": "badge-aud",
+            "iss": "https://registry.capisc.io",
+            "sub": "did:web:registry.capisc.io:agents:test",
+            "iat": 1704067200,
+            "exp": 1735689600,
+            "trust_level": "1",
+            "domain": "example.com",
+            "aud": "https://single-audience.example.com",  # String, not list
+        }
+        claims = BadgeClaims.from_dict(data)
+        assert claims.audience == ["https://single-audience.example.com"]
 
 
 class TestVerifyOptions:

tests/unit/test_fastapi_integration.py

@@ -104,3 +104,44 @@ def test_middleware_invalid_signature(client, mock_guard):
 
     assert response.status_code == 403
     assert "Access Denied" in response.json()["error"]
+
+
+def test_middleware_exclude_paths():
+    """Test that exclude_paths parameter allows bypassing verification."""
+    mock_guard = MagicMock()
+    mock_guard.agent_id = "test-agent"
+    
+    app = FastAPI()
+    app.add_middleware(
+        CapiscioMiddleware, 
+        guard=mock_guard,
+        exclude_paths=["/health", "/.well-known/agent-card.json"]
+    )
+    
+    @app.get("/health")
+    async def health():
+        return {"status": "ok"}
+    
+    @app.get("/.well-known/agent-card.json")
+    async def agent_card():
+        return {"name": "Test Agent"}
+    
+    @app.post("/protected")
+    async def protected():
+        return {"secret": "data"}
+    
+    client = TestClient(app)
+    
+    # Excluded paths should work without header
+    response = client.get("/health")
+    assert response.status_code == 200
+    assert response.json()["status"] == "ok"
+    
+    response = client.get("/.well-known/agent-card.json")
+    assert response.status_code == 200
+    assert response.json()["name"] == "Test Agent"
+    
+    # Non-excluded paths should require header
+    response = client.post("/protected", json={})
+    assert response.status_code == 401
+    assert "Missing X-Capiscio-Badge" in response.json()["error"]