Coverage for /home/admin/Documents/AI/applications/lexigram-dev/lexigram/experimental/ai/lexigram-ai-governance/src/lexigram/ai/governance/exceptions.py: 55%

1"""Exception hierarchy for AI Governance.""" 

2 

3from __future__ import annotations 

4 

5from lexigram.contracts.ai.governance import ( 

6 BudgetExceededError, 

7 GovernanceError, 

8 ResourceExhaustedError, 

9) 

10 

11 

12class RateLimitExceededError(GovernanceError): 

13 """Raised when RPM or TPM limits are exceeded. 

14 

15 Attributes: 

16 limit: Configured limit value. 

17 current: Current counter value. 

18 limit_type: Type of limit exceeded (``"rpm"`` or ``"tpm"``). 

19 """ 

20 

21 _code: str = "LEX_ERR_GOV_006" 

22 

23 def __init__( 

24 self, 

25 limit: int, 

26 current: int, 

27 limit_type: str = "rpm", 

28 user_id: str | None = None, 

29 ) -> None: 

30 self.limit = limit 

31 self.current = current 

32 self.limit_type = limit_type 

33 self.user_id = user_id 

34 super().__init__( 

35 f"{limit_type.upper()} exceeded: {current}/{limit} (user={user_id})" 

36 ) 

37 

38 

39class ModelAccessDeniedError(GovernanceError): 

40 """Raised when a user is denied access to a model by policy. 

41 

42 Attributes: 

43 model: Model identifier that was denied. 

44 reason: Why access was denied (``"restricted"``, ``"not_in_allowlist"``, 

45 ``"in_denylist"``). 

46 """ 

47 

48 _code: str = "LEX_ERR_GOV_007" 

49 

50 def __init__( 

51 self, 

52 model: str, 

53 reason: str, 

54 user_id: str | None = None, 

55 ) -> None: 

56 self.model = model 

57 self.reason = reason 

58 self.user_id = user_id 

59 super().__init__( 

60 f"Model access denied: model={model}, reason={reason} (user={user_id})" 

61 ) 

62 

63 

64class GovernancePersistenceError(GovernanceError): 

65 """Raised when a governance persistence backend is unavailable. 

66 

67 Raised by 

68 :class:`~lexigram.ai.governance.persistence.RedisGovernancePersistence` 

69 when the cache backend reports failure (an ``Err`` result). The 

70 :class:`~lexigram.ai.governance.manager.AIGovernanceManager` catches this at 

71 the policy boundary and applies the configured fail-open / fail-closed 

72 decision instead of letting a fabricated value inform the allow/deny 

73 verdict. 

74 """ 

75 

76 _code: str = "LEX_ERR_GOV_008" 

77 

78 

79__all__ = [ 

80 "BudgetExceededError", 

81 "GovernanceError", 

82 "GovernancePersistenceError", 

83 "ModelAccessDeniedError", 

84 "RateLimitExceededError", 

85 "ResourceExhaustedError", 

86]