指纹的数据结构（security/fingerprint.py:41）：

# security/fingerprint.py:41
class Fingerprint(BaseModel):
    """dual identifiers: human-readable ID + Fingerprint UUID for tracking/auditing."""
    _uuid_str: str = PrivateAttr(default_factory=lambda: str(uuid4()))   # 私有：默认随机 UUID
    _created_at: datetime = PrivateAttr(default_factory=datetime.now)    # 私有：创建时间
    metadata: Annotated[dict[str, Any], BeforeValidator(_validate_metadata)] = Field(
        default_factory=dict)                                           # 公开：附加元数据

    @property
    def uuid_str(self) -> str:      # 只读暴露
        return self._uuid_str
    @property
    def created_at(self) -> datetime:
        return self._created_at
    @property
    def uuid(self) -> UUID:
        return UUID(self.uuid_str)

确定性生成是指纹最有意思的能力（security/fingerprint.py:75）：

# security/fingerprint.py:75
@classmethod
def _generate_uuid(cls, seed: str) -> str:
    if not seed.strip():
        raise ValueError("Seed cannot be empty or whitespace")
    return str(uuid5(CREW_AI_NAMESPACE, seed))    # ★命名空间 + 种子 → 确定性 UUID

# :90
@classmethod
def generate(cls, seed: str | None = None, metadata=None) -> Self:
    fingerprint = cls(metadata=metadata or {})
    if seed:
        fingerprint.__dict__["_uuid_str"] = cls._generate_uuid(seed)   # 有种子就覆盖成确定值
    return fingerprint

命名空间是一个写死的常量（security/constants.py:13）：

# security/constants.py:13
CREW_AI_NAMESPACE: Annotated[UUID, "deterministic UUID v5 (SHA-1). Custom namespace for CrewAI."] = \
    UUID("f47ac10b-58cc-4372-a567-0e02b2c3d479")

指纹重写了 __eq__/__hash__ 并提供字典互转（security/fingerprint.py:113）：

# security/fingerprint.py:113
def __eq__(self, other: Any) -> bool:
    if type(other) is Fingerprint:
        return self.uuid_str == other.uuid_str   # 只按 UUID 比，不看 metadata/时间
    return False

def __hash__(self) -> int:
    return hash(self.uuid_str)                    # 能进 set / 当 dict key

# :123
def to_dict(self):
    return {"uuid_str": self.uuid_str,
            "created_at": self.created_at.isoformat(),
            "metadata": self.metadata}

# :135
@classmethod
def from_dict(cls, data):
    if not data:
        return cls()
    fingerprint = cls(metadata=data.get("metadata", {}))
    if "uuid_str" in data:
        fingerprint.__dict__["_uuid_str"] = data["uuid_str"]      # 还原保存的 UUID
    if "created_at" in data and isinstance(data["created_at"], str):
        fingerprint.__dict__["_created_at"] = datetime.fromisoformat(data["created_at"])
    return fingerprint

指纹通过 SecurityConfig 容器挂载（security/security_config.py:20）：

# security/security_config.py:20
class SecurityConfig(BaseModel):
    """authentication *TODO*, identity (fingerprints), scoping *TODO*, delegation *TODO*"""
    model_config = ConfigDict(arbitrary_types_allowed=True)
    fingerprint: Fingerprint = Field(
        default_factory=Fingerprint,                # ★默认自动生成一枚随机指纹
        description="Unique identifier for the component")

    @field_validator("fingerprint", mode="before")
    @classmethod
    def validate_fingerprint(cls, v):
        if v is None:            return Fingerprint()
        if isinstance(v, str):                        # 传字符串 → 当种子确定性生成
            if not v.strip():    raise ValueError("Fingerprint seed cannot be empty")
            return Fingerprint.generate(seed=v)
        if isinstance(v, dict):  return Fingerprint.from_dict(v)   # 传 dict → 还原
        if isinstance(v, Fingerprint): return v
        raise ValueError(f"Invalid fingerprint type: {type(v)}")

Agent 基类上就是一个默认字段（agents/agent_builder/base_agent.py:344）：

# agents/agent_builder/base_agent.py:344
security_config: SecurityConfig = Field(
    default_factory=SecurityConfig,
    description="Security configuration for the agent, including fingerprinting.")

回到 Day 08 的执行器，工具调用前会把指纹打包进上下文（agents/crew_agent_executor.py:403）：

# agents/crew_agent_executor.py:403
fingerprint_context = {}
if (self.agent
        and hasattr(self.agent, "security_config")
        and hasattr(self.agent.security_config, "fingerprint")):
    fingerprint_context = {
        "agent_fingerprint": str(self.agent.security_config.fingerprint)  # __str__ → uuid_str
    }
...
tool_result = execute_tool_and_check_finality(
    ...,
    fingerprint_context=fingerprint_context,   # :417 随工具调用一起传下去（审计用）
)