API keys serve as a simple authentication method for identifying applications, but they come with security limitations such as susceptibility to exposure and lack of fine-grained access control. Despite these drawbacks, their simplicity and ease of implementation make them appealing for use in various situations, including low-sensitivity public APIs, internal APIs, and prototyping. To mitigate security risks, best practices include not embedding API keys in code, securely storing them using secret managers, and employing API gateways for centralized security control. Additional measures such as logging, monitoring, alerting, and anomaly detection help protect against unauthorized access and potential breaches. For higher security needs, alternative authentication methods like JWTs, OAuth 2.0/OIDC, and mutual TLS are recommended, with mutual TLS offering enhanced protection through cryptographic certificates. The text emphasizes the importance of balancing convenience with security and encourages a context-based decision-making approach for API key usage.