OAuth remains the gold standard in security with features like automated expiry and a secure token flow, providing robust safeguards for accounts. However, there are valid reasons why OAuth might not be feasible, such as complexity or lack of support from integrations or frameworks. Vectara offers simpler API keys as an alternative, but they are less secure. The company understands that different API keys have varying levels of security and access, with Query API Keys being the safest for read-only operations, Index and Query API Keys offering more powerful write-and-read capabilities, and Personal API Keys being the most powerful but requiring utmost caution. Vectara recommends using OAuth in production environments or where higher security is necessary, while using different API keys carefully depending on use cases. The company also provides best practices for choosing authentication methods based on application context and exposure.