API Keys
Definition
Secret tokens used to authenticate and authorize access to cloud services and APIs, ensuring secure interactions between applications.
Use Cases
- Twilio: Authenticate server-to-server requests to send SMS and make voice calls via Twilio’s communications APIs. — Developers create an API key in the Twilio Console and use it (often with a secret) in their backend services to sign/authenticate API requests. Keys can be rotated and revoked without changing the main account credentials. (Enables secure, automated access to messaging/voice capabilities from applications while supporting operational practices like key rotation and revocation.)
- Stripe: Process payments from web and mobile applications using Stripe’s payment APIs. — Applications use Stripe API keys (publishable key on the client for tokenization and secret key on the server for privileged operations). Keys are scoped by environment (test vs live) and can be rolled/rotated if exposed. (Allows developers to integrate payments quickly while separating client-side identification from server-side privileged access and supporting safe testing with non-production keys.)
Provider Equivalents
- AWS: AWS Identity and Access Management (IAM) Access Keys
- Azure: Azure API Management Subscription Keys
- GCP: Google Cloud API Keys (in APIs & Services)
- OCI: OCI API Signing Keys
Frequently Asked Questions
- What's the difference between API keys and OAuth tokens?
- API keys usually identify an application and are often long-lived until rotated or revoked. OAuth tokens are typically short-lived and represent a user or delegated authorization (for example, “this app can access this user’s data”). OAuth is generally better for user-facing apps where you need user consent and fine-grained delegated access.
- When should I use API keys?
- Use API keys when you need a simple way to identify a calling application, apply usage limits/quotas, or control access to an API—especially for public APIs or internal services where user-level authorization isn’t required. For sensitive operations or user data access, prefer stronger approaches like OAuth, workload identity, or signed requests with short-lived credentials.
- How much does API keys cost?
- API keys themselves are typically free to create and manage, but the APIs they access may have usage-based pricing (per request, per GB, per minute, etc.). Costs depend on the provider’s API pricing, your request volume, and any API gateway features you enable (such as Azure API Management tiers or Google Maps Platform usage).
Category: security
Difficulty: basic
Related Terms
See Also