API Key
An API key is a unique secret string that identifies the application calling an API and authorizes its access. Providers use keys to authenticate requests, enforce quotas, and bill usage. Anyone holding the key can act as your application, so secret keys must stay on trusted servers.
Technical Architecture & Deep-Dive
API keys are simple: include the key in a header like `Authorization` or `x-api-key`, and the provider grants access. That simplicity is also the risk. Keys embedded in JavaScript bundles, mobile apps, or public repositories are routinely scraped by bots within minutes.
Some providers issue publishable keys designed for clients and secret keys for servers. Secret keys belong in an encrypted vault, injected at an edge proxy so client code only ever holds a restricted, revocable client token.
Key Architectural Benefits
Hide Your API Keys at the Edge
Store keys in an encrypted vault and give clients a restricted token instead.
Frequently Asked Questions
Q:Is it safe to put an API key in environment variables of a frontend app?
No. Frontend build tools inline environment variables into the shipped bundle, where anyone can read them. Only server-side or edge code should hold secret keys.
Q:How do I use a secret API key from a mobile app?
Route requests through an edge proxy that injects the key server-side, and authenticate the app with a restricted client token instead.
Related Architecture Concepts
Edge Secret Injection is a security pattern where sensitive upstream API credentials (e.g. Stripe Secret Keys, OpenAI Tokens) are stored in an encrypted vault and injected into HTTP request headers exclusively at the edge runtime, ensuring client browsers and mobile apps never see or store the keys.
A Client Token is a scoped, revocable authentication credential designed for frontend web and mobile applications. It grants permission to invoke specific edge API pipelines while enforcing allowed-origin domains and rate limits, safely abstracting sensitive upstream API secrets.
Credential leakage is the unintended exposure of secrets such as API keys, tokens, and passwords. Common sources include JavaScript bundles, decompiled mobile apps, public Git repositories, browser network logs, and low-code platform configurations visible to users.
Secret rotation is the practice of periodically replacing API keys, passwords, and other credentials with new values and revoking the old ones. Rotation limits how long a leaked secret remains useful and is required by many security standards.
Ready-to-Use Edge Recipes
To use OpenAI in a client-side React app without leaking your secret key, never include OPENAI_API_KEY or REACT_APP_OPENAI_API_KEY in frontend .env files. Instead, route your fetch calls through a RealComposer edge endpoint that injects your secret key server-side on Cloudflare Workers and enforces CORS origin whitelisting.
To solve protect api key in vue spa, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.
To solve reverse proxy for third party api key protection, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.