API Proxy
An API proxy is an intermediary endpoint that receives client requests and forwards them to an upstream API, returning the upstream response to the client. It is commonly used to hide API keys, add CORS headers, enforce rate limits, cache results, and transform responses.
Technical Architecture & Deep-Dive
An API proxy decouples clients from upstream providers. Instead of embedding `https://api.openai.com` and a secret key in a frontend, the client calls your proxy URL, and the proxy attaches credentials server-side.
Proxies range from simple pass-through forwarders to full gateways with aggregation and payload slimming. Running them at the edge keeps added latency negligible while providing a secure control point for every third-party API call.
Key Architectural Benefits
Implement API Proxy at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:Is an API proxy the same as a reverse proxy?
An API proxy is a reverse proxy specialized for API traffic, typically adding credential injection, transformation, and API-aware policies.
Related Architecture Concepts
A Reverse Proxy is an intermediate server that intercepts requests from client applications and forwards them to one or more backend origin servers. The reverse proxy terminates TLS, applies security filtering, caches responses, and returns the result to the client as if it originated from the proxy itself.
An API Gateway is a single entry point that sits between client applications and backend services. It routes requests, enforces authentication and rate limits, transforms payloads, and aggregates responses so clients talk to one stable endpoint instead of many internal APIs.
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 forward proxy is a server that sits in front of client devices and makes outbound requests to external servers on their behalf. It is used to filter traffic, enforce corporate policies, cache content, or mask client IP addresses from the destination servers.
Ready-to-Use Edge Recipes
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.
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 secure anthropic claude api proxy for frontend, 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.