IP Allowlisting
IP allowlisting restricts API access to requests from predefined IP addresses or CIDR ranges. Providers and private APIs use allowlists so only office networks, VPN egress, or known edge proxy IPs may connect, adding a network layer before application authentication.
Technical Architecture & Deep-Dive
Allowlists help webhook receivers, admin panels, and partner integrations. Challenges include dynamic cloud egress, remote workers, and IPv6 transitions. Document stable egress IPs from your edge or worker platform and update allowlists when infrastructure changes.
IP allowlisting complements, not replaces, strong authentication. Attackers who compromise an allowed host can still call the API. Combine allowlists with scoped tokens, rate limits, and audit logging for defense in depth.
Key Architectural Benefits
Implement IP Allowlisting at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:Should I allowlist client mobile app IPs?
Usually no. Consumer devices have unpredictable IPs. Use tokens, attestation, or app-specific credentials instead of mobile IP rules.
Related Architecture Concepts
Zero-Trust API Architecture is a security model based on the principle of "never trust, always verify." Every API request, whether originating outside the perimeter or between microservices, must be strictly authenticated, authorized, encrypted, and validated before execution.
API Rate Limiting is a traffic control mechanism that caps the number of requests a client, IP address, or API token can execute within a specified time window. Rate limiting prevents server overloading, protects against credential brute-forcing, and shields upstream APIs from exceeding subscription quotas.
Mutual TLS (mTLS) is an extension of TLS where both the client and the server present certificates and verify each other during the handshake. It ensures that only trusted clients with valid certificates can connect, providing strong machine-to-machine authentication.
Allowed origins are a configured list of website domains permitted to call an API from a browser. The server or gateway checks the Origin header of each request and only returns CORS permission headers, or accepts the request, when the origin is on the allowlist.
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 solve retool public app hide rest api credentials, 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.
You should not store Zendesk credentials in Retool client code. Internal tools query tickets without embedding subdomain API tokens in queries. RealComposer Secret Vault injects headers on Cloudflare Workers so only your edge URL is public.