Server-Side API Configuration with Environment Variables
Configure blockchain API access on the server with explicit network and endpoint settings, while preventing credentials from entering browser bundles or logs.
Overview
When translating these concepts into an integration, keep the scope described by the wallet history api with the result. The examples in wallet transaction history and smart contract event logs show how the same distinction affects neighbouring data questions.
Environment variables are one way to deliver configuration to a backend process. They do not automatically make a credential safe, nor do they define the API access model by themselves.
Separate public and private settings
An endpoint, expected chain and timeout can be configuration, while the API key is a secret. Validate required values at startup and fail with safe messages. Frontend build systems can embed selected environment values into public bundles, so placing a secret in a frontend environment file does not keep it server-side.
Worked example: a backend proxy
A browser calls the application backend. The backend reads its credential from the configured secret-delivery mechanism, validates the target network and performs the authorised data request. The response contains only the data needed by the browser, not the upstream key or complete request headers.
Plan changes and rotation
Document variable names without publishing real values. Test missing keys, malformed origins and a valid endpoint on the wrong network. Keep development and production credentials separate. Rotation should update the intended process configuration under an authorised operational procedure, with old-key revocation verified separately from simply editing a local file.
A practical acceptance test
Use synthetic configuration values to test missing keys, an invalid origin and a valid endpoint reporting the wrong chain. Assert safe startup errors and no secret in output. Build the frontend and inspect its public configuration boundary: the backend credential must not appear in bundled code, HTML or browser-visible connection-test responses.
Questions about the topic
Frequently asked questions
Is a frontend environment variable private?
Not if the build embeds it into public browser code.
Should startup errors print the key?
No. Report the missing or invalid setting by safe name only.
Standards & technical documentation
