How do you protect your tokens and API credentials from leaks?

API credentials for Reddit — the client ID, client secret, and OAuth access tokens — grant the holder the ability to perform actions on behalf of your Reddit application or account. Leaked credentials can be exploited to post spam, harvest data, manipulate votes, or compromise accounts. Treating these credentials with the same care as passwords is essential. The most common cause of credential leaks is accidentally committing them to version control. Developers who hardcode API keys directly in source code and push that code to a public GitHub repository expose credentials to automated scanning tools that continuously search public repositories for strings matching known credential formats. The countermeasure is to store all credentials in environment variables or a secrets manager rather than in code. In Python, the `python-dotenv` library makes it straightforward to load credentials from a `.env` file that is excluded from version control through the `.gitignore` configuration. Services like GitHub automatically scan new commits for known secret patterns and alert developers, but prevention is far more effective than detection after the fact. For production applications deployed on cloud infrastructure, cloud-native secrets management tools — AWS Secrets Manager, Google Cloud Secret Manager, HashiCorp Vault — store credentials outside the application code and inject them at runtime. This eliminates the credential-from-environment-variable approach's vulnerability to environment variable exposure through logs or error messages. OAuth access tokens have limited lifetimes — Reddit's OAuth tokens expire after one hour — and the refresh token used to obtain new access tokens is the higher-value credential that must be protected. Storing refresh tokens in encrypted storage (a secure keystore on mobile, an encrypted database column in a server application) and rotating them after credential rotation events reduces the window of exposure if a leak occurs. When credentials are compromised, the response is immediate revocation. Navigate to `reddit.com/prefs/apps`, find the application whose credentials are compromised, and regenerate the client secret or revoke the application entirely. Any active tokens derived from the compromised credentials become invalid as soon as the secret is regenerated.