API Key & Credential Security
API keys give access to value, not just data. That’s especially true in crypto-fintech systems, where a leaked key can mean irreversible loss of funds, user trust, or infrastructure control.
This guide teaches how to securely manage API keys and credentials across your stack: dev, staging, production, CI/CD, and internal tools. Whether you're a solo developer or building with a team, these practices will help you operate at production-grade from day one.
What You’ll Learn
How to manage API keys across environments
How to prevent accidental exposure
How to rotate and audit key usage
How to respond to compromise quickly
Advanced practices used by top-tier teams
How to log and trace transactions from API to user
Never hardcode keys
Avoid hardcoding credentials into your source code — even in private repos.
Use .env, system-level secrets, or vault systems (see below) and keep them out of Git.
Separate Sandbox and Production Keys
Each environment should use different API credentials.
Keep API Keys Out of the Frontend
API keys must only live on your server or secure backend functions. Never expose them in:
Web apps (browser dev tools)
Mobile apps (decompiled APKs/IPAs)
Client-side JavaScript
Rotate Keys Regularly
Keys should be rotated at least every 60–90 days, and immediately if:
An engineer leaves your team
A staging credential is accidentally exposed
You onboard new partners or contractors
Where possible, enable overlapping keys during rotation to avoid downtime:
Add new key (Key B)
Deploy with Key B
Remove old key (Key A)
Use a Secret Manager in Production
Don’t use .env files in production. Use a vault system like:
AWS Secrets Manager
GCP Secret Manager
HashiCorp Vault
Doppler, Infisical, or 1Password Secrets Automation
These tools:
Handle all messaging via webhooks
Store secrets securely
Provide access logs
Allow key rotation and versioning
Monitor for Leaks (Automatically)
Use scanning tools to detect exposed credentials early:
You can also write internal scripts to detect anything matching sklive or sktest.
Redact Keys in Logs
Never log or expose the Authorization header or full key string in logs, dashboards, or monitoring tools.
Build for the Possibility of Compromise
Plan as if your key will leak eventually. That means:
Quick key rotation scripts
Audit logs of which service made which request
Correlating reference IDs with internal logs
Alerts for suspicious behavior (see below)
This limits your blast radius and recovery time.
Audit API Usage for Anomalies
Track usage of your API key to detect abuse:
Unusual volume (e.g. airtime purchases spike)
API calls from unfamiliar IPs or geo regions
Endpoints being called that your app never uses
Start simple: alert if traffic spikes 10x, or swap requests happen outside your expected flows.
Monitor:
api.requests.total
api.requests.by-endpoint
api.requests.by-country
api.failures.by-code
If you use observability tools (Datadog, Prometheus, etc.), make this part of your standard dashboard.
Use Signed Tokens Between Internal Services
If your internal services (e.g. frontend → backend, or job worker → billing service) need to authenticate requests, don’t reuse your Bitnob API key.
Instead
Generate short-lived signed tokens (e.g. JWT)
Only include required claims (user ID, action, expiry)
Verify them inside your own infrastructure
Build a Proxy Layer for Your API Access (Optional)
Larger teams or API resellers often create a gateway service to manage:.
API key rotation
Logging
Rate limiting
Multi-tenant isolation
It also makes it easier to scale when you’re supporting users, partners, or white-label apps.
Support Key Expiry and Versioning (If You Issue Keys)
If you’re building your own API or multi-tenant product on top of Bitnob, implement:
Instead
Expirable keys (e.g. 90-day lifetime)
Version prefixes (v1_key_abc)
User-facing key management (generate, revoke)
This prepares your product to scale securely.
Create an API Key Audit Tool
Internally, build a simple admin tool to:
List all active keys
Show last used time, IP, and endpoint
Revoke and rotate with a click
Filter by service or role
This is an incredible asset during an incident.
Summary Table
| PRINCIPLE | WHY IT MATTERS |
|---|---|
| Never hardcode keys | Prevent leaks in source control |
| Use env vars and secret managers | Manage config safely |
| Rotate keys regularly | Minimize damage if leaked |
| Use per-env keys | Avoid prod test mixups |
| Monitor for abuse | Detect misuse early |
| Use signed tokens internally | Don’t reuse Bitnob keys internally |
| Build for compromise | Recovery should be fast and clean |
| Audit usage patterns | Stay ahead of fraud or misbehavior |
| Proxy or expire keys | Scale securely with trust boundaries |
You're now equipped to treat API keys like production-grade access controls, not convenience tokens.
If you're ready, let’s move on to Webhooks & Event Handling →, where we’ll cover secure, reliable, and scalable delivery of real-time financial events.
