💬Common Questions
This page answers the most common questions developers, agencies, startups, and software vendors ask when working with DevPayr. If you’re wondering “Can DevPayr do this?” or “What happens if…?”, you’ll likely find the answer here.
Do I need an API Key to use DevPayr?
No. If all you need is runtime license validation, you can use a License Key alone.
API Keys are only required when you want to:
Create or manage licenses programmatically
Manage domains or devices
Work with injectables
Automate billing or provisioning
Build backend tooling or dashboards
In short:
License Key → validates software at runtime
API Key → lets your backend control DevPayr
Can I use DevPayr without an SDK?
Yes. DevPayr is built API-first. All SDKs are thin wrappers around the REST API.
If you prefer:
cURL
Postman
Axios / Fetch
Custom HTTP clients
Unsupported languages
You can use the REST API directly. Just remember that raw HTTP requests must always include the required authentication headers, including X-Devpayr-Domain
What exactly is the “domain” in DevPayr?
Despite the name, a “domain” is not limited to websites.
The domain represents a runtime identifier for where your software is running. It can be:
A website domain
A subdomain
A machine fingerprint
A device hash
An installation ID
Any stable identifier you choose
This identifier is sent using the X-Devpayr-Domain header (or explicitly set in SDKs) and is used to:
Enforce domain or device limits
Detect reuse on unauthorized environments
Track usage
Separate installations
Think of it as “where this copy of the software lives.”
Do SDKs automatically handle the domain?
No — and this is intentional.
You are expected to explicitly define the domain when bootstrapping the SDK. This ensures:
The correct identifier is always sent
No guessing or unreliable detection
Full control over how installations are identified
The SDK simply forwards the domain you provide as the X-Devpayr-Domain header.
Can one license be used on multiple domains or devices?
Yes, if you allow it.
Licenses can be configured to:
Allow a fixed number of domains/devices
Allow unlimited domains
Restrict subdomains
Be locked to a single domain
Automatically register domains until limits are reached
If a license exceeds its allowed limits, validation will fail.
What happens if a license is revoked or expires?
Once a license is:
Revoked
Expired
Suspended
It will fail validation, even if:
The project is marked as paid
The domain was previously allowed
Your application should handle this by:
Blocking access
Showing a message
Redirecting the user
Entering restricted mode
DevPayr does not decide how your app reacts — you do.
Can I change license rules after issuing a license?
Yes.
You can:
Increase or reduce domain limits
Suspend or reactivate licenses
Change expiration dates
Toggle test/production behavior
Changes take effect immediately on the next validation request.
What are test licenses?
Test licenses are meant for:
Development
Staging
QA
Local testing
They are more relaxed and typically allowed only on:
localhost.testdomainsNon-production environments
They should never be used in production.
Are injectables required to use DevPayr?
No.
Injectables are optional. DevPayr works perfectly without them.
They are an advanced feature used to:
Inject scripts or configuration
Deliver paid-only features dynamically
Enable or disable behavior remotely
Injectable handling in SDKs is currently beta, and you are encouraged to override the default handler if you use them.
Should injectables be written to disk?
No, not permanently.
Best practice is to:
Stream injectables at runtime
Apply them in memory
Avoid bundling them into final builds
This reduces the risk of redistribution or tampering.
Can DevPayr work with my own payment system?
Yes.
DevPayr does not process payments for you. Instead, it integrates with your flow.
Typical setup:
Your system receives payment
You mark the project or domain as paid or issue a license
DevPayr enforces access at runtime
This works with:
Stripe
Paystack
Flutterwave
Paddle
Custom billing systems
Can I use DevPayr for self-hosted software?
Yes — this is one of its strongest use cases.
DevPayr is ideal for:
Self-hosted SaaS
Licensed enterprise software
Plugins and extensions
Desktop or CLI tools
Each installation identifies itself using a domain or fingerprint and is validated independently.
Can DevPayr stop piracy completely?
No tool can stop piracy 100%.
What DevPayr does is:
Make unauthorized usage difficult
Detect reuse and abuse
Give you control over access
Let you react quickly (revoke, suspend, limit)
Security is about raising the cost of abuse, not chasing perfection.
What happens if DevPayr is temporarily unavailable?
SDKs and integrations are designed to be configurable.
You decide:
Whether your app fails open or closed
Whether it retries
Whether it caches validation results
DevPayr never forces a single behavior on your application.
Is DevPayr only for developers?
No.
DevPayr is built for:
Developers
Agencies
SaaS founders
Software vendors
Teams selling digital products
If you deliver software and need control after delivery, DevPayr fits.
Where should I start if I’m new?
If you’re new, the recommended order is:
Installation & Setup
Getting API Keys
Issuing Your First License
Basic License Validation
Validation Flow
Domains & Restrictions
If you still have questions after reading this page, the answer is usually not a limitation, but a configuration or design choice. DevPayr is intentionally flexible — how strict or relaxed it behaves is always up to you.
“I built DevPayr because delivering software shouldn’t mean giving up control. Developers, agencies, and founders deserve a simple way to protect their work, enforce fairness, and still ship fast — without turning licensing into a nightmare.” — Founder, DevPayr
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