CS-Cart & Print-on-Demand API Integration

We need to integrate our CS-Cart store with a third-party Print-on-Demand / fulfillment platform through its API.

The integration will involve:

* API authentication
* Access-token management
* Product synchronization
* Product and variant mapping
* SKU mapping
* Order synchronization
* Order creation through API
* Customer and shipping information mapping
* Payment-status mapping
* Order-status synchronization where applicable
* Shipment/tracking synchronization where supported
* API error handling
* Duplicate-order prevention
* Webhook/API response handling

The integration must work correctly with the existing CS-Cart product and order workflow.

Important Order Requirement

The store contains both products belonging to the external fulfillment platform and regular marketplace products.

For example, an order could contain:

* Fulfillment-platform product
* Regular marketplace product
* Fulfillment-platform product

The API integration must send only the relevant fulfillment-platform products to the external platform.

Regular marketplace products must never be sent to the fulfillment platform.

If an order contains no products belonging to the fulfillment platform, no fulfillment API order should be created.

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Existing Implementation

A custom CS-Cart add-on for the integration has already been partially developed.

The selected developer will need to:

1. Audit the existing implementation.
2. Understand the current CS-Cart architecture.
3. Identify incomplete or incorrect functionality.
4. Complete the integration using the official API documentation.
5. Fix existing issues where required.
6. Avoid unnecessarily rebuilding working functionality.

The API documentation and existing source code will be provided privately to the selected developer.

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Payment Gateway Compatibility

The store currently supports multiple payment methods, including online payment and COD.

Additional payment gateways may be introduced in the future.

The integration should therefore be designed in a payment-gateway-independent manner, using the actual payment/order status rather than hard-coding the logic around a particular payment provider.

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Ongoing CS-Cart Development

The role is not limited to this API integration.

The developer will also be responsible for ongoing CS-Cart requirements, including:

* Custom CS-Cart add-ons
* CS-Cart hooks
* PHP/MySQL development
* Checkout modifications
* Order workflow changes
* Payment gateway changes
* Shipment/tracking functionality
* Email notification troubleshooting
* Email template modifications
* Product functionality
* Vendor functionality
* Third-party API integrations
* Bug fixing
* Database-related issues
* Performance troubleshooting
* General CS-Cart customization
* New features and business requirements

We expect the developer to diagnose problems independently and provide proper technical solutions, rather than simply implementing isolated code changes.

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Development Standards

The developer should:

* Have strong CS-Cart/Multi-Vendor knowledge
* Avoid modifying CS-Cart core files wherever possible
* Use proper CS-Cart add-ons and hooks
* Write clean and maintainable PHP
* Follow upgrade-safe development practices
* Test changes before production deployment
* Maintain appropriate backups
* Document significant changes
* Keep API credentials secure

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Testing Requirements

The integration must be tested for:

1. Regular product → no API order
2. One integrated product → API order created correctly
3. Multiple integrated products → correctly mapped
4. Mixed order → only relevant products sent
5. COD → correct payment mapping
6. Online payment → correct payment mapping
7. Repeated status changes → no duplicate API orders
8. API failure → original CS-Cart order remains safe
9. Invalid API response → handled gracefully
10. Shipment/tracking → synchronized where supported

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Required Experience

Must have

* Strong CS-Cart experience
* CS-Cart Multi-Vendor experience
* PHP
* MySQL
* CS-Cart add-on development
* CS-Cart hooks
* REST API integration
* JSON
* E-commerce order workflows

Preferred

* Third-party e-commerce API integrations
* Payment gateway integrations
* Product synchronization
* Order synchronization
* Webhooks
* Shipment/tracking APIs
* Print-on-Demand integrations

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Long-Term Opportunity

We are looking for a long-term developer, not someone interested only in completing the initial API integration.

Future work will include:

CS-Cart development + API integrations + troubleshooting + maintenance + new features.

Please provide:

1. Your CS-Cart experience
2. Number of years working with CS-Cart
3. Examples of CS-Cart projects
4. Multi-Vendor experience
5. API integration experience
6. Examples of third-party API integrations
7. Monthly full-time rate
8. Availability
9. Expected response time for urgent issues
10. Whether you are available for ongoing development

Important

Please do not apply if you are primarily a generic PHP/WordPress developer without strong CS-Cart experience.

We specifically need someone who understands:

CS-Cart architecture + Multi-Vendor + PHP + hooks + add-ons + order lifecycle + API integrations.