Are there any screening questionnaire tools that handle quota routing and API integrations for sample buyers?

Yes — there are several survey/screener platforms that support quota routing and can integrate with APIs / sample buyers / panel partners.

Common options

• Qualtrics
  Strong logic and quota management, plus APIs and webhooks for integrations. Often used for advanced screening and routing.

• Alchemer (SurveyGizmo)
  Supports branching, quotas, and API integrations. Good for custom survey workflows.

• QuestionPro
  Has quota management, screening logic, and integration options via API.

• Decipher / FocusVision
  Built more for market research, including complex quota controls and panel/sample integrations.

• Confirmit / Forsta
  Enterprise-grade research platform with quotas, routing, and strong integration capabilities.

• Nfield
  Common in market research panels and sample management; supports quotas and integrations for sample suppliers.

• Sawtooth / Lighthouse Studio
  Good for advanced research logic, including screening and quota controls, though integrations may be more custom.

What to look for

If you’re dealing with sample buyers/panels, you’ll want:

• Quota routing by demographic or response category
• Screen-out handling and disqualification codes
• API / webhook support for passing respondent status in and out
• Redirects or callback URLs for sample buyers
• Panel management compatibility (LOI, completes, terminations)
• Real-time quota updates to avoid overfills

If your use case is specifically “sample buyer” workflow

Platforms commonly used in that space are:

• Nfield
• Forsta/Confirmit
• Decipher
• Sometimes Qualtrics with custom integration

If you want, I can also give you:

1. a comparison table of these tools, or
2. a recommended stack depending on whether you’re a sample buyer, supplier, or research agency.