Written by Josh Hutter

Originally published in 2024, updated for Deals API 4.0.0 in 2026.

Welcome to the latest edition of FMTC’s Tech Corner. If you’re building with FMTC data, the Deals API is one of the most powerful tools available for accessing high-quality affiliate deals at scale. Since our earlier 3.2.1 release, the API has evolved significantly.

In this updated 2026 guide, we’ll walk through:

  • What’s changed since 3.x
  • Key improvements in Deals API 4.0.0
  • Best practices for implementation
  • Common pitfalls to avoid

What the FMTC Deals API Does

The FMTC Deals API aggregates and standardizes affiliate deals across thousands of programs, giving publishers a single, normalized feed of monetizable offers.

  • Pull up-to-date deals across networks
  • Normalize data fields across sources
  • Easily power coupon pages, deal widgets, and content integrations

What’s New in Deal API 4.0.0?

The primary update in version 4.0.0 is:
The API now returns an error when request parameters are mismatched.

Why This Matters

In previous versions, incompatible or conflicting parameters could:

  • Return unexpected results
  • Fail silently
  • Make debugging more difficult

With 4.0.0:

  • Invalid parameter combinations now trigger explicit errors
  • Issues are easier to identify and fix
  • Integrations become more predictable and reliable

Quick Recap: What changed in 3.2.1

Version 3.2.1 introduced a single update: the renaming of the last_update field to last_updated. This change aligns with the naming conventions used throughout the rest of the FMTC API. Beyond this adjustment, all other fields and behaviors remain unchanged, ensuring that your integration continues to work seamlessly.

Recap of Version 3.2.0

In case you missed it, version 3.2.0 introduced significant enhancements to deal management and filtering exclusive deals. Here’s a summary of what’s new:

  • New Field: exclusive
    • Value of 0: Public deal available to everyone.
    • Value of 1: Exclusive deal automatically pulled in through the API.
    • Value of 2: Exclusive deal manually added into FMTC.
  • New Parameters: exclusive_only and public_only
    • These parameters allow filtering deals by the exclusive field.
    • Default Behavior: Both parameters default to 0.
    • Exclusive Deals: If exclusive_only is set to 1, the API will return deals where exclusive is 1 or 2.
    • Public Deals: If public_only is set to 1, the API will return deals where exclusive is 0.
    • Only one parameter can be set to 1 at a time to avoid conflicts.

Example API Calls

To return exclusive deals (with exclusive values of 1 or 2), use:

To return public deals (with exclusive value of 0), use:

Note: Both exclusive_only and public_only cannot be set to 1 simultaneously. This call will fail as only one filter can be applied at a time to ensure clarity and avoid conflicts between deal types. (Note that version 3.2.0 is the minimum version required for this to work.) An invalid call example would be:

Why Version 3.2.1 Matters

While 3.2.1 may seem like a minor update, the field name change plays a critical role in making the API easier to work with for developers who integrate across multiple FMTC endpoints. Consistency in field names ensures better predictability and reduces the potential for errors, especially when working with data from multiple sources.

This update ensures our API remains as developer-friendly and efficient as possible. As always, we recommend updating to the latest version to take advantage of these changes.

For full API notes, please visit our documentation.

Need Assistance?

As always, a dedicated team is here to assist you! If you have any questions or concerns, feel free to contact your account manager or email us at support@fmtc.co. 

Curious about other FMTC technologies? Find more information on FMTC’s tools in Tech Corner:

• FMTC Tech Corner: Subscriber Exclusive Deals

• FMTC Tech Corner: Deal Types

• FMTC Tech Corner: New Incremental

The post Tech Corner: FMTC Deals API 4.0.0: What Changed & What Developers Need to Know (2026 Update) appeared first on FMTC.