Forcing Authorization Code over Client Credentials in an integration connector breaks fundamental integration design

The current behavior of the Salesforce Marketing Cloud native connector reflects a serious architectural misalignment that is difficult to justify in any modern integration platform.

This is not about missing a feature. This is about breaking a fundamental expectation of how backend integrations are supposed to work.

Core issue

The connector effectively enforces Authorization Code flow (user-to-server) while Client Credentials (server-to-server) is not properly supported.

At the same time, the UI exposes client_credentials, which creates the false impression that this flow is supported. Exposing a standard OAuth2 parameter such as client_credentials in the UI without providing the necessary behavior to support it in practice results in misleading capabilities and incorrect architectural assumptions.

Why this is a critical design problem

This is not a matter of opinion:

• Server-to-server integrations are the baseline use case for platforms like webMethods.
• Client Credentials is the standard OAuth2 flow for this scenario.
• Authorization Code is explicitly designed for user interaction and consent.

Requiring a user-centric flow in a headless, backend integration context is not just inconvenient, it is architecturally incorrect.

What this breaks in practice

This design choice directly impacts real-world systems:

• Breaks stateless authentication models.
• Forces handling of refresh tokens where they should not exist.
• Introduces unnecessary state management and failure points.
• Violates common security policies (no user context, no interactive flows).
• Makes the connector unsuitable for automation-heavy environments.

In short, this prevents building clean, robust, and compliant integrations.

The most concerning aspect

This is currently being treated as a feature request. It is not.

Calling this a feature request implies that:

• Supporting server-to-server authentication is optional.
• Aligning with industry-standard OAuth2 usage is optional.

Neither is true.

This is baseline functionality. Without it, the connector does not meet the minimum expectations of an integration tool.

Expected behavior

At minimum:

• Full, reliable support for Client Credentials (grant_type=client_credentials).
• Automatic token acquisition and renewal without user interaction.
• True headless operation.
• Alignment with Salesforce Marketing Cloud’s official server-to-server model.

Final statement

If an integration platform cannot correctly support the primary authentication pattern used in backend integrations, then the issue is not a missing enhancement, it is a capability gap that directly limits the viability of the product in real-world architectures.