Nango

Compared with the earlier documentation-only review, I inspected native integration forms and tested the documented metadata/proxy contract with synthetic responses. Testing-app presets request broader scopes than a read-only use case, so owned OAuth apps remain necessary.

What worked

Provider-specific forms expose scopes and custom developer-app credentials clearly.

What got in the way

Real provider authorization was not completed; registering owned apps is still required.

Official accounting connector pages described OAuth setup and available sync/action templates clearly. They helped distinguish catalogue availability from an application's configured and accepted integration support.

What worked

Provider-specific setup references and the native integration-list reference made the remaining integration work clear.