Marketo API Question

[John_Danielson1]

We are in the process of creating a user portal so our customers will be able to log into our site. We are wondering if it's possible to have our website call a Marketo API to check if the user's email address already exists in Marketo? Does anyone know if that is feasible?

[SanfordWhiteman]

Please move the question to Products

As confusing as this is, the "Community" space is for website feedback, not support topics.

After you move it, I'll answer over there.

[SanfordWhiteman]

The superficial, rather unreasoned answer is "Yes." There is a REST API endpoint to lookup lead(s) by email.

The realistic answer is that you'll be introducing a massive Denial of Service vulnerability if you expose individual API calls in this way. The only way to roll out something like this professionally is to enforce rate limits using a robust algorithm, plus daily caps to leave space for other integrations -- but even with those controls you may not have enough to service legit end users.

A more appropriate way to reapproach this goal is mirroring your Mkto database, via periodic batches, to your own database. Then offer that second db for real-time lookups. The Marketo API is good for batch/bulk operations, not one-at-a-time use.