Zoho,

We have been heavy Zoho Books users for 6+ years. We run thousand of API calls/day to Zoho Books, many of them through Zoho Flow. We are continuing to see a degraded experience with your API. In particular, we are sending API requests to create invoices or bills (or customers), often from custom functions in Zoho Flow, and on about 3% of our calls we will run into an issue where the API returns with the following message:
"The task has been terminated since the API call is taking too long to respond. Please try again after sometime, at line number 78. Resolve the errors and try executing it again."

We are seeing these sort of errors more frequently in the last month, especially in the last week. Something needs to be done about it as we had 10 errors like this from yesterday alone.

Also, Zoho Flow's handling of this slow response is really poor IF you're using a standard action (Create Customer, Create Invoice, etc). If there is a step in Zoho Flow that uses an action from Zoho Books, what's happening is that Zoho Books takes too long to respond to the API call so Zoho Flow halts that step...however, at some point after initial API call, Zoho Books actually processes the request (let's say Create Customer). After a minute or two Zoho Flow will attempt to make the API call again to Zoho Books and this time Zoho Books will respond with error message saying "
"The customer {name} already exists. Please specify a different name"
Below is the perfect example:
1. We have a step where we search for customer in Zoho Books. 

- Zoho Books Returns No customer Found
2. We have a decision step saying if no customer is found create new customer in Zoho Books

3. As you see, when we try to create a customer with the SAME details we searched for, this step (executed 6 minutes later!!) shows that the customer cannot be created because the customer already exists.

The issue is that the customer clearly did not exists in the step immediately preceding. Given Zoho Books terrible API responses, Zoho Flow didn't get a response from Zoho Books quick enough, so it doesn't know if Zoho Books processed the request or not...as such Zoho Flows waits a few minutes and tries to execute the step again, but on second try it gets an error since Zoho Books actually processed the first request but didn't provide feedback fast enough to initiator (Zoho Flow in this case).

The core of the issue is that Zoho Books API is responding way too slow for most applications and it's getting worse. Zoho Flow's handling of this is not ideal and is causing many issues.

Zoho Books team needs to fix their API ASAP!