Strange Behavior in Incremental Export API for ticket_metric_events

Hi all,

I’m running into some odd behavior with the Zendesk Incremental Export API for ticket_metric_events, and I’m hoping to get some insight or confirmation from others or the Zendesk team.

Scenario:

• I’m using the endpoint:
  GET /api/v2/incremental/ticket_metric_events.json?start_time=...
• When I set start_time=1735689600 (which is 1 June 2025), I get:
  • ~3MB of data
  • Pagination cursor (end_of_stream = false)
• However, when I use an older start_time=1646873940 (which is 10 March 2022), I get:
  • Only ~192KB of data
  • end_of_stream = true in the very first response

This is confusing because:

• I would expect the API to return all ticket metric events from 10 March 2022 up to now, including all events in 2025
• But that doesn’t seem to happen — I’m only getting a small chunk and no continuation
• According to the docs, the API should return everything with updated_at >= start_time

What I've checked:

• The newer data does exist — it shows up fine when I start from 2025 directly
• I’ve reviewed the documentation and didn’t find any official explanation for this cutoff

Has anyone else experienced this?

• Is this expected behavior?
• Is there a recommended max range for start_time?
• Could there be an undocumented retention-related limit on how far back the API can walk?

Any advice, clarification, or input from Zendesk staff would be greatly appreciated.

Thanks in advance!