OPTIMADE /v1/structures returns empty dataset (data_available=0) for all queries

Materials Project
1

Hi MP team,

We are seeing a consistent issue with the MP OPTIMADE endpoint in EMOS.

Date tested (UTC): 2026-07-29 15:13
Endpoint: https://optimade.materialsproject.org/v1/structures
Accept header: application/json

Observed behavior:

  • HTTP 200 responses
  • meta.data_available = 0
  • meta.data_returned = 0
  • data =

This occurs for:

  1. No filter:
    /v1/structures?page_limit=1
  2. HAS filter:
    /v1/structures?page_limit=1&filter=elements%20HAS%20%22Fe%22
  3. HAS ALL filter:
    /v1/structures?page_limit=1&filter=elements%20HAS%20ALL%20%22Fe%22

For comparison:

  • /v1/info still returns HTTP 200 with data_available=1 and data_returned=1.

Expected:

  • /v1/structures should return at least some records (or a clear maintenance/degraded message if temporarily unavailable).

Could you confirm whether this is a temporary index/data sync issue on the MP OPTIMADE service?

Thanks!

2

Hi @adixit ,

That’s odd, no major updates to our optimade service have occurred. Logs aren’t surfacing any errors currently either. Will take a deeper look and check back in

3

Hi @adixit,

Things should be back to normal now!