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Module read

haystack_server::ops

Module read 

Source
Expand description

The read op — read entities by filter or by id.

§Overview

POST /api/read returns entity records matching a filter expression or a list of explicit IDs. Results include local entities and, when federation is enabled, matching entities from remote connectors.

§Request Grid Columns

Two mutually-exclusive request forms:

Filter read — first row contains:

ColumnKindDescription
filterStrHaystack filter expression (e.g. "site", "point and siteRef==@s1")
limitNumber(optional) Max entities to return (0 = no limit)

ID read — each row contains:

ColumnKindDescription
idRefEntity reference

§Response Grid Columns

The response grid has one column per unique tag across all matched entities. For ID reads, rows for unknown IDs appear as stubs with only the id column.

§Errors

  • 400 Bad Request — missing filter/id column, invalid filter syntax, or request decode failure.
  • 500 Internal Server Error — graph or encoding error.

Functions§

handle
POST /api/read