op: merge

Shallow-merge an object into an existing field or bound variable.

Allowed phases

PhaseStatus
preflight✗ forbidden
core✓ allowed
side_effects✗ forbidden

Syntax

- op: merge
  path: /metadata
  value:
    last_seen: "event.ts"
    source: "event.source"

Parameters

FieldRequiredDescription
pathyesObject field path or variable from find
valueyesKey-value map; values may be expressions

Behavior

  • Shallow merge only — nested objects are replaced, not deep-merged. Use multiple set ops for nested paths.
  • Common pattern after find: merge into existing_item variable to update an array element in place.

set · find · push

See also