diff --git a/api/openapi-spec/v1.0.yaml b/api/openapi-spec/v1.0.yaml
index 5c22847..276df1f 100644
--- a/api/openapi-spec/v1.0.yaml
+++ b/api/openapi-spec/v1.0.yaml
@@ -6641,6 +6641,18 @@ components:
             $ref: '#/components/schemas/aggregationOption'
         '@libre.graph.metricDefinition':
           $ref: '#/components/schemas/metricDefinition'
+        '@libre.graph.geohashPrecision':
+          type: integer
+          format: int32
+          description: |
+            When greater than 0, this is a geohash-grid aggregation over `field`,
+            which must resolve to a geo-point field (e.g. `location`). Each
+            returned `searchBucket` carries a geohash cell as `key` and its
+            count, suitable for density/heatmap rendering. The value is the
+            geohash length (1-12); higher means finer cells. Libregraph
+            extension not present in MS Graph.
+          minimum: 1
+          maximum: 12
     metricDefinition:
       type: object
       description: |