From 6c6a85e8cb4dbc29c577cdfcec1509da5089f9d5 Mon Sep 17 00:00:00 2001
From: Ben Bellick <ben.bellick@datadoghq.com>
Date: Tue, 11 Nov 2025 11:29:11 -0500
Subject: [PATCH 1/2] feat: add simple extension for JSON

---
 extensions/json.yaml | 61 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 extensions/json.yaml

diff --git a/extensions/json.yaml b/extensions/json.yaml
new file mode 100644
index 000000000..ea1f7f9fe
--- /dev/null
+++ b/extensions/json.yaml
@@ -0,0 +1,61 @@
+%YAML 1.2
+---
+urn: extension:io.substrait:json
+types:
+  - name: json
+    structure:
+      content: string
+    description: >-
+      A JSON type representing arbitrary JSON values (objects, arrays,
+      strings, numbers, booleans, or null).
+
+scalar_functions:
+  - name: "parse_json"
+    description: >-
+      Parse a JSON string into a JSON value.
+    impls:
+      - args:
+          - name: json_string
+            value: string
+        options:
+          on_error:
+            description: Controls behavior when input is not valid JSON
+            values: [ ERROR, "NULL" ]
+        return: u!json?
+
+  - name: "to_string"
+    description: "Convert a JSON value to its string representation"
+    impls:
+      - args:
+          - name: json_value
+            value: u!json
+        return: string
+
+  - name: "json_extract"
+    description: >-
+      Extract a value from JSON using a JSONPath expression.
+      JSONPath expressions should follow RFC 9535 (https://datatracker.ietf.org/doc/html/rfc9535).
+    impls:
+      - args:
+          - name: json_value
+            value: u!json
+          - name: path
+            value: string
+        options:
+          on_invalid_path:
+            description: Controls behavior when the JSONPath expression is syntactically invalid
+            values: [ ERROR, "NULL", UNDEFINED ]
+          on_path_not_found:
+            description: Controls behavior when the path does not exist in the JSON document
+            values: [ ERROR, "NULL" ]
+        return: u!json?
+
+  - name: "is_json_valid"
+    description: >-
+      Returns true if the input string is valid JSON, false otherwise.
+      This function does not parse the JSON, only validates syntax.
+    impls:
+      - args:
+          - name: json_string
+            value: string
+        return: boolean

From 914e6b1ff0a9f9ee2f7aef920314c3350bf1e439 Mon Sep 17 00:00:00 2001
From: Ben Bellick <ben.bellick@datadoghq.com>
Date: Tue, 11 Nov 2025 19:03:05 -0500
Subject: [PATCH 2/2] tweak: fix @yongchul's comments

---
 extensions/json.yaml | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/extensions/json.yaml b/extensions/json.yaml
index ea1f7f9fe..910a5b4b5 100644
--- a/extensions/json.yaml
+++ b/extensions/json.yaml
@@ -12,19 +12,20 @@ types:
 scalar_functions:
   - name: "parse_json"
     description: >-
-      Parse a JSON string into a JSON value.
+      Parses a JSON string into a JSON value.
     impls:
       - args:
           - name: json_string
             value: string
         options:
           on_error:
-            description: Controls behavior when input is not valid JSON
+            description: Controls behavior when input is not valid JSON.
             values: [ ERROR, "NULL" ]
         return: u!json?
 
   - name: "to_string"
-    description: "Convert a JSON value to its string representation"
+    description: >-
+      Converts a JSON value to its string representation.
     impls:
       - args:
           - name: json_value
@@ -33,7 +34,7 @@ scalar_functions:
 
   - name: "json_extract"
     description: >-
-      Extract a value from JSON using a JSONPath expression.
+      Extracts a value from JSON using a JSONPath expression.
       JSONPath expressions should follow RFC 9535 (https://datatracker.ietf.org/doc/html/rfc9535).
     impls:
       - args:
@@ -43,10 +44,10 @@ scalar_functions:
             value: string
         options:
           on_invalid_path:
-            description: Controls behavior when the JSONPath expression is syntactically invalid
+            description: Controls behavior when the JSONPath expression is syntactically invalid.
             values: [ ERROR, "NULL", UNDEFINED ]
           on_path_not_found:
-            description: Controls behavior when the path does not exist in the JSON document
+            description: Controls behavior when the path does not exist in the JSON document.
             values: [ ERROR, "NULL" ]
         return: u!json?