diff --git a/extensions/unsigned_integers.yaml b/extensions/unsigned_integers.yaml
new file mode 100644
index 000000000..2e03208d4
--- /dev/null
+++ b/extensions/unsigned_integers.yaml
@@ -0,0 +1,309 @@
+%YAML 1.2
+---
+urn: extension:io.substrait:unsigned_integers
+
+types:
+  - name: u8
+    description: >
+      Unsigned 8-bit integer (0 to 255).
+      Values are encoded as decimal strings in the structure representation.
+    structure:
+      value: string
+  - name: u16
+    description: >
+      Unsigned 16-bit integer (0 to 65535).
+      Values are encoded as decimal strings in the structure representation.
+    structure:
+      value: string
+  - name: u32
+    description: >
+      Unsigned 32-bit integer (0 to 4294967295).
+      Values are encoded as decimal strings in the structure representation.
+    structure:
+      value: string
+  - name: u64
+    description: >
+      Unsigned 64-bit integer (0 to 18446744073709551615).
+      Values are encoded as decimal strings in the structure representation.
+    structure:
+      value: string
+
+scalar_functions:
+  -
+    name: "add"
+    description: "Add two unsigned integer values."
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+          - name: y
+            value: u!u8
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u8
+      - args:
+          - name: x
+            value: u!u16
+          - name: y
+            value: u!u16
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u16
+      - args:
+          - name: x
+            value: u!u32
+          - name: y
+            value: u!u32
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u32
+      - args:
+          - name: x
+            value: u!u64
+          - name: y
+            value: u!u64
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u64
+  -
+    name: "subtract"
+    description: "Subtract one unsigned integer value from another."
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+          - name: y
+            value: u!u8
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u8
+      - args:
+          - name: x
+            value: u!u16
+          - name: y
+            value: u!u16
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u16
+      - args:
+          - name: x
+            value: u!u32
+          - name: y
+            value: u!u32
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u32
+      - args:
+          - name: x
+            value: u!u64
+          - name: y
+            value: u!u64
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u64
+  -
+    name: "multiply"
+    description: "Multiply two unsigned integer values."
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+          - name: y
+            value: u!u8
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u8
+      - args:
+          - name: x
+            value: u!u16
+          - name: y
+            value: u!u16
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u16
+      - args:
+          - name: x
+            value: u!u32
+          - name: y
+            value: u!u32
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u32
+      - args:
+          - name: x
+            value: u!u64
+          - name: y
+            value: u!u64
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        return: u!u64
+  -
+    name: "divide"
+    description: >
+      Divide x by y. Partial values are truncated (i.e. rounded towards 0).
+      The `on_division_by_zero` option governs behavior in cases where y is 0.
+      If either x or y are out of range, behavior will be governed by `on_domain_error`.
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+          - name: y
+            value: u!u8
+        options:
+          on_domain_error:
+            values: [ "NULL", ERROR ]
+          on_division_by_zero:
+            values: [ "NULL", ERROR ]
+        return: u!u8
+      - args:
+          - name: x
+            value: u!u16
+          - name: y
+            value: u!u16
+        options:
+          on_domain_error:
+            values: [ "NULL", ERROR ]
+          on_division_by_zero:
+            values: [ "NULL", ERROR ]
+        return: u!u16
+      - args:
+          - name: x
+            value: u!u32
+          - name: y
+            value: u!u32
+        options:
+          on_domain_error:
+            values: [ "NULL", ERROR ]
+          on_division_by_zero:
+            values: [ "NULL", ERROR ]
+        return: u!u32
+      - args:
+          - name: x
+            value: u!u64
+          - name: y
+            value: u!u64
+        options:
+          on_domain_error:
+            values: [ "NULL", ERROR ]
+          on_division_by_zero:
+            values: [ "NULL", ERROR ]
+        return: u!u64
+
+aggregate_functions:
+  - name: "sum"
+    description: Sum a set of unsigned integer values. The sum of zero elements yields null.
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u64?
+        return: u!u64?
+      - args:
+          - name: x
+            value: u!u16
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u64?
+        return: u!u64?
+      - args:
+          - name: x
+            value: u!u32
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u64?
+        return: u!u64?
+      - args:
+          - name: x
+            value: u!u64
+        options:
+          overflow:
+            values: [ SILENT, SATURATE, ERROR ]
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u64?
+        return: u!u64?
+  - name: "min"
+    description: Min of a set of unsigned integer values.
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u8?
+        return: u!u8?
+      - args:
+          - name: x
+            value: u!u16
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u16?
+        return: u!u16?
+      - args:
+          - name: x
+            value: u!u32
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u32?
+        return: u!u32?
+      - args:
+          - name: x
+            value: u!u64
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u64?
+        return: u!u64?
+  - name: "max"
+    description: Max of a set of unsigned integer values.
+    impls:
+      - args:
+          - name: x
+            value: u!u8
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u8?
+        return: u!u8?
+      - args:
+          - name: x
+            value: u!u16
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u16?
+        return: u!u16?
+      - args:
+          - name: x
+            value: u!u32
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u32?
+        return: u!u32?
+      - args:
+          - name: x
+            value: u!u64
+        nullability: DECLARED_OUTPUT
+        decomposable: MANY
+        intermediate: u!u64?
+        return: u!u64?
diff --git a/site/docs/extensions/generate_function_docs.py b/site/docs/extensions/generate_function_docs.py
index 3a4425aa3..d68410411 100644
--- a/site/docs/extensions/generate_function_docs.py
+++ b/site/docs/extensions/generate_function_docs.py
@@ -21,7 +21,7 @@ def write_markdown(file_obj: dict, file_name: str) -> None:
                 mdFile.new_line(f"{key}: {value}")
 
     for function_classification, _value in file_obj.items():
-        if function_classification == "urn":
+        if function_classification in ("urn", "dependencies"):
             continue
         function_classification_str = function_classification.replace("_", " ").title()
         mdFile.new_header(level=2, title=f"{function_classification_str}")
diff --git a/tests/baseline.json b/tests/baseline.json
index 07b82ff00..8cccd8fc0 100644
--- a/tests/baseline.json
+++ b/tests/baseline.json
@@ -1,16 +1,16 @@
 {
   "registry": {
-    "extension_count": 15,
-    "dependency_count": 15,
+    "extension_count": 16,
+    "dependency_count": 18,
     "function_count": 174,
-    "num_aggregate_functions": 28,
-    "num_scalar_functions": 170,
+    "num_aggregate_functions": 31,
+    "num_scalar_functions": 174,
     "num_window_functions": 11,
-    "num_function_overloads": 498
+    "num_function_overloads":530
   },
   "coverage": {
-    "total_test_count": 1177,
-    "num_function_variants": 498,
-    "num_covered_function_variants": 245
+    "total_test_count": 1297,
+    "num_function_variants": 530,
+    "num_covered_function_variants": 277
   }
 }
diff --git a/tests/cases/arithmetic_unsigned/add.test b/tests/cases/arithmetic_unsigned/add.test
new file mode 100644
index 000000000..56bddde77
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/add.test
@@ -0,0 +1,16 @@
+### SUBSTRAIT_SCALAR_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+add(('200')::u!u8, ('50')::u!u8) = ('250')::u!u8
+add(('50000')::u!u16, ('10000')::u!u16) = ('60000')::u!u16
+add(('3000000000')::u!u32, ('1000000000')::u!u32) = ('4000000000')::u!u32
+add(('10000000000000000000')::u!u64, ('1000000000000000000')::u!u64) = ('11000000000000000000')::u!u64
+
+# overflow: Examples demonstrating overflow behavior
+add(('200')::u!u8, ('100')::u!u8) [overflow:ERROR] = <!ERROR>
+add(('60000')::u!u16, ('10000')::u!u16) [overflow:ERROR] = <!ERROR>
+add(('4000000000')::u!u32, ('1000000000')::u!u32) [overflow:ERROR] = <!ERROR>
+add(('18446744073709551615')::u!u64, ('1')::u!u64) [overflow:ERROR] = <!ERROR>
+add(('200')::u!u8, ('100')::u!u8) [overflow:SATURATE] = ('255')::u!u8
+add(('200')::u!u8, ('100')::u!u8) [overflow:SILENT] = <!UNDEFINED>
diff --git a/tests/cases/arithmetic_unsigned/divide.test b/tests/cases/arithmetic_unsigned/divide.test
new file mode 100644
index 000000000..37c11b528
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/divide.test
@@ -0,0 +1,12 @@
+### SUBSTRAIT_SCALAR_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+divide(('250')::u!u8, ('5')::u!u8) = ('50')::u!u8
+divide(('60000')::u!u16, ('100')::u!u16) = ('600')::u!u16
+divide(('4000000000')::u!u32, ('200')::u!u32) = ('20000000')::u!u32
+divide(('10000000000000000000')::u!u64, ('5000')::u!u64) = ('2000000000000000')::u!u64
+
+# division_by_zero: Examples demonstrating division by zero
+divide(('5')::u!u8, ('0')::u!u8) [on_division_by_zero:NULL] = null::u!u8?
+divide(('5')::u!u8, ('0')::u!u8) [on_division_by_zero:ERROR] = <!ERROR>
diff --git a/tests/cases/arithmetic_unsigned/max.test b/tests/cases/arithmetic_unsigned/max.test
new file mode 100644
index 000000000..a0cfea748
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/max.test
@@ -0,0 +1,13 @@
+### SUBSTRAIT_AGGREGATE_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+max(('20', '3', '1', '10', '0', '5')::u!u8) = ('20')::u!u8?
+max(('32768', '32767', '20000', '30000')::u!u16) = ('32768')::u!u16?
+max(('214748648', '214748647', '21470048', '4000000')::u!u32) = ('214748648')::u!u32?
+max(('2000000000', '3217908979', '629000000', '100000000', '0', '987654321')::u!u64) = ('3217908979')::u!u64?
+
+# null_handling: Examples with null as input or output
+max((Null, Null, Null)::u!u16) = Null::u!u16?
+max(()::u!u16) = Null::u!u16?
+max(('200', Null, '50', '100', Null, '5')::u!u64) = ('200')::u!u64?
diff --git a/tests/cases/arithmetic_unsigned/min.test b/tests/cases/arithmetic_unsigned/min.test
new file mode 100644
index 000000000..9cb4a1bf8
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/min.test
@@ -0,0 +1,13 @@
+### SUBSTRAIT_AGGREGATE_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+min(('20', '3', '1', '10', '0', '5')::u!u8) = ('0')::u!u8?
+min(('32768', '32767', '20000', '30000')::u!u16) = ('20000')::u!u16?
+min(('214748648', '214748647', '21470048', '4000000')::u!u32) = ('4000000')::u!u32?
+min(('2000000000', '3217908979', '629000000', '100000000', '0', '987654321')::u!u64) = ('0')::u!u64?
+
+# null_handling: Examples with null as input or output
+min((Null, Null, Null)::u!u16) = Null::u!u16?
+min(()::u!u16) = Null::u!u16?
+min(('200', Null, '50', '100', Null, '5')::u!u64) = ('5')::u!u64?
diff --git a/tests/cases/arithmetic_unsigned/multiply.test b/tests/cases/arithmetic_unsigned/multiply.test
new file mode 100644
index 000000000..b1813294c
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/multiply.test
@@ -0,0 +1,16 @@
+### SUBSTRAIT_SCALAR_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+multiply(('25')::u!u8, ('5')::u!u8) = ('125')::u!u8
+multiply(('200')::u!u16, ('100')::u!u16) = ('20000')::u!u16
+multiply(('300')::u!u32, ('200')::u!u32) = ('60000')::u!u32
+multiply(('80000')::u!u64, ('5000')::u!u64) = ('400000000')::u!u64
+
+# overflow: Examples demonstrating overflow behavior
+multiply(('200')::u!u8, ('2')::u!u8) [overflow:ERROR] = <!ERROR>
+multiply(('40000')::u!u16, ('2')::u!u16) [overflow:ERROR] = <!ERROR>
+multiply(('3000000000')::u!u32, ('2')::u!u32) [overflow:ERROR] = <!ERROR>
+multiply(('10000000000000000000')::u!u64, ('2')::u!u64) [overflow:ERROR] = <!ERROR>
+multiply(('200')::u!u8, ('2')::u!u8) [overflow:SATURATE] = ('255')::u!u8
+multiply(('200')::u!u8, ('2')::u!u8) [overflow:SILENT] = <!UNDEFINED>
diff --git a/tests/cases/arithmetic_unsigned/subtract.test b/tests/cases/arithmetic_unsigned/subtract.test
new file mode 100644
index 000000000..764701c2d
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/subtract.test
@@ -0,0 +1,16 @@
+### SUBSTRAIT_SCALAR_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+subtract(('250')::u!u8, ('50')::u!u8) = ('200')::u!u8
+subtract(('60000')::u!u16, ('10000')::u!u16) = ('50000')::u!u16
+subtract(('4000000000')::u!u32, ('1000000000')::u!u32) = ('3000000000')::u!u32
+subtract(('11000000000000000000')::u!u64, ('1000000000000000000')::u!u64) = ('10000000000000000000')::u!u64
+
+# overflow: Examples demonstrating overflow behavior
+subtract(('0')::u!u8, ('1')::u!u8) [overflow:ERROR] = <!ERROR>
+subtract(('0')::u!u16, ('1')::u!u16) [overflow:ERROR] = <!ERROR>
+subtract(('0')::u!u32, ('1')::u!u32) [overflow:ERROR] = <!ERROR>
+subtract(('0')::u!u64, ('1')::u!u64) [overflow:ERROR] = <!ERROR>
+subtract(('0')::u!u8, ('1')::u!u8) [overflow:SATURATE] = ('0')::u!u8
+subtract(('0')::u!u8, ('1')::u!u8) [overflow:SILENT] = <!UNDEFINED>
diff --git a/tests/cases/arithmetic_unsigned/sum.test b/tests/cases/arithmetic_unsigned/sum.test
new file mode 100644
index 000000000..622f57309
--- /dev/null
+++ b/tests/cases/arithmetic_unsigned/sum.test
@@ -0,0 +1,16 @@
+### SUBSTRAIT_AGGREGATE_TEST: v1.0
+### SUBSTRAIT_INCLUDE: extension:io.substrait:unsigned_integers
+
+# basic: Basic unsigned integer examples
+sum(('0', '1', '2', '20')::u!u8) = ('23')::u!u64?
+sum(('100', '200', '50')::u!u16) = ('350')::u!u64?
+sum(('2000000', '3217908', '629000', '100000', '0', '987654')::u!u32) = ('6934562')::u!u64?
+sum(('1000000000000', '2000000000000', '3000000000000')::u!u64) = ('6000000000000')::u!u64?
+
+# overflow: Examples demonstrating overflow behavior
+sum(('18446744073709551614', '1', '1', '1', '1', '10000000000')::u!u64) [overflow:ERROR] = <!ERROR>
+
+# null_handling: Examples with null as input or output
+sum((Null, Null, Null)::u!u16) = Null::u!u64?
+sum(()::u!u16) = Null::u!u64?
+sum(('200', Null, '50', '0', Null, '100')::u!u32) = ('350')::u!u64?
diff --git a/tests/coverage/extensions.py b/tests/coverage/extensions.py
index 65a364a01..40920a4e1 100644
--- a/tests/coverage/extensions.py
+++ b/tests/coverage/extensions.py
@@ -161,10 +161,16 @@ def add_functions_to_map(func_list, function_map, suffix, extension, urn):
     @staticmethod
     def read_substrait_extensions(dir_path: str):
         # read files from extensions directory
+        # Scan all YAML files, not just functions_* prefixed ones, so that
+        # self-contained extension type files (e.g. unsigned_integers.yaml)
+        # with function definitions are also discovered. Files without
+        # scalar_functions/aggregate_functions/window_functions sections are
+        # safely skipped by the guards below. unknown.yaml is excluded
+        # because it defines an "unknown" type not in the type mapping.
         extensions = []
         for root, _dirs, files in os.walk(dir_path):
             for file in files:
-                if file.endswith(".yaml") and file.startswith("functions_"):
+                if file.endswith(".yaml") and file != "unknown.yaml":
                     extensions.append(os.path.join(root, file))
 
         extensions.sort()