diff --git a/exercises/practice/clock/.meta/Example.roc b/exercises/practice/clock/.meta/Example.roc
index acdd522f..a400ee04 100644
--- a/exercises/practice/clock/.meta/Example.roc
+++ b/exercises/practice/clock/.meta/Example.roc
@@ -1,5 +1,5 @@
 Clock :: { hour : U8, minute : U8 }.{
-	create : { hour : I64, minute : I64 } -> Clock
+	create : { hour : I64 ?? 0, minute : I64 ?? 0 } -> Clock
 	create = |{ hour, minute }| {
 		hour24 = (hour % 24 + minute // 60) % 24
 		minute60 = minute % 60
@@ -20,14 +20,14 @@ Clock :: { hour : U8, minute : U8 }.{
 		"${zero_padded(hour)}:${zero_padded(minute)}"
 	}
 
-	add : Clock, { hour : I64, minute : I64 } -> Clock
+	add : Clock, { hour : I64 ?? 0, minute : I64 ?? 0 } -> Clock
 	add = |clock, { hour, minute }| {
 		total_hour = clock.hour.to_i64() + (hour % 24 + minute // 60)
 		total_minute = clock.minute.to_i64() + minute % 60
 		create({ hour: total_hour, minute: total_minute })
 	}
 
-	subtract : Clock, { hour : I64, minute : I64 } -> Clock
+	subtract : Clock, { hour : I64 ?? 0, minute : I64 ?? 0 } -> Clock
 	subtract = |clock, { hour, minute }| {
 		clock.add({ hour: -(hour % 24 + minute // 60), minute: -(minute % 60) })
 	}
diff --git a/exercises/practice/clock/.meta/plugins.py b/exercises/practice/clock/.meta/plugins.py
index ff8f8f05..7852c6f3 100644
--- a/exercises/practice/clock/.meta/plugins.py
+++ b/exercises/practice/clock/.meta/plugins.py
@@ -1,4 +1,9 @@
 def to_hour_minute_record(input):
     hour = input.get("hour", 0)
     minute = input.get("minute", 0)
-    return f'{{hour: {hour}, minute: {minute}}}'
\ No newline at end of file
+    fields = []
+    if hour != 0:
+        fields.append(f"hour: {hour}")
+    if minute != 0:
+        fields.append(f"minute: {minute}")
+    return "{ " + ", ".join(fields) + " }" if fields else "{}"
diff --git a/exercises/practice/clock/.meta/template.j2 b/exercises/practice/clock/.meta/template.j2
index 90b02c56..b9a3fadd 100644
--- a/exercises/practice/clock/.meta/template.j2
+++ b/exercises/practice/clock/.meta/template.j2
@@ -17,7 +17,7 @@ expect {
 {%- elif case["property"] in ["add", "subtract"] %}
 expect {
     clock = create({{ plugins.to_hour_minute_record(case["input"]) }})
-    result = clock.{{ case["property"] | to_snake }}({ hour: 0, minute: {{ case["input"]["value"] }} }).to_str()
+    result = clock.{{ case["property"] | to_snake }}({ minute: {{ case["input"]["value"] }} }).to_str()
     expected = {{ case["expected"] | to_roc }} 
     result == expected
 }
diff --git a/exercises/practice/clock/Clock.roc b/exercises/practice/clock/Clock.roc
index 48e440b1..4ec59248 100644
--- a/exercises/practice/clock/Clock.roc
+++ b/exercises/practice/clock/Clock.roc
@@ -1,5 +1,5 @@
 Clock :: { hour : U8, minute : U8 }.{
-	create : { hour : I64, minute : I64 } -> Clock
+	create : { hour : I64 ?? 0, minute : I64 ?? 0 } -> Clock
 	create = |{ hour, minute }| {
 		crash "Please implement the 'create' function"
 	}
@@ -9,12 +9,12 @@ Clock :: { hour : U8, minute : U8 }.{
 		crash "Please implement the 'to_str' function"
 	}
 
-	add : Clock, { hour : I64, minute : I64 } -> Clock
+	add : Clock, { hour : I64 ?? 0, minute : I64 ?? 0 } -> Clock
 	add = |clock, { hour, minute }| {
 		crash "Please implement the 'add' function"
 	}
 
-	subtract : Clock, { hour : I64, minute : I64 } -> Clock
+	subtract : Clock, { hour : I64 ?? 0, minute : I64 ?? 0 } -> Clock
 	subtract = |clock, { hour, minute }| {
 		crash "Please implement the 'subtract' function"
 	}
diff --git a/exercises/practice/clock/clock-test.roc b/exercises/practice/clock/clock-test.roc
index 7a364e53..297d720a 100644
--- a/exercises/practice/clock/clock-test.roc
+++ b/exercises/practice/clock/clock-test.roc
@@ -1,6 +1,6 @@
 # These tests are auto-generated with test data from:
 # https://github.com/exercism/problem-specifications/tree/main/exercises/clock/canonical-data.json
-# File last updated on 2026-08-01
+# File last updated on 2026-08-18
 
 import Clock exposing [create, add, subtract, to_str]
 
@@ -10,7 +10,7 @@ import Clock exposing [create, add, subtract, to_str]
 
 # on the hour
 expect {
-	clock = create({ hour: 8, minute: 0 })
+	clock = create({ hour: 8 })
 	result = clock.to_str()
 	expected = "08:00"
 	result == expected
@@ -26,7 +26,7 @@ expect {
 
 # midnight is zero hours
 expect {
-	clock = create({ hour: 24, minute: 0 })
+	clock = create({ hour: 24 })
 	result = clock.to_str()
 	expected = "00:00"
 	result == expected
@@ -34,7 +34,7 @@ expect {
 
 # hour rolls over
 expect {
-	clock = create({ hour: 25, minute: 0 })
+	clock = create({ hour: 25 })
 	result = clock.to_str()
 	expected = "01:00"
 	result == expected
@@ -42,7 +42,7 @@ expect {
 
 # hour rolls over continuously
 expect {
-	clock = create({ hour: 100, minute: 0 })
+	clock = create({ hour: 100 })
 	result = clock.to_str()
 	expected = "04:00"
 	result == expected
@@ -58,7 +58,7 @@ expect {
 
 # minutes roll over
 expect {
-	clock = create({ hour: 0, minute: 160 })
+	clock = create({ minute: 160 })
 	result = clock.to_str()
 	expected = "02:40"
 	result == expected
@@ -66,7 +66,7 @@ expect {
 
 # minutes roll over continuously
 expect {
-	clock = create({ hour: 0, minute: 1723 })
+	clock = create({ minute: 1723 })
 	result = clock.to_str()
 	expected = "04:43"
 	result == expected
@@ -106,7 +106,7 @@ expect {
 
 # negative hour rolls over
 expect {
-	clock = create({ hour: -25, minute: 0 })
+	clock = create({ hour: -25 })
 	result = clock.to_str()
 	expected = "23:00"
 	result == expected
@@ -114,7 +114,7 @@ expect {
 
 # negative hour rolls over continuously
 expect {
-	clock = create({ hour: -91, minute: 0 })
+	clock = create({ hour: -91 })
 	result = clock.to_str()
 	expected = "05:00"
 	result == expected
@@ -174,8 +174,8 @@ expect {
 
 # add minutes
 expect {
-	clock = create({ hour: 10, minute: 0 })
-	result = clock.add({ hour: 0, minute: 3 }).to_str()
+	clock = create({ hour: 10 })
+	result = clock.add({ minute: 3 }).to_str()
 	expected = "10:03"
 	result == expected
 }
@@ -183,31 +183,31 @@ expect {
 # add no minutes
 expect {
 	clock = create({ hour: 6, minute: 41 })
-	result = clock.add({ hour: 0, minute: 0 }).to_str()
+	result = clock.add({ minute: 0 }).to_str()
 	expected = "06:41"
 	result == expected
 }
 
 # add to next hour
 expect {
-	clock = create({ hour: 0, minute: 45 })
-	result = clock.add({ hour: 0, minute: 40 }).to_str()
+	clock = create({ minute: 45 })
+	result = clock.add({ minute: 40 }).to_str()
 	expected = "01:25"
 	result == expected
 }
 
 # add more than one hour
 expect {
-	clock = create({ hour: 10, minute: 0 })
-	result = clock.add({ hour: 0, minute: 61 }).to_str()
+	clock = create({ hour: 10 })
+	result = clock.add({ minute: 61 }).to_str()
 	expected = "11:01"
 	result == expected
 }
 
 # add more than two hours with carry
 expect {
-	clock = create({ hour: 0, minute: 45 })
-	result = clock.add({ hour: 0, minute: 160 }).to_str()
+	clock = create({ minute: 45 })
+	result = clock.add({ minute: 160 }).to_str()
 	expected = "03:25"
 	result == expected
 }
@@ -215,7 +215,7 @@ expect {
 # add across midnight
 expect {
 	clock = create({ hour: 23, minute: 59 })
-	result = clock.add({ hour: 0, minute: 2 }).to_str()
+	result = clock.add({ minute: 2 }).to_str()
 	expected = "00:01"
 	result == expected
 }
@@ -223,7 +223,7 @@ expect {
 # add more than one day (1500 min = 25 hrs)
 expect {
 	clock = create({ hour: 5, minute: 32 })
-	result = clock.add({ hour: 0, minute: 1500 }).to_str()
+	result = clock.add({ minute: 1500 }).to_str()
 	expected = "06:32"
 	result == expected
 }
@@ -231,7 +231,7 @@ expect {
 # add more than two days
 expect {
 	clock = create({ hour: 1, minute: 1 })
-	result = clock.add({ hour: 0, minute: 3500 }).to_str()
+	result = clock.add({ minute: 3500 }).to_str()
 	expected = "11:21"
 	result == expected
 }
@@ -243,7 +243,7 @@ expect {
 # subtract minutes
 expect {
 	clock = create({ hour: 10, minute: 3 })
-	result = clock.subtract({ hour: 0, minute: 3 }).to_str()
+	result = clock.subtract({ minute: 3 }).to_str()
 	expected = "10:00"
 	result == expected
 }
@@ -251,7 +251,7 @@ expect {
 # subtract to previous hour
 expect {
 	clock = create({ hour: 10, minute: 3 })
-	result = clock.subtract({ hour: 0, minute: 30 }).to_str()
+	result = clock.subtract({ minute: 30 }).to_str()
 	expected = "09:33"
 	result == expected
 }
@@ -259,23 +259,23 @@ expect {
 # subtract more than an hour
 expect {
 	clock = create({ hour: 10, minute: 3 })
-	result = clock.subtract({ hour: 0, minute: 70 }).to_str()
+	result = clock.subtract({ minute: 70 }).to_str()
 	expected = "08:53"
 	result == expected
 }
 
 # subtract across midnight
 expect {
-	clock = create({ hour: 0, minute: 3 })
-	result = clock.subtract({ hour: 0, minute: 4 }).to_str()
+	clock = create({ minute: 3 })
+	result = clock.subtract({ minute: 4 }).to_str()
 	expected = "23:59"
 	result == expected
 }
 
 # subtract more than two hours
 expect {
-	clock = create({ hour: 0, minute: 0 })
-	result = clock.subtract({ hour: 0, minute: 160 }).to_str()
+	clock = create({})
+	result = clock.subtract({ minute: 160 }).to_str()
 	expected = "21:20"
 	result == expected
 }
@@ -283,7 +283,7 @@ expect {
 # subtract more than two hours with borrow
 expect {
 	clock = create({ hour: 6, minute: 15 })
-	result = clock.subtract({ hour: 0, minute: 160 }).to_str()
+	result = clock.subtract({ minute: 160 }).to_str()
 	expected = "03:35"
 	result == expected
 }
@@ -291,7 +291,7 @@ expect {
 # subtract more than one day (1500 min = 25 hrs)
 expect {
 	clock = create({ hour: 5, minute: 32 })
-	result = clock.subtract({ hour: 0, minute: 1500 }).to_str()
+	result = clock.subtract({ minute: 1500 }).to_str()
 	expected = "04:32"
 	result == expected
 }
@@ -299,7 +299,7 @@ expect {
 # subtract more than two days
 expect {
 	clock = create({ hour: 2, minute: 20 })
-	result = clock.subtract({ hour: 0, minute: 3000 }).to_str()
+	result = clock.subtract({ minute: 3000 }).to_str()
 	expected = "00:20"
 	result == expected
 }
@@ -366,8 +366,8 @@ expect {
 
 # clocks with minute overflow
 expect {
-	clock1 = create({ hour: 0, minute: 1 })
-	clock2 = create({ hour: 0, minute: 1441 })
+	clock1 = create({ minute: 1 })
+	clock2 = create({ minute: 1441 })
 	clock1 == clock2
 }
 
@@ -415,8 +415,8 @@ expect {
 
 # full clock and zeroed clock
 expect {
-	clock1 = create({ hour: 24, minute: 0 })
-	clock2 = create({ hour: 0, minute: 0 })
+	clock1 = create({ hour: 24 })
+	clock2 = create({})
 	clock1 == clock2
 }
 
@@ -443,7 +443,7 @@ expect {
 # Can add max I64 values to a clock
 expect {
 	clock = create({ hour: 23, minute: 59 })
-	result = clock.add({ hour: 0, minute: 9223372036854775807 }).to_str()
+	result = clock.add({ minute: 9223372036854775807 }).to_str()
 	expected = "18:06"
 	result == expected
 }
@@ -451,7 +451,7 @@ expect {
 # Can add min I64 values to a clock
 expect {
 	clock = create({ hour: 23, minute: 59 })
-	result = clock.add({ hour: 0, minute: -9223372036854775808 }).to_str()
+	result = clock.add({ minute: -9223372036854775808 }).to_str()
 	expected = "05:51"
 	result == expected
 }
@@ -459,7 +459,7 @@ expect {
 # Can subtract max I64 values from a clock
 expect {
 	clock = create({ hour: 23, minute: 59 })
-	result = clock.subtract({ hour: 0, minute: 9223372036854775807 }).to_str()
+	result = clock.subtract({ minute: 9223372036854775807 }).to_str()
 	expected = "05:52"
 	result == expected
 }
@@ -467,7 +467,7 @@ expect {
 # Can subtract min I64 values from a clock
 expect {
 	clock = create({ hour: 23, minute: 59 })
-	result = clock.subtract({ hour: 0, minute: -9223372036854775808 }).to_str()
+	result = clock.subtract({ minute: -9223372036854775808 }).to_str()
 	expected = "18:07"
 	result == expected
 }
diff --git a/exercises/practice/killer-sudoku-helper/.meta/Example.roc b/exercises/practice/killer-sudoku-helper/.meta/Example.roc
index 93301294..6833c77e 100644
--- a/exercises/practice/killer-sudoku-helper/.meta/Example.roc
+++ b/exercises/practice/killer-sudoku-helper/.meta/Example.roc
@@ -1,7 +1,7 @@
 KillerSudokuHelper :: {}.{
 	Combination : List(U8)
 
-	combinations : { sum : U8, size : U8, exclude : List(U8) } -> List(Combination)
+	combinations : { sum : U8, size : U8, exclude : List(U8) ?? [] } -> List(Combination)
 	combinations = |{ sum, size, exclude }| {
 		help = |target, digits| {
 			if target == 0 {
diff --git a/exercises/practice/killer-sudoku-helper/.meta/template.j2 b/exercises/practice/killer-sudoku-helper/.meta/template.j2
index 068045d8..b7030e07 100644
--- a/exercises/practice/killer-sudoku-helper/.meta/template.j2
+++ b/exercises/practice/killer-sudoku-helper/.meta/template.j2
@@ -5,7 +5,7 @@
 import {{ exercise | to_pascal }} exposing [combinations]
 
 {% macro to_cage(cage) -%}
-{ sum: {{ cage["sum"] }}, size: {{ cage["size"] }}, exclude: {{ cage["exclude"] | to_roc }} }
+{ sum: {{ cage["sum"] }}, size: {{ cage["size"] }}{% if cage["exclude"] %}, exclude: {{ cage["exclude"] | to_roc }}{% endif %} }
 {%- endmacro %}
 
 {% for supercase in cases %}
diff --git a/exercises/practice/killer-sudoku-helper/KillerSudokuHelper.roc b/exercises/practice/killer-sudoku-helper/KillerSudokuHelper.roc
index be7f7c12..3954827c 100644
--- a/exercises/practice/killer-sudoku-helper/KillerSudokuHelper.roc
+++ b/exercises/practice/killer-sudoku-helper/KillerSudokuHelper.roc
@@ -1,7 +1,7 @@
 KillerSudokuHelper :: {}.{
 	Combination : List(U8)
 
-	combinations : { sum : U8, size : U8, exclude : List(U8) } -> List(Combination)
+	combinations : { sum : U8, size : U8, exclude : List(U8) ?? [] } -> List(Combination)
 	combinations = |{ sum, size, exclude }| {
 		crash "Please implement the 'combinations' function"
 	}
diff --git a/exercises/practice/killer-sudoku-helper/killer-sudoku-helper-test.roc b/exercises/practice/killer-sudoku-helper/killer-sudoku-helper-test.roc
index 10b26cb5..e79f7c0c 100644
--- a/exercises/practice/killer-sudoku-helper/killer-sudoku-helper-test.roc
+++ b/exercises/practice/killer-sudoku-helper/killer-sudoku-helper-test.roc
@@ -1,79 +1,79 @@
 # These tests are auto-generated with test data from:
 # https://github.com/exercism/problem-specifications/tree/main/exercises/killer-sudoku-helper/canonical-data.json
-# File last updated on 2026-08-01
+# File last updated on 2026-08-18
 
 import KillerSudokuHelper exposing [combinations]
 
 ## Trivial 1-digit cages
 # 1
 expect {
-	result = combinations({ sum: 1, size: 1, exclude: [] })
+	result = combinations({ sum: 1, size: 1 })
 	result == [[1]]
 }
 
 # 2
 expect {
-	result = combinations({ sum: 2, size: 1, exclude: [] })
+	result = combinations({ sum: 2, size: 1 })
 	result == [[2]]
 }
 
 # 3
 expect {
-	result = combinations({ sum: 3, size: 1, exclude: [] })
+	result = combinations({ sum: 3, size: 1 })
 	result == [[3]]
 }
 
 # 4
 expect {
-	result = combinations({ sum: 4, size: 1, exclude: [] })
+	result = combinations({ sum: 4, size: 1 })
 	result == [[4]]
 }
 
 # 5
 expect {
-	result = combinations({ sum: 5, size: 1, exclude: [] })
+	result = combinations({ sum: 5, size: 1 })
 	result == [[5]]
 }
 
 # 6
 expect {
-	result = combinations({ sum: 6, size: 1, exclude: [] })
+	result = combinations({ sum: 6, size: 1 })
 	result == [[6]]
 }
 
 # 7
 expect {
-	result = combinations({ sum: 7, size: 1, exclude: [] })
+	result = combinations({ sum: 7, size: 1 })
 	result == [[7]]
 }
 
 # 8
 expect {
-	result = combinations({ sum: 8, size: 1, exclude: [] })
+	result = combinations({ sum: 8, size: 1 })
 	result == [[8]]
 }
 
 # 9
 expect {
-	result = combinations({ sum: 9, size: 1, exclude: [] })
+	result = combinations({ sum: 9, size: 1 })
 	result == [[9]]
 }
 
 ## Cage with sum 45 contains all digits 1:9
 expect {
-	result = combinations({ sum: 45, size: 9, exclude: [] })
+	result = combinations({ sum: 45, size: 9 })
 	result == [[1, 2, 3, 4, 5, 6, 7, 8, 9]]
 }
 
 ## Cage with only 1 possible combination
 expect {
-	result = combinations({ sum: 7, size: 3, exclude: [] })
+	result = combinations({ sum: 7, size: 3 })
 	result == [[1, 2, 4]]
 }
 
 ## Cage with several combinations
 expect {
-	result = combinations({ sum: 10, size: 2, exclude: [] })
+	result = combinations({ sum: 10, size: 2 })
 	result == [[1, 9], [2, 8], [3, 7], [4, 6]]
 }
 
diff --git a/exercises/practice/rest-api/.meta/Example.roc b/exercises/practice/rest-api/.meta/Example.roc
index aab15f00..0ba79469 100644
--- a/exercises/practice/rest-api/.meta/Example.roc
+++ b/exercises/practice/rest-api/.meta/Example.roc
@@ -10,10 +10,15 @@ RestApi :: {}.{
 
 	Loan : { lender : Str, borrower : Str, amount : Dec }
 
-	get : Database, { url : Str, payload : Str } -> Try(Str, [Http404(Str), Http422(Str)])
+	get : Database, { url : Str, payload ?: Str } -> Try(Str, [Http404(Str), Http422(Str)])
 	get = |database, { url, payload }| {
 		match url {
-			"/users" | "/users/" => (database |> get_users(payload)).map_err(|_| Http422(payload))
+			"/users" | "/users/" => {
+				match payload {
+					Ok(request_payload) => (database |> get_users(request_payload)).map_err(|_| Http422(request_payload))
+					Err(MissingField) => Ok(users_to_json(database.users))
+				}
+			}
 			bad_url => Err(Http404(bad_url))
 		}
 	}
@@ -36,14 +41,8 @@ RestApi :: {}.{
 
 get_users : RestApi.Database, Str -> Try(Str, [InvalidJson])
 get_users = |database, payload| {
-	users =
-		if payload == "" {
-			database.users
-		} else {
-			names = get_user_names(payload)?
-			database.users
-				.keep_if(|user| names.contains(user.name))
-		}
+	names = get_user_names(payload)?
+	users = database.users.keep_if(|user| names.contains(user.name))
 	Ok(users_to_json(users))
 }
 
@@ -91,8 +90,8 @@ add_user = |_database, payload| {
 add_loan : RestApi.Database, Str -> Try(Str, [NotFound, InvalidJson])
 add_loan = |database, payload| {
 	loan = parse_json_loan(payload)?
-	lender = database -> get_user(loan.lender)?
-	borrower = database -> get_user(loan.borrower)?
+	lender = database |> get_user(loan.lender)?
+	borrower = database |> get_user(loan.borrower)?
 	updated_lender = lender |> update_lender(borrower.name, loan.amount)
 	updated_borrower = borrower |> update_lender(lender.name, -loan.amount)
 	Ok(users_to_json([updated_lender, updated_borrower]))
diff --git a/exercises/practice/rest-api/.meta/template.j2 b/exercises/practice/rest-api/.meta/template.j2
index a445f181..5bd288f5 100644
--- a/exercises/practice/rest-api/.meta/template.j2
+++ b/exercises/practice/rest-api/.meta/template.j2
@@ -33,11 +33,9 @@ expect {
         ]
     }
     result_json = database |> {{ case["property"] | to_snake }}({
-        url: {{ case["input"]["url"] | to_roc }},
+        url: {{ case["input"]["url"] | to_roc }}
     {%- if case["input"].get("payload", {}) != {} %}
-        payload: {{ case["input"]["payload"] | tojson | to_roc }}
-    {%- else %}
-        payload: ""
+        , payload: {{ case["input"]["payload"] | tojson | to_roc }}
     {%- endif %}
     })?
     expected_json = {{ case["expected"] | tojson | to_roc }}
diff --git a/exercises/practice/rest-api/RestApi.roc b/exercises/practice/rest-api/RestApi.roc
index d5142fad..10d3515f 100644
--- a/exercises/practice/rest-api/RestApi.roc
+++ b/exercises/practice/rest-api/RestApi.roc
@@ -8,7 +8,7 @@ RestApi :: {}.{
 
 	Database : { users : List(User) }
 
-	get : Database, { url : Str, payload : Str } -> Try(Str, _)
+	get : Database, { url : Str, payload ?: Str } -> Try(Str, _)
 	get = |database, { url, payload }| {
 		crash "Please implement the 'get' function"
 	}
diff --git a/exercises/practice/rest-api/rest-api-test.roc b/exercises/practice/rest-api/rest-api-test.roc
index 7053fdd2..abf29246 100644
--- a/exercises/practice/rest-api/rest-api-test.roc
+++ b/exercises/practice/rest-api/rest-api-test.roc
@@ -1,6 +1,6 @@
 # These tests are auto-generated with test data from:
 # https://github.com/exercism/problem-specifications/tree/main/exercises/rest-api/canonical-data.json
-# File last updated on 2026-08-15
+# File last updated on 2026-08-18
 
 import RestApi exposing [get, post]
 
@@ -12,7 +12,7 @@ import RestApi exposing [get, post]
 expect {
 	database = { users: [] }
 	result_json = database
-		|> get({ url: "/users", payload: "" })?
+		|> get({ url: "/users" })?
 	expected_json = "{\"users\": []}"
 	result_json |> is_equivalent_to(expected_json)?
 }
diff --git a/exercises/practice/robot-simulator/.meta/Example.roc b/exercises/practice/robot-simulator/.meta/Example.roc
index 570529b1..082804a4 100644
--- a/exercises/practice/robot-simulator/.meta/Example.roc
+++ b/exercises/practice/robot-simulator/.meta/Example.roc
@@ -2,6 +2,11 @@ RobotSimulator :: {}.{
 	Direction : [North, East, South, West]
 	Robot : { x : I64, y : I64, direction : Direction }
 
+	create : { x : I64 ?? 0, y : I64 ?? 0, direction : Direction ?? North } -> Robot
+	create = |{ x, y, direction }| {
+		{ x, y, direction }
+	}
+
 	move : Robot, Str -> Robot
 	move = |robot, instructions| {
 		instructions
diff --git a/exercises/practice/robot-simulator/.meta/plugins.py b/exercises/practice/robot-simulator/.meta/plugins.py
index 2615ad25..b110bb96 100644
--- a/exercises/practice/robot-simulator/.meta/plugins.py
+++ b/exercises/practice/robot-simulator/.meta/plugins.py
@@ -1,5 +1,12 @@
-def to_robot(robot):
+def to_robot(robot, with_defaults):
     x = robot["position"]["x"]
     y = robot["position"]["y"]
     direction = robot["direction"]
-    return f"{{x : {x}, y : {y}, direction : {direction.capitalize()}}}"
+    fields = []
+    if x != 0 or not with_defaults:
+        fields.append(f"x: {x}")
+    if y != 0 or not with_defaults:
+        fields.append(f"y: {y}")
+    if direction != "north" or not with_defaults:
+        fields.append(f"direction: {direction.capitalize()}")
+    return "{" + ", ".join(fields) + "}"
diff --git a/exercises/practice/robot-simulator/.meta/template.j2 b/exercises/practice/robot-simulator/.meta/template.j2
index eac820c5..a9952405 100644
--- a/exercises/practice/robot-simulator/.meta/template.j2
+++ b/exercises/practice/robot-simulator/.meta/template.j2
@@ -2,7 +2,7 @@
 {{ macros.canonical_ref() }}
 {{ macros.header() }}
 
-import {{ exercise | to_pascal }} exposing [move]
+import {{ exercise | to_pascal }} exposing [create, move]
 
 {% for supercase in cases %}
 ##
@@ -12,9 +12,13 @@ import {{ exercise | to_pascal }} exposing [move]
 {% for case in supercase["cases"] -%}
 # {{ case["description"] }}
 expect {
-    robot = {{ plugins.to_robot(case["input"]) }}
-    result = robot|>move({{ case["input"]["instructions"] | to_roc }})
-    result == {{ plugins.to_robot(case["expected"]) }}
+  {%- if case["input"]["instructions"] %}
+    robot = create({{ plugins.to_robot(case["input"], with_defaults=True) }})
+    result = robot |> move({{ case["input"]["instructions"] | to_roc }})
+  {%- else %}
+    result = create({{ plugins.to_robot(case["input"], with_defaults=True) }})
+  {%- endif %}
+    result == {{ plugins.to_robot(case["expected"], with_defaults=False) }}
 }
 
 {% endfor %}
diff --git a/exercises/practice/robot-simulator/.meta/tests.toml b/exercises/practice/robot-simulator/.meta/tests.toml
index f2e52b19..16da03d4 100644
--- a/exercises/practice/robot-simulator/.meta/tests.toml
+++ b/exercises/practice/robot-simulator/.meta/tests.toml
@@ -11,11 +11,9 @@
 
 [c557c16d-26c1-4e06-827c-f6602cd0785c]
 description = "Create robot -> at origin facing north"
-include = false
 
 [bf0dffce-f11c-4cdb-8a5e-2c89d8a5a67d]
 description = "Create robot -> at negative position facing south"
-include = false
 
 [8cbd0086-6392-4680-b9b9-73cf491e67e5]
 description = "Rotating clockwise -> changes north to east"
diff --git a/exercises/practice/robot-simulator/RobotSimulator.roc b/exercises/practice/robot-simulator/RobotSimulator.roc
index 0933626b..ef62152d 100644
--- a/exercises/practice/robot-simulator/RobotSimulator.roc
+++ b/exercises/practice/robot-simulator/RobotSimulator.roc
@@ -2,6 +2,11 @@ RobotSimulator :: {}.{
 	Direction : [North, East, South, West]
 	Robot : { x : I64, y : I64, direction : Direction }
 
+	create : { x : I64 ?? 0, y : I64 ?? 0, direction : Direction ?? North } -> Robot
+	create = |{ x, y, direction }| {
+		crash "Please implement the 'create' function"
+	}
+
 	move : Robot, Str -> Robot
 	move = |robot, instructions| {
 		crash "Please implement the 'move' function"
diff --git a/exercises/practice/robot-simulator/robot-simulator-test.roc b/exercises/practice/robot-simulator/robot-simulator-test.roc
index f6a1b917..25107fe8 100644
--- a/exercises/practice/robot-simulator/robot-simulator-test.roc
+++ b/exercises/practice/robot-simulator/robot-simulator-test.roc
@@ -1,8 +1,24 @@
 # These tests are auto-generated with test data from:
 # https://github.com/exercism/problem-specifications/tree/main/exercises/robot-simulator/canonical-data.json
-# File last updated on 2026-08-01
+# File last updated on 2026-08-17
 
-import RobotSimulator exposing [move]
+import RobotSimulator exposing [create, move]
+
+##
+## Create robot
+##
+
+# at origin facing north
+expect {
+	result = create({})
+	result == { x: 0, y: 0, direction: North }
+}
+
+# at negative position facing south
+expect {
+	result = create({ x: -1, y: -1, direction: South })
+	result == { x: -1, y: -1, direction: South }
+}
 
 ##
 ## Rotating clockwise
@@ -10,28 +26,28 @@ import RobotSimulator exposing [move]
 
 # changes north to east
 expect {
-	robot = { x: 0, y: 0, direction: North }
+	robot = create({})
 	result = robot |> move("R")
 	result == { x: 0, y: 0, direction: East }
 }
 
 # changes east to south
 expect {
-	robot = { x: 0, y: 0, direction: East }
+	robot = create({ direction: East })
 	result = robot |> move("R")
 	result == { x: 0, y: 0, direction: South }
 }
 
 # changes south to west
 expect {
-	robot = { x: 0, y: 0, direction: South }
+	robot = create({ direction: South })
 	result = robot |> move("R")
 	result == { x: 0, y: 0, direction: West }
 }
 
 # changes west to north
 expect {
-	robot = { x: 0, y: 0, direction: West }
+	robot = create({ direction: West })
 	result = robot |> move("R")
 	result == { x: 0, y: 0, direction: North }
 }
@@ -42,28 +58,28 @@ expect {
 
 # changes north to west
 expect {
-	robot = { x: 0, y: 0, direction: North }
+	robot = create({})
 	result = robot |> move("L")
 	result == { x: 0, y: 0, direction: West }
 }
 
 # changes west to south
 expect {
-	robot = { x: 0, y: 0, direction: West }
+	robot = create({ direction: West })
 	result = robot |> move("L")
 	result == { x: 0, y: 0, direction: South }
 }
 
 # changes south to east
 expect {
-	robot = { x: 0, y: 0, direction: South }
+	robot = create({ direction: South })
 	result = robot |> move("L")
 	result == { x: 0, y: 0, direction: East }
 }
 
 # changes east to north
 expect {
-	robot = { x: 0, y: 0, direction: East }
+	robot = create({ direction: East })
 	result = robot |> move("L")
 	result == { x: 0, y: 0, direction: North }
 }
@@ -74,28 +90,28 @@ expect {
 
 # facing north increments Y
 expect {
-	robot = { x: 0, y: 0, direction: North }
+	robot = create({})
 	result = robot |> move("A")
 	result == { x: 0, y: 1, direction: North }
 }
 
 # facing south decrements Y
 expect {
-	robot = { x: 0, y: 0, direction: South }
+	robot = create({ direction: South })
 	result = robot |> move("A")
 	result == { x: 0, y: -1, direction: South }
 }
 
 # facing east increments X
 expect {
-	robot = { x: 0, y: 0, direction: East }
+	robot = create({ direction: East })
 	result = robot |> move("A")
 	result == { x: 1, y: 0, direction: East }
 }
 
 # facing west decrements X
 expect {
-	robot = { x: 0, y: 0, direction: West }
+	robot = create({ direction: West })
 	result = robot |> move("A")
 	result == { x: -1, y: 0, direction: West }
 }
@@ -106,28 +122,28 @@ expect {
 
 # moving east and north from README
 expect {
-	robot = { x: 7, y: 3, direction: North }
+	robot = create({ x: 7, y: 3 })
 	result = robot |> move("RAALAL")
 	result == { x: 9, y: 4, direction: West }
 }
 
 # moving west and north
 expect {
-	robot = { x: 0, y: 0, direction: North }
+	robot = create({})
 	result = robot |> move("LAAARALA")
 	result == { x: -4, y: 1, direction: West }
 }
 
 # moving west and south
 expect {
-	robot = { x: 2, y: -7, direction: East }
+	robot = create({ x: 2, y: -7, direction: East })
 	result = robot |> move("RRAAAAALA")
 	result == { x: -3, y: -8, direction: South }
 }
 
 # moving east and north
 expect {
-	robot = { x: 8, y: 4, direction: South }
+	robot = create({ x: 8, y: 4, direction: South })
 	result = robot |> move("LAAARRRALLLL")
 	result == { x: 11, y: 5, direction: North }
 }