gosuperscript · robertvansteen · Aug 5, 2026 · Aug 6, 2026
diff --git a/composer.json b/composer.json
@@ -3,15 +3,22 @@
     "description": "Monetary extension for Axiom - provides schema types, parsers, and operators for monetary values with strong type safety and currency validation",
     "type": "library",
     "license": "MIT",
-    "keywords": ["money", "currency", "schema", "validation", "monetary", "interval"],
+    "keywords": [
+        "money",
+        "currency",
+        "schema",
+        "validation",
+        "monetary",
+        "interval"
+    ],
     "homepage": "https://github.com/gosuperscript/axiom-money",
     "require": {
         "php": "^8.4",
         "ext-intl": "*",
-        "brick/money": "^0.10.1",
-        "gosuperscript/axiom": "^0.6.0",
-        "superscript/interval": "^1.0",
-        "superscript/monetary-interval": "^0.1.2"
+        "brick/money": "^0.14.1",
+        "gosuperscript/axiom": "^0.6.9",
+        "superscript/interval": "^2.0",
+        "superscript/monetary-interval": "^0.2.0"
     },
     "require-dev": {
         "infection/infection": "^0.29.14",

diff --git a/src/MoneyExtension.php b/src/MoneyExtension.php
@@ -9,6 +9,7 @@
 use Brick\Money\Currency;
 use Brick\Money\Money;
 use Superscript\Axiom\Extension;
+use Superscript\Axiom\Money\MoneyParser;
 use Superscript\Axiom\Money\Types\MonetaryIntervalType;
 use Superscript\Axiom\Money\Types\MonetaryType;
 use Superscript\Axiom\Operators\Operator;
@@ -51,7 +52,7 @@ final class MoneyExtension extends Extension
      */
     public function __construct(
         private readonly array $currencies,
-        private readonly RoundingMode $roundingMode = RoundingMode::HALF_UP,
+        private readonly RoundingMode $roundingMode = RoundingMode::HalfUp,
     ) {}
 
     public function operators(): array
@@ -78,7 +79,7 @@ public function operators(): array
                 ->evaluatesWith(fn(int|float $left, Money $right) => $this->scale($right, $left));
             $rules[] = Operator::infix('/')->takes($money, $number)->returns($money)
                 ->evaluatesWith(fn(Money $left, int|float $right) => attempt(
-                    fn() => $left->toRational()->dividedBy($right)->to(new DefaultContext(), $this->roundingMode),
+                    fn() => $left->toRational()->dividedBy(MoneyParser::exact($right))->toContext(new DefaultContext(), $this->roundingMode),
                 ));
 
             // Ordering: same currency.
@@ -94,11 +95,11 @@ public function operators(): array
             // Equality: Brick's amount-and-currency comparison, not identity.
             foreach (['=', '==', '==='] as $operator) {
                 $rules[] = Operator::infix($operator)->takes($money, $money)->returns($boolean)
-                    ->evaluatesWith(fn(Money $left, Money $right) => $left->isAmountAndCurrencyEqualTo($right));
+                    ->evaluatesWith(fn(Money $left, Money $right) => $left->isSameValueAs($right));
             }
             foreach (['!=', '!=='] as $operator) {
                 $rules[] = Operator::infix($operator)->takes($money, $money)->returns($boolean)
-                    ->evaluatesWith(fn(Money $left, Money $right) => !$left->isAmountAndCurrencyEqualTo($right));
+                    ->evaluatesWith(fn(Money $left, Money $right) => !$left->isSameValueAs($right));
             }
 
             // A monetary interval compared against a money of its currency.
@@ -138,6 +139,7 @@ public function literals(): array
 
     private function scale(Money $money, int|float $scalar): Money
     {
-        return $money->toRational()->multipliedBy($scalar)->to(new DefaultContext(), $this->roundingMode);
+        return $money->toRational()->multipliedBy(MoneyParser::exact($scalar))->toContext(new DefaultContext(), $this->roundingMode);
     }
+
 }
diff --git a/src/MoneyParser.php b/src/MoneyParser.php
@@ -47,7 +47,7 @@ public static function parse(mixed $money): Result
 
             if ($amount !== false) {
                 try {
-                    return Ok(Money::of($amount, non_empty_string()->assert($currency)));
+                    return Ok(Money::of(self::exact($amount), non_empty_string()->assert($currency)));
                 } catch (RoundingNecessaryException $exception) {
                     return Err(new InvalidArgumentException(sprintf('Could not parse [%s] as money', new Exporter()->shortenedExport($money)), previous: $exception));
                 }
@@ -58,4 +58,35 @@ public static function parse(mixed $money): Result
             message: sprintf('Could not parse [%s] as money', new Exporter()->shortenedExport($money)),
         ));
     }
+
+    /**
+     * Renders a raw scalar amount in the form brick accepts.
+     *
+     * brick rejects floats throughout its monetary and arithmetic APIs, because
+     * a binary float carries no exact decimal value to compute with: the literal
+     * 0.1 is not one tenth. A float that reaches here is therefore spelled as
+     * the shortest decimal that round-trips back to it, so brick receives the
+     * number the caller actually holds.
+     *
+     * That spelling is `json_encode`'s, because it honours `serialize_precision`
+     * (-1). A `(string)` cast honours `precision` instead — 14 significant
+     * digits by default — so it truncates and can emit exponent notation:
+     * `(string) 123456789012345.67` gives `1.2345678901235E+14`, a different
+     * amount. Ints and numeric strings are already exact and pass through
+     * untouched.
+     *
+     * @throws InvalidArgumentException if the float is not finite, and so names no decimal at all
+     */
+    public static function exact(string|float|int $amount): string|int
+    {
+        if (! is_float($amount)) {
+            return $amount;
+        }
+
+        if (! is_finite($amount)) {
+            throw new InvalidArgumentException(sprintf('[%s] is not a monetary amount.', $amount));
+        }
+
+        return json_encode($amount, JSON_THROW_ON_ERROR);
+    }
 }
diff --git a/src/Types/DynamicMonetaryType.php b/src/Types/DynamicMonetaryType.php
@@ -16,6 +16,7 @@
 use Superscript\Axiom\Types\Shapes\Shape;
 use Superscript\Axiom\Types\Type;
 
+use function Psl\Type\instance_of;
 use function Psl\Type\non_empty_string;
 use function Superscript\Monads\Option\Some;
 use function Superscript\Monads\Result\Err;
@@ -26,7 +27,7 @@
  */
 final readonly class DynamicMonetaryType implements Type
 {
-    public function __construct(public RoundingMode $roundingMode = RoundingMode::HALF_UP) {}
+    public function __construct(public RoundingMode $roundingMode = RoundingMode::HalfUp) {}
 
     /**
      * @return Result<Option<Money>, TransformValueException>
@@ -46,7 +47,7 @@ public function assert(mixed $value): Result
     public function coerce(mixed $value): Result
     {
         if ($value instanceof RationalMoney) {
-            return Ok(Some($value->to(new DefaultContext(), $this->roundingMode)));
+            return Ok(Some($value->toContext(new DefaultContext(), $this->roundingMode)));
         }
 
         return MoneyParser::parse($value)->map(fn(Money $money) => Some($money))
@@ -55,8 +56,9 @@ public function coerce(mixed $value): Result
 
     public function format(mixed $value): string
     {
+        $money = instance_of(Money::class)->assert($value);
         $formatter = new \NumberFormatter('en_GB', \NumberFormatter::CURRENCY);
-        $result = $formatter->formatCurrency($value->getAmount()->toFloat(), $value->getCurrency()->getCurrencyCode());
+        $result = $formatter->formatCurrency($money->getAmount()->toFloat(), $money->getCurrency()->getCurrencyCode());
         return non_empty_string()->assert($result);
     }
 

diff --git a/src/Types/MinorMonetaryType.php b/src/Types/MinorMonetaryType.php
@@ -13,13 +13,15 @@
 use Superscript\Monads\Option\Option;
 use Superscript\Monads\Result\Result;
 use Superscript\Axiom\Exceptions\TransformValueException;
+use Superscript\Axiom\Money\MoneyParser;
 use Superscript\Axiom\Types\Shapes\LiteralShape;
 use Superscript\Axiom\Types\Shapes\OpaqueShape;
 use Superscript\Axiom\Types\Shapes\Shape;
 use Superscript\Axiom\Types\Type;
 
 use function Psl\Type\float;
 use function Psl\Type\int;
+use function Psl\Type\instance_of;
 use function Psl\Type\non_empty_string;
 use function Psl\Type\string;
 use function Psl\Type\union;
@@ -33,7 +35,7 @@
  */
 final readonly class MinorMonetaryType implements Type
 {
-    public function __construct(public Currency $currency, public RoundingMode $roundingMode = RoundingMode::HALF_UP) {}
+    public function __construct(public Currency $currency, public RoundingMode $roundingMode = RoundingMode::HalfUp) {}
 
     /**
      * @return Result<Option<Money>, TransformValueException>
@@ -44,7 +46,7 @@ public function assert(mixed $value): Result
             return Err(new TransformValueException(type: 'money', value: $value));
         }
 
-        if (!$value->getCurrency()->is($this->currency)) {
+        if (!$value->getCurrency()->isEqualTo($this->currency)) {
             return Err(new TransformValueException(type: 'money', value: $value));
         }
 
@@ -57,16 +59,16 @@ public function assert(mixed $value): Result
     public function coerce(mixed $value): Result
     {
         $candidate = $value instanceof RationalMoney
-            ? $value->to(new DefaultContext(), $this->roundingMode)
+            ? $value->toContext(new DefaultContext(), $this->roundingMode)
             : $value;
 
         return (match (true) {
-            $candidate instanceof Money => $candidate->getCurrency()->is($this->currency)
+            $candidate instanceof Money => $candidate->getCurrency()->isEqualTo($this->currency)
                 ? Ok($candidate)
                 : Err(new InvalidArgumentException(sprintf("Mismatching currencies: expected %s, got %s", $this->currency->getCurrencyCode(), $candidate->getCurrency()->getCurrencyCode()))),
             default => attempt(function () use ($candidate) {
-                union(string(), float(), int())->assert($candidate);
-                return Money::ofMinor($candidate, $this->currency);
+                $amount = union(string(), float(), int())->assert($candidate);
+                return Money::ofMinor(MoneyParser::exact($amount), $this->currency);
             }),
         })
             ->map(fn(Money $money) => Some($money))
@@ -75,8 +77,9 @@ public function coerce(mixed $value): Result
 
     public function format(mixed $value): string
     {
+        $money = instance_of(Money::class)->assert($value);
         $formatter = new \NumberFormatter('en_GB', \NumberFormatter::CURRENCY);
-        $result = $formatter->formatCurrency($value->getAmount()->toFloat(), $value->getCurrency()->getCurrencyCode());
+        $result = $formatter->formatCurrency($money->getAmount()->toFloat(), $money->getCurrency()->getCurrencyCode());
         return non_empty_string()->assert($result);
     }
 

diff --git a/src/Types/MonetaryIntervalType.php b/src/Types/MonetaryIntervalType.php
@@ -18,6 +18,7 @@
 use Superscript\Axiom\Types\Shapes\Shape;
 use Superscript\Axiom\Types\Type;
 
+use function Psl\Type\instance_of;
 use function Superscript\Monads\Option\Some;
 use function Superscript\Monads\Result\attempt;
 use function Superscript\Monads\Result\Err;
@@ -39,7 +40,7 @@ public function assert(mixed $value): Result
             return Err(new TransformValueException(type: 'monetary-interval', value: $value));
         }
 
-        if (!$value->left->getCurrency()->is($this->currency)) {
+        if (!$value->left->getCurrency()->isEqualTo($this->currency)) {
             return Err(new TransformValueException(type: 'monetary-interval', value: $value));
         }
 
@@ -52,7 +53,7 @@ public function assert(mixed $value): Result
     public function coerce(mixed $value): Result
     {
         return (match (true) {
-            $value instanceof MonetaryInterval => $value->left->getCurrency()->is($this->currency)
+            $value instanceof MonetaryInterval => $value->left->getCurrency()->isEqualTo($this->currency)
                 ? Ok($value)
                 : Err(new InvalidArgumentException(sprintf("Mismatching currencies: expected %s, got %s", $this->currency->getCurrencyCode(), $value->left->getCurrency()->getCurrencyCode()))),
             is_string($value) => attempt(fn() => Interval::fromString($value))
@@ -69,7 +70,7 @@ public function coerce(mixed $value): Result
 
     public function format(mixed $value): string
     {
-        return (string) $value;
+        return (string) instance_of(MonetaryInterval::class)->assert($value);
     }
 
     /**

diff --git a/src/Types/MonetaryType.php b/src/Types/MonetaryType.php
@@ -13,13 +13,15 @@
 use Superscript\Monads\Option\Option;
 use Superscript\Monads\Result\Result;
 use Superscript\Axiom\Exceptions\TransformValueException;
+use Superscript\Axiom\Money\MoneyParser;
 use Superscript\Axiom\Types\Shapes\LiteralShape;
 use Superscript\Axiom\Types\Shapes\OpaqueShape;
 use Superscript\Axiom\Types\Shapes\Shape;
 use Superscript\Axiom\Types\Type;
 
 use function Psl\Type\float;
 use function Psl\Type\int;
+use function Psl\Type\instance_of;
 use function Psl\Type\non_empty_string;
 use function Psl\Type\string;
 use function Psl\Type\union;
@@ -33,7 +35,7 @@
  */
 final readonly class MonetaryType implements Type
 {
-    public function __construct(public Currency $currency, public RoundingMode $roundingMode = RoundingMode::HALF_UP) {}
+    public function __construct(public Currency $currency, public RoundingMode $roundingMode = RoundingMode::HalfUp) {}
 
     /**
      * @return Result<Option<Money>, TransformValueException>
@@ -44,7 +46,7 @@ public function assert(mixed $value): Result
             return Err(new TransformValueException(type: 'money', value: $value));
         }
 
-        if (!$value->getCurrency()->is($this->currency)) {
+        if (!$value->getCurrency()->isEqualTo($this->currency)) {
             return Err(new TransformValueException(type: 'money', value: $value));
         }
 
@@ -57,16 +59,16 @@ public function assert(mixed $value): Result
     public function coerce(mixed $value): Result
     {
         $candidate = $value instanceof RationalMoney
-            ? $value->to(new DefaultContext(), $this->roundingMode)
+            ? $value->toContext(new DefaultContext(), $this->roundingMode)
             : $value;
 
         return (match (true) {
-            $candidate instanceof Money => $candidate->getCurrency()->is($this->currency)
+            $candidate instanceof Money => $candidate->getCurrency()->isEqualTo($this->currency)
                 ? Ok($candidate)
                 : Err(new InvalidArgumentException(sprintf("Mismatching currencies: expected %s, got %s", $this->currency->getCurrencyCode(), $candidate->getCurrency()->getCurrencyCode()))),
             default => attempt(function () use ($candidate) {
-                union(string(), float(), int())->assert($candidate);
-                return Money::of($candidate, $this->currency);
+                $amount = union(string(), float(), int())->assert($candidate);
+                return Money::of(MoneyParser::exact($amount), $this->currency);
             }),
         })
             ->map(fn(Money $money) => Some($money))
@@ -75,8 +77,9 @@ public function coerce(mixed $value): Result
 
     public function format(mixed $value): string
     {
+        $money = instance_of(Money::class)->assert($value);
         $formatter = new \NumberFormatter('en_GB', \NumberFormatter::CURRENCY);
-        $result = $formatter->formatCurrency($value->getAmount()->toFloat(), $value->getCurrency()->getCurrencyCode());
+        $result = $formatter->formatCurrency($money->getAmount()->toFloat(), $money->getCurrency()->getCurrencyCode());
         return non_empty_string()->assert($result);
     }