MPT (#2661)

MPT Support for library and binary codec

packages/ripple-binary-codec/HISTORY.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+### Added
+* Support for the Multi-Purpose Token amendment (XLS-33)
+
 ## 2.1.0 (2024-06-03)
 
 ### Added

packages/ripple-binary-codec/src/types/amount.ts

@@ -6,6 +6,7 @@ import { JsonObject, SerializedType } from './serialized-type'
 import BigNumber from 'bignumber.js'
 import { bytesToHex, concat, hexToBytes } from '@xrplf/isomorphic/utils'
 import { readUInt32BE, writeUInt32BE } from '../utils'
+import { Hash192 } from './hash-192'
 
 /**
  * Constants for validating amounts
@@ -16,6 +17,7 @@ const MAX_IOU_PRECISION = 16
 const MAX_DROPS = new BigNumber('1e17')
 const MIN_XRP = new BigNumber('1e-6')
 const mask = BigInt(0x00000000ffffffff)
+const mptMask = BigInt(0x8000000000000000)
 
 /**
  * BigNumber configuration for Amount IOUs
@@ -27,20 +29,28 @@ BigNumber.config({
   ],
 })
 
-/**
- * Interface for JSON objects that represent amounts
- */
-interface AmountObject extends JsonObject {
+interface AmountObjectIOU extends JsonObject {
   value: string
   currency: string
   issuer: string
 }
 
+interface AmountObjectMPT extends JsonObject {
+  value: string
+  mpt_issuance_id: string
+}
+
 /**
- * Type guard for AmountObject
+ * Interface for JSON objects that represent amounts
  */
-function isAmountObject(arg): arg is AmountObject {
+type AmountObject = AmountObjectIOU | AmountObjectMPT
+
+/**
+ * Type guard for AmountObjectIOU
+ */
+function isAmountObjectIOU(arg): arg is AmountObjectIOU {
   const keys = Object.keys(arg).sort()
+
   return (
     keys.length === 3 &&
     keys[0] === 'currency' &&
@@ -49,6 +59,17 @@ function isAmountObject(arg): arg is AmountObject {
   )
 }
 
+/**
+ * Type guard for AmountObjectMPT
+ */
+function isAmountObjectMPT(arg): arg is AmountObjectMPT {
+  const keys = Object.keys(arg).sort()
+
+  return (
+    keys.length === 2 && keys[0] === 'mpt_issuance_id' && keys[1] === 'value'
+  )
+}
+
 /**
  * Class for serializing/Deserializing Amounts
  */
@@ -60,7 +81,7 @@ class Amount extends SerializedType {
   }
 
   /**
-   * Construct an amount from an IOU or string amount
+   * Construct an amount from an IOU, MPT or string amount
    *
    * @param value An Amount, object representing an IOU, or a string
    *     representing an integer amount
@@ -88,7 +109,7 @@ class Amount extends SerializedType {
       return new Amount(amount)
     }
 
-    if (isAmountObject(value)) {
+    if (isAmountObjectIOU(value)) {
       const number = new BigNumber(value.value)
       Amount.assertIouIsValid(number)
 
@@ -124,6 +145,24 @@ class Amount extends SerializedType {
       return new Amount(concat([amount, currency, issuer]))
     }
 
+    if (isAmountObjectMPT(value)) {
+      Amount.assertMptIsValid(value.value)
+
+      let leadingByte = new Uint8Array(1)
+      leadingByte[0] |= 0x60
+
+      const num = BigInt(value.value)
+
+      const intBuf = [new Uint8Array(4), new Uint8Array(4)]
+      writeUInt32BE(intBuf[0], Number(num >> BigInt(32)), 0)
+      writeUInt32BE(intBuf[1], Number(num & BigInt(mask)), 0)
+
+      amount = concat(intBuf)
+
+      const mptIssuanceID = Hash192.from(value.mpt_issuance_id).toBytes()
+      return new Amount(concat([leadingByte, amount, mptIssuanceID]))
+    }
+
     throw new Error('Invalid type to construct an Amount')
   }
 
@@ -134,8 +173,12 @@ class Amount extends SerializedType {
    * @returns An Amount object
    */
   static fromParser(parser: BinaryParser): Amount {
-    const isXRP = parser.peek() & 0x80
-    const numBytes = isXRP ? 48 : 8
+    const isIOU = parser.peek() & 0x80
+    if (isIOU) return new Amount(parser.read(48))
+
+    // the amount can be either MPT or XRP at this point
+    const isMPT = parser.peek() & 0x20
+    const numBytes = isMPT ? 33 : 8
     return new Amount(parser.read(numBytes))
   }
 
@@ -156,7 +199,9 @@ class Amount extends SerializedType {
       const num = (msb << BigInt(32)) | lsb
 
       return `${sign}${num.toString()}`
-    } else {
+    }
+
+    if (this.isIOU()) {
       const parser = new BinaryParser(this.toString())
       const mantissa = parser.read(8)
       const currency = Currency.fromParser(parser) as Currency
@@ -182,6 +227,27 @@ class Amount extends SerializedType {
         issuer: issuer.toJSON(),
       }
     }
+
+    if (this.isMPT()) {
+      const parser = new BinaryParser(this.toString())
+      const leadingByte = parser.read(1)
+      const amount = parser.read(8)
+      const mptID = Hash192.fromParser(parser) as Hash192
+
+      const isPositive = leadingByte[0] & 0x40
+      const sign = isPositive ? '' : '-'
+
+      const msb = BigInt(readUInt32BE(amount.slice(0, 4), 0))
+      const lsb = BigInt(readUInt32BE(amount.slice(4), 0))
+      const num = (msb << BigInt(32)) | lsb
+
+      return {
+        value: `${sign}${num.toString()}`,
+        mpt_issuance_id: mptID.toString(),
+      }
+    }
+
+    throw new Error('Invalid amount to construct JSON')
   }
 
   /**
@@ -224,6 +290,29 @@ class Amount extends SerializedType {
     }
   }
 
+  /**
+   * Validate MPT.value amount
+   *
+   * @param decimal BigNumber object representing MPT.value
+   * @returns void, but will throw if invalid amount
+   */
+  private static assertMptIsValid(amount: string): void {
+    if (amount.indexOf('.') !== -1) {
+      throw new Error(`${amount.toString()} is an illegal amount`)
+    }
+
+    const decimal = new BigNumber(amount)
+    if (!decimal.isZero()) {
+      if (decimal < BigNumber(0)) {
+        throw new Error(`${amount.toString()} is an illegal amount`)
+      }
+
+      if (Number(BigInt(amount) & BigInt(mptMask)) != 0) {
+        throw new Error(`${amount.toString()} is an illegal amount`)
+      }
+    }
+  }
+
   /**
    * Ensure that the value after being multiplied by the exponent does not
    * contain a decimal.
@@ -248,7 +337,25 @@ class Amount extends SerializedType {
    * @returns true if Native (XRP)
    */
   private isNative(): boolean {
-    return (this.bytes[0] & 0x80) === 0
+    return (this.bytes[0] & 0x80) === 0 && (this.bytes[0] & 0x20) === 0
+  }
+
+  /**
+   * Test if this amount is in units of MPT
+   *
+   * @returns true if MPT
+   */
+  private isMPT(): boolean {
+    return (this.bytes[0] & 0x80) === 0 && (this.bytes[0] & 0x20) !== 0
+  }
+
+  /**
+   * Test if this amount is in units of IOU
+   *
+   * @returns true if IOU
+   */
+  private isIOU(): boolean {
+    return (this.bytes[0] & 0x80) !== 0
   }
 }
 

packages/ripple-binary-codec/src/types/hash-192.ts

@@ -0,0 +1,19 @@
+import { Hash } from './hash'
+
+/**
+ * Hash with a width of 192 bits
+ */
+class Hash192 extends Hash {
+  static readonly width = 24
+  static readonly ZERO_192: Hash192 = new Hash192(new Uint8Array(Hash192.width))
+
+  constructor(bytes?: Uint8Array) {
+    if (bytes && bytes.byteLength === 0) {
+      bytes = Hash192.ZERO_192.bytes
+    }
+
+    super(bytes ?? Hash192.ZERO_192.bytes)
+  }
+}
+
+export { Hash192 }

packages/ripple-binary-codec/src/types/index.ts

@@ -4,6 +4,7 @@ import { Blob } from './blob'
 import { Currency } from './currency'
 import { Hash128 } from './hash-128'
 import { Hash160 } from './hash-160'
+import { Hash192 } from './hash-192'
 import { Hash256 } from './hash-256'
 import { Issue } from './issue'
 import { PathSet } from './path-set'
@@ -25,6 +26,7 @@ const coreTypes: Record<string, typeof SerializedType> = {
   Currency,
   Hash128,
   Hash160,
+  Hash192,
   Hash256,
   Issue,
   PathSet,
@@ -51,6 +53,7 @@ export {
   Currency,
   Hash128,
   Hash160,
+  Hash192,
   Hash256,
   PathSet,
   STArray,

packages/ripple-binary-codec/src/types/serialized-type.ts

@@ -67,7 +67,7 @@ class SerializedType {
    *                          Can be customized for sidechains and amendments.
    * @returns any type, if not overloaded returns hexString representation of bytes
    */
-  toJSON(_definitions?: XrplDefinitionsBase): JSON {
+  toJSON(_definitions?: XrplDefinitionsBase, _fieldName?: string): JSON {
     return this.toHex()
   }
 

packages/ripple-binary-codec/src/types/st-object.ts

@@ -10,6 +10,7 @@ import { BinaryParser } from '../serdes/binary-parser'
 import { BinarySerializer, BytesList } from '../serdes/binary-serializer'
 
 import { STArray } from './st-array'
+import { UInt64 } from './uint-64'
 
 const OBJECT_END_MARKER_BYTE = Uint8Array.from([0xe1])
 const OBJECT_END_MARKER = 'ObjectEndMarker'
@@ -137,6 +138,8 @@ class STObject extends SerializedType {
           ? this.from(xAddressDecoded[field.name], undefined, definitions)
           : field.type.name === 'STArray'
           ? STArray.from(xAddressDecoded[field.name], definitions)
+          : field.type.name === 'UInt64'
+          ? UInt64.from(xAddressDecoded[field.name], field.name)
           : field.associatedType.from(xAddressDecoded[field.name])
 
       if (associatedValue == undefined) {
@@ -182,7 +185,7 @@ class STObject extends SerializedType {
 
       accumulator[field.name] = objectParser
         .readFieldValue(field)
-        .toJSON(definitions)
+        .toJSON(definitions, field.name)
     }
 
     return accumulator

packages/ripple-binary-codec/src/types/uint-64.ts

@@ -2,10 +2,20 @@ import { UInt } from './uint'
 import { BinaryParser } from '../serdes/binary-parser'
 import { bytesToHex, concat, hexToBytes } from '@xrplf/isomorphic/utils'
 import { readUInt32BE, writeUInt32BE } from '../utils'
+import { DEFAULT_DEFINITIONS, XrplDefinitionsBase } from '../enums'
 
 const HEX_REGEX = /^[a-fA-F0-9]{1,16}$/
+const BASE10_REGEX = /^[0-9]{1,20}$/
 const mask = BigInt(0x00000000ffffffff)
 
+function useBase10(fieldName: string): boolean {
+  return (
+    fieldName === 'MaximumAmount' ||
+    fieldName === 'OutstandingAmount' ||
+    fieldName === 'MPTAmount'
+  )
+}
+
 /**
  * Derived UInt class for serializing/deserializing 64 bit UInt
  */
@@ -29,7 +39,10 @@ class UInt64 extends UInt {
    * @param val A UInt64, hex-string, bigInt, or number
    * @returns A UInt64 object
    */
-  static from<T extends UInt64 | string | bigint | number>(val: T): UInt64 {
+  static from<T extends UInt64 | string | bigint | number>(
+    val: T,
+    fieldName = '',
+  ): UInt64 {
     if (val instanceof UInt64) {
       return val
     }
@@ -51,11 +64,18 @@ class UInt64 extends UInt {
     }
 
     if (typeof val === 'string') {
-      if (!HEX_REGEX.test(val)) {
+      if (useBase10(fieldName)) {
+        if (!BASE10_REGEX.test(val)) {
+          throw new Error(`${fieldName} ${val} is not a valid base 10 string`)
+        }
+        val = BigInt(val).toString(16) as T
+      }
+
+      if (typeof val === 'string' && !HEX_REGEX.test(val)) {
         throw new Error(`${val} is not a valid hex-string`)
       }
 
-      const strBuf = val.padStart(16, '0')
+      const strBuf = (val as string).padStart(16, '0')
       buf = hexToBytes(strBuf)
       return new UInt64(buf)
     }
@@ -76,8 +96,16 @@ class UInt64 extends UInt {
    *
    * @returns a hex-string
    */
-  toJSON(): string {
-    return bytesToHex(this.bytes)
+  toJSON(
+    _definitions: XrplDefinitionsBase = DEFAULT_DEFINITIONS,
+    fieldName = '',
+  ): string {
+    const hexString = bytesToHex(this.bytes)
+    if (useBase10(fieldName)) {
+      return BigInt('0x' + hexString).toString(10)
+    }
+
+    return hexString
   }
 
   /**

packages/ripple-binary-codec/test/amount.test.ts

@@ -1,5 +1,7 @@
 import { coreTypes } from '../src/types'
 import fixtures from './fixtures/data-driven-tests.json'
+
+import { makeParser } from '../src/binary'
 const { Amount } = coreTypes
 
 function amountErrorTests() {
@@ -25,6 +27,16 @@ describe('Amount', function () {
   it('can be parsed from', function () {
     expect(Amount.from('1000000') instanceof Amount).toBe(true)
     expect(Amount.from('1000000').toJSON()).toEqual('1000000')
+
+    // it not valid to have negative XRP. But we test it anyways
+    // to ensure logic correctness for toJSON of the Amount class
+    {
+      const parser = makeParser('0000000000000001')
+      const value = parser.readType(Amount)
+      const json = value.toJSON()
+      expect(json).toEqual('-1')
+    }
+
     const fixture = {
       value: '1',
       issuer: '0000000000000000000000000000000000000000',
@@ -38,5 +50,35 @@ describe('Amount', function () {
     }
     expect(amt.toJSON()).toEqual(rewritten)
   })
+
+  it('can be parsed from MPT', function () {
+    let fixture = {
+      value: '100',
+      mpt_issuance_id: '00002403C84A0A28E0190E208E982C352BBD5006600555CF',
+    }
+    let amt = Amount.from(fixture)
+    expect(amt.toJSON()).toEqual(fixture)
+
+    fixture = {
+      value: '9223372036854775807',
+      mpt_issuance_id: '00002403C84A0A28E0190E208E982C352BBD5006600555CF',
+    }
+    amt = Amount.from(fixture)
+    expect(amt.toJSON()).toEqual(fixture)
+
+    // it not valid to have negative MPT. But we test it anyways
+    // to ensure logic correctness for toJSON of the Amount class
+    {
+      const parser = makeParser(
+        '20000000000000006400002403C84A0A28E0190E208E982C352BBD5006600555CF',
+      )
+      const value = parser.readType(Amount)
+      const json = value.toJSON()
+      expect(json).toEqual({
+        mpt_issuance_id: '00002403C84A0A28E0190E208E982C352BBD5006600555CF',
+        value: '-100',
+      })
+    }
+  })
   amountErrorTests()
 })

packages/ripple-binary-codec/test/binary-parser.test.ts

@@ -22,6 +22,7 @@ function assertEqualAmountJSON(actual, expected) {
   }
   expect(actual.currency).toEqual(expected.currency)
   expect(actual.issuer).toEqual(expected.issuer)
+  expect(actual.mpt_issuance_id).toEqual(expected.mpt_issuance_id)
   expect(
     actual.value === expected.value ||
       new BigNumber(actual.value).eq(new BigNumber(expected.value)),
@@ -207,12 +208,12 @@ function amountParsingTests() {
         return
       }
       const parser = makeParser(f.expected_hex)
-      const testName = `values_tests[${i}] parses ${f.expected_hex.slice(
+      const hexToJsonTestName = `values_tests[${i}] parses ${f.expected_hex.slice(
         0,
         16,
       )}...
           as ${JSON.stringify(f.test_json)}`
-      it(testName, () => {
+      it(hexToJsonTestName, () => {
         const value = parser.readType(Amount)
         // May not actually be in canonical form. The fixtures are to be used
         // also for json -> binary;
@@ -223,6 +224,15 @@ function amountParsingTests() {
           expect((exponent.e ?? 0) - 15).toEqual(f?.exponent)
         }
       })
+
+      const jsonToHexTestName = `values_tests[${i}] parses ${JSON.stringify(
+        f.test_json,
+      )}...
+          as ${f.expected_hex.slice(0, 16)}`
+      it(jsonToHexTestName, () => {
+        const amt = Amount.from(f.test_json)
+        expect(amt.toHex()).toEqual(f.expected_hex)
+      })
     })
 }
 

packages/ripple-binary-codec/test/fixtures/data-driven-tests.json

@@ -2499,7 +2499,7 @@
             "type_id": 6,
             "is_native": true,
             "type": "Amount",
-            "expected_hex": "0000000000000001",
+            "error": "Value is negative",
             "is_negative": true
         },
         {
@@ -2914,6 +2914,170 @@
             "type": "Amount",
             "error": "10000000000000000000 absolute XRP is bigger than max native value 100000000000.0",
             "is_negative": true
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "9223372036854775808"
+            },
+            "type": "Amount",
+            "error": "Value is too large"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "18446744073709551615"
+            },
+            "type": "Amount",
+            "error": "Value is too large"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "-1"
+            },
+            "type": "Amount",
+            "error": "Value is negative"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "10.1"
+            },
+            "type": "Amount",
+            "error": "Value has decimal point"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "10",
+                "value": "10"
+            },
+            "type": "Amount",
+            "error": "mpt_issuance_id has invalid hash length"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "10",
+                "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji"
+            },
+            "type": "Amount",
+            "error": "Issuer not valid for MPT"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "10",
+                "currency": "USD"
+            },
+            "type": "Amount",
+            "error": "Currency not valid for MPT"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "a"
+            },
+            "type": "Amount",
+            "error": "Value has incorrect hex format"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "0xy"
+            },
+            "type": "Amount",
+            "error": "Value has bad hex character"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "/"
+            },
+            "type": "Amount",
+            "error": "Value has bad character"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "0x8000000000000000"
+            },
+            "type": "Amount",
+            "error": "Hex value out of range"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "0xFFFFFFFFFFFFFFFF"
+            },
+            "type": "Amount",
+            "error": "Hex value out of range"
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "9223372036854775807"
+            },
+            "type_id": 6,
+            "is_native": false,
+            "type": "Amount",
+            "expected_hex": "607FFFFFFFFFFFFFFF00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+            "is_negative": false
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "0"
+            },
+            "type_id": 6,
+            "is_native": false,
+            "type": "Amount",
+            "expected_hex": "60000000000000000000002403C84A0A28E0190E208E982C352BBD5006600555CF",
+            "is_negative": false
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "-0"
+            },
+            "type_id": 6,
+            "is_native": false,
+            "type": "Amount",
+            "expected_hex": "60000000000000000000002403C84A0A28E0190E208E982C352BBD5006600555CF",
+            "is_negative": false
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "100"
+            },
+            "type_id": 6,
+            "is_native": false,
+            "type": "Amount",
+            "expected_hex": "60000000000000006400002403C84A0A28E0190E208E982C352BBD5006600555CF",
+            "is_negative": false
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "0xa"
+            },
+            "type_id": 6,
+            "is_native": false,
+            "type": "Amount",
+            "expected_hex": "60000000000000000A00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+            "is_negative": false
+        },
+        {
+            "test_json": {
+                "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+                "value": "0x7FFFFFFFFFFFFFFF"
+            },
+            "type_id": 6,
+            "is_native": false,
+            "type": "Amount",
+            "expected_hex": "607FFFFFFFFFFFFFFF00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+            "is_negative": false
         }
     ]
 }

packages/ripple-binary-codec/test/hash.test.ts

@@ -1,4 +1,11 @@
-import { Hash128, Hash160, Hash256, AccountID, Currency } from '../src/types'
+import {
+  Hash128,
+  Hash160,
+  Hash192,
+  Hash256,
+  AccountID,
+  Currency,
+} from '../src/types'
 
 describe('Hash128', function () {
   it('has a static width member', function () {
@@ -51,6 +58,33 @@ describe('Hash160', function () {
   })
 })
 
+describe('Hash192', function () {
+  it('has a static width member', function () {
+    expect(Hash192.width).toBe(24)
+  })
+  it('has a ZERO_192 member', function () {
+    expect(Hash192.ZERO_192.toJSON()).toBe(
+      '000000000000000000000000000000000000000000000000',
+    )
+  })
+  it('can be compared against another', function () {
+    const h1 = Hash192.from('100000000000000000000000000000000000000000000000')
+    const h2 = Hash192.from('200000000000000000000000000000000000000000000000')
+    const h3 = Hash192.from('000000000000000000000000000000000000000000000003')
+    expect(h1.lt(h2)).toBe(true)
+    expect(h3.lt(h2)).toBe(true)
+  })
+
+  it('throws when constructed from invalid hash length', () => {
+    expect(() =>
+      Hash192.from('10000000000000000000000000000000000000000000000'),
+    ).toThrow(new Error('Invalid Hash length 23'))
+    expect(() =>
+      Hash192.from('10000000000000000000000000000000000000000000000000'),
+    ).toThrow(new Error('Invalid Hash length 25'))
+  })
+})
+
 describe('Hash256', function () {
   it('has a static width member', function () {
     expect(Hash256.width).toBe(32)

packages/ripple-binary-codec/test/uint.test.ts

@@ -1,5 +1,5 @@
 import { UInt8, UInt64 } from '../src/types'
-import { encode } from '../src'
+import { encode, decode } from '../src'
 
 const binary =
   '11007222000300003700000000000000003800000000000000006280000000000000000000000000000000000000005553440000000000000000000000000000000000000000000000000166D5438D7EA4C680000000000000000000000000005553440000000000AE123A8556F3CF91154711376AFB0F894F832B3D67D5438D7EA4C680000000000000000000000000005553440000000000F51DFC2A09D62CBBA1DFBDD4691DAC96AD98B90F'
@@ -96,6 +96,40 @@ const jsonEntry2 = {
   index: '0000041EFD027808D3F78C8352F97E324CB816318E00B977C74ECDDC7CD975B2',
 }
 
+const mptIssuanceEntryBinary =
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
+
+const mptIssuanceEntryJson = {
+  AssetScale: 3,
+  Flags: 98,
+  Issuer: 'rGpdGXDV2RFPeLEfWS9RFo5Nh9cpVDToZa',
+  LedgerEntryType: 'MPTokenIssuance',
+  MPTokenMetadata:
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
+  MaximumAmount: '9223372036854775807',
+  OutstandingAmount: '100',
+  OwnerNode: '0000000000000000',
+  PreviousTxnID:
+    '2E78C1FFBDDAEE077253CEB12CFEA83689AA0899F94762190A357208DADC76FE',
+  PreviousTxnLgrSeq: 740,
+  Sequence: 735,
+}
+
+const mptokenEntryJson = {
+  Account: 'raDQsd1s8rqGjL476g59a9vVNi1rSwrC44',
+  Flags: 0,
+  LedgerEntryType: 'MPToken',
+  MPTAmount: '100',
+  MPTokenIssuanceID: '000002DF71CAE59C9B7E56587FFF74D4EA5830D9BE3CE0CC',
+  OwnerNode: '0000000000000000',
+  PreviousTxnID:
+    '222EF3C7E82D8A44984A66E2B8E357CB536EC2547359CCF70E56E14BC4C284C8',
+  PreviousTxnLgrSeq: 741,
+}
+
+const mptokenEntryBinary =
+  '11007F220000000025000002E5340000000000000000301A000000000000006455222EF3C7E82D8A44984A66E2B8E357CB536EC2547359CCF70E56E14BC4C284C881143930DB9A74C26D96CB58ADFFD7E8BB78BCFE62340115000002DF71CAE59C9B7E56587FFF74D4EA5830D9BE3CE0CC'
+
 it('compareToTests[0]', () => {
   expect(UInt8.from(124).compareTo(UInt64.from(124))).toBe(0)
 })
@@ -144,3 +178,20 @@ it('valueOf tests', () => {
 
   expect(val.valueOf() | 0x2).toBe(3)
 })
+
+it('UInt64 is parsed as base 10 for MPT amounts', () => {
+  expect(encode(mptIssuanceEntryJson)).toEqual(mptIssuanceEntryBinary)
+  expect(decode(mptIssuanceEntryBinary)).toEqual(mptIssuanceEntryJson)
+
+  expect(encode(mptokenEntryJson)).toEqual(mptokenEntryBinary)
+  expect(decode(mptokenEntryBinary)).toEqual(mptokenEntryJson)
+
+  const decodedIssuance = decode(mptIssuanceEntryBinary)
+  expect(typeof decodedIssuance.MaximumAmount).toBe('string')
+  expect(decodedIssuance.MaximumAmount).toBe('9223372036854775807')
+  expect(decodedIssuance.OutstandingAmount).toBe('100')
+
+  const decodedToken = decode(mptokenEntryBinary)
+  expect(typeof decodedToken.MPTAmount).toBe('string')
+  expect(decodedToken.MPTAmount).toBe('100')
+})