---
title: Types
description: Translates JavaScript values into equivalent Cadence compatible values
---

Status

- Last Updated: July 10 2020
- Stable: Yes
- Risk of Breaking Change: Medium

Install

``bash
npm install --save @onflow/types
`

Usage

$3

`javascript
import * as sdk from "@onflow/sdk"
import * as t from "@onflow/types"

sdk.build([
sdk.transaction
transaction(to: Address, amount: UFix64) {
execute {
let addr: Address = to
let value: UFix64 = amount
}
}
,
sdk.args([
sdk.arg(to, t.Address),
sdk.arg(amount, t.UFix64),
]),
])
`

$3

`javascript
import * as sdk from "@onflow/sdk"
import * as t from "@onflow/types"

sdk.build([
sdk.script
pub fun main(a: Int, b: Int): Int {
return a + b
}
,
sdk.args([
sdk.arg(1, t.Int),
sdk.arg(2, t.Int),
]),
])
`

Available Types

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(1, t.UInt) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(1, t.Int) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(8, t.UInt8) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(8, t.Int8) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(16, t.UInt16) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(16, t.Int16) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(32, t.UInt32) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(32, t.Int32) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(64, t.UInt64) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(64, t.Int64) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(128, t.UInt128) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(128, t.Int128) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(256, t.UInt256) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(256, t.Int256) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(8, t.Word8) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(16, t.Word16) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(32, t.Word32) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(64, t.Word64) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(128, t.Word128) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(256, t.Word256) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("64.123", t.UFix64) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("64.123", t.Fix64) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("128.123456789012345678901234", t.UFix128) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("128.123456789012345678901234", t.Fix128) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("Flow", t.String) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("c", t.Character) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(true, t.Bool) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("0xABC123DEF456", t.Address) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg("Flow", t.Optional(t.String)) ])
])

sdk.build([
sdk.args([ sdk.arg(null, t.Optional(t.String)) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(["First", "Second"], t.Array(t.String)) ])
])

sdk.build([
sdk.args([ sdk.arg(["First", 2], t.Array([t.String, t.Int])) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([
sdk.arg(
[
{key: 1, value: "one"},
{key: 2, value: "two"},
],
t.Dictionary({key: t.Int, value: t.String})
)
])
])

sdk.build([
sdk.args([
sdk.arg(
[
{key: "a", value: "one"},
{key: "b", value: "two"},
],
t.Dictionary({key: t.String, value: t.String})
)
])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([
sdk.arg(
{
domain: "public" // public | private | storage
identifier: "flowTokenVault"
},
t.Path
)
])
])
`

Exist but not supported

The following, while technically possible, are impractical. We strongly recommend not using them as arguments for transactions or scripts.

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg(null, t.Void) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([
sdk.arg(
{
fields: [{name: "wasTheCodeClean?", value: "absolutely"}],
},
t.Event("0xABC123DEF456.JeffWroteSomeJS", [{value: t.String}]),
)
])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg({address: "0xABC123DEF456", type: "0xABC123DEF456.CryptoKitty"}, t.Reference) ])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([
sdk.arg(
{
fields: [{name: "CryptoKitty_name", value: "Lil' Jimmy The CryptoKitty"}],
},
t.Struct("0xABC123DEF456.CryptoKitty", [{value: t.String}])
)
])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([
sdk.arg(
{
fields: [{name: "Jeffysaur_Name", value: "Mr Jeff The Dinosaur"}],
}
t.Resource("0x01.Jeffysaur", [{value: t.String}]),
)
])
])
`

$3

`javascript
import * as t from "@onflow/types"

sdk.build([
sdk.args([ sdk.arg({start: "1", end: "10", step: "1"}, t.InclusiveRange(t.Int)) ])
])
``