Advanced Usage

This guide covers advanced features of Relaycode for power users and developers.

Bi-Directional Editing

Relaycode supports seamless switching between form-based and hex-based editing. Changes in either pane are instantly reflected in the other.

Form → Hex Flow

Fill in the form fields
Watch the hex pane update in real-time
Each field change re-encodes the entire call

Form Input:                         Hex Output:
┌───────────────────────────┐       ┌───────────────────────────┐
│ dest: 5GrwvaEF...utQY     │  ───► │ 0x0503d43593c715...      │
│ value: 1 DOT              │       │                          │
└───────────────────────────┘       └───────────────────────────┘

Hex → Form Flow

Paste or edit hex in the right pane
The system decodes and populates the form
Invalid hex shows an error message

Hex Input:                          Form Output:
┌───────────────────────────┐       ┌───────────────────────────┐
│ 0x0503d43593c715...       │  ───► │ dest: 5GrwvaEF...utQY     │
│                           │       │ value: 1000000000000      │
└───────────────────────────┘       └───────────────────────────┘

Decoding Existing Call Data

To decode an existing extrinsic:

Select the correct pallet and method first
Paste the arguments hex (not the full extrinsic)
The form populates with decoded values

Note: The hex should be just the encoded arguments, not including the pallet/method prefix.

Batch Transactions

Use Utility.batch or Utility.batchAll to execute multiple calls in a single transaction.

Creating a Batch

Select Utility pallet
Select batch or batchAll method
Add calls using the nested Call input

batch vs batchAll

Method	Behavior on Failure
`batch`	Continues executing remaining calls
`batchAll`	Rolls back all calls (atomic)

Example: Multiple Transfers

Utility.batchAll
└── calls
    ├── [0] Balances.transferKeepAlive
    │       dest: 5FHneW46...
    │       value: 1 DOT
    │
    └── [1] Balances.transferKeepAlive
            dest: 5DAAnrj7...
            value: 2 DOT

Nested Batch Calls

Batches can contain any calls, including other batches:

Utility.batch
└── calls
    ├── [0] Balances.transferKeepAlive
    │
    └── [1] Utility.batch  ← Nested batch
            └── calls
                ├── [0] System.remark
                └── [1] System.remark

Complex Types

Structs

Structs group multiple named fields together. Relaycode renders each field with its appropriate input component.

ProposalInfo {
  title: String     → Text input
  description: String → Text input
  budget: Balance   → Balance input
  recipient: AccountId → Account input
}

Tuples

Tuples are ordered collections of typed values. They appear as numbered elements:

(AccountId, Balance, bool)

Element 0: [Account input]
Element 1: [Balance input]
Element 2: [Boolean toggle]

Enums

Enums represent a choice between variants. Some variants have associated data:

Origin {
  Root         → No additional input
  Signed(AccountId) → Shows Account input when selected
  None         → No additional input
}

Usage:

Select the variant from the dropdown
If the variant has data, fill in the inner input

Nested Calls

The Call input allows building any extrinsic as a parameter:

Sudo.sudo
└── call: Call
    └── [Nested pallet/method selector]
        └── [Parameters for nested call]

Common uses:

Sudo.sudo - Execute privileged calls
Utility.batch - Batch multiple calls
Multisig.asMulti - Multi-signature calls
Proxy.proxy - Proxy calls

Working with Vectors

Vector inputs allow dynamic arrays of any type.

Adding Items

Click "+ Add Item" to add a new element. A new input row appears.

Removing Items

Click the trash icon next to an item to remove it.

Constraints

Some vectors have min/max constraints:

Recipients (min: 1, max: 10)  ← Shows constraint info

Cannot remove items below minimum
Cannot add items above maximum

Nested Vectors

Vectors can contain any type, including other vectors:

Vec<Vec<AccountId>>

[0] ─┬─ [0] 5GrwvaEF...
     └─ [1] 5FHneW46...

[1] ─┬─ [0] 5DAAnrj7...
     └─ [1] 5GNJqTPy...

Fixed-Length Arrays

Fixed-length arrays like [u8; 32] render a fixed number of input fields:

[u8; 32] — 32 elements
├── [0]: [u8 input]
├── [1]: [u8 input]
├── ...
└── [31]: [u8 input]

Unlike Vec<T>, you cannot add or remove elements. The count is determined by the type definition.

BTreeMap and BTreeSet

BTreeMap<K, V>

Key-value maps render as a list of entries, each with typed key and value inputs:

BTreeMap<AccountId, Balance>
├── Entry 0:  Key: [Account input]  Value: [Balance input]
├── Entry 1:  Key: [Account input]  Value: [Balance input]
└── [+ Add Entry]

In the SCALE metadata, BTreeMap is encoded as a Sequence of Tuples — Relaycode resolves the key and value types automatically from the chain registry.

BTreeSet

Sets render similarly to vectors but with duplicate detection:

BTreeSet<AccountId>
├── Item 0: [Account input]
├── Item 1: [Account input]
└── [+ Add Item]

⚠ Set contains duplicate values  ← shown when duplicates detected

Option Types

Optional values can be present or absent.

Enabling/Disabling

Toggle the switch to enable or disable the value:

Enabled: Shows the inner input, value is included
Disabled: Inner input is dimmed, value is null/None

In Encoded Output

Enabled:  Some(value) → 0x01[encoded_value]
Disabled: None        → 0x00

Denominations and Balance Precision

Available Denominations

For Polkadot:

Denomination	Multiplier	Example
DOT	10^10 planck	1 DOT = 10,000,000,000 planck
mDOT	10^7 planck	1 mDOT = 10,000,000 planck
planck	1	Base unit

Precision Handling

Each denomination has a maximum decimal precision
DOT allows up to 10 decimal places
Planck allows only whole numbers (integers)

Valid:   1.5 DOT     → 15000000000 planck
Valid:   0.0000000001 DOT → 1 planck
Invalid: 0.00000000001 DOT → Error (excess precision)

Conversion

Switching denominations converts the displayed value:

1.5 DOT → 1500 mDOT → 15000000000 planck

The underlying planck value remains the same.

Error Handling

Encoding Errors

When a value can't be encoded:

The hex pane shows the last valid encoding
An error message appears below the field
Submit is disabled until fixed

Common causes:

Invalid address format
Wrong type (e.g., text in number field)
Missing required fields

Decoding Errors

When hex can't be decoded:

Form fields show last valid values
Error message in hex pane
Invalid hex is highlighted