Increases deposit cost for larger identities, discouraging excessive field usage.
Current Value
Conversion: ÷ 10^9 (RAO → TAO)
The Big Picture
Each additional field in your identity requires extra deposit. This creates an economic incentive to keep identities concise. Total deposit = InitialDeposit + (FieldDeposit * number of additional fields). More fields = more locked TAO.
Why This Matters
If you want a rich identity with custom fields, you'll pay more deposit. This constant tells you the per-field cost so you can calculate the total and decide if extra fields are worth it.
Example
InitialDeposit is 0.1 TAO, FieldDeposit is 0.1 TAO. A basic identity costs 0.1 TAO deposit. Adding 1 additional field (like 'discord') brings total to 0.2 TAO. Adding 2 fields costs 0.3 TAO. All refundable when you clear the identity.
Common Questions
- Does this apply to standard fields too?
- No, only to additional (custom) fields beyond the standard set. Standard fields (display, email, etc.) are covered by InitialDeposit.
- Can I reduce my deposit by removing fields?
- Yes, call set_identity with fewer fields. The deposit adjusts down and excess is returned.
From Chain Metadata
The amount held on deposit per additional field for a registered identity.
Use Cases
- Calculate total deposit for identity with additional fields
- Design identity forms with cost awareness
- Understand economics of rich vs minimal identities
Code Examples
import { ApiPromise, WsProvider } from "@polkadot/api";
import { stringCamelCase } from "@polkadot/util";
const provider = new WsProvider("wss://entrypoint-finney.opentensor.ai:443");
const api = await ApiPromise.create({ provider });
// Query FieldDeposit constant
const value = api.consts[stringCamelCase("Registry")][stringCamelCase("FieldDeposit")];
console.log("FieldDeposit:", value.toHuman());
// Convert RAO to TAO if this is a balance value
const taoValue = value.toBigInt() / BigInt(1e9);
console.log("TAO:", taoValue.toString());Type Information
- Type
- u64
- Byte Size
- 8 bytes
- Encoding
- fixed
- Raw Hex
- 0x00e1f50500000000
Runtime Info
- Pallet
- Registry
- First Version
- v136
- Latest Version
- v136
- Current Runtime
- v393