sudo_set_min_difficulty
Call v138 → v277, v290 → current #4Sets the minimum POW difficulty for a subnet .
View calls on chainCall Workflow
This diagram shows the call execution flow: starting with sudo_set_min_difficulty, passing through validation
(signature, nonce, mortality, fee payment), then pre-dispatch checks, followed by dispatch and modifies storage: SubtensorModule.MinDifficulty, and finally post-dispatch where ExtrinsicSuccess is emitted and fees are settled.
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Used by: subnet owners
The Big Picture
Sets a floor for POW registration difficulty. Even if registration demand is low, difficulty won't drop below this.
Use Cases
- Preventing difficulty from dropping too low
- Maintaining minimum security guarantees
From Chain Metadata
The extrinsic sets the minimum difficulty for a subnet. It is only callable by the root account or subnet owner. The extrinsic will call the Subtensor pallet to set the minimum difficulty.
Input Parameters
Permissions
Origin
Root
Required Role
Requirements
- Caller is root or subnet owner
- Subnet exists
- Value <= max_difficulty
Effects
Storage Modified
Postconditions
- MinDifficulty updated for subnet
Side Effects
- Registration difficulty cannot go below this floor
Code Examples
import { createClient, Binary } from "polkadot-api";
import { getWsProvider } from "polkadot-api/ws";
import { sub } from "@polkadot-api/descriptors"; // generated by: npx papi add sub -w wss://entrypoint-finney.opentensor.ai:443
const client = createClient(getWsProvider("wss://entrypoint-finney.opentensor.ai:443"));
const api = client.getTypedApi(sub);
// Build sudo_set_min_difficulty call (typed, named args)
const netuid = 1;
const min_difficulty = 0n;
const tx = api.tx.AdminUtils.sudo_set_min_difficulty({
netuid,
min_difficulty,
});Version History
v138 block 1,907,363 2 args
v290 block 5,947,548 2 args Current
Runtime Info
View Source- Pallet Index
- 19
- Call Index
- 4
- First Version
- v138
- Current Version
- v411