cancel
Call v133 → v148, v149 → current #1Cancel an anonymously scheduled task by its block and index.
View calls on chainCall Workflow
This diagram shows the call execution flow: starting with cancel, passing through validation
(signature, nonce, mortality, fee payment), then pre-dispatch checks, followed by dispatch which emits events: Canceled, RetryCancelled and modifies storage: Agenda, and finally post-dispatch where ExtrinsicSuccess is emitted and fees are settled.
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Used by: developersanalytics
The Big Picture
Cancellation is the safety valve for scheduled operations when circumstances change.
Use Cases
- Cancel pending governance actions
- Abort scheduled maintenance
From Chain Metadata
See [`Pallet::cancel`].
Input Parameters
Permissions
Origin
Unknown
Required Role
Permission data inferred from metadata. May be incomplete.
Requirements
- Task exists at (when, index)
- Caller has permission to cancel
Effects
Events Emitted
Storage Modified
Postconditions
- Task removed from Agenda
- Task will not execute
Side Effects
- Reserved deposit returned
- Emits Canceled event
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 cancel call (typed, named args)
const when = 0;
const index = 0;
const tx = api.tx.Scheduler.cancel({
when,
index,
});Version History
v133 block 1,404,224 2 args
v149 block 3,014,339 2 args Current
Runtime Info
- Pallet Index
- 15
- Call Index
- 1
- First Version
- v133
- Current Version
- v411