approve_as_multi

Call v123 → current #2

Register approval without providing full call data (hash only).

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Used by: developerswalletsvalidators

The Big Picture

approve_as_multi lets intermediate approvers just submit a hash, proving they've reviewed the call without re-transmitting it. The final approver uses as_multi with full data.

Use Cases

  • Approve a pending multisig without needing full call data
  • Gas-efficient intermediate approvals
  • Sign off on operations you've verified off-chain

From Chain Metadata

Register approval for a dispatch to be made from a deterministic composite account if approved by a total of `threshold - 1` of `other_signatories`. Payment: `DepositBase` will be reserved if this is the first approval, plus `threshold` times `DepositFactor`. It is returned once this dispatch happens or is cancelled. The dispatch origin for this call must be _Signed_. `threshold`: The total number of approvals for this dispatch before it is executed. `other_signatories`: The accounts (other than the sender) who can approve this dispatch. May not be empty. `maybe_timepoint`: If this is the first approval, then this must be `None`. If it is not the first approval, then it must be `Some`, with the timepoint (block number and transaction index) of the first approval transaction. `call_hash`: The hash of the call to be executed. NOTE: If this is the final approval, you will want to use `as_multi` instead. ## Complexity `O(S)`. Up to one balance-reserve or unreserve operation. One passthrough operation, one insert, both `O(S)` where `S` is the number of signatories. `S` is capped by `MaxSignatories`, with weight being proportional. One encode & hash, both of complexity `O(S)`. Up to one binary search and insert (`O(logS + S)`). I/O: 1 read `O(S)`, up to 1 mutate `O(S)`. Up to one remove. One event. Storage: inserts one item, value size bounded by `MaxSignatories`, with a deposit taken for its lifetime of `DepositBase + threshold * DepositFactor`.

Input Parameters

#NameTypeDescription
0
threshold
u16 Number of approvals required (2 or higher)
1
other_signatories
Vec<AccountId> VecList of other signatory accounts (sorted, excludes caller)
2
maybe_timepoint
→ timepoint
Option Timepoint from first approval (None for first approval)
3
call_hash
[u8; 32] [32]Blake2-256 hash of the call to approve
4
max_weight
Weight Maximum weight allowed for the call execution

Permissions

Origin
Signed
Required Role
Any

Permission data inferred from metadata. May be incomplete.

Requirements

  • Caller is one of the signatories
  • Threshold is 2 or greater
  • Multisig operation exists (or this is first approval)
  • Caller hasn't already approved this operation

Effects

Storage Modified

Multisigs

Postconditions

  • Approval recorded for this signatory
  • Call NOT executed (even if threshold reached - need as_multi for final)

Side Effects

  • Deposit reserved on first approval
  • Emits MultisigApproval event
  • Lighter weight than as_multi (no call data)

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 });

// Build approve_as_multi call
const threshold = 0;
const other_signatories = "5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY";
const maybe_timepoint = 0 as any /* Option */;
const call_hash = 0;
const max_weight = 0 as any /* Weight */;

const call = api.tx[stringCamelCase("Multisig")][stringCamelCase("approve_as_multi")](
  threshold,
  other_signatories,
  maybe_timepoint,
  call_hash,
  max_weight
);

Runtime Info

Pallet Index
13
Call Index
2
First Version
v123
Current Version
v393
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