Preimage

Calls

notePreimage

Register a preimage on-chain.

If the preimage was previously requested, no fees or deposits are taken for providing the preimage. Otherwise, a deposit is taken proportional to the size of the preimage.

Namespace

api.tx.preimage.notePreimage

Type

function notePreimage(
  bytes: Bytes
)

requestPreimage

Request a preimage be uploaded to the chain without paying any fees or deposits.

If the preimage requests has already been provided on-chain, we unreserve any deposit a user may have paid, and take the control of the preimage out of their hands.

Namespace

api.tx.preimage.requestPreimage

Type

function requestPreimage(
  hash: H256
)

unnotePreimage

Clear an unrequested preimage from the runtime storage.

Namespace

api.tx.preimage.unnotePreimage

Type

function unnotePreimage(
  hash: H256
)

unrequestPreimage

Clear a previously made request for a preimage.

IMPORTANT: This must not be called onhashmore times thanrequest_preimage.

Namespace

api.tx.preimage.unrequestPreimage

Type

function unrequestPreimage(
  hash: H256
)

Storage

preimageFor

The preimages stored by this pallet.

Namespace

api.query.preimage.preimageFor

Type

function preimageFor(
  H256
): Option<Bytes>

statusFor

The request status of a given hash.

Namespace

api.query.preimage.statusFor

Type

function statusFor(
  H256
): Option<PalletPreimageRequestStatus>

Events

Cleared

A preimage has ben cleared.

Namespace

api.events.preimage.Cleared

Type

type Cleared = {
  hash: H256
}

Noted

A preimage has been noted.

Namespace

api.events.preimage.Noted

Type

type Noted = {
  hash: H256
}

Requested

A preimage has been requested.

Namespace

api.events.preimage.Requested

Type

type Requested = {
  hash: H256
}

Errors

AlreadyNoted

Preimage has already been noted on-chain.

Namespace

api.errors.preimage.AlreadyNoted

NotAuthorized

The user is not authorized to perform this action.

Namespace

api.errors.preimage.NotAuthorized

NotNoted

The preimage cannot be removed since it has not yet been noted.

Namespace

api.errors.preimage.NotNoted

NotRequested

The preimage request cannot be removed since no outstanding requests exist.

Namespace

api.errors.preimage.NotRequested

Requested

A preimage may not be removed when there are outstanding requests.

Namespace

api.errors.preimage.Requested

TooLarge

Preimage is too large to store on-chain.

Namespace

api.errors.preimage.TooLarge

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Source: https://docs.therootnetwork.com/build/substrate/api-reference/runtime-pallets/preimage · captured 2026-05-16 · part of TRN Docs source map