Struct Pallet 

pub struct Pallet<T>(/* private fields */);

The Pallet struct, the main type that implements traits and standalone functions within the pallet.

Implementations

impl<T: Config> Pallet<T>

pub fn mint( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, external_amount: <<T as Config>::Fungibles as FungiblesInspect<<T as Config>::AccountId>>::Balance, max_fee: Permill, ) -> DispatchResult

Swap external asset for internal on a specific PSM instance.

Dispatch Origin

Must be Signed by the user performing the swap.

Details

Transfers external_amount of external_asset from the caller to the internal_asset’s PSM reserve account, then mints internal_asset to the caller minus the minting fee. The fee is calculated using ceiling rounding (mul_ceil), ensuring the protocol never undercharges. The fee is transferred to PsmInfo::fee_destination of the targeted instance.

Parameters

• internal_asset: The internal stablecoin that identifies the PSM instance.
• external_asset: The external asset to deposit (must be approved on internal_asset).
• external_amount: Amount of external asset to deposit.
• max_fee: Maximum minting fee rate accepted by the caller.

Errors

• Error::PsmNotFound: If no PSM is registered for internal_asset.
• Error::UnsupportedAsset: If external_asset is not approved on this PSM.
• Error::MintingStopped: If the per-external circuit breaker is at MintingDisabled or higher.
• Error::BelowMinimumSwap: If the internal-equivalent of external_amount is below the instance’s min_swap_amount.
• Error::FeeTooHigh: If the configured minting fee exceeds max_fee.
• Error::ExceedsMaxPsmDebt: If minting would exceed this PSM’s debt ceiling (aggregate or per-asset).
• Error::DecimalsMismatch: If live decimals diverged from the snapshot taken at registration.
• Error::AmountTooSmallAfterConversion: If the conversion to the counter-asset rounds to zero; swap would transfer nothing.

Events

• Event::Minted: Emitted on successful mint.

pub fn redeem( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, internal_amount: <<T as Config>::Fungibles as FungiblesInspect<<T as Config>::AccountId>>::Balance, max_fee: Permill, ) -> DispatchResult

Swap internal for external asset on a specific PSM instance.

Dispatch Origin

Must be Signed by the user performing the swap.

Details

Burns internal_amount of internal_asset from the caller minus fee (transferred to the instance’s PsmInfo::fee_destination), then transfers the resulting amount in external_asset from the PSM reserve to the caller. The fee is calculated using ceiling rounding (mul_ceil), ensuring the protocol never undercharges. Redemptions use the decimals snapshotted when the PSM/external pair was registered, allowing existing positions to unwind even if live metadata later changes.

Parameters

• internal_asset: The internal stablecoin that identifies the PSM instance.
• external_asset: The external asset to receive (must be approved on internal_asset).
• internal_amount: Amount of internal_asset to redeem.
• max_fee: Maximum redemption fee rate accepted by the caller.

Errors

• Error::PsmNotFound: If no PSM is registered for internal_asset.
• Error::UnsupportedAsset: If external_asset is not approved on this PSM.
• Error::AllSwapsStopped: If the per-external circuit breaker is at AllDisabled.
• Error::BelowMinimumSwap: If internal_amount is below the instance’s min_swap_amount.
• Error::FeeTooHigh: If the configured redemption fee exceeds max_fee.
• Error::InsufficientReserve: If the PSM holds less of external_asset than the redemption requires.
• Error::AmountTooSmallAfterConversion: If the conversion to the counter-asset rounds to zero; swap would transfer nothing.

Events

• Event::Redeemed: Emitted on successful redemption.

pub fn create_psm( origin: OriginFor<T>, internal_asset: T::AssetId, full_admin: Box<T::PalletsOrigin>, emergency_admin: Box<T::PalletsOrigin>, fee_destination: T::AccountId, max_debt: <<T as Config>::Fungibles as FungiblesInspect<<T as Config>::AccountId>>::Balance, min_swap_amount: <<T as Config>::Fungibles as FungiblesInspect<<T as Config>::AccountId>>::Balance, ) -> DispatchResult

Create a PSM for a given internal asset.

If Config::CreateOrigin resolves to Some(account), takes a Config::Consideration deposit from that account for the instance’s footprint (refunded on remove_psm). If it resolves to None, no deposit is taken. The full_admin and emergency_admin origins are set from the provided arguments and may later be reassigned via Pallet::set_full_admin / Pallet::set_emergency_admin.

Dispatch Origin

Config::CreateOrigin, parameterised by internal_asset. With the recommended EnsureAssetOwner this is a signed origin that owns internal_asset.

Parameters

• internal_asset: The internal stablecoin keying the new PSM. Must exist in the fungibles backend; must not already have a PSM registered.
• full_admin: Origin granted full management of the new PSM.
• emergency_admin: Origin granted emergency management of the new PSM.
• fee_destination: Account that will receive mint/redeem fees.
• max_debt: Initial absolute internal-asset debt ceiling.
• min_swap_amount: Minimum swap amount for this instance, in internal-asset units. Must be non-zero.

Errors

• [DispatchError::BadOrigin]: The origin is not permitted by Config::CreateOrigin.
• Error::PsmAlreadyExists: A PSM is already registered for internal_asset.
• Error::ZeroMinSwapAmount: min_swap_amount is zero.
• Error::AssetDoesNotExist: The internal asset does not exist.
• Any error from establishing the Config::Consideration deposit when one is needed (e.g. the account cannot afford it).

Events

• Event::PsmCreated.

pub fn remove_psm( origin: OriginFor<T>, internal_asset: T::AssetId, ) -> DispatchResult

Remove a PSM. Callable by the current full_admin. All approved externals must be removed first and aggregate PSM debt must be zero.

If a creation deposit was taken, it is always returned to the account that originally paid it, regardless of any later admin reassignment.

Dispatch Origin

Must match the PSM’s full_admin.

Parameters

• internal_asset: The PSM instance to remove.

Errors

• Error::PsmNotFound: No PSM is registered for internal_asset.
• Error::PsmHasApprovedExternals: Approved externals still exist.
• Error::PsmHasDebt: Outstanding aggregate debt is non-zero.

Events

• Event::PsmRemoved.

pub fn set_minting_fee( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, fee: Permill, ) -> DispatchResult

Set the minting fee for an (internal_asset, external_asset) pair.

Dispatch Origin

Must match the PSM instance’s full_admin (the Full privilege level).

Parameters

• internal_asset: The PSM instance to configure.
• external_asset: The external asset whose minting fee is being updated.
• fee: The new minting fee.

Errors

• Error::InsufficientPrivilege: If the origin only has Emergency privileges.
• Error::AssetNotApproved: If external_asset is not approved on internal_asset.

Events

• Event::MintingFeeUpdated: Emitted with old and new values.

pub fn set_redemption_fee( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, fee: Permill, ) -> DispatchResult

Set the redemption fee for an (internal_asset, external_asset) pair.

Dispatch Origin

Must match the PSM instance’s full_admin (the Full privilege level).

Parameters

• internal_asset: The PSM instance to configure.
• external_asset: The external asset whose redemption fee is being updated.
• fee: The new redemption fee.

Errors

• Error::InsufficientPrivilege: If the origin only has Emergency privileges.
• Error::AssetNotApproved: If external_asset is not approved on internal_asset.

Events

• Event::RedemptionFeeUpdated: Emitted with old and new values.

pub fn set_max_debt( origin: OriginFor<T>, internal_asset: T::AssetId, value: <<T as Config>::Fungibles as FungiblesInspect<<T as Config>::AccountId>>::Balance, ) -> DispatchResult

Set the PSM debt ceiling per internal asset, shared across all approved external assets.

Dispatch Origin

Must match the PSM instance’s full_admin; only the Full privilege level may use this call.

Parameters

• internal_asset: The PSM instance to configure.
• value: The new absolute debt ceiling, in internal-asset units.

Errors

• Error::InsufficientPrivilege: If the origin level cannot set the debt ceiling.
• Error::PsmNotFound: If no PSM is registered for internal_asset.

Events

• Event::MaxDebtUpdated: Emitted with old and new values.

pub fn set_asset_status( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, status: CircuitBreakerLevel, ) -> DispatchResult

Set the circuit breaker per external asset on a PSM instance.

Dispatch Origin

Must match the PSM instance’s full_admin or emergency_admin; either the Full or Emergency privilege level may use this call.

Parameters

• internal_asset: The PSM instance to configure.
• external_asset: The external asset whose status is being updated.
• status: The new circuit breaker level for that external.

Errors

• Error::AssetNotApproved: If external_asset is not approved on internal_asset.

Events

• Event::AssetStatusUpdated: Emitted on a successful update.

pub fn set_asset_ceiling_weight( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, weight: Permill, ) -> DispatchResult

Set the ceiling weight per external asset on a PSM instance.

Weights are normalised against the sum of weights within the same instance: max_asset_debt = (weight / sum_of_weights) * info.max_debt.

Dispatch Origin

Must match the PSM instance’s full_admin; only the Full privilege level may use this call.

Parameters

• internal_asset: The PSM instance to configure.
• external_asset: The external asset whose ceiling weight is being updated.
• weight: The new ceiling weight. Zero disables minting for this external.

Errors

• Error::InsufficientPrivilege: If the origin level cannot set ceiling weights.
• Error::AssetNotApproved: If external_asset is not approved on internal_asset.

Events

• Event::AssetCeilingWeightUpdated: Emitted with old and new values.

pub fn add_external_asset( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, ) -> DispatchResult

Approve an external asset for a given internal asset.

Snapshots the external asset’s live decimals at registration time and increments PsmInfo::external_count.

Dispatch Origin

Must match the PSM instance’s full_admin (the Full privilege level).

Parameters

• internal_asset: The PSM instance to approve the external on.
• external_asset: The external asset to approve.

Errors

• Error::InsufficientPrivilege: If the origin only has Emergency privileges.
• Error::PsmNotFound: If no PSM is registered for internal_asset.
• Error::TooManyAssets: If the PSM is already at Config::MaxExternals.
• Error::AssetAlreadyApproved: If external_asset is already approved on this PSM.
• Error::AssetDoesNotExist: If external_asset does not exist in the underlying fungibles backend.
• Error::DecimalsMismatch: If the internal asset’s live decimals diverged from the snapshot in PsmInfo.
• Error::DecimalsRangeExceeded: If |asset_decimals − internal_decimals| exceeds MAX_DECIMALS_DIFF.

Events

• Event::ExternalAssetAdded: Emitted on a successful approval.

pub fn remove_external_asset( origin: OriginFor<T>, internal_asset: T::AssetId, external_asset: T::AssetId, ) -> DispatchResult

Remove an external asset from a PSM instance.

Wipes the external’s per-instance state (status, decimals, fees, ceiling weight, debt counter) and decrements PsmInfo::external_count. The external must have zero outstanding debt on this instance.

Dispatch Origin

Must match the PSM instance’s full_admin (the Full privilege level).

Parameters

• internal_asset: The PSM instance to remove the external from.
• external_asset: The external asset to remove.

Errors

• Error::InsufficientPrivilege: If the origin only has Emergency privileges.
• Error::PsmNotFound: If no PSM is registered for internal_asset.
• Error::AssetNotApproved: If external_asset is not approved on this PSM.
• Error::AssetHasDebt: If the external still has non-zero outstanding debt.

Events

• Event::ExternalAssetRemoved: Emitted on a successful removal.

pub fn set_full_admin( origin: OriginFor<T>, internal_asset: T::AssetId, new_admin: Box<T::PalletsOrigin>, ) -> DispatchResult

Reassign the PSM’s full_admin. Callable by the current full_admin.

Dispatch Origin

Must match the PSM’s current full_admin.

Parameters

• internal_asset: The PSM whose full_admin is being changed.
• new_admin: The new full_admin origin.

Errors

• Error::PsmNotFound: No PSM is registered for internal_asset.

Events

• Event::FullAdminChanged.

pub fn set_emergency_admin( origin: OriginFor<T>, internal_asset: T::AssetId, new_admin: Box<T::PalletsOrigin>, ) -> DispatchResult

Reassign the PSM’s emergency_admin. Callable by the current full_admin.

Dispatch Origin

Must match the PSM’s current full_admin.

Parameters

• internal_asset: The PSM whose emergency_admin is being changed.
• new_admin: The new emergency_admin origin.

Errors

• Error::PsmNotFound: No PSM is registered for internal_asset.

Events

• Event::EmergencyAdminChanged.

impl<T: Config> Pallet<T>

pub fn psm_account(internal_asset: &T::AssetId) -> T::AccountId

Derive the reserve account for a PSM instance from the full hash of the pallet-id domain separator, pallet id, and internal asset.

Trait Implementations

impl<T: Config> BeforeAllRuntimeMigrations for Pallet<T>

fn before_all_runtime_migrations() -> Weight

Something that should happen before runtime migrations are executed.

impl<T> Benchmarking for Pallet<T>

where T: Config + Config, T::Fungibles: FungiblesCreate<T::AccountId>,

Available on crate features runtime-benchmarks only.

fn benchmarks(extra: bool) -> Vec<BenchmarkMetadata>

Get the benchmarks available for this pallet. Generally there is one benchmark per extrinsic, so these are sometimes just called “extrinsics”.

fn run_benchmark( extrinsic: &[u8], c: &[(BenchmarkParameter, u32)], whitelist: &[TrackedStorageKey], verify: bool, internal_repeats: u32, ) -> Result<Vec<BenchmarkResult>, BenchmarkError>

Run the benchmarks for this pallet.

impl<T: Config> Callable<T> for Pallet<T>

type RuntimeCall = Call<T>

impl<T> Clone for Pallet<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Pallet<T>

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Config> DispatchViewFunction for Pallet<T>

fn dispatch_view_function<O: Output>( id: &ViewFunctionId, input: &mut &[u8], output: &mut O, ) -> Result<(), ViewFunctionDispatchError>

impl<T: Config> GetStorageVersion for Pallet<T>

type InCodeStorageVersion = StorageVersion

This type is generated by the pallet macro.

fn in_code_storage_version() -> Self::InCodeStorageVersion

Returns the in-code storage version as specified in the storage_version attribute, or [NoStorageVersionSet] if the attribute is missing.

fn on_chain_storage_version() -> StorageVersion

Returns the storage version of the pallet as last set in the actual on-chain storage.

impl<T: Config> Hooks<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn integrity_test()

Check the integrity of this pallet’s configuration.

fn try_state(_n: BlockNumberFor<T>) -> Result<(), TryRuntimeError>

Execute the sanity checks of this pallet, per block.

fn on_initialize(_n: BlockNumber) -> Weight

Block initialization hook. This is called at the very beginning of block execution.

fn on_finalize(_n: BlockNumber)

Block finalization hook. This is called at the very end of block execution.

fn on_idle(_n: BlockNumber, _remaining_weight: Weight) -> Weight

Hook to consume a block’s idle time. This will run when the block is being finalized (before [Hooks::on_finalize]).

fn on_poll(_n: BlockNumber, _weight: &mut WeightMeter)

A hook to run logic after inherent application.

fn on_runtime_upgrade() -> Weight

Hook executed when a code change (aka. a “runtime upgrade”) is detected by the FRAME Executive pallet.

fn pre_upgrade() -> Result<Vec<u8>, DispatchError>

Execute some pre-checks prior to a runtime upgrade.

fn post_upgrade(_state: Vec<u8>) -> Result<(), DispatchError>

Execute some post-checks after a runtime upgrade.

fn offchain_worker(_n: BlockNumber)

Implementing this function on a pallet allows you to perform long-running tasks that are dispatched as separate threads, and entirely independent of the main blockchain execution.

impl<T: Config> IntegrityTest for Pallet<T>

fn integrity_test()

See [Hooks::integrity_test].

impl<T: Config> OffchainWorker<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn offchain_worker(n: BlockNumberFor<T>)

This function is being called after every block import (when fully synced).

impl<T: Config> OnFinalize<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn on_finalize(n: BlockNumberFor<T>)

See [Hooks::on_finalize].

impl<T: Config> OnGenesis for Pallet<T>

fn on_genesis()

Something that should happen at genesis.

impl<T: Config> OnIdle<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn on_idle(n: BlockNumberFor<T>, remaining_weight: Weight) -> Weight

See [Hooks::on_idle].

impl<T: Config> OnInitialize<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn on_initialize(n: BlockNumberFor<T>) -> Weight

See [Hooks::on_initialize].

impl<T: Config> OnPoll<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn on_poll(n: BlockNumberFor<T>, weight: &mut WeightMeter)

Code to execute every now and then at the beginning of the block after inherent application.

impl<T: Config> OnRuntimeUpgrade for Pallet<T>

fn on_runtime_upgrade() -> Weight

See [Hooks::on_runtime_upgrade].

fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError>

See [Hooks::pre_upgrade].

fn post_upgrade(state: Vec<u8>) -> Result<(), TryRuntimeError>

See [Hooks::post_upgrade].

fn try_on_runtime_upgrade(checks: bool) -> Result<Weight, DispatchError>

The expected and default behavior of this method is to handle executing pre_upgrade -> on_runtime_upgrade -> post_upgrade hooks for a migration.

impl<T: Config> PalletInfoAccess for Pallet<T>

fn index() -> usize

Index of the pallet as configured in the runtime.

fn name() -> &'static str

Name of the pallet as configured in the runtime.

fn name_hash() -> [u8; 16]

Two128 hash of name.

fn module_name() -> &'static str

Name of the Rust module containing the pallet.

fn crate_version() -> CrateVersion

Version of the crate containing the pallet.

impl<T: Config> PalletsInfoAccess for Pallet<T>

fn count() -> usize

The number of pallets’ information that this type represents.

fn infos() -> Vec<PalletInfoData>

All of the pallets’ information that this type represents.

impl<T> PartialEq for Pallet<T>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Config> StorageInfoTrait for Pallet<T>

fn storage_info() -> Vec<StorageInfo>

impl<T: Config> TryDecodeEntireStorage for Pallet<T>

fn try_decode_entire_state() -> Result<usize, Vec<TryDecodeEntireStorageError>>

Decode the entire data under the given storage, returning Ok(bytes_decoded) if success.

impl<T: Config> TryState<<<<T as Config>::Block as HeaderProvider>::HeaderT as Header>::Number> for Pallet<T>

fn try_state( n: BlockNumberFor<T>, _s: TryStateSelect, ) -> Result<(), TryRuntimeError>

Execute the state checks.

impl<T: Config> ViewFunctionIdPrefix for Pallet<T>

fn prefix() -> [u8; 16]

impl<T: Config> WhitelistedStorageKeys for Pallet<T>

fn whitelisted_storage_keys() -> Vec<TrackedStorageKey>

Returns a Vec<TrackedStorageKey> indicating the storage keys that should be whitelisted during benchmarking. This means that those keys will be excluded from the benchmarking performance calculation.

impl<T> Eq for Pallet<T>