Account Changes

AccountBuilder::with_auth_component was removed — auth components are now passed through with_component like any other, and identified by their MASM @auth_script attribute. Auth components take an Approver instead of a raw key and scheme. Every standard component's NAME constant changed, and because component metadata feeds the storage schema commitment, accounts rebuilt from the same seed will have different commitments.

Quick Fix

// Before (0.15)
let account = AccountBuilder::new(init_seed)
    .account_type(AccountType::Public)
    .with_auth_component(AuthSingleSig::new(pub_key, auth_scheme))
    .with_component(BasicWallet)
    .build()?;

// After (0.16)
let account = AccountBuilder::new(init_seed)
    .account_type(AccountType::Public)
    .with_component(AuthSingleSig::new(Approver::new(pub_key, auth_scheme)))
    .with_component(BasicWallet)
    .build()?;

If you encounter errors, continue reading for detailed migration steps.

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Summary

Three independent shifts land on accounts in this release.

Auth stops being special. In 0.15 the builder had a dedicated auth slot; in 0.16 the auth component is just a component, and the builder finds it by looking for the @auth_script attribute in its MASM. This is what makes the fee change possible — the auth procedure is now also where fees get paid, so it needed to compose with everything else.

Keys are wrapped in an Approver. AuthSingleSig::new took a public-key commitment and a scheme; it now takes a single Approver carrying both. Multi-signature components take an ApproverSet with a threshold. This is a mechanical rewrite, but it touches every account you construct.

Component names were normalised, which changes commitments. Every standard component's NAME dropped its components:: segment. Since the name feeds component metadata, and metadata feeds the storage schema commitment, this silently changes account commitments even when nothing else about your account changed.

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AccountBuilder::with_auth_component removed

Summary

AccountBuilder now takes all components uniformly through with_component, and identifies the auth component by its @auth_script MASM attribute.

Affected Code

  let account = AccountBuilder::new(init_seed)
      .account_type(AccountType::Public)
-     .with_auth_component(auth_component)
+     .with_component(auth_component)
      .with_component(BasicWallet)
      .build()?;

Reach for with_component whenever you are naming a component yourself — it takes impl Into<AccountComponent>, so no explicit .into() is needed. with_components is for the case where the count is not known at the call site: a configuration value that expands into one or several components depending on its variant. AuthNetworkAccount is the example in this release — see Network accounts require a fee policy.

AccountBuilder also gained with_asset_callbacks(AssetCallbackFlag). Whether a faucet's assets trigger callbacks is now encoded in the account ID rather than in separate storage, so this is set at construction time.

Migration Steps

1. Drop with_auth_component and pass the auth component through with_component, like any other.
2. If you author a custom auth component, make sure its entry procedure carries the @auth_script attribute — that is how the builder recognises it.
3. If you build a faucet whose assets should trigger callbacks, set with_asset_callbacks.

Common Errors

Error Message	Cause	Solution
no method named with_auth_component	Method removed	Use with_component.
Build fails reporting no auth component	Custom component lacks the attribute	Annotate the entry procedure with @auth_script.

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Approver and ApproverSet replace raw key arguments

Summary

Approver bundles a public-key commitment with its signature scheme; ApproverSet bundles a list of approvers with a threshold. Both are new in 0.16. The AuthMethod enum was removed, and AuthSingleSigAcl / AuthSingleSigAclConfig were removed outright.

Affected Code

// Before (0.15)
AuthSingleSig::new(pub_key: PublicKeyCommitment, auth_scheme: AuthScheme) -> Self

// After (0.16)
Approver::new(pub_key: PublicKeyCommitment, auth_scheme: AuthScheme) -> Approver
AuthSingleSig::new(approver: Approver) -> Self
ApproverSet::new(approvers: Vec<Approver>, threshold: u32) -> Result<Self, AccountError>
AuthMultisig::new(approver_set: ApproverSet) -> Self

The convenience constructors are unchanged and remain the shortest path when you have a concrete key:

// Identical in 0.15 and 0.16
AuthSingleSig::falcon512_poseidon2(pub_key)
AuthSingleSig::ecdsa_k256_keccak(pub_key)
AuthSingleSig::from_public_key(pub_key)

New accessors: AuthSingleSig::approver(), ApproverSet::approvers(), and ApproverSet::threshold().

Migration Steps

1. Wrap existing AuthSingleSig::new(pub_key, scheme) arguments in Approver::new(pub_key, scheme).
2. Replace multi-signature construction with ApproverSet::new(approvers, threshold)? — note it is fallible.
3. Remove any use of AuthMethod; the scheme now travels inside the Approver.
4. If you used AuthSingleSigAcl, there is no drop-in replacement. Rebuild the access-control policy using the components under miden::standards::access (for example RoleBasedAccessControl or Authority).

Common Errors

Error Message	Cause	Solution
this function takes 1 argument but 2 were supplied on AuthSingleSig::new	Signature changed	Wrap the arguments in Approver::new.
cannot find type AuthMethod	Removed	Use Approver / AuthScheme.
cannot find type AuthSingleSigAcl	Removed	Rebuild with an access-control component.

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Component names changed, and account commitments with them

Summary

Every standard component's NAME constant was normalised by dropping the components:: segment. Component metadata feeds the storage schema commitment, so the commitment of an account built from the same seed and the same components differs between 0.15 and 0.16.

Affected Code

- "miden::standards::components::auth::singlesig"
+ "miden::standards::auth::singlesig"

- "miden::standards::components::wallets::basic_wallet"
+ "miden::standards::wallets::basic_wallet"

- "miden::standards::components::access::rbac"
+ "miden::standards::access::rbac"

- "miden::standards::components::faucets::fungible_faucet"
+ "miden::standards::faucets::fungible"

A few names already lacked the segment in 0.15 — miden::standards::auth::network_account and miden::standards::access::ownable2step are unchanged. Note that the fungible faucet also lost its _faucet suffix, so it is not a pure prefix change.

The miden::standards::account::metadata module was also renamed to miden::standards::account::inspection, both in MASM and in Rust.

Migration Steps

1. Update any hard-coded component name strings.
2. Expect new account IDs and commitments for accounts rebuilt from the same seed. If you have persisted an account ID derived under 0.15, it will not be reproduced by 0.16 construction.
3. Update references to account::metadata to account::inspection.

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Component MASM must annotate exported procedures

Summary

Account component MASM must annotate every exported procedure with @account_procedure. Un-annotated procedures are not exported. This attribute is new in 0.16 — the protocol's own MASM went from zero uses to 99.

@auth_script and @note_script already existed in 0.15 and are unchanged.

Affected Code

# After (0.16)
@account_procedure
pub proc receive_asset(asset: word)
    # …
end

@auth_script
pub proc auth_tx(auth_args: word)
    # …
end

Migration Steps

1. Add @account_procedure to every procedure your component intends to export.
2. Re-check the resulting AccountCode procedure list — a missing annotation shows up as a procedure that silently is not callable, not as a compile error.

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AccountCode::from_parts is now fallible

Summary

AccountCode::from_parts validated its procedure count with assert! in 0.15 and now returns a Result instead of panicking.

Affected Code

// Before (0.15)
pub fn from_parts(mast: Arc<MastForest>, procedures: Vec<AccountProcedureRoot>) -> Self

// After (0.16)
pub fn from_parts(
    mast: Arc<MastForest>,
    procedures: Vec<AccountProcedureRoot>,
) -> Result<Self, AccountError>

Migration Steps

Add ? or explicit error handling at every call site.

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AccountId no longer converts into [Felt; 2]

Summary

The impl From<AccountId> for [Felt; 2] was removed. Use the prefix() and suffix() accessors instead. Conversions to [u8; 15] and u128 are unchanged.

Affected Code

// Before (0.15)
let felts: [Felt; 2] = account_id.into();

// After (0.16)
let prefix: AccountIdPrefix = account_id.prefix();
let suffix: Felt = account_id.suffix();

Migration Steps

Replace the into() conversion with the two accessors. Note prefix() returns an AccountIdPrefix, not a bare Felt.

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Account updates move from AccountDelta to AccountPatch

Summary

Account updates moved from the relative AccountDelta to the absolute AccountPatch. ExecutedTransaction and AccountUpdateDetails now carry a patch, and Account::apply_delta was replaced by applying a patch.

This is not a wholesale removal. AccountDelta remains, and TransactionSummary::account_delta() deliberately still returns one — the signed transaction summary binds a relative delta. Only account update representation moved to the absolute patch model. The same split exists on the TypeScript side, where TransactionSummary.accountDelta() is unchanged while the result's accountDelta() became accountPatch().

Affected Code

// Before (0.15)
let delta = executed_tx.account_delta();
account.apply_delta(&delta)?;

// After (0.16)
let patch = executed_tx.account_patch();
account.apply_patch(&patch)?;

// Or build a fresh account from the patch instead of mutating one:
let account = Account::try_from(&patch)?;

apply_patch is the direct replacement for apply_delta and keeps the same in-place shape, so it is the smaller edit for existing code. The same rename applies further down: AssetVault::apply_delta became apply_patch, taking an AccountVaultPatch.

Migration Steps

1. Replace account_delta() with account_patch() on ExecutedTransaction and on client transaction results.
2. Replace Account::apply_delta(&delta) with Account::apply_patch(&patch), or construct a new account with Account::try_from(&patch).
3. Leave TransactionSummary::account_delta() call sites alone — that one is intentionally still a delta.

---

Network accounts require a fee policy

Summary

AuthNetworkAccount::new now takes a FeePolicyManager alongside the allowed-note set. The manager carries the fee faucet and the active fee policy, and expands into the policy's components when the auth component is installed — so you do not install policy components separately.

Fee policies describe how an account that sponsors or charges fees estimates them. An ordinary user account paying a fee does not install one; it supplies fee conversion info per transaction instead. See Transaction Changes.

Affected Code

// After (0.16)
let manager = FeePolicyManager::builder()
    .fee_faucet_id(fee_faucet_id)
    .active_fee_policy(FeePolicy::from(BasicConstantFeePolicy::new()))
    .build();

let auth = AuthNetworkAccount::new(allowed_notes, manager)?;

AuthNetworkAccount no longer converts into a single AccountComponent — it expands into several, so install it through with_components.

Migration Steps

1. Build a FeePolicyManager with the fee faucet and an active fee policy, registering any alternatives with allowed_fee_policy for runtime switching.
2. Pass it to AuthNetworkAccount::new, which is fallible.
3. Install the auth component with with_components, not with_component, since it expands to several components.

---

Common Errors

Error Message	Cause	Solution
no method named with_auth_component	Removed	Use with_component, or with_components for AuthNetworkAccount.
this function takes 1 argument but 2 were supplied	AuthSingleSig::new takes an Approver	Wrap in Approver::new.
cannot find type AuthMethod / AuthSingleSigAcl	Removed	See the auth section above.
expected Result, found AccountCode	from_parts is fallible	Add ?.
the trait From<AccountId> is not implemented for [Felt; 2]	Conversion removed	Use prefix() / suffix().
Account commitment differs from 0.15 for the same seed	Component names changed	Expected; re-record the new ID.
Component procedure is not callable but compiles	Missing @account_procedure	Annotate the procedure.