Enum ErrorReason 

#[non_exhaustive]
pub enum ErrorReason {
    InsufficientFunds,
    InvalidExactEvmPayloadAuthorizationValidAfter,
    InvalidExactEvmPayloadAuthorizationValidBefore,
    InvalidExactEvmPayloadAuthorizationValueMismatch,
    InvalidExactEvmPayloadSignature,
    InvalidExactEvmPayloadRecipientMismatch,
    InvalidNetwork,
    InvalidPayload,
    InvalidPaymentRequirements,
    InvalidScheme,
    UnsupportedScheme,
    InvalidX402Version,
    InvalidTransactionState,
    UnexpectedVerifyError,
    UnexpectedSettleError,
    DuplicateSettlement,
    NonceAlreadyUsed,
    Permit2AllowanceRequired,
    InvalidUptoEvmPayloadSettlementExceedsAmount,
    UptoFacilitatorMismatch,
    UptoUnauthorizedFacilitator,
    UptoAmountExceedsPermitted,
    InvalidExactSolanaPayloadMemoMismatch,
    InvalidExactSolanaPayloadMemoCount,
    Custom(CompactString),
}

Canonical error code returned on the wire when a payment fails.

The variants form a closed set of well-known codes the SDK can pattern match against. Any unknown wire code is preserved via Self::Custom so deserialisation is total and idempotent.

The enum is #[non_exhaustive]: new well-known variants may be added in minor releases without breaking semver.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

InsufficientFunds

Client does not have enough tokens to complete the payment. Wire code: insufficient_funds.

InvalidExactEvmPayloadAuthorizationValidAfter

Payment authorization is not yet valid (before validAfter timestamp). Wire code: invalid_exact_evm_payload_authorization_valid_after.

InvalidExactEvmPayloadAuthorizationValidBefore

Payment authorization has expired (after validBefore timestamp). Wire code: invalid_exact_evm_payload_authorization_valid_before.

InvalidExactEvmPayloadAuthorizationValueMismatch

Payment amount does not exactly match the required amount. Wire code: invalid_exact_evm_payload_authorization_value_mismatch.

InvalidExactEvmPayloadSignature

Payment authorization signature is invalid or improperly signed. Wire code: invalid_exact_evm_payload_signature.

InvalidExactEvmPayloadRecipientMismatch

Recipient address does not match payment requirements. Wire code: invalid_exact_evm_payload_recipient_mismatch.

InvalidNetwork

Specified blockchain network is not supported. Wire code: invalid_network.

InvalidPayload

Payment payload is malformed or contains invalid data. Wire code: invalid_payload.

InvalidPaymentRequirements

Payment requirements object is invalid or malformed. Wire code: invalid_payment_requirements.

InvalidScheme

Specified payment scheme is not supported. Wire code: invalid_scheme.

UnsupportedScheme

Payment scheme is not supported by the facilitator. Wire code: unsupported_scheme.

InvalidX402Version

Protocol version is not supported. Wire code: invalid_x402_version.

InvalidTransactionState

Blockchain transaction failed or was rejected. Wire code: invalid_transaction_state.

UnexpectedVerifyError

Unexpected error occurred during payment verification. Wire code: unexpected_verify_error.

UnexpectedSettleError

Unexpected error occurred during payment settlement. Wire code: unexpected_settle_error.

DuplicateSettlement

Facilitator detected a duplicate settlement attempt and rejected it. Wire code: duplicate_settlement.

NonceAlreadyUsed

EIP-3009 authorization nonce has already been consumed on-chain. Wire code: nonce_already_used.

Permit2AllowanceRequired

Permit2 allowance is insufficient; the payer must call approve on the token contract pointing at the Permit2 address first. Wire code: permit2_allowance_required. HTTP mapping: 412 Precondition Failed.

InvalidUptoEvmPayloadSettlementExceedsAmount

Resource server requested a settlement amount exceeding the buyer’s signed maximum authorisation. Reserved by schemes/upto/scheme_upto_evm.md §4. Wire code: invalid_upto_evm_payload_settlement_exceeds_amount.

UptoFacilitatorMismatch

witness.facilitator doesn’t match any of the facilitator’s signer addresses. Buyer signed a stale or unauthorised facilitator address. Wire code: upto_facilitator_mismatch.

UptoUnauthorizedFacilitator

On-chain proxy reverted with UnauthorizedFacilitator (msg.sender is not the witness-bound facilitator). Wire code: upto_unauthorized_facilitator.

UptoAmountExceedsPermitted

On-chain proxy reverted with AmountExceedsPermitted. Wire code: upto_amount_exceeds_permitted.

InvalidExactSolanaPayloadMemoMismatch

SVM extra.memo field did not match the memo instruction data. Wire code: invalid_exact_solana_payload_memo_mismatch.

InvalidExactSolanaPayloadMemoCount

Number of memo instructions attached is invalid (spec requires exactly one when extra.memo is declared). Wire code: invalid_exact_solana_payload_memo_count.

Custom(CompactString)

Catch-all preserving any unknown wire code verbatim. Round-trips losslessly through serialisation so clients never lose information.

Implementations

impl ErrorReason

pub fn as_str(&self) -> &str

Returns the wire-format code (snake_case per spec §9).

pub fn from_wire(code: &str) -> Self

Constructs an ErrorReason from any wire code, mapping known strings to their canonical variants and preserving unknown codes as Self::Custom.

Trait Implementations

impl Clone for ErrorReason

fn clone(&self) -> ErrorReason

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ErrorReason

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ErrorReason

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Display for ErrorReason

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

Formats the value using the given formatter.

impl Eq for ErrorReason

impl From<&str> for ErrorReason

fn from(value: &str) -> Self

Converts to this type from the input type.

impl From<CompactString> for ErrorReason

fn from(value: CompactString) -> Self

Converts to this type from the input type.

impl From<String> for ErrorReason

fn from(value: String) -> Self

Converts to this type from the input type.

impl Hash for ErrorReason

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ErrorReason

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for ErrorReason

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ErrorReason