Enum DeadLetterReason 

#[non_exhaustive]
pub enum DeadLetterReason {
    UnknownPid {
        pid: Pid,
        context: AuditContext,
    },
    UnknownConversation {
        conversation_id: String,
        context: AuditContext,
    },
    VersionMismatch {
        expected: String,
        received: String,
        context: AuditContext,
    },
    DuplicateMessage {
        inbox_key: String,
        context: AuditContext,
    },
    ProcessingError {
        message: String,
        context: AuditContext,
    },
    TestMessage {
        context: AuditContext,
    },
    MissingInterchangeParty {
        qualifier: &'static str,
        context: AuditContext,
    },
    NotDispatchable {
        workflow_name: String,
        pid: Pid,
        reason: String,
        context: AuditContext,
    },
    OutboxExhausted {
        message_id: OutboxMessageId,
        message_type: String,
        recipient: String,
        last_error: String,
        attempts: u32,
    },
}

Structured reason why an inbound message was rejected.

The variant gives the dispatch path enough information to emit an actionable CONTRL or log entry. Each variant carries an AuditContext with the § 147 AO / GoBD fields required for regulatory audit logging.

Adding new variants is a non-breaking change thanks to #[non_exhaustive].

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.

UnknownPid

No workflow is registered for this PID in the PidRouter.

The PID is either from a future BDEW release not yet deployed or a malformed message. Respond with a CONTRL negative acknowledgement.

Fields

pid: Pid

The numeric Prüfidentifikator that had no registered workflow.

context: AuditContext

§ 147 AO / GoBD structured audit context.

UnknownConversation

No in-flight process matched the inbound conversation_id.

This typically means the process completed, was never started, or the ProcessRegistry was lost on restart (see.

Fields

conversation_id: String

The conversation_id from the inbound EDIFACT interchange.

context: AuditContext

§ 147 AO / GoBD structured audit context.

VersionMismatch

The message’s format version has no registered MessageAdapter.

Either the adapter registry is incomplete (see or the sender is using a deprecated / future format version.

Fields

expected: String

The format version string the adapter registry expected.

received: String

The format version string carried in the inbound message.

context: AuditContext

§ 147 AO / GoBD structured audit context.

DuplicateMessage

A message with this inbox key was already accepted (AS4 duplicate).

The AS4 sender retries for up to 72 hours. The InboxStore detected the duplicate and the message must not be processed again.

Fields

inbox_key: String

The inbox deduplication key (typically the AS4 MessageId).

context: AuditContext

§ 147 AO / GoBD structured audit context.

ProcessingError

A workflow or adapter returned a processing error.

The message was routed correctly but could not be processed. Use this variant when the failure is definitive (not retriable).

Fields

message: String

Short, human-readable description of the failure.

context: AuditContext

§ 147 AO / GoBD structured audit context.

TestMessage

An interchange flagged with UNB DE0035 = 1 (test indicator) was received on a production endpoint.

Per Allgemeine Festlegungen V6.1d §3, test interchanges must not be processed as production. The interchange is rejected at the ingest boundary without being forwarded to any workflow.

Fields

context: AuditContext

§ 147 AO / GoBD structured audit context (contains sender, receiver, control_ref).

MissingInterchangeParty

A business message arrived without the NAD party the answer is addressed with, or the one the Sparte is resolved from.

BDEW Allgemeine Festlegungen V6.1d §2.13 identifies the fachliche sender and receiver on message level in NAD+MS / NAD+MR DE 3035 and states the approach applies “für alle EDI@Energy EDIFACT Nachrichten und -dateien einheitlich”. Both are load-bearing here: the sender is who the answer and the APERAK go back to, and the receiver is which of the operator’s own MP-IDs — and therefore which Sparte and which Marktrolle — the message is addressed to.

Substituting an empty MP-ID produces a process whose answer is addressed to nobody and whose Sparte silently defaults, so the message is refused at the boundary instead. CONTRL carries no NAD at all — it is a UN/EDIFACT syntax acknowledgement rather than an EDI@Energy business message — and is exempt.

Fields

qualifier: &'static str

"MS" or "MR" — which of the two was absent or empty.

context: AuditContext

§ 147 AO / GoBD structured audit context.

NotDispatchable

The PID resolved to a workflow, but the ingest dispatcher has no arm for it — so makod claimed to route the message and then dropped it.

Always a coverage bug on this side, never a defect in the sender’s message: PidRouter answered, the transport acknowledged, and the business payload went nowhere. It is recorded rather than logged because an acknowledged inbound message that produced no process is exactly what § 147 AO / GoBD require a trace of.

Fields

workflow_name: String

The workflow name PidRouter resolved the PID to.

pid: Pid

The Prüfidentifikator carried by the message.

reason: String

Machine-readable skip reason from the dispatcher.

context: AuditContext

§ 147 AO / GoBD structured audit context.

OutboxExhausted

The outbox delivery worker gave up after exhausting all retry attempts.

The message was re-queued max_attempts times and never successfully delivered to the AS4 endpoint (or ERP webhook). The message is removed from the outbox and recorded here for regulatory audit.

Fields

message_id: OutboxMessageId

The outbox message ID of the undeliverable message.

message_type: String

The message type (e.g. "APERAK", "CONTRL").

recipient: String

The intended recipient GLN.

last_error: String

The last error returned by the AS4 sender.

attempts: u32

How many delivery attempts were made.

Implementations

impl DeadLetterReason

pub fn label(&self) -> &'static str

Short label identifying the rejection category.

Suitable for structured log fields and metric labels.

pub fn audit_context(&self) -> Option<&AuditContext>

Return the AuditContext embedded in this reason, if present.

OutboxExhausted does not carry an AuditContext because it refers to an outbound message (not an inbound AS4 message).

Trait Implementations

impl Clone for DeadLetterReason

fn clone(&self) -> DeadLetterReason

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DeadLetterReason

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

Formats the value using the given formatter.

impl Display for DeadLetterReason

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

Formats the value using the given formatter.