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Lerian SLC is event-first at its edges. It consumes Núclea’s inbound messages. It writes its business facts to a transactional outbox, which delivers them to webhook subscriptions and, when streaming is on, to the platform’s streaming backbone. On the streaming backbone each event is a CloudEvents record. A webhook delivers the event payload as JSON.

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What it consumes

From Núclea, over the RSFN:
  • GEN0015 (a file is available for pickup, which starts the pull of the returns)
  • SLC0001 (clearing preview and final)
  • SLC0002
  • PAG0101 (operational status)
On the SFN inbound bus:
  • From Lerian SILOC, the SILOC cycle and funding messages: PAG0102, PAG0103, and LDL0021.
  • From Lerian SILOC, the gross and bilateral settlement announcements: LTR0001, LTR0007, and LTR0012.
  • The outcome of each settlement command that Lerian SLC sends.
From Núclea over REST, Lerian SLC polls the SLC0915 verdicts, the PRO / ERR / RET returns, and the ASLC return messages. It correlates each return seam by the key the counterparty echoes: a RET line or an SLC0915 verdict by its 20-position control number, an ASLC023 or D+1 line by its NUliquid, and a PRO at file level by the control number of the transmitted file.

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What it emits

Lifecycle events and status relays are written in the same transaction as the state change they report.
  • Operation lifecycle events: one for each state the operation enters, from operation.created to operation.cancelled. operation.manually_advanced reports an audited override. operation.d1_rejected reports a credit that the IF Domicílio refused after it settled.
  • operation.status_relayed: the rail relayed the IF Domicílio’s answer to the credenciadora.
  • operation.forward_rejected: an outbound submission was parked and needs operator action. The payload, not the event name, says which leg and why. stage identifies the affected leg: forward to the IF Domicílio or dispatch to Núclea. In both cases, parkReason is attempt_budget_exhausted. operationIdsScope says whether operationIds is complete for the file or only a sample. GET /v1/operations?transmitHold=parked lists every parked operation.
  • operation.verdict_unresolved: Núclea’s verdict on a submission did not resolve into an acceptance or a refusal, so the operation did not move.
  • Schedule alerts: operation.stuck_detected, d1.missing_confirmation, confirmation.overdue, and schedule.cutoff_approaching.
  • cancellation.confirmed_by_domicile: the IF Domicílio confirmed a cancellation and the event carries the NUliquid.
  • d1.value_mismatch: a D0-versus-D+1 value divergence.
  • certificate.expiring: a certificate approaching expiry.
  • The clearing.* family: cycle_opened, cycle_closed, cycle_recalculated, preview_available, final_available, deposit_required, deposit_deadline_approaching, and divergence_reported.
  • funding.deposit_failed: the client reported that it could not make a deposit.
  • report.request_acknowledged and report.result_available: Núclea acknowledged a report request, or its result is available.
Lifecycle events carry the NUliquid once Núclea assigns it, and so do cancellation.confirmed_by_domicile and d1.value_mismatch. Consumers use it to correlate each operation’s merchant credit and its domicile-return evidence.

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Midaz touchpoint

Lerian SLC is standalone. It does not post to a ledger itself. Midaz is an optional consumer. Midaz can subscribe to Lerian SLC’s events or call its API to mirror settlement into the ledger. Lerian SLC does not depend on Midaz.

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Money-path boundary

Lerian SLC owns the card-settlement messaging with Núclea. It does not perform the monetary settlement itself. The netted position settles at the SLC and Núclea. The reserve leg settles at BACEN. The card-domain deferred-net settlement family reaches Lerian SLC relayed from Lerian SILOC, the participant-side SILOC connectivity.

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API conventions

  • Idempotent intake. Operation intake refuses an externalId that another operation already uses, with 409 and SLC-0104. In a batch, a line with a duplicate externalId is refused alone, and its error names the existing operation.
  • Idempotent writes. Operation intake, batch intake, and the deposit acknowledgement accept an optional X-Idempotency header. The signing-key and settlement-command operations require it and answer 400 without it. A retry that reuses the key within 24 hours receives the stored response, and the request does not run again.
  • Signed webhooks. Lerian SLC signs each webhook with HMAC-SHA256 and sends the signature in X-Webhook-Signature.
  • Online auth. mTLS and a per-request JWS signature secure each individual online operation over REST.
  • Certificates are references, not secrets. A registered certificate carries its public certificate and a custody reference, not the private key.