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Lerian SLC runs against two constraints of Nuclea’s SLC: rigid daily settlement windows, and regulated ICP-Brasil credentials. The rail enforces the windows, holds the credentials in client custody, and reconciles at several grains.

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Settlement windows and grade horária

Nuclea’s SLC settles on rigid daily windows set by its grade horária. Lerian SLC evaluates each window as OPEN, PRE_CUTOFF, or CLOSED, and gates dispatch on the result. The rail holds an operation submitted outside its window in the QUEUED state. It dispatches the operation when the window opens. This avoids Nuclea’s out-of-window rejection (ESLC0029). Lerian SLC raises a proactive alert as a window approaches its cutoff.

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Certificates and custody

Lerian SLC delegates signing to a client-controlled custody backend. The client’s private key never enters the rail. The signing credential is an ICP-Brasil A1, RSA-2048 certificate. You select the custody backend per deployment: a software key, a PKCS#11 HSM, or a cloud KMS.
  • SaaS deployments lock custody to a cloud KMS. The client wraps the private key locally and imports it. The rail then stores only the public certificate and a key reference.
  • Rotation is atomic. The client resolves the active certificate at connection time, so a rotation takes effect transparently.
  • Expiry alerts escalate at 30, 15, 7, and 1 day before expiry. The rail emits each one as a certificate.expiring event.

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Contingency and recovery

  • Dead-letter queue. The rail parks any inbound RSFN message it cannot process. It holds the message for review and never drops it.
  • Retransmit and recovery endpoints. An operator can retransmit a transmitted file. The recovery endpoints re-run dispatch, forwarding, and status polling. An outbound operation is parked with an alert instead of retrying forever, for one of two reasons that depend on the leg. A file forwarded to the IF Domicílio parks when one response is classified as final. A file dispatched to Núclea parks when consecutive refusals exhaust its transmit-attempt budget. The un-park endpoint is the only way out: it returns the operation to the eligible backlog so the next tick re-drives it. It does not reset the attempt counter — that zeroes only after a submit succeeds, so un-parking without fixing the cause parks the operation again on the next refusal.

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Reconciliation

Lerian SLC reconciles at several grains so state never drifts:
  • Per operation — the rail tracks each operation by its NUliquid.
  • Per file — the rail tracks each file through its lifecycle and its returns.
  • Per NUliquid — the settlement identifier stays queryable for 30 days.
  • Per clearing cycle — the rail tracks the clearing net position per cycle and stage. It reports a bilateral divergence. It detects a D0-versus-D+1 value divergence on the D+1 confirmation and flags it.