> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Integrating with Lerian SILOC

> Integrating with Lerian SILOC: opt-in SFN ingestion, supported-message dispatch, participant CloudEvents, and API conventions.

Lerian SILOC is event-driven at its edges. When enabled, it consumes supported SFN messages from Nuclea and emits participant facts onto the platform. It has **no client-facing webhook consumers**. Downstream systems subscribe to the streaming topics rather than receive callbacks.

## What it consumes

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SFN ingestion is opt-in: `SFN_INGEST_ENABLED` defaults to `false`, so the consumer starts only when you explicitly enable it. When enabled, Lerian SILOC decrypts and decodes inbound messages from the regulated envelope and accepts `PAG0102`, `LDL0021`, `LDL0020`/`LDL0020R2`, `LDL0006`/`LDL0006R2`, and `PAG0103`. It does **not** route `PAG0101`.

## Ingestion and delivery semantics

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* Delivery and dispatch are **at-least-once**. For a successfully decoded, supported message with a nonblank `BCMSG.NUOp`, the durable deduplication key is **(`BCMSG.NUOp`, `CodMsg`)**, not a message ID alone.
* The service writes that processed-message record only after a successful dispatch. It creates no processed-message record for an undecoded or unsupported message. A failure before the record is written can result in another delivery, so this behavior is not an unconditional end-to-end exactly-once guarantee.

## What it emits

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* **Participant facts** — `siloc.participant.registered` and `siloc.participant.updated` — published as CloudEvents on the platform's streaming backbone. Downstream systems track the participant directory without polling.

## No Midaz touchpoint

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Lerian SILOC has **no** direct ledger integration. It holds no accounting position and performs no monetary arithmetic. It routes bytes and emits facts. This rail does not book money. The settlement of the net position happens at SILOC and the STR. Any ledger posting lives with the service that owns the money movement.

## Money-path boundary

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The separate STR rail, [Lerian SPB](/en/rails/native/spb/what-is-lerian-spb), executes the **STR deposit leg** — the monetary settlement at BACEN. SILOC does not. Lerian SILOC carries the SILOC messages and administers the connection. It never moves money.

## API conventions

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* **Base path** is `/api/v1/siloc`, and errors follow the RFC 9457 problem-detail format.
* **Auth** follows the platform's standard bearer-token scheme.
* **Participant registration is idempotent** through an idempotency key, so a retried registration does not create a duplicate.
* **Certificates are references, not secrets.** A registered certificate carries a public certificate and an external custody reference. It stores or returns no private key.