---
title: "Mediation, transformation, and delivery assurance"
chapter: "20"
---

# Mediation, transformation, and delivery assurance

Mediation converts technology-specific output into the authorized handover profile while preserving meaning, provenance, ordering, and evidence. Delivery assurance proves more than connectivity: it addresses acceptance, gaps, duplicates, backlog, delay, and safe recovery.

> **Safety boundary:** this chapter teaches lawful, governed system design from
> public standards. It does not provide operational targeting, activation,
> decryption, surveillance-evasion, or covert collection instructions.

## The mental model

| Concept | Plain meaning | Control that must travel with it |
|---|---|---|
| **Normalization** | Maps service-specific objects into agreed handover form | Never silently invent missing meaning |
| **Provenance** | Records source function and transformation version | Keep operational evidence payload-free |
| **Validation** | Checks profile, scope reference, structure, and policy | Malformed authorized data is still unsafe |
| **Delivery queue** | Buffers bounded receiver or network interruption | Capacity and expiry behavior are explicit |
| **Receipt/reconciliation** | Compares sent, accepted, rejected, and replayed objects | Transport ACK is not semantic acceptance |
| **High availability** | Preserves service through component failure | Failover must not duplicate or widen scope |

## Apply it as a controlled workflow

1. Define an immutable transformation specification per input/output version pair.
2. Validate authorization reference and current lifecycle state at intake.
3. Separate IRI and CC processing, storage, keys, and capacity.
4. Use bounded durable queues with sequence and duplicate protection.
5. Exchange privacy-safe receipts and reconcile counts.
6. Test replay, partial acceptance, receiver outage, and disaster recovery.

## Evidence to demand

- Every output can be traced to source and transformation version.
- Unmappable objects are quarantined with visible case impact.
- Backlog age and lawful timing thresholds alert before data loss.
- Failover/replay tests show complete-once semantic outcomes where required.

## Failure to reason about

A mediation upgrade changes how an optional field is represented. Both formats parse, but receiver analytics interpret them differently. Canary synthetic traffic and semantic golden fixtures catch the issue before production.

## Feynman check

Mediation is a careful translator and courier. It must not change the story, lose pages, copy pages twice, or deliver to the wrong reader.