Augment-existing adoption

The augment-existing adopter already has consumers: EN 18222 clients, UNTP tooling, or both. The adoption adds the neutral core behind a translation edge and changes nothing the consumers see. unidpp-gateway runs in front of one unidpp-issuer and renders the same core state through both foreign protocol bindings.

This path implements Part 10 (client retrieval) in its binding- plural form: one capability, two protocols, one identity. The gateway’s integration surface is the documented binding set; the issuer behind it implements Part 2.

What the adopter holds

• The unidpp-issuer binary (the core that fronts the old system’s successor), and
• The unidpp-gateway binary, pointed at it.

The quickstart

The exercised form is unidpp-demo quickstart gateway in unidpp-e2e (CI test 8):

$ UNIDPP_ISSUER_BIND=127.0.0.1:18521 \
  UNIDPP_ISSUER_STATE_FILE=issuer-journal.jsonl unidpp-issuer &
$ UNIDPP_GATEWAY_BIND=127.0.0.1:18522 \
  UNIDPP_ISSUER_URL=http://127.0.0.1:18521 unidpp-gateway &
unidpp-gateway: issuer upstream http://127.0.0.1:18521

# EN 18222 consumers, unchanged:
$ curl -s http://127.0.0.1:18522/en18222/v1/dppsByProductId/4006381333931 \
    | jq .uniqueProductIdentifier
"4006381333931"

# UNTP consumers, unchanged:
$ curl -s http://127.0.0.1:18522/untp/product/4006381333931 \
    | jq '.passport.productIdentifiers[0].value'
"(01)4006381333931"

The two answers are the same identity in two spellings (the GS1 AI-delimited form UNTP carries and the bare key EN 18222 carries. The quickstart asserts exactly this parity, and that a passport newly issued at the upstream serves through the binding under its passport id.

The ingest direction

The gateway also runs the import direction: POST /untp/ingest accepts a UNTP passport (VC or triad) and mints a core passport with a deterministic identity, idempotent per subject. An adopter whose existing assets are UNTP documents can pull them in rather than re-issue.

The reversibility check

The quickstart’s closing step removes the gateway and confirms the upstream issuer is whole: no state was lent out, and none needs returning. The adoption is additive and reversible by construction. For a sustained deployment of the same edge, see federation gateway.