feat: support TAP trust advertisement

Author: nkavian

README.md

@@ -85,6 +85,8 @@ async def main() -> None:
         inspection = await service.inspect()
         print(inspection.document.name)
         print([operation.name.value for operation in inspection.document.operations])
+        protocols = inspection.document.protocols
+        print([protocol.name.value for protocol in protocols.trust] if protocols else [])
 
         page = await service.search_offerings(
             OfferingSearchRequest(query="plant"),
@@ -200,7 +202,7 @@ a fragment reference such as `#node`.
 `Service.handle()`, and copy the returned status, headers, and body into the framework response.
 
 ```python
-from offering_protocol.core import Collection, Offering
+from offering_protocol.core import Collection, Offering, Protocol, TrustProtocol
 from offering_protocol.service import ServiceBuilder, StaticCatalog, StaticCatalogOptions
 
 catalog = StaticCatalog(
@@ -226,6 +228,7 @@ service = (
         endpoint_base="/odp",
     )
     .keywords(["houseplants", "indoor-plants"])
+    .protocols([], [], [TrustProtocol(name=Protocol.TAP)])
     .website_url("https://example.com")
     .build(catalog)
 )
@@ -245,9 +248,9 @@ See [examples/README.md](./examples/README.md) for a runnable Service and Agent.
 ## Protocol composition
 
 ODP discovers what a Service offers and how an Agent can act on an Offering. A Service document and
-its Actions can advertise AEP enrollment and MPP or x402 payment requirements, but ODP does not
-create credentials, invoke Actions, or submit payments. Applications compose the appropriate
-enrollment and payment client around an Action resolved through ODP.
+its Actions can advertise enrollment, payment, and trust protocols, but ODP does not create
+credentials, invoke Actions, submit payments, or implement trust protocols. Applications compose
+the appropriate protocol clients around an Action resolved through ODP.
 
 ## Errors and validation
 

src/offering_protocol/service/service.py

@@ -31,6 +31,7 @@
     ServiceDocument,
     ServiceOpenApi,
     ServiceProtocols,
+    TrustProtocol,
     is_local_resource_identifier,
     parse_collection,
     parse_collection_page,
@@ -155,13 +156,18 @@ def payment_origins(self, values: list[str]) -> ServiceBuilder:
         return self._updated(payment_origins=values)
 
     def protocols(
-        self, enrollment: list[EnrollmentProtocol], payments: list[PaymentProtocol]
+        self,
+        enrollment: list[EnrollmentProtocol],
+        payments: list[PaymentProtocol],
+        trust: list[TrustProtocol] | None = None,
     ) -> ServiceBuilder:
         values: dict[str, object] = {}
         if enrollment:
             values["enrollment"] = enrollment
         if payments:
             values["payments"] = payments
+        if trust:
+            values["trust"] = trust
         return self._updated(protocols=ServiceProtocols.model_validate(values))
 
     def search_capabilities(self, value: SearchCapabilities) -> ServiceBuilder:

tests/helpers.py

@@ -41,7 +41,8 @@ def response(
   "operations":[
     {"authentication":"not-required","name":"get-offering"},
     {"authentication":"not-required","name":"list-offerings"}
-  ]
+  ],
+  "protocols":{"trust":[{"name":"tap"}]}
 }"""
 
 OFFERING = """{

tests/test_agent.py

@@ -52,6 +52,7 @@
     MissingPlacement,
     OfferingSearchRequest,
     OpenApiActionTarget,
+    Protocol,
     SearchCapabilities,
     SortCapabilitySource,
     SortDefinition,
@@ -99,6 +100,8 @@ async def test_inspects_support_before_fetching_and_caches_document() -> None:
     first = await client.inspect()
     second = await client.inspect()
     assert first.freshness is Freshness.FETCHED
+    assert first.document.protocols is not None
+    assert first.document.protocols.trust[0].name is Protocol.TAP
     assert second.freshness is Freshness.FRESH
     assert (await client.get_offering("rubber-plant")).name == "Rubber Plant"
     assert transport.requests[-1].url.endswith("/odp/offerings/rubber-plant?representation=full")

tests/test_service.py

@@ -18,6 +18,7 @@
     PaymentProtocol,
     Protocol,
     Representation,
+    TrustProtocol,
 )
 from offering_protocol.service import (
     MEDIA_TYPE,
@@ -76,7 +77,11 @@ def _service(catalog: Catalog | None = None) -> Service:
         .status_url("/status")
         .payment_origins(["https://demo.inflowpay.ai"])
         .operation_authentication(Operation.GET_OFFERING, AuthenticationRequirement.REQUIRED)
-        .protocols([EnrollmentProtocol(name=Protocol.AEP)], [])
+        .protocols(
+            [EnrollmentProtocol(name=Protocol.AEP)],
+            [],
+            [TrustProtocol(name=Protocol.TAP)],
+        )
         .build(catalog or _catalog())
     )
 
@@ -87,6 +92,7 @@ async def test_serves_document_offerings_and_collections() -> None:
     document = await service.handle(Request("GET", "/.well-known/odp"))
     assert document.status == 200
     assert json.loads(document.body)["name"] == "Indica Flowers"
+    assert json.loads(document.body)["protocols"]["trust"] == [{"name": "tap"}]
     assert service.document.operations[0].authentication is AuthenticationRequirement.REQUIRED
     offerings = await service.handle(
         Request("GET", "/odp/offerings", headers={"Accept": MEDIA_TYPE}, query="limit=1")