Decisions & Open Questions
Activity Configuration Schema Design System · Sections 7–9
7. Session 3.5 Decisions
ID Decision StatusS3.5-1 The three-layer schema model CLOSED (Capability / Configuration /
Collection) is the normative
structure for all activity
categories in the Activity Travel
Protocol registry. All three layers are required for every category.
S3.5-2 Discriminated union with fragment CLOSED composition is the normative schema architecture. Inheritance is
explicitly rejected. The $uses
syntax is the normative fragment
reference mechanism.
S3.5-3 Fragment Library v1 contains 15 CLOSED fragments as specified in Section
3. Fragment identifiers are stable
across registry versions. New
fragments require a Category
Proposal or Foundation TSC
amendment.
S3.5-4 The IANA registry model governs the CLOSED Activity Category Registry. The
Foundation is the registry
authority.
activitytravel.pro/registry/ is the canonical publication endpoint.
S3.5-5 The Starter Catalogue contains six CLOSED categories: ACCOMMODATION_ROOM,
FARM_EXPERIENCE, SKI_ALPINE,
CULTURAL_EXPERIENCE,
CULINARY_CLASS, ENTRANCE_TICKET.
All SDK implementations must
support all six.
S3.5-6 SafetyCompliance has three modes: CLOSED SOFT_ADVISORY,
HARD_ACKNOWLEDGEMENT,
SUPPLIER_VERIFIED.
HARD_ACKNOWLEDGEMENT produces an
IEventLog entry. SUPPLIER_VERIFIED
additionally requires MCP Server
confirmation by supplier staff.
S3.5-7 SubSupplierDependency uses a CLOSED ResolutionChain of ordered
FulfilmentOptions. The system
attempts each option in rank order. FALLBACK options with
requires_guest_consent == true
require explicit guest consent
before activation.
S3.5-8 PricingRule conditions may CLOSED reference Collection schema field
values using the ATP Condition
Expression Syntax. This enables
measurement-based pricing
(height-dependent gear pricing) and behaviour-based pricing (instructor fee on skill level).
S3.5-9 InventoryFeed fragment with CLOSED feed_type MANUAL causes the SDK to
set an AVAILABILITY_UNVERIFIED flag on the Booking Object. CONFIRMED
state requires operator manual
confirmation before the flag is
cleared.
S3.5-10 The UI Generation Contract is CLOSED normative for the @atp/ui package. Third-party frontend
implementations must produce
equivalent UI behaviour for all
form element types,
SafetyCompliance modes, and
conditional display rules.
S3.5-11 The registry AI query interface at CLOSED activitytravel.pro/registry/query
is a first-class ATP interface.
Field description attributes are
written to AI agent readability
standards and are normative
registry content.
S3.5-12 GearCategory is an open enumeration CLOSED maintained in the registry. v1
values are defined in Section 3,
Fragment 6. New gear categories are added via Category Proposal without requiring a MAJOR schema version
bump.
8. Open Questions
ID Question Priority Owner OQ-AS-1 ATP Condition Expression HIGH Session 6 Syntax v1 covers the field
reference and comparison cases
identified in this document.
Full expression grammar and
parser specification is
deferred to Session 6 (Layer 4
SDK). Is the v1 syntax
sufficient for the Starter
Catalogue PricingRule cases?
OQ-AS-2 HarvestCalendar fragment: MEDIUM Foundation TSC Ponyhouse's produce
availability depends on what
is actually growing at the
time of visit. This is more
specific than
SeasonalAvailability (season
dates) and WeatherDependency
(weather cancellation). A
HarvestCalendar fragment would
allow the operator to declare
current produce and have the
Collection schema present it
to the guest. Defer to
Fragment Library v2?
OQ-AS-3 OCTO Bridge: the registry HIGH Session 4 entry includes an
octo_product_type field for
mapping. The complete mapping
between ATP category schemas
and OCTO product types
requires validation against
the OCTO v2 specification.
This mapping is an input to
Session 4 (MCP Server) and
Session 6 (SDK).
OQ-AS-4 Community namespace: MEDIUM Foundation TSC community-submitted categories
use a namespace prefix (e.g.
atp_community.WINE_TASTING).
The namespace governance rules
— who may claim a namespace,
collision resolution — are
not specified in this
document. Required before the
registry accepts community
submissions.
OQ-AS-5 SUPPLIER_VERIFIED HIGH Session 4 SafetyCompliance uses
atp_record_safety_check MCP
Server tool. This tool is not
yet specified. It is an input
to Session 4 (MCP Server
Specification).
9. Next Session
Session 4 — ATP MCP Server Specification (ATP_MCP_Server_Spec_v1.docx). Inputs from this session: atp_record_safety_check tool (OQ-AS-5), OCTO Bridge product type mapping (OQ-AS-3), atp_collect_pre_arrangement_data tool contract (Section 5, UI Generation Contract), Seasalt.AI integration guide (from ATP_RefImpl_MyAuberge_v1.docx Section 5.3). Upload at session start: ATP_ProjectBrief_v41.docx, ATP_RefImpl_MyAuberge_v1.docx, and ATP_ActivitySchema_v1.docx.
Appendix A — Fragment Dependency Map
The following table shows which Starter Catalogue categories reference which fragments. A filled cell indicates the fragment is referenced by that category.
Fragment ACCOM FARM SKI CULTURAL CULINARY TICKET SeasonalAvailability ✓ ✓ ✓ ✓ ✓ ✓
CapacityModel ✓ ✓ ✓ ✓ ✓ ✓
AgeEligibility ✓ ✓ ✓ ✓ ✓ ✓
GroupSizeConstraint — ✓ ✓ ✓ ✓ ---
MeasurementRecord — — ✓ — — ---
EquipmentAssignment — — ✓ — — ---
SkillLevel — — ✓ — — ---
SafetyCompliance — ✓ ✓ ✓ ✓ ---
DietaryRequirement ✓ ✓ — — ✓ ---
MeetingPoint ✓ ✓ ✓ ✓ ✓ ✓
GuideAllocation — ✓ ✓ ✓ ✓ ---
WeatherDependency — ✓ ✓ — — ---
SubSupplierDependency — — ✓ — — ---
PricingRule — — ✓ — — ---
InventoryFeed — — ✓ — — ✓
Appendix B — Version History
v1.0 April 2026 Initial release --- Track 3 Session 3.5 output. Three-layer schema model defined. Fragment Library v1 (15 fragments). Starter Catalogue (6 categories). UI Generation Contract. IANA-model registry specification. 12 decisions closed. 5 open questions.
Activity Travel Protocol Foundation — ATP_ActivitySchema_v1.docx --- Apache 2.0