ARPA–TRQP Interoperability Architecture

Status: Informative companion to ARPA Candidate v0.10.0
Profile: arpa-trqp-query-projection-0.1

Purpose

ARPA and TRQP address different layers of a trust-registry system. ARPA governs agent identity, relationships, delegated authority, recognition, lifecycle state, evidence, events, enforcement convergence, federation, and redress. TRQP provides a minimal, read-only interface for asking authorization and recognition questions of an authoritative system of record.

The integration is therefore a governed query projection, not protocol adoption, merger, derivation, or transfer of normative authority.

ARPA records + lifecycle + policy + evidence
                  |
                  v
       ARPA–TRQP projection adapter
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                  v
      TRQP authorization / recognition

Authority boundary

Concern	ARPA responsibility	TRQP-facing responsibility
State creation and mutation	Defines registration, delegation, suspension, revocation and recognition lifecycle	None; query only
Authorization	Evaluates bounded authority, status, conditions and prohibitions	Returns a portable answer derived from current authoritative state
Recognition	Stores scoped, time-bound and withdrawable recognition	Returns whether one authority recognizes another for an action and resource
Evidence	Retains source records, receipts, event history and proofs	May expose references in response details
Discovery	Publishes registry capabilities and optional endpoint metadata	Uses a declared endpoint; no mandatory registry-of-registries is inferred
Conformance	ARPA profiles and evidence	Separately declared TRQP endpoint/consumer conformance

ARPA conformance does not imply TRQP conformance. TRQP conformance does not imply ARPA conformance.

Authorization sequence

sequenceDiagram
  participant C as TRQP Consumer
  participant P as Projection Adapter
  participant R as ARPA Registry
  participant E as ARPA Evaluator
  C->>P: POST /authorization
  P->>R: Resolve agent, envelope, status and evidence
  R-->>P: Current authoritative records
  P->>E: Evaluate action, resource and context
  E-->>P: Decision receipt
  P-->>C: TRQP-compatible response + evidence details

An affirmative response is prohibited when authority is expired, revoked, suspended for the requested operation, outside delegated scope, stale where freshness is required, unsupported, or materially conflicting.

Recognition sequence

sequenceDiagram
  participant C as TRQP Consumer
  participant P as Projection Adapter
  participant R as ARPA Registry
  C->>P: POST /recognition
  P->>R: Resolve recognition record and current status
  R-->>P: Scope, validity, withdrawal and provenance
  P-->>C: TRQP-compatible recognition response

Recognition is explicit, scoped, non-transitive by default, and does not transfer authority. Technical federation does not imply governance recognition.

Historical/as-of projection

ARPA v0.9.4 makes historical authority resolution explicit. When a TRQP-facing query carries a requested time, an ARPA projection SHOULD preserve the distinction between the requested historical time and the later evaluation time, resolve ARPA state at the requested time, and retain current-state/later-event context in ARPA evidence where the TRQP response surface cannot carry it directly.

A projected affirmative historical result MUST NOT be interpreted as a claim that the subject remains authorized or recognized now. Likewise, a later revocation, compromise, supersession, or recognition withdrawal MUST NOT silently rewrite historical ARPA state unless an applicable governance rule or authoritative event declares retroactive effect.

The projection adapter MUST disclose information loss where TRQP cannot carry ARPA’s reconstruction status, selected record versions, later material events, retention boundary, or evidence-integrity status. ARPA and TRQP conformance remain independently declared.

Lifecycle projection

ARPA state	Query class	Required interpretation
active	Affirmative only when all other checks pass	Current evidence required
suspended	Negative	Temporary inactivity must be visible
revoked	Negative	Revocation evidence retained
expired	Negative	Validity window ended
unknown	Indeterminate	No reliable state available
conflicting	Indeterminate	Conflict must not be resolved optimistically
unavailable	Indeterminate	Source failure is not affirmative trust

Discovery declaration

An ARPA registry may publish an optional trqp capability block containing endpoint, version, query types, projection profile, governance profile and security profile. This is an ARPA interoperability declaration. It is not a mandatory TRQP discovery architecture.

Information loss

TRQP core answers cannot carry the full ARPA delegation path, conditions, prohibitions, lifecycle history, enforcement acknowledgements or redress context. The mapping therefore records information loss and includes evidence references in response details where supported.

Conformance and assurance

The repository validates the mapping, safety rules, positive and negative vectors, two independent projection implementations, networked endpoint behavior, durable event handling and evidence reproducibility. The current normative ARPA source baseline is Candidate v0.10.0; this TRQP document remains an informative interoperability companion. These results demonstrate the supplied candidate implementation package only. They do not constitute certification, legal recognition, universal interoperability, or formal approval by the TRQP project.