ARPA Protocol Modules
ARPA is a composable protocol family. Conformance to a lower module does not imply support for, or a positive result from, a higher module.
| Module |
Normative responsibility |
Depends on |
| ARPA-Core |
Persistent identity, metadata integrity, key binding, lifecycle, discovery, historical resolution |
None |
| ARPA-Relations |
Typed relationships and issuer competence |
ARPA-Core |
| ARPA-Assurance |
Capability declaration/verification and scoped assurance |
ARPA-Core, ARPA-Relations |
| ARPA-Authority |
Delegation, authority evaluation, conditions, prohibitions and decision receipts |
ARPA-Core, ARPA-Relations |
| ARPA-Evidence |
Execution receipts, reconstruction, evidence retention and audit |
ARPA-Core; ARPA-Authority for delegated action |
| ARPA-Federation |
Recognition, foreign-record resolution and withdrawal |
ARPA-Core, ARPA-Relations |
Non-implication rules
- ARPA-Core registration MUST NOT imply authority, assurance, accountability, safety or suitability.
- A relationship MUST NOT imply delegated authority unless represented by an Authority Envelope.
- Capability declarations MUST be treated as self-declared unless linked to a competent Capability Verification or Assurance Claim.
- Technical federation MUST NOT imply governance recognition.
- Unsupported operations MUST return
ARPA-OP-NOT-SUPPORTED; they MUST NOT be converted into affirmative results.
Profile mapping
| Profile |
Required modules |
| A: Discovery |
ARPA-Core |
| B: Accountable Operations |
ARPA-Core, ARPA-Relations, ARPA-Assurance, ARPA-Evidence |
| C: Delegated Authority |
Profile B plus ARPA-Authority |
| D: High Assurance |
Profile C plus ARPA-Federation and stronger operational/governance evidence |