buzz/docs/nips/NIP-FI-DELEG.md

NIP-FI-DELEG

Delegated agent authorization profile

draft optional relay

Protocol dependency: NIP-FI core.

The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as described in BCP 14 (RFC 2119 and RFC 8174) when, and only when, they appear in all capitals.

Scope

This profile authorizes a delegate key from separately validated delegation evidence rooted in a currently eligible NIP-FI owner binding. The delegate proves its own key. It does not present a federated assertion and never receives or inherits the owner's binding.

This profile defines the normalized delegation result and its additional preparation, final-admission, and lease witnesses. It does not define a wire format for creating delegation relationships; NIP-OA or another protocol may supply the evidence if it satisfies this contract.

Delegation evidence

A validator returns this closed result:

DelegationEvidence = (
  domain,
  owner_key,
  delegate_key,
  relationship_id,
  relationship_revision,
  audience,
  operations,
  resource_or_target,
  not_before?,
  mandatory_expiry
)

relationship_id and relationship_revision are deployment-local dependency identifiers. All other fields are interoperability-critical in meaning even when their concrete encoding belongs to the supplying delegation protocol.

The evidence authenticates every field, has one unambiguous owner and delegate, matches the server-owned domain and exact request or target, and has a finite expiry. If present, not_before is live. Equality at either temporal boundary is expired. The proven actor equals delegate_key. [FI-DELEG-EVIDENCE-CLOSED]

A delegated request carries fresh request-appropriate Nostr proof and no Nostr-Federated-Identity or profile provenance field. Mixed direct and delegated evidence denies rather than selecting a path. [FI-DELEG-PATH-SEPARATION]

Preparation

Preparation resolves the exact server-owned domain, target context, operation, resource, and proven delegate actor before validating delegation evidence. It then atomically reads:

• the active owner binding and exact binding version;
• every owner tombstone, key-revocation, administrative, and profile lifecycle gate applicable to that binding;
• the exact relationship identifier and revision;
• current local policy and resource versions; and
• every invalidation dependency and deadline.

The owner binding is current and authorization-eligible at preparation. A cached owner lease is not authority. The requested capability is the intersection of the delegation's operation, audience, conditions, and target with current local policy; an unsupported operation or empty intersection denies. [FI-DELEG-OWNER-CURRENT]

Preparation remains read-only under FI-INV-08. It cannot create or change an owner or delegate binding, identity, provenance, lifecycle fact, relationship, last-seen value, replay claim, receipt, lease, or application effect. [FI-DELEG-NO-BINDING]

Final admission

Core final admission additionally requires:

1. the exact delegation evidence and delegate proof remain live;
2. domain, actor, target, audience, operation, resource, and relationship match the prepared value;
3. the exact current owner binding and binding version remain eligible;
4. relationship identity and revision remain current;
5. current capability intersection equals the prepared intersection; and
6. changed dependencies are reread and the complete delegated decision is recomputed before atomic commit.

Any mismatch, expiry, owner retirement, owner key revocation, owner binding version change, relationship change, unreadable dependency, or unsupported capability denies. Rotation makes the former owner key non-current; its relationships do not transfer to the new key. [FI-DELEG-OWNER-CURRENT]

The delegated path creates no owner or delegate binding and cannot consume an enrollment opportunity. Its receipt identifies the delegate actor and exact owner-binding and relationship dependencies without publishing identity material. [FI-DELEG-NO-BINDING]

Delegated leases

A deployment configures a positive finite delegated maximum. The lease deadline is no later than the minimum of:

• delegation expiry;
• delegate proof or connection bound;
• owner binding administrative bound, when applicable;
• current relationship bound;
• local policy bound;
• the configured delegated maximum; and
• any stronger owner-assertion bound the deployment requires.

Missing finite configuration denies. Equality is expired and arithmetic is overflow-safe. [FI-DELEG-LEASE-BOUND]

Before each protected use, the service checks the delegate actor, owner binding and version, relationship and revision, capability intersection, target, resource, local policy, deadline, and invalidation state. It closes or rejects the lease within the deployment's tested revocation-detection bound after any owner or relationship dependency becomes ineligible. The claimed bound is no smaller than measured worst-case detection plus enforcement delay. [FI-DELEG-INVALIDATION-BOUND]

Owner retirement, revocation, rotation, disablement under NIP-FI-LIFECYCLE, or binding replacement invalidates dependent delegates on the same effective schedule as owner authority. A delegate lease never authorizes another delegate or owner key on the same connection. [FI-DELEG-OWNER-CURRENT]

Discovery

A relay claiming this profile MAY add "delegation": true to the NIP-FI object in NIP-11 only when owner-current resolution, the positive finite maximum, uniform final admission, and all profile oracles are active. It does not advertise relationship IDs, owner keys, private delegation protocol names, or policy detail. [FI-DELEG-DISCOVERY]

Behavioral oracles

ID	Required outcome
FI-DELEG-EVIDENCE-CLOSED	Valid closed evidence passes; unauthenticated, ambiguous, wrong-domain/actor/target/audience, not-yet-valid, and expiry-equality variants deny.
FI-DELEG-PATH-SEPARATION	Delegation plus any direct assertion/provenance field denies; neither path falls back to the other.
FI-DELEG-OWNER-CURRENT	Exact current owner succeeds; retirement, revocation, rotation, replacement, stale owner version, stale relationship, and unreadable owner state deny without inheritance.
FI-DELEG-NO-BINDING	Successful, denied, and concurrent delegated requests create or change no owner/delegate binding or lifecycle state.
FI-DELEG-LEASE-BOUND	Every authority bound and equality boundary closes the lease; absent finite maximum denies.
FI-DELEG-INVALIDATION-BOUND	Measured owner/relationship revocation closes prepared evidence and live leases within the claimed detection bound.
FI-DELEG-DISCOVERY	Discovery is false/absent until the complete active profile passes; public output contains no relationship or owner detail.

NIP-FI-CONF defines evidence packaging and mutation adequacy. Each uppercase requirement above names the oracle that detects its violation.

Security considerations

Delegation expands authority only by intersection and never by copying owner capabilities. A stolen delegation still requires the delegate key. A stolen delegate key is bounded by the relationship and finite lease. Owner rotation cannot silently transfer delegation because the exact owner key and binding version are dependencies. Implementations should invalidate by dependency index rather than wait for incidental delegate traffic.