{
  "schema_version": "1.3.0",
  "slug": "under-what-conditions-must-an-instance-reject-an-aaif-delegated-credential-chain-whose-scope-appears-to-attenuate-correctly",
  "title": "Under what conditions must an instance reject an AAIF delegated credential chain whose scope appears to attenuate correctly",
  "date_of_record": "2026 November 7",
  "scope": "Applies to AAIF v0.9/v1.0 delegated credential chains (three or more hops) evaluated by a resource server performing scope attenuation checks against a presented chain. Does not apply to single-hop bearer tokens, to root-issued credentials without delegation, or to chains evaluated solely by the issuing authority's introspection endpoint.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-reject-an-aaif-delegated-credential-chain-whose-scope-appears-to-attenuate-correctly.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-reject-an-aaif-delegated-credential-chain-whose-scope-appears-to-attenuate-correctly.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-reject-an-aaif-delegated-credential-chain-whose-scope-appears-to-attenuate-correctly.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1399,
    "python_slice_tokens": 294,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure mode is not \"scope escalation\" in the naive sense of a child scope containing a privilege absent from its parent. It is **scope-name collision under heterogeneous namespace resolution**: two hops in a chain can each appear to attenuate correctly against their immediate parent while the composed chain silently *widens* effective authority, because...",
    "what_was_observed": "A three-hop chain: root `svc:orchestrator` → `svc:planner` → `svc:executor`. The planner hop declared `scope_registry: urn:aaif:reg:planner-local` and requested `[\"data:read\", \"data:write\"]`. The root's registry was `urn:aaif:reg:platform`, where `data:write` denotes append-only writes to an audit log. In `planner-local`, `data:write` was bound to the planner's scratch store. The executor hop inherited `planner-local...",
    "condition_of_validity": "The rejection rule is valid, and must be enforced, precisely when all of the following hold: 1. The chain has length ≥ 3 (a re-homing at hop *n* can only be inherited by hop *n+1*). 2. At least one non-root hop declares a `scope_registry` differing from its parent's. 3. A descendant hop omits `scope_registry` and therefore inherits a re-homed namespace. 4. T...",
    "decision_boundary": "Reject the chain and fail closed. Do **not** attempt to repair it by re-pinning descendant scopes to the root registry: the descendant's intent was expressed in the inherited namespace, and silent re-resolution can *narrow* authority in ways the requester did not authorize, causing downstream partial failures that are harder to diagnose than a clean rejectio...",
    "operational_effect": "Enforcing this rule eliminated a class of one-bit privilege widening that had passed every per-hop verifier in the fleet for the duration of the v0.9 deployment. The cost was a small increase in rejected chains — all traced to delegating services that relied on inheritance-by-omission across a re-homing hop, each fixed by restating the registry. The general ..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "e6b0bf569e8b49bdf1f1543643c88bcf250813079075a9a1ca60ff6e055a7999",
    "verified_classes": [
      "ScopeRegistryDiscontinuityError",
      "Hop"
    ],
    "verified_functions": [
      "verify_chain",
      "admit"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "ScopeRegistryDiscontinuityError"
    ],
    "sample_fail_closed_invariants": [
      "empty chain"
    ],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}