{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-reject-a-federated-peer-s-capability-grant-despite-a-valid-trust-anchor-signature",
  "title": "In what scenarios must an instance reject a federated peer's capability grant despite a valid trust anchor signature",
  "date_of_record": "2026 November 13",
  "scope": "Applies to cross-organizational multi-agent federations where a local policy translation gateway (PTG) admits remote capability grants that carry a trust-anchor signature from a recognized root. Does not apply to intra-org delegation, where the anchor and the policy authority are the same principal, nor to signed-but-unscoped bearer tokens that bypass the gateway.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-a-federated-peer-s-capability-grant-despite-a-valid-trust-anchor-signature.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-a-federated-peer-s-capability-grant-despite-a-valid-trust-anchor-signature.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-a-federated-peer-s-capability-grant-despite-a-valid-trust-anchor-signature.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1264,
    "python_slice_tokens": 141,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "A trust anchor answers *who* signed a grant. A capability scope answers *what* the grant permits *here*. The two are orthogonal, and the failure mode this record addresses is the conflation of them: a gateway that treats signature validity as sufficient for admission, then translates the remote scope into local policy. The non-obvious invariant is that **a v...",
    "what_was_observed": "During a federation between org A (anchor `A-root`, capability vocabulary `A-cap/2`) and org B (local policy language `B-pol/1`), a peer agent in A requested a grant scoped to `A-cap:read:telemetry[region=eu-west]`. The grant carried a valid `A-root` signature, a correct subject binding, and a non-expired validity window. B's PTG verified the signature, found no exact match for `A-cap:read:telemetry` in `B-pol/1`, an...",
    "condition_of_validity": "The rejection rule is valid when and only when all of the following hold: 1. The remote scope carries at least one qualifier (region, depth, rate, time-window, data-class) that has no exact, semantics-preserving counterpart in the local policy algebra. 2. The local policy algebra is *not* a superset of the remote vocabulary—i.e., the translator cannot expres...",
    "decision_boundary": "The gateway must reject (fail closed) when the translation is *widening and unauthorized*. It must admit when the translation is *exact or narrowing*. It must escalate to human policy review when the translation is *widening but plausibly intended*—i.e., the remote qualifier is present but the local org has a standing exception that might cover it. The bound...",
    "operational_effect": "Fail-closed on widening translation converts a silent privilege-escalation surface into an explicit, auditable rejection. The cost is false rejections when the remote vocabulary is richer than the local one and the peer legitimately needs the broader primitive—those cases route to policy review and a local grant, which is the correct place for the decision. ..."
  },
  "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": "ec2ba3832f32bde5dcbd216f1c72420e8ec8f42a25825f9dddbfb578b54a4b26",
    "verified_classes": [
      "ScopeWideningError"
    ],
    "verified_functions": [
      "admit_federated_grant"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "ScopeWideningError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}