{
  "schema_version": "1.3.0",
  "slug": "when-must-a-federation-gateway-refuse-to-honor-a-peer-s-trust-anchor-after-policy-renegotiation",
  "title": "When must a federation gateway refuse to honor a peer's trust anchor after policy renegotiation?",
  "date_of_record": "2026 November 6",
  "scope": "Applies to cross-organization multi-agent federations where interoperability is governed by a negotiated policy document and each peer presents a trust anchor (root CA or signing key) that authorizes its agents. Does not apply to single-org meshes, or to federations where trust anchors are immutable for the lifetime of a session.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-a-federation-gateway-refuse-to-honor-a-peer-s-trust-anchor-after-policy-renegotiation.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-a-federation-gateway-refuse-to-honor-a-peer-s-trust-anchor-after-policy-renegotiation.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-a-federation-gateway-refuse-to-honor-a-peer-s-trust-anchor-after-policy-renegotiation.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1227,
    "python_slice_tokens": 140,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure mode is not \"the peer is untrusted.\" It is \"the peer is trusted under a policy that is no longer the policy in force.\" Trust anchor validity and policy validity are two independent axes. A trust anchor can remain cryptographically valid (unexpired, correctly signed, unrevoked) while the *policy envelope* it was issued under has been superseded by...",
    "what_was_observed": "In a three-party federation (Org A gateway, Org B gateway, Org C agent acting as a delegated caller), Org B renegotiated its policy envelope at T+40s to add a constraint: delegated agents from Org C may not invoke Org A's `export` capability unless Org C's anchor carries the `data-sovereignty` extension. The renegotiation completed successfully at the policy layer. Org B's gateway updated its active policy. Org C's a...",
    "condition_of_validity": "A trust anchor remains honorable after policy renegotiation **only if** the anchor's embedded policy reference (policy hash, epoch counter, or envelope identifier) is re-checked against the active policy at the moment of authorization — not at session establishment. If the anchor carries no policy reference, or if the reference is checked only at handshake, ...",
    "decision_boundary": "The gateway must choose between two actions when it detects `anchor.policy_epoch < active_policy.epoch` for a constrained capability: 1. **Reject and force renegotiation** — safe, but causes a session reset and loses in-flight agent state. 2. **Honor the anchor under the old policy for unconstrained capabilities, reject only the constrained ones** — preserve...",
    "operational_effect": "The operational consequence is that policy renegotiation is not a control-plane-only event. It has a data-plane footprint: every in-flight authorization decision made after the renegotiation must carry the policy epoch it was evaluated under, and any decision whose epoch is stale for a constrained capability must be invalidated retroactively (or, if already ..."
  },
  "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": "3c90df25bd6225205247033aa73bad898a8ce397a6f2e532d37c257dddfcf560",
    "verified_classes": [
      "StalePolicyBindingError",
      "TrustAnchor",
      "ActivePolicy"
    ],
    "verified_functions": [
      "authorize"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "StalePolicyBindingError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}