{
  "schema_version": "1.3.0",
  "slug": "where-must-an-instance-refuse-to-bootstrap-a-federation-trust-anchor-from-a-peer-supplied-policy-bundle",
  "title": "Where must an instance refuse to bootstrap a federation trust anchor from a peer-supplied policy bundle",
  "date_of_record": "2026 November 13",
  "scope": "Applies to cross-organization agent federation where an agent instance obtains its trust anchors (signing keys, issuer identities, revocation endpoints) from a policy bundle fetched from a peer organization during join or refresh. Does not apply to single-organization deployments with a pre-provisioned, offline-signed root bundle, nor to pure message-authentication checks performed after anchors are already pinned.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/where-must-an-instance-refuse-to-bootstrap-a-federation-trust-anchor-from-a-peer-supplied-policy-bundle.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/where-must-an-instance-refuse-to-bootstrap-a-federation-trust-anchor-from-a-peer-supplied-policy-bundle.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/where-must-an-instance-refuse-to-bootstrap-a-federation-trust-anchor-from-a-peer-supplied-policy-bundle.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1686,
    "python_slice_tokens": 337,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure is not \"untrusted peer sends bad policy.\" It is the *bootstrap circularity*: an instance that has no pinned anchor must validate the first policy bundle against something. Operators frequently assume the bundle's own signature chain provides that something. It does not. A self-consistent bundle — one whose leaf key signs the bundle, whose interme...",
    "what_was_observed": "During a federation join between two agent meshes, Org B's onboarding endpoint returned a policy bundle containing: a root CA certificate, an intermediate, a leaf signing key for the federation gateway, a policy document listing Org B's revocation endpoint, and an `anchor_epoch` field. Org A's join code called a standard X.509 chain verifier with the bundle's own root as the trust store. Verification passed. The inst...",
    "condition_of_validity": "The invariant holds only when all of the following are true; if any is false, the boundary case does not apply and the standard chain-validation path is sufficient: - The instance has **no prior pinned anchor** for the peer organization (true first join, or anchor store was reset/rebuilt). - The peer policy bundle is delivered over a channel whose authentici...",
    "decision_boundary": "The operational rule is a single predicate evaluated before any chain verification: > A bundle element may be promoted to trust anchor **only if** it is either (a) present in a locally pinned anchor set established by an out-of-band channel (manual pin, offline-signed root, pre-shared fingerprint), or (b) a descendant of such an anchor whose chain terminates...",
    "operational_effect": "Instances that enforce this boundary fail the join loudly and early, with a distinct error class, instead of silently pinning attacker-controlled anchors. The practical cost is that first-join requires an out-of-band step — an operator-supplied fingerprint, an offline-signed root, or a pre-shared anchor manifest — which cannot be eliminated, only relocated. ..."
  },
  "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": "3fce4514e4eff02552e128f7dfec3b45d28fcd32e1e304d1fc676001b4e05e1b",
    "verified_classes": [
      "AnchorBootstrapError",
      "PinnedAnchor",
      "PolicyBundle"
    ],
    "verified_functions": [
      "establish_or_extend_anchor",
      "fingerprint"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 6,
    "raised_exceptions": [
      "AnchorBootstrapError"
    ],
    "sample_fail_closed_invariants": [
      "epoch field not signed by pinned anchor; bundle leaf cannot authorize anchor rotation",
      "out-of-band anchor absent from bundle chain; cannot verify"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "hashlib"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}