{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-refuse-delegated-authority-across-a-federation-bridge-when-the-trust-chain-s-attestation-freshness-window-has-expir",
  "title": "In what scenarios must an instance refuse delegated authority across a federation bridge when the trust chain's attestation freshness window has expired",
  "date_of_record": "2026 November 9",
  "scope": "Applies to any agent instance that receives a capability token or delegation grant originating in a foreign trust domain and relayed through a protocol bridge (e.g., an A2A-to-MCP gateway, an OAuth 2.0 Token Exchange shim, or a bespoke SOAP-to-REST adapter). Does not apply to intra-org delegation where the issuer and verifier share a single trust root and a single clock authority.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-refuse-delegated-authority-across-a-federation-bridge-when-the-trust-chain-s-attestation-freshness-window-has-expir.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-refuse-delegated-authority-across-a-federation-bridge-when-the-trust-chain-s-attestation-freshness-window-has-expir.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-refuse-delegated-authority-across-a-federation-bridge-when-the-trust-chain-s-attestation-freshness-window-has-expir.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1594,
    "python_slice_tokens": 220,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure mode is not \"expired credentials.\" Expired credentials are a well-understood, easily-detected condition. The non-obvious boundary is this: **a delegation chain can be structurally valid, cryptographically intact, and nominally within its stated `exp` window, yet still be unusable because the *attestation freshness* of an intermediate bridge is st...",
    "what_was_observed": "During a three-org federation drill (Org A issues capability, Org B bridges A2A→MCP, Org C consumes), the following sequence was recorded: 1. Org A's trust authority rotated its policy epoch at T+00:00, invalidating all bridge attestations issued under epoch `E-1`. 2. Org B's bridge held a cached attestation under `E-1`, valid until T+45:00 by its own local lease. 3. Org C's agent received a delegated capability toke...",
    "condition_of_validity": "A delegated capability relayed through a bridge is *operationally valid* at the consuming instance if and only if all of the following hold simultaneously: - `token.exp > now` (token clock) - `bridge.attestation.issued_at > verifier.policy_epoch_start` (freshness clock) - `bridge.attestation.issuer ∈ verifier.trusted_attestation_issuers` (authority clock) - ...",
    "decision_boundary": "The decision procedure at the consuming instance: The critical branch is the second: **stale attestation is an escalation, not a rejection.** The bridge may be able to re-attest within seconds. Hard-rejecting on stale attestation causes cascading federation failures during routine epoch rotations — a failure mode observed at T+00:05 in the drill when three c...",
    "operational_effect": "Implementing this boundary changes three things: 1. **Bridge attestations become first-class objects** in the consumer's trust store, with their own freshness tracking, independent of token lifetimes. This roughly doubles the state an agent must maintain per active delegation, but it is the only way to detect epoch-relative staleness without a live call to t..."
  },
  "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": "f237018fdfec9c472c6f81c4153b3059903e825902ef5e96d6e436ca491ee3b7",
    "verified_classes": [
      "StaleAttestationError",
      "ScopeCeilingViolation",
      "Attestation",
      "DelegationToken",
      "VerifierPolicy"
    ],
    "verified_functions": [
      "verify_delegation"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "ScopeCeilingViolation",
      "StaleAttestationError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "datetime"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}