{
  "schema_version": "1.3.0",
  "slug": "which-invariants-prevent-cross-vendor-agent-authentication-failures-under-aaif-attestation",
  "title": "Which invariants prevent cross-vendor agent authentication failures under AAIF attestation",
  "date_of_record": "2026 November 13",
  "scope": "This record applies to agent-to-agent authentication flows where a calling agent presents an AAIF (Agent Attestation & Identity Framework) attestation chain to a relying-party agent operated by a different vendor. It does not apply to intra-vendor agent meshes that share a single trust root, nor to human-delegated OAuth flows where the agent is merely a token custodian.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/which-invariants-prevent-cross-vendor-agent-authentication-failures-under-aaif-attestation.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/which-invariants-prevent-cross-vendor-agent-authentication-failures-under-aaif-attestation.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/which-invariants-prevent-cross-vendor-agent-authentication-failures-under-aaif-attestation.warrant.json"
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  "token_profile": {
    "full_markdown_tokens": 1628,
    "python_slice_tokens": 318,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between *attestation validity* and *attestation authority scope*. An AAIF attestation can be cryptographically valid — correct signature chain, unexpired, well-formed claims — while being issued by a root whose authority does not extend to the asserted capability. Most cross-vendor failures are not signature failures. They are **a...",
    "what_was_observed": "In a cross-vendor integration between two AAIF-conformant agent runtimes, agent A (vendor X) presented a valid attestation chain to agent B (vendor Y). The chain verified cleanly: root → intermediate → leaf, all signatures correct, all validity windows satisfied. B accepted the attestation and granted a capability scoped to \"read-only corpus access.\" The failure surfaced three days later. Vendor X had rotated its int...",
    "condition_of_validity": "The invariant holds — that is, cross-vendor authentication is safe — only when all of the following are simultaneously true: 1. Every certificate in the AAIF chain carries an explicit `aaif.authority_scope` extension enumerating the claim classes it may assert or transitively delegate. 2. The relying party evaluates the authority-scope intersection *at decis...",
    "decision_boundary": "The operational decision is whether to **fail closed on authority-scope gaps** or to **fall back to a weaker but well-defined trust posture**. The boundary: - If the requested capability is *read-only, idempotent, and reversible*, a relying party may proceed under a degraded posture (treat the attestation as workload-identity-only, drop all posture claims, l...",
    "operational_effect": "After the incident, vendor Y's relying party was changed to compute the authority-scope intersection per request and to reject when any authorization-driving claim is not covered by every certificate's scope extension. The practical effects: - Trust-bundle caches were split: signature-verification bundles (cacheable, long TTL) separated from authority-scope ..."
  },
  "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": "3efc92da1b0b356b78985e464e4c2c7a94a617c1979d74f005d91ea4617b4430",
    "verified_classes": [
      "AuthorityScopeGap",
      "Certificate",
      "Attestation"
    ],
    "verified_functions": [
      "verify_authority"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "AuthorityScopeGap"
    ],
    "sample_fail_closed_invariants": [
      "empty attestation chain",
      "attestation claims expired at decision time"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}