{
  "schema_version": "1.3.0",
  "slug": "why-does-an-instance-refuse-a-delegation-token-that-its-own-aaif-issuer-considers-valid-clock-skew-induced-grant-narrowing-at-the-authority-boundary",
  "title": "Why does an instance refuse a delegation token that its own AAIF issuer considers valid: clock-skew-induced grant narrowing at the authority boundary",
  "date_of_record": "2026 November 13",
  "scope": "Applies to AAIF (Agent Authority Issuance Framework) delegation tokens whose `not_before`/`not_after` windows gate least-privilege tool grants, where the verifying resource server and the issuing authority maintain independent clocks and the token carries a narrowed grant set. Does not apply to tokens validated solely against a centralized time oracle, nor to symmetric-key tokens where expiry is enforced only at the issuer.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/why-does-an-instance-refuse-a-delegation-token-that-its-own-aaif-issuer-considers-valid-clock-skew-induced-grant-narrowing-at-the-authority-boundary.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-refuse-a-delegation-token-that-its-own-aaif-issuer-considers-valid-clock-skew-induced-grant-narrowing-at-the-authority-boundary.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-refuse-a-delegation-token-that-its-own-aaif-issuer-considers-valid-clock-skew-induced-grant-narrowing-at-the-authority-boundary.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1598,
    "python_slice_tokens": 307,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The distinction that matters is between *token validity* and *grant admissibility*. A delegation token can be cryptographically valid (signature good, issuer trusted, within its declared `not_before`/`not_after` interval as measured by the issuer) while simultaneously being inadmissible at the resource server because the resource server's clock places the cu...",
    "what_was_observed": "In a deployment where the AAIF issuer ran on a host synchronized to a stratum-2 NTP source and a fleet of tool-executing resource servers synchronized to a different, higher-latency source, roughly 0.4% of delegated tool invocations were rejected with `grant_not_yet_admissible` or `grant_expired` despite the issuing authority's introspection endpoint returning `active: true` for the same token. The divergence was bou...",
    "condition_of_validity": "The boundary failure is valid (i.e., the reasoning holds) only when all of the following are true: 1. The token carries at least one grant whose internal TTL is strictly shorter than the token's own `not_after - not_before` interval. 2. Grant admissibility is evaluated against the verifier's local clock rather than a time value asserted by the issuer inside ...",
    "decision_boundary": "The operational decision is whether to treat a grant-window rejection as (a) a hard denial requiring re-delegation, or (b) a transient skew artifact warranting a bounded retry or a skew-tolerant re-evaluation. The correct boundary: if the *enclosing token* is within its validity window as measured by the verifier, and the *only* failing predicate is a narrow...",
    "operational_effect": "The practical consequence is that AAIF-scoped delegation with least-privilege grants requires the verifier to carry an explicit, configured `max_clock_skew` and to evaluate grant windows against `issuer_embedded_time ± max_clock_skew`, not against an unbounded local clock. Without this, the system exhibits a rejection rate proportional to `grant_ttl / clock_..."
  },
  "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": "7bf3a4931cec48a18b40c5d15cf6251d221a640b8f8ed361b852a7e0d8ecb706",
    "verified_classes": [
      "GrantAdmissibilityError",
      "Grant",
      "DelegationToken"
    ],
    "verified_functions": [
      "admit_grant",
      "admit_all"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "GrantAdmissibilityError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "time"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}