{
  "schema_version": "1.3.0",
  "slug": "why-does-an-instance-of-a-delegated-credential-chain-fail-scope-narrowing-validation-when-the-parent-token-is-refreshed-mid-chain",
  "title": "Why does an instance of a delegated credential chain fail scope-narrowing validation when the parent token is refreshed mid-chain",
  "date_of_record": "2026 November 12",
  "scope": "Applies to AAIF delegated credential chains where a child token's scope is a strict subset of its parent's scope and the parent is subject to automatic refresh or rotation. Does not apply to chains where all tokens share a single fixed lifetime or where scope is evaluated only at chain issuance time.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-delegated-credential-chain-fail-scope-narrowing-validation-when-the-parent-token-is-refreshed-mid-chain.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-delegated-credential-chain-fail-scope-narrowing-validation-when-the-parent-token-is-refreshed-mid-chain.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-delegated-credential-chain-fail-scope-narrowing-validation-when-the-parent-token-is-refreshed-mid-chain.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1374,
    "python_slice_tokens": 189,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "A delegated credential chain is not a snapshot of authorization; it is a live graph of references. Each child token carries a pointer to its parent and a declared scope that must remain a subset of the parent's *current* scope at every validation, not merely at issuance. The non-obvious boundary is this: **scope-narrowing is a relation over time, not a relat...",
    "what_was_observed": "During a routine parent-token rotation (triggered by a 15-minute refresh cadence), a three-hop chain — orchestrator → sub-agent → tool-proxy — began rejecting tool-proxy calls with `scope_not_subset` errors despite identical request scopes. The child token's declared scope was `read:dataset/{id}` with an explicit numeric id. The refreshed parent carried `read:dataset/*`, which the validator normalized by expanding wi...",
    "condition_of_validity": "The scope-narrowing invariant `child.scope ⊆ parent.scope` holds only when the following conditions are simultaneously true: 1. **Normalization is idempotent and version-stable.** The function that maps a declared scope to a comparable set must produce the same output for the same input across all hops and all validation times. If wildcard expansion depends ...",
    "decision_boundary": "The operator must choose between two policies at the refresh boundary, and the choice is not free: - **Pin-and-revalidate:** Children pin the parent version. On parent refresh, the chain validator re-runs the subset check against the new parent and, on failure, either (a) rejects the child (safe, but causes spurious outages on benign rotations) or (b) re-iss...",
    "operational_effect": "The practical consequence is that delegated chains must treat scope as a *versioned artifact*, not a property. Validators that compare scopes by re-deriving them from live state will exhibit rotation-correlated, hop-count-amplified, non-deterministic rejections that are invisible in single-hop tests and absent in static-lifetime deployments. The failure surf..."
  },
  "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": "681c883282b4850ec0291cd9b74f0a27004480fad7ced17cedde7a5a8c114cc9",
    "verified_classes": [
      "ScopeNarrowingViolation"
    ],
    "verified_functions": [
      "validate_delegated_chain",
      "refresh_parent_and_validate"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "ScopeNarrowingViolation"
    ],
    "sample_fail_closed_invariants": [
      "scope normalization is not idempotent; subset relation is undefined across hops"
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}