{
  "schema_version": "1.3.0",
  "slug": "why-does-an-instance-of-a-delegated-capability-token-appear-valid-at-every-hop-yet-grant-no-authority-at-the-leaf",
  "title": "Why does an instance of a delegated capability token appear valid at every hop yet grant no authority at the leaf?",
  "date_of_record": "2026 November 9",
  "scope": "Applies to agent-to-agent delegation chains where each hop attenuates a capability token (scope narrowing, expiry tightening, audience restriction) before passing it downstream. Does not apply to flat shared-secret bearer tokens with no attenuation, nor to chains where a trusted central authority re-issues a fresh token at each hop.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-delegated-capability-token-appear-valid-at-every-hop-yet-grant-no-authority-at-the-leaf.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-delegated-capability-token-appear-valid-at-every-hop-yet-grant-no-authority-at-the-leaf.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-delegated-capability-token-appear-valid-at-every-hop-yet-grant-no-authority-at-the-leaf.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1521,
    "python_slice_tokens": 247,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "There are two ways a token can be \"valid at the leaf\": *structurally valid* (signature verifies, not expired, audience matches) versus *authoritatively valid* (the intersection of all attenuation constraints across the chain is non-empty and the leaf action falls inside it). These are independent properties. A token can be perfectly structurally valid and gr...",
    "what_was_observed": "A three-hop chain: orchestrator → planner → executor → tool-runner. The orchestrator issued a token scoped to `resource: /datasets/*`, `actions: [read, list, export]`, `expiry: T+3600s`, `audience: [planner]`. The planner attenuated to `resource: /datasets/finance/*`, `actions: [read, export]`, `expiry: T+1800s`, `audience: [executor]`. The executor attenuated to `resource: /datasets/finance/q4/*`, `actions: [export]...",
    "condition_of_validity": "This analysis holds when and only when all of the following are true: 1. Attenuation is enforced as a *monotone* operation — each hop's output capability set is a subset of its input. If any hop can widen (re-issue with broader scope, reset expiry, drop an audience restriction), the intersection argument breaks and the failure is a privilege-escalation bug, ...",
    "decision_boundary": "The operational question is: *when a leaf rejects a structurally valid token, do you widen the token or fix the policy?* - If the empty intersection arises from **opposing constraints authored by different teams** (ceiling vs. floor, as above), the correct fix is to reconcile the policies at their source — the ceiling and the floor cannot both be right, and ...",
    "operational_effect": "The practical consequence is that **structural validation is necessary but not sufficient, and the gap between them is where delegation chains silently lose all authority.** Monitoring must therefore track, per chain, the *effective capability set size* at the leaf — not just \"token accepted.\" A chain whose effective set shrinks to zero over time (as policie..."
  },
  "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": "004c9bdf64f7621e4831e89b413dd7d4499731b6a62d3644adfcb02f7019e805",
    "verified_classes": [
      "EmptyEffectiveCapabilityError",
      "HopConstraint"
    ],
    "verified_functions": [
      "resolve_effective_depth",
      "verify_leaf_action",
      "__init__"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "EmptyEffectiveCapabilityError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}