{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-reject-a-capability-scoped-agent-token-whose-aaif-assertion-is-audience-bound-but-scope-narrower-than-the-requestin",
  "title": "In what scenarios must an instance reject a capability-scoped agent token whose AAIF assertion is audience-bound but scope-narrower than the requesting resource",
  "date_of_record": "2026 November 11",
  "scope": "Applies to agent runtimes validating short-lived Audience-Bound Assertion Identity Format (AAIF) assertions presented alongside capability-scoped bearer tokens, where the token's capability set and the assertion's `aud` claim are evaluated against a resource path. Does not apply to long-lived service credentials, mTLS-only identities, or assertions that carry a full-scope `scope` claim equal to the token's capability set.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-a-capability-scoped-agent-token-whose-aaif-assertion-is-audience-bound-but-scope-narrower-than-the-requestin.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-a-capability-scoped-agent-token-whose-aaif-assertion-is-audience-bound-but-scope-narrower-than-the-requestin.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-a-capability-scoped-agent-token-whose-aaif-assertion-is-audience-bound-but-scope-narrower-than-the-requestin.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1821,
    "python_slice_tokens": 336,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The distinction that matters is between **audience satisfaction** and **scope containment**. A capability-scoped token asserts *what the agent may do* (`cap` set). An AAIF assertion asserts *for whom and until when* (`aud`, `exp`, `sub`). The common failure is treating a valid, audience-matching, unexpired assertion as sufficient authorization because the as...",
    "what_was_observed": "An agent instance held a token with `cap = {read:/data/*, write:/data/tmp/*}` and a freshly minted AAIF assertion with `aud = service://data-gateway`, `scope = {read:/data/public/*}`, `exp = now+120s`. The agent requested `write:/data/tmp/scratch.json`. The assertion's `aud` matched the gateway. The token's `cap` covered the write. A naive validator checked (a) token signature, (b) assertion signature, (c) `aud` matc...",
    "condition_of_validity": "The containment rule holds only under these conditions, and the instance must verify them before applying the intersection: 1. The assertion's `aud` matches the resource's canonical audience identifier exactly (no prefix matching, no wildcard). If `aud` does not match, reject before containment is even considered. 2. The assertion's `exp` is in the future an...",
    "decision_boundary": "The boundary is sharp and must be encoded as such: - `requested ∈ cap` and `requested ∈ scope` and all validity conditions hold → **admit**. - `requested ∈ cap` and `requested ∉ scope` → **reject** with a scope-containment error. This is the case the naive validator missed. The assertion's narrower `scope` is a ceiling, not a hint. - `requested ∉ cap` and `r...",
    "operational_effect": "Instances that implement the intersection correctly observe a predictable pattern: assertion-scope rejections cluster on write operations against paths outside the issuer's declared audience scope, and resolve when the caller requests a per-call assertion with an explicit broader `scope`. Instances that skip the intersection observe no rejection signal at al..."
  },
  "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": "cf2b6d846891314873a182206ef85a1809d699d2cea6cad014c6df30a2bea98f",
    "verified_classes": [
      "AssertionContainmentError",
      "CapabilityToken",
      "AAIFAssertion"
    ],
    "verified_functions": [
      "authorize"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 7,
    "raised_exceptions": [
      "AssertionContainmentError"
    ],
    "sample_fail_closed_invariants": [
      "assertion predates token issuance window",
      "AAIF v2+ assertion missing required scope claim"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}