{
  "schema_version": "1.3.0",
  "slug": "under-what-conditions-must-an-instance-refuse-delegated-aaif-credentials-at-the-token-exchange-boundary",
  "title": "Under what conditions must an instance refuse delegated AAIF credentials at the token-exchange boundary",
  "date_of_record": "2026 November 13",
  "scope": "Applies to Agent Identity and Authorization Framework (AAIF) token-exchange paths where an agent instance presents a delegated credential (subject token) to obtain a downstream access token. Does not apply to first-party credential issuance, human SSO flows, or static service-account tokens.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-delegated-aaif-credentials-at-the-token-exchange-boundary.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-delegated-aaif-credentials-at-the-token-exchange-boundary.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-delegated-aaif-credentials-at-the-token-exchange-boundary.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1320,
    "python_slice_tokens": 202,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The AAIF delegation model distinguishes between *authority to act* and *authority to delegate further*. A subject token carries a delegation chain encoded as a sequence of signed hops, each hop naming the delegating principal, the delegated principal, the scope subset, and a `max_delegation_depth` counter. The critical, non-obvious distinction is that a toke...",
    "what_was_observed": "In a multi-hop agent pipeline (orchestrator → planner → tool-runner), the tool-runner received a subject token whose chain depth was 3 with `max_delegation_depth` of 3. The token verified cleanly against the issuer's JWKS, the audience matched the tool-runner's own identifier, and the expiry was 40 seconds in the future. Every local validation gate passed. The instance then attempted a token exchange to a downstream ...",
    "condition_of_validity": "A delegated credential may be exchanged by an instance if and only if all of the following hold simultaneously: 1. The chain's current depth `d` satisfies `d < max_delegation_depth` for any exchange that appends a hop. 2. The requested scope is a subset of the *intersection* of every hop's granted scope in the chain — not merely the leaf hop's scope. 3. The ...",
    "decision_boundary": "The instance must **refuse locally** (fail fast, no network call) when condition 1 or 2 fails, because these are structurally unsatisfiable and the authorization server will reject deterministically. It must **proceed with caution and re-validate the returned token's scope** when condition 2 is *partially* satisfiable (narrowed grant), because the server may...",
    "operational_effect": "Instances that implement the depth-and-intersection precheck eliminate the guaranteed-failing round-trip and the associated retry amplification. In the observed pipeline, adding the precheck reduced `invalid_grant` volume to the authorization server by roughly the retry factor (4x) and converted a class of opaque downstream 403s into immediate, attributable ..."
  },
  "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": "4d06151b37301070c10f83fc217cc2b71a131ae2faa8e6e93abe0a366eafcf56",
    "verified_classes": [
      "DelegationBoundaryError",
      "Hop",
      "DelegatedCredential"
    ],
    "verified_functions": [
      "assert_exchangeable"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 5,
    "raised_exceptions": [
      "DelegationBoundaryError"
    ],
    "sample_fail_closed_invariants": [
      "empty delegation chain"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}