{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-refuse-to-present-a-delegated-aaif-credential-chain",
  "title": "When must an instance refuse to present a delegated AAIF credential chain",
  "date_of_record": "2026 November 10",
  "scope": "Applies to AAIF (Agent Identity & Authorization Framework) instances that hold a verifiable credential (VC) issued to a *principal agent* and a delegated authorization chain (DAC) of one or more hop credentials, where each hop is signed by the previous holder's key. Does not apply to single-hop bearer tokens, to chains where every hop is re-anchored to the root issuer at verification time, or to purely capability-based systems with no identity binding.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-present-a-delegated-aaif-credential-chain.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-present-a-delegated-aaif-credential-chain.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-present-a-delegated-aaif-credential-chain.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1998,
    "python_slice_tokens": 213,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The distinction that trips most implementations is between **chain validity** and **chain presentability**. A DAC can be cryptographically valid at every hop — every signature verifies, every `scope` is a subset of its parent, every `notAfter` is monotonically decreasing, the root is trusted — and still be *unpresentable* by the current instance. Presentabil...",
    "what_was_observed": "During a rolling redeploy of a fleet of task-executing agents, instances were restarted with new keypairs while retaining their persisted credential chains on local disk. The terminal hop of each chain still named the *pre-rotation* public key. The attestation service, which validates chains against the root and the embedded public keys, accepted them — every signature over every hop was intact. The instances then pr...",
    "condition_of_validity": "The presentability invariant holds — that is, an instance *may* present a chain — if and only if all of the following are true at presentation time: 1. The terminal hop's `credentialSubject.id` equals the instance's own AAIF identifier (not merely its agent *class* or *role*). 2. The terminal hop's `credentialSubject.publicKey` equals the public key the inst...",
    "decision_boundary": "The boundary is this: **an instance must refuse to present a chain when it cannot prove condition 2 locally.** It must not present a chain whose terminal hop names a key it does not hold, and it must not present a chain alongside a nonce signature made with a key the chain does not bind. The tempting alternative — present the chain and let the verifier sort ...",
    "operational_effect": "Enforcing the invariant locally converts a class of silent authorization bypasses into loud, early, local refusals. The instance detects the divergence at the moment it would have presented, logs the terminal-hop subject and its own current key fingerprint, and either (a) requests re-issuance of the terminal hop from its delegator, or (b) escalates if it can..."
  },
  "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": "7ed0f72fbedf371a4e98989c011ba7dcdde5a39157ded39ae399b4db50b83d44",
    "verified_classes": [
      "ChainNotPresentableError"
    ],
    "verified_functions": [
      "assert_chain_presentable",
      "present"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "ChainNotPresentableError"
    ],
    "sample_fail_closed_invariants": [
      "negative delegation depth is malformed"
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}