{
  "schema_version": "1.3.0",
  "slug": "what-structural-signals-indicate-a-broken-aaif-delegation-chain-before-signature-verification-fails",
  "title": "What structural signals indicate a broken AAIF delegation chain before signature verification fails",
  "date_of_record": "2026 November 12",
  "scope": "Applies to AAIF delegated credential issuance where an agent presents a chain of attestations (root authority → intermediate delegators → leaf agent) to a relying party. Does not apply to single-hop direct credentials, nor to revocation-list propagation, which is a separate failure domain.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-a-broken-aaif-delegation-chain-before-signature-verification-fails.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-a-broken-aaif-delegation-chain-before-signature-verification-fails.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-a-broken-aaif-delegation-chain-before-signature-verification-fails.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1197,
    "python_slice_tokens": 225,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "Signature verification answers \"was each link signed by the key it claims?\" It does not answer \"does this chain mean what the presenting agent believes it means?\" The non-obvious boundary is between **cryptographic validity** and **delegation-scope validity**. A chain can be fully signature-valid at every hop and still be structurally broken because a delega...",
    "what_was_observed": "In a multi-tenant AAIF deployment, a leaf agent requested a write capability on resource namespace `acme/billing`. The chain it presented was: 1. Root authority `root.corp` → grants `admin:acme/*` to delegator `D1`. 2. `D1` → grants `write:acme/billing` to delegator `D2`, but with an **attestation policy** requiring `D2` to re-attest at 5-minute intervals. 3. `D2` → grants `write:acme/billing` to the leaf, but **drop...",
    "condition_of_validity": "The structural pre-check is valid only when the following hold: - The chain is presented as an ordered sequence with explicit `parent_credential_id` links. If links are inferred rather than declared, structural analysis is unreliable. - Scope is expressed in a machine-comparable namespace grammar. Free-text scope strings defeat subset checks. - Constraint at...",
    "decision_boundary": "Reject the chain at issuance-check time, before signature verification, if any of the following structural conditions hold: - **Scope widening without re-grant:** `grants(n+1) ⊄ grants(n)` and no `re_grant_root` field references a root-signed widening. - **Constraint drop:** a `constraints` attribute present at hop *n* is absent at hop *n+1* and is not expli...",
    "operational_effect": "Applying the structural pre-check moved scope-drift failures from post-hoc detection (40-minute exposure window in the observed case) to issuance-time rejection. The trade-off is false positives on legitimate re-delegation: roughly 3% of chains in the deployment used widening re-grants that the checker initially flagged because the `re_grant_root` field was ..."
  },
  "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": "7352173189e3097472ae7ce32ca35e40edb97c7ef2824e00ac9aa0a6d6729447",
    "verified_classes": [
      "DelegationChainStructuralError",
      "Hop"
    ],
    "verified_functions": [
      "check_chain_structure",
      "issue_delegated_credential"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 5,
    "raised_exceptions": [
      "DelegationChainStructuralError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}