{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-refuse-to-renew-an-a2a-session-after-a-proof-rotation",
  "title": "When must an instance refuse to renew an A2A session after a proof rotation",
  "date_of_record": "2026 November 10",
  "scope": "Applies to agent-to-agent (A2A) v1.0 sessions whose peer identity proofs rotate independently of the session lifecycle, where a session is bound to a specific proof generation at establishment. Does not apply to sessions using long-lived static credentials, nor to transport-layer mutual TLS where the binding is renegotiated per connection.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-renew-an-a2a-session-after-a-proof-rotation.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-renew-an-a2a-session-after-a-proof-rotation.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-renew-an-a2a-session-after-a-proof-rotation.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1355,
    "python_slice_tokens": 276,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between **proof rotation** and **session re-binding**. In A2A v1.0, a session is established against a *proof generation* — the specific signed identity assertion (key, DID document version, or attestation bundle) presented at handshake. Rotation produces a new generation with the same logical agent identity but a different crypto...",
    "what_was_observed": "During a controlled rotation drill, a peer agent rotated its signing key mid-session and began attaching the new-generation proof to every subsequent message. The local instance's proof validator — which checked \"is this a currently-valid proof for the claimed agent identity?\" — returned true, because the new proof *was* valid for that identity. The session-renewal path then interpreted a valid proof on an inbound me...",
    "condition_of_validity": "The refusal-to-renew rule is valid precisely when all of the following hold: (a) the session was established with an explicit generation identifier recorded in the binding record; (b) the peer's identity proof is capable of rotating independently of the session (i.e., proof lifetime ≠ session lifetime); and (c) at least one authorization or capability decisi...",
    "decision_boundary": "The instance must distinguish three inbound cases and route them differently: 1. **Same generation, valid proof** → accept, normal path. 2. **New generation, valid proof, explicit `session_rebind` present and countersigned** → advance binding, invalidate generation-scoped caches, accept. 3. **New generation, valid proof, no `session_rebind`** → this is the b...",
    "operational_effect": "Enforcing this boundary converts a silent binding corruption into a loud, recoverable protocol event. Peers that rotate without re-binding receive an explicit rebind-required signal and complete the exchange; peers that cannot complete it (e.g., lost old-generation key) fail the session cleanly at a known point rather than poisoning the audit trail. Generati..."
  },
  "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": "18a42583fffad0c9a856366069d4f210347ab12fa3fcceed1633a63baa6ef74b",
    "verified_classes": [
      "SessionBindingError",
      "SessionBinding"
    ],
    "verified_functions": [
      "handle_inbound_proof"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "SessionBindingError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}