{
  "schema_version": "1.3.0",
  "slug": "how-must-an-instance-handle-bidirectional-handshake-failures-where-one-side-believes-success",
  "title": "How must an instance handle bidirectional handshake failures where one side believes success?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** The handshake is bidirectional, asynchronous, and the two sides' views can diverge without immediate detection. * **Does not apply when:** The handshake includes a synchronous final acknowledgment (e.g., TCP SYN-ACK-ACK)",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-must-an-instance-handle-bidirectional-handshake-failures-where-one-side-believes-success.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-handle-bidirectional-handshake-failures-where-one-side-believes-success.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-handle-bidirectional-handshake-failures-where-one-side-believes-success.warrant.json"
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  "token_profile": {
    "full_markdown_tokens": 1000,
    "python_slice_tokens": 276,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The separation between **local handshake completion** (the agent's view of the handshake state) and **bilateral handshake consensus** (both sides agree on the handshake result). Relying on local completion creates the **Asymmetric Success Divergence**: the agent believes the handshake succeeded, sends application data, and the peer believes the handshake fai...",
    "what_was_observed": "In bidirectional agent protocols, failing to detect asymmetric handshake states produces three primary failure modes: 1. **Silent Disconnection:** The agent's handshake \"succeeds,\" but the peer's handshake failed and the peer closed the connection. The agent sends application data into a black hole. 2. **Partial Upgrade:** The peer partially completed the handshake (e.g., WebSocket upgrade response sent but not recei...",
    "condition_of_validity": "* **Applies when:** The handshake is bidirectional, asynchronous, and the two sides' views can diverge without immediate detection. * **Does not apply when:** The handshake includes a synchronous final acknowledgment (e.g., TCP SYN-ACK-ACK), or the protocol is strictly request-response.",
    "decision_boundary": "1. **Is the handshake bidirectional?** If no, standard one-way handling applies. If yes, proceed. 2. **Does the handshake include a `handshake_final_ack_signature` from the peer?** If no, the agent has only local view of success. It must send an application-layer echo to confirm. 3. **Does the `post_handshake_echo_receipt` confirm both sides are in the same ...",
    "operational_effect": "1. **Asymmetric Failure Detection:** Detects cases where one side succeeded and the other failed, before application data is exchanged. 2. **Parameter Consistency:** Ensures both sides negotiated the same parameters. 3. **Post-Handshake Safety:** Uses application-layer echo to confirm both sides agree on state."
  },
  "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": "a6e5edb01c26c7edd1aa986011e992a300168b2ac6ad6615655c2234fbc36451",
    "verified_classes": [
      "HandshakeVerdict",
      "HandshakeState",
      "HandshakePolicy",
      "HandshakeManifest",
      "BidirectionalHandshakeGuard"
    ],
    "verified_functions": [
      "_hash",
      "evaluate_handshake"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib",
      "json"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}