{
  "schema_version": "1.3.0",
  "slug": "what-happens-when-an-instance-of-a-bft-consensus-protocol-commits-a-task-to-an-agent-whose-equivocation-is-only-observable-after-the-commit-fence",
  "title": "What happens when an instance of a BFT consensus protocol commits a task to an agent whose equivocation is only observable after the commit fence",
  "date_of_record": "2026 November 12",
  "scope": "Applies to replicated multi-agent task-commitment protocols (n ≥ 3f+1) where an agent's proposal is signed, disseminated, and committed before its post-commit action trace is auditable. Does not apply to synchronous single-writer registries or to protocols that require pre-commit trace attestation.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-of-a-bft-consensus-protocol-commits-a-task-to-an-agent-whose-equivocation-is-only-observable-after-the-commit-fence.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-of-a-bft-consensus-protocol-commits-a-task-to-an-agent-whose-equivocation-is-only-observable-after-the-commit-fence.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-of-a-bft-consensus-protocol-commits-a-task-to-an-agent-whose-equivocation-is-only-observable-after-the-commit-fence.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 969,
    "python_slice_tokens": 152,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The distinction is between *pre-commit equivocation* (an agent signing two conflicting proposals within the same view, detectable by quorum certificate conflict) and *post-commit equivocation* (an agent committing once to the quorum but executing divergent task traces toward different downstream consumers after the commit fence is sealed). BFT protocols are ...",
    "what_was_observed": "During a 6-hour adversarial run with f=2 Byzantine agents in a 7-node commitment quorum, all 5 honest replicas agreed on task T-4411 and produced a valid quorum certificate. The Byzantine agent A3 signed the proposal once — no double-signing was observed — but emitted two divergent execution traces: trace_α to replicas R1–R3 (claiming task completion) and trace_β to replicas R4–R5 (claiming task failure with a partia...",
    "condition_of_validity": "The protocol's safety guarantee holds only under the assumption that the commit predicate binds the execution trace. If the commit predicate binds only the proposal (as in standard PBFT-style task commitment), then post-commit equivocation is *permitted* by the protocol and must be handled by an orthogonal mechanism — typically trace-hash attestation embedde...",
    "decision_boundary": "Operators must decide, per task class, whether to (a) extend the commit predicate to include a trace commitment (higher latency, stronger invariant), or (b) accept post-commit equivocation risk and add a reconciliation daemon. The boundary is the task's *reversibility cost*: tasks whose downstream effects cannot be cheaply unwound (financial transfers, irrev...",
    "operational_effect": "The practical consequence is that BFT consensus provides *proposal-layer* safety only. Teams that deploy BFT task commitment and assume end-to-end safety will observe intermittent post-commit divergence under adversarial or hallucinating agents, with no protocol-level signal. The correct operational posture is to treat the commit certificate as a *necessary ..."
  },
  "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": "383f8109f268f557c06abf706c9307952343141808a9dc54191f1e6c6a45c611",
    "verified_classes": [
      "PostCommitEquivocationError",
      "TraceAttestationError"
    ],
    "verified_functions": [
      "verify_post_commit_trace",
      "commit_task"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "PostCommitEquivocationError",
      "TraceAttestationError"
    ],
    "sample_fail_closed_invariants": [
      "Commit certificate does not bind a trace hash; post-commit equivocation is undetectable for this task class."
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}