{
  "schema_version": "1.3.0",
  "slug": "why-does-an-instance-of-bft-consensus-for-multi-agent-task-commit-fail-at-the-f-1-boundary-when-agents-are-ephemeral-and-rejoin-under-new-identities",
  "title": "Why does an instance of BFT consensus for multi-agent task commit fail at the f+1 boundary when agents are ephemeral and rejoin under new identities",
  "date_of_record": "2026 November 9",
  "scope": "Applies to leaderless or rotating-leader BFT protocols (PBFT, HotStuff, Tendermint-style) where the voting set is defined by a static or slowly changing membership and the identity of a voter is bound to a long-lived cryptographic key. Does not apply to protocols with explicit epoch-based reconfiguration where rejoin is treated as a membership change requiring a view change quorum.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/why-does-an-instance-of-bft-consensus-for-multi-agent-task-commit-fail-at-the-f-1-boundary-when-agents-are-ephemeral-and-rejoin-under-new-identities.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-bft-consensus-for-multi-agent-task-commit-fail-at-the-f-1-boundary-when-agents-are-ephemeral-and-rejoin-under-new-identities.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-bft-consensus-for-multi-agent-task-commit-fail-at-the-f-1-boundary-when-agents-are-ephemeral-and-rejoin-under-new-identities.warrant.json"
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  "token_profile": {
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  "remnant_summary": {
    "core_distinction": "The safety of BFT consensus is usually stated as: with `n = 3f + 1` replicas, the protocol tolerates `f` Byzantine faults. This invariant is a statement about *distinct faulty replicas within a single configuration*. It is not a statement about *distinct faulty identities over time*. The non-obvious boundary appears when agents are ephemeral: an agent crashe...",
    "what_was_observed": "In a multi-agent task-commit workload (agents claiming tasks from a shared queue and committing completion records to a replicated log), a single agent process was observed to crash during a long-running task, be restarted by the supervisor with a new UUID, and re-submit its vote on the same proposal. The leader counted both votes. A second agent did the same. With a configured `n = 7`, `f = 2`, two physical agents p...",
    "condition_of_validity": "The `3f+1` bound remains valid if and only if the mapping from voting identity to physical agent is injective over the lifetime of any proposal's voting window. Concretely: - Identity issuance is authorized by a membership service that refuses to issue a second identity to an agent that already holds one in the current configuration, or - Rejoin is treated a...",
    "decision_boundary": "Do not treat a rejoin as a no-op. On any rejoin event, the correct decision is: if the agent's prior identity has an outstanding vote or in-flight proposal in the current view, the rejoin must either (a) resume the prior identity under the same key, or (b) trigger a view change that invalidates the prior identity's votes before the new identity is admitted. ...",
    "operational_effect": "After applying the boundary, the observed divergence rate went to zero across a 72-hour soak at 40 restarts/minute. The cost was an increase in view changes under restart storms (roughly 3x baseline), which the supervisor absorbed by rate-limiting restarts and by preferring identity resumption over re-issuance. The lesson for operators: the safety parameter ..."
  },
  "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": "ee2178bf678d2d10ac40cbf06b41a168c2ac59a46f5c6d22fd0491b17e4df638",
    "verified_classes": [
      "IdentityReuseViolation",
      "VoteLedger"
    ],
    "verified_functions": [
      "admit_rejoin",
      "__init__",
      "record",
      "prior_votes"
    ],
    "verified_functions_count": 4,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "IdentityReuseViolation"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}