{
  "schema_version": "1.3.0",
  "slug": "what-happens-when-an-instance-speculatively-executes-a-tool-whose-commit-quorum-is-later-invalidated-by-a-byzantine-validator",
  "title": "What happens when an instance speculatively executes a tool whose commit quorum is later invalidated by a Byzantine validator",
  "date_of_record": "2026 November 10",
  "scope": "Applies to optimistic agent orchestrators that execute tool calls in parallel before commit-quorum validation, and to any system where a Byzantine-validated commit layer can retroactively reject a result the executor already consumed. Does not apply to strictly serialized orchestrators or to systems where commit validation is a pure local predicate over the tool's own output.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-speculatively-executes-a-tool-whose-commit-quorum-is-later-invalidated-by-a-byzantine-validator.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-speculatively-executes-a-tool-whose-commit-quorum-is-later-invalidated-by-a-byzantine-validator.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-speculatively-executes-a-tool-whose-commit-quorum-is-later-invalidated-by-a-byzantine-validator.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1443,
    "python_slice_tokens": 176,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure is not a rollback failure, and it is not a Byzantine-validator failure in isolation. It is a *speculation-commit skew*: the executor's local state advances on the strength of a tool's side effects, while the commit layer's quorum later determines that the tool's *evidence* was insufficient — not that the tool's *result* was wrong. The result may ...",
    "what_was_observed": "An orchestrator dispatched four tool calls in parallel (a database write, a filesystem mutation, an HTTP POST, and a read used to validate the other three). Each tool's output was signed by the executing worker and forwarded to a Byzantine commit layer with a 3-of-4 quorum. The read tool returned a stale value because its worker had been partitioned from the replica set; the write and POST tools nonetheless returned ...",
    "condition_of_validity": "The failure requires all four of the following to hold simultaneously: 1. **Parallel dispatch** of at least one tool whose output feeds the argument of another tool dispatched in the same batch. 2. **Optimistic consumption**: the orchestrator binds tool output into plan state before commit confirmation, with no speculative marker. 3. **A commit predicate tha...",
    "decision_boundary": "The boundary is whether the orchestrator can express *provisional* consumption. If tool results are bound to plan state only after commit confirmation, the failure cannot occur but parallel execution collapses to serialized execution with a commit barrier per batch — throughput falls to the quorum round-trip time. If results are bound optimistically, the orc...",
    "operational_effect": "Systems that adopt the ledger observe a sharp reduction in duplicate side effects at the cost of a mandatory compensation path for every non-idempotent tool. Systems that do not adopt it observe either duplicate writes (if they retry on rejection) or silent plan-state divergence (if they ignore rejection). The divergence is the more dangerous failure because..."
  },
  "matched_failure_symptoms": [
    "SPLIT_BRAIN_OR_ZOMBIE_WORKER"
  ],
  "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": "9fe2aee172df40daff0c82e0396ea49c4a46e156514fe00944a8d45e0b257ab7",
    "verified_classes": [
      "SpeculationCommitSkewError",
      "SpeculationLedger"
    ],
    "verified_functions": [
      "handle_commit_rejection",
      "__init__",
      "record",
      "classify_recovery"
    ],
    "verified_functions_count": 4,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "SpeculationCommitSkewError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}