{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-abort-speculative-multi-agent-rollback-when-parallel-tool-call-hedging-produces-divergent-side-effects",
  "title": "In what scenarios must an instance abort speculative multi-agent rollback when parallel tool-call hedging produces divergent side effects",
  "date_of_record": "2026 November 14",
  "scope": "Applies to orchestration layers that run speculative branches of an agent plan concurrently, hedge tool calls across branches, and rely on branch-and-verify rollback to commit a single winning branch. Does not apply to single-branch execution, to read-only tool surfaces, or to systems where all tool calls are idempotent and externally observable state is fully reversible.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-abort-speculative-multi-agent-rollback-when-parallel-tool-call-hedging-produces-divergent-side-effects.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-abort-speculative-multi-agent-rollback-when-parallel-tool-call-hedging-produces-divergent-side-effects.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-abort-speculative-multi-agent-rollback-when-parallel-tool-call-hedging-produces-divergent-side-effects.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1746,
    "python_slice_tokens": 274,
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  "remnant_summary": {
    "core_distinction": "Speculative multi-agent execution conflates two different notions of \"divergence\": *result divergence* (branches produce different outputs, which is expected and is what verification resolves) and *effect divergence* (branches produce different, externally committed side effects, which verification cannot resolve because the effects have already escaped the ...",
    "what_was_observed": "In a planner-executor deployment with three speculative branches and a hedge window of 400 ms, a booking task produced three concurrent `reserve_seat` calls. The hedge key was the normalized intent `reserve_seat(flight=...)`, so the hedge layer treated all three as the same logical call and did not deduplicate; each branch had independently resolved passenger preferences and emitted different seat/ancillary arguments...",
    "condition_of_validity": "Rollback-based speculative commit is valid if and only if, for every mutating tool call emitted by any branch, at least one of the following holds: 1. **Payload identity under hedge key.** All branches' materialized arguments for a shared hedge key are byte-identical, so hedging is genuine duplicate suppression and at most one effect commits. 2. **Compensabl...",
    "decision_boundary": "The operational decision is: at hedge-dispatch time, classify the tool call. If it is mutating and the hedge key does not guarantee payload identity, the dispatcher must either (a) collapse to a single in-flight call with the other branches waiting on the same future, or (b) acquire a per-resource lease keyed on the *materialized resource identifier* (not th...",
    "operational_effect": "Teams that cross this boundary see a characteristic signature: rollback succeeds (no errors), commit succeeds (no errors), and yet the final external state is inconsistent — duplicate holds, phantom reads, double charges, quota exhaustion, or uniqueness-constraint collisions on retry. Because every individual call reports success, standard error-rate and ret..."
  },
  "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": "e497355d6c156337c91d5e3ff830d1fdf6071a326a22b547dd591599973cf3c2",
    "verified_classes": [
      "DivergentHedgeError",
      "ToolCall"
    ],
    "verified_functions": [
      "assert_hedge_safe",
      "dispatch_hedged",
      "payload_fingerprint"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "DivergentHedgeError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "__future__",
      "dataclasses",
      "hashlib",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}