{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-refuse-to-roll-back-a-speculative-branch-in-multi-agent-execution",
  "title": "In what scenarios must an instance refuse to roll back a speculative branch in multi-agent execution",
  "date_of_record": "2026 November 13",
  "scope": "Applies to orchestrators that fan out speculative sub-agents across divergent branches and reconcile by rollback when a branch loses arbitration. Does not apply to single-agent speculative decoding or to branches that never emit externally observable side effects.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-refuse-to-roll-back-a-speculative-branch-in-multi-agent-execution.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-refuse-to-roll-back-a-speculative-branch-in-multi-agent-execution.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-refuse-to-roll-back-a-speculative-branch-in-multi-agent-execution.warrant.json"
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  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between *reversible speculation* and *irreversible speculation*. A speculative branch is reversible only while every effect it has produced is either (a) held in a buffer private to the branch, or (b) compensable by an inverse operation the orchestrator can prove will succeed. The moment a branch emits an effect whose inverse is n...",
    "what_was_observed": "In a three-way speculative fan-out (planner → executor A, B, C), branch B lost arbitration after executor B had already published a task-completion event to a shared event bus. The orchestrator's reconciler executed the standard rollback path: it reverted B's private store, released B's lease, and emitted a `branch_discarded` audit record. The event bus, however, had already delivered B's completion event to a downst...",
    "condition_of_validity": "Rollback on divergence is valid **if and only if** the following predicate holds for every effect the losing branch produced: `not_yet_observed(e)` means no external party has acted on `e` in a way the orchestrator cannot undo. This is strictly stronger than \"the write succeeded.\" A committed row that a downstream poller has already read is observed; deletin...",
    "decision_boundary": "The decision boundary is not \"did the branch diverge\" but \"has the branch escaped.\" Concretely: - **Rollback freely** when the branch's effects are all in branch-private buffers, staged writes with no readers, or leases that expire without external consequence. - **Do not roll back** when any effect has crossed a publication barrier (sent, committed-and-read...",
    "operational_effect": "Once the orchestrator distinguishes reversible from irreversible speculation, two things change. First, arbitration must sometimes *select the loser*: if branch B has escaped and branch A has not, the only consistent outcome is to adopt B's effects and discard A's, regardless of which branch scored higher on the speculative objective. The scoring function mu..."
  },
  "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": "db12a4142d88258c08b842c046a615d24fd70e8742628fb80abbad4cf5ccf93e",
    "verified_classes": [
      "BranchState",
      "UnrollableBranchError",
      "Effect",
      "Branch"
    ],
    "verified_functions": [
      "rollback_branch",
      "arbitrate",
      "is_reversible"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "UnrollableBranchError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
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    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
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}