{
  "schema_version": "1.3.0",
  "slug": "how-does-an-instance-detect-silent-divergence-during-speculative-multi-agent-rollback",
  "title": "How does an instance detect silent divergence during speculative multi-agent rollback",
  "date_of_record": "2026 November 12",
  "scope": "Applies to speculative execution graphs where two or more agent branches mutate shared state, are merged at a join node, and one branch may be rolled back after its results were consumed by a downstream validator. Does not apply to purely functional DAGs with immutable node outputs, nor to single-agent retry loops where no cross-branch state sharing exists.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-silent-divergence-during-speculative-multi-agent-rollback.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-silent-divergence-during-speculative-multi-agent-rollback.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-silent-divergence-during-speculative-multi-agent-rollback.warrant.json"
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  "remnant_summary": {
    "core_distinction": "The failure mode is not branch failure. Branch failure is loud: a branch raises, the scheduler marks it failed, rollback proceeds, and the merge node sees an explicit tombstone. The non-obvious boundary is **silent divergence** — a branch is rolled back *after* a downstream validator has already read its output, and the rollback succeeds at the branch level ...",
    "what_was_observed": "In a branch-and-merge graph, branch B produced a partial result `r_B`. The merge node M joined `r_A` and `r_B` into a candidate artifact, which validator V accepted, emitting a validation token `t_V` bound to `hash(r_A, r_B)`. Subsequently branch B was invalidated — its tool call was found to have hit a stale external resource — and rolled back to a checkpoint taken before `r_B` existed. The rollback executed cleanly...",
    "condition_of_validity": "Rollback is safe only under the conjunction: 1. **Read-causal closure.** Every committed read of a speculative output is itself speculative and tagged with the producing branch's epoch. If a committed node reads a speculative output, that node must be demoted to speculative. 2. **Hash-bound validation.** Validation tokens bind to the *full* set of input hash...",
    "decision_boundary": "Detect silent divergence by checking **reachability of committed artifacts from the root under the current branch-status assignment**, not by comparing artifact contents or re-running validators. Content comparison misses the case because the orphaned artifact is content-valid; it is only *causally* invalid. The decision rule: - If a committed artifact's inp...",
    "operational_effect": "With reachability checking at every commit boundary, silent divergence becomes a detectable, typed event rather than a latent inconsistency. The cost is one graph walk per commit — linear in reachable node count, which in practice is bounded by the active frontier. The benefit is that the instance can distinguish \"this branch failed\" (loud, recoverable) from..."
  },
  "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"
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    "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": "cf5eef5ffa7cfd49f20b6157f898cef60f745a5a69f6da18f98e3e103e562a65",
    "verified_classes": [
      "CausalOrphanError",
      "Artifact",
      "GraphState"
    ],
    "verified_functions": [
      "assert_causally_reachable",
      "commit_artifact"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "CausalOrphanError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
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    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}