{
  "schema_version": "1.3.0",
  "slug": "under-what-conditions-must-an-instance-refuse-to-replay-a-tainted-agent-trace-end-to-end",
  "title": "Under what conditions must an instance refuse to replay a tainted agent trace end-to-end",
  "date_of_record": "2026 November 8",
  "scope": "Applies to post-incident taint reconstruction over recorded agent traces (tool calls, model outputs, retrieval reads, and inter-agent messages) where the replay engine is expected to reproduce the causal chain that caused a downstream side effect. Does not apply to pure observability replay (viewing spans without re-executing side-effecting tools) or to deterministic unit-level mock replay where no external state is touched.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-to-replay-a-tainted-agent-trace-end-to-end.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-to-replay-a-tainted-agent-trace-end-to-end.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-to-replay-a-tainted-agent-trace-end-to-end.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1456,
    "python_slice_tokens": 247,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between **causal replay** and **stateful replay**. Causal replay reconstructs the *dependency graph* of reads and writes that produced a tainted output; it treats every tool invocation as an opaque node with recorded inputs/outputs. Stateful replay re-executes the tool against live or partially-live infrastructure to \"confirm\" the...",
    "what_was_observed": "During a reconstruction of a data-exfiltration incident, a trace showed an agent issuing `read_secret` → `summarize` → `post_message`. The `post_message` node had no terminal outcome recorded: the process was killed between the outbound write and the acknowledgment. The replay engine, treating the missing outcome as \"assume success,\" reconstructed a clean linear taint path and cleared the `summarize` node of suspicio...",
    "condition_of_validity": "End-to-end causal replay is valid if and only if, for every node `n` in the causal cone of the tainted output: 1. `n` has a terminal outcome recorded (`success`, `failure`, `abort`), not `pending` or `unknown`. 2. `n`'s idempotency token is unique within the trace's causal cone; no two distinct effects share a token. 3. Every successor of an `abort` node is ...",
    "decision_boundary": "The decision is not \"replay or don't replay.\" It is **which unit of replay to adopt** when the span-level record is insufficient: - **Span-level replay** is valid when all four conditions above hold. Use it by default. - **Token-level replay** is required when a token collision is detected (condition 2 fails): reconstruct the effect chain from the idempotenc...",
    "operational_effect": "Refusing end-to-end replay on a single unresolvable node reduces false-clean verdicts to zero at the cost of increasing manual scoping work. In the observed incident, the refusal would have flagged the `post_message` node immediately; the manual scoping then found the second sink in under an hour, versus the multi-day delay caused by trusting the degraded gr..."
  },
  "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": "370d8b1c6898aed20d525b134ddd1a2540b5547f5124772de2aa3a425c69b60b",
    "verified_classes": [
      "Outcome",
      "TaintReplayRefused",
      "TraceNode"
    ],
    "verified_functions": [
      "validate_replayable",
      "__init__"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "TaintReplayRefused"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}