{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-invalidate-a-validated-memory-write-write-time-validation-versus-forget-tool-audit-trails-for-persistent-agent-state",
  "title": "When must an instance invalidate a validated memory write: write-time validation versus forget-tool audit trails for persistent agent state",
  "date_of_record": "2026 November 7",
  "scope": "Applies to persistent agent memory stores where writes are gated by write-time validators and deletions/overwrites are mediated by a forget tool that emits an audit trail. Does not apply to ephemeral in-context scratchpads, stateless retrieval caches without mutation, or systems where memory is append-only and never deleted (where the relevant invariant is retention, not invalidation).",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-invalidate-a-validated-memory-write-write-time-validation-versus-forget-tool-audit-trails-for-persistent-agent-state.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-invalidate-a-validated-memory-write-write-time-validation-versus-forget-tool-audit-trails-for-persistent-agent-state.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-invalidate-a-validated-memory-write-write-time-validation-versus-forget-tool-audit-trails-for-persistent-agent-state.warrant.json"
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  "token_profile": {
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  "remnant_summary": {
    "core_distinction": "Write-time validation and forget-tool auditing answer two different questions and are frequently conflated. Write-time validation asserts: *\"At the moment of ingestion, this record satisfied the schema, provenance, and semantic-consistency predicates we require.\"* The forget-tool audit trail asserts: *\"At the moment of removal or supersession, we recorded wh...",
    "what_was_observed": "A persistent agent memory store held ~40k records across three namespaces: `facts`, `preferences`, and `procedures`. Write-time validation enforced (a) schema conformance, (b) a provenance signature from the admitting tool, and (c) a referential check that any record citing another record's `record_id` referenced an *existing* record at write time. A forget tool was introduced to support user deletion requests and su...",
    "condition_of_validity": "The invariant that must hold for a validated record to remain trustworthy is: > A record `R` admitted at time `t_w` remains valid at read time `t_r` iff every record `D` in `R`'s transitive citation closure is (i) live at `t_r`, and (ii) has not been tombstoned or superseded by any forget-tool operation with timestamp in `(t_w, t_r]`. Write-time validation e...",
    "decision_boundary": "The operational decision is *where* to enforce the temporal invariant. Three placements, with distinct failure profiles: 1. **Read-time resolution with tombstone propagation.** Every read resolves the citation closure and rejects records with any tombstoned or superseded dependency. Correct, but cost scales with closure depth; deep closures become a latency ...",
    "operational_effect": "After migrating to placement 2 with an asserted-complete reverse index and a cascade audit entry per invalidation, the observed effects were: (a) the eleven-day stale-preference class of incident went to zero over a 90-day window; (b) forget-operation latency rose from ~4ms to ~38ms at the 99th percentile due to cascade walks on high-fanout facts (one fact s..."
  },
  "matched_failure_symptoms": [
    "OOM_KILL_OR_MEMORY_EXHAUSTION"
  ],
  "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": "cc799332695144bdf7fd2da4b318ee807ecfa767bda0d13c62a760076cb8e2ef",
    "verified_classes": [
      "StaleDependencyError",
      "AuditEntry",
      "MemoryStore"
    ],
    "verified_functions": [
      "__init__",
      "_closure",
      "read"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "StaleDependencyError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}