{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-distrust-a-forget-acknowledgement-before-it-can-safely-answer-recall-queries",
  "title": "In what scenarios must an instance distrust a \"forget\" acknowledgement before it can safely answer recall queries",
  "date_of_record": "2026 November 10",
  "scope": "Applies to agents operating a read/write/forget memory tool whose backing store separates a logically scoped retention policy (per-tenant, per-subject, per-purpose) from an asynchronous physical erasure path. Does not apply to stores where the forget call is synchronous and transactional against the same index that serves reads, nor to purely append-only logs with no read path.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-distrust-a-forget-acknowledgement-before-it-can-safely-answer-recall-queries.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-distrust-a-forget-acknowledgement-before-it-can-safely-answer-recall-queries.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-distrust-a-forget-acknowledgement-before-it-can-safely-answer-recall-queries.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1251,
    "python_slice_tokens": 206,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between **erasure of the record** and **erasure of the record's influence on reads**. A memory tool's `forget(scope)` typically acknowledges when the retention policy has been updated and the tombstone committed, not when every derived artifact — vector index entries, inverted-index postings, cache shards, embedding neighbors, sum...",
    "what_was_observed": "A memory tool exposed `write(key, value, retention={subject, purpose, ttl})`, `read(key)`, `recall(query, scope)`, and `forget(subject=...)`. `forget` returned `{\"status\": \"erased\", \"keys\": 412}` in ~40ms. The vector index was rebuilt lazily on a 15-minute compaction cycle. During that window, `recall(\"contact details for <subject>\", scope=tenant)` returned passages whose source keys were among the 412 — the tombston...",
    "condition_of_validity": "The acknowledgement from `forget` is a valid precondition for *answering recall queries that may touch the erased scope* only when all of the following hold: 1. The read path resolves candidates through the same tombstone/version index that `forget` mutates, **or** the store publishes a monotonic `erasure_epoch` and every read carries a `min_epoch` that the ...",
    "decision_boundary": "The operational rule: **after `forget`, the instance may assert erasure to a user or auditor, but it may not assert non-recallability until the store reports `erasure_epoch >= read_epoch` for the scope, or a store-specific `compaction_complete(epoch)` signal has fired.** If the store exposes neither, the instance must either (a) block scoped recall until a c...",
    "operational_effect": "Instances that conflate the two events produce two failure modes: **premature assurance** (telling a user their data is gone while recall still serves it) and **contaminated recall** (answering a query from a scope that includes erased content, laundering it through a tenant-level digest). Both are GDPR-relevant. The mitigation is to treat `forget` as a two-..."
  },
  "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": "4bdfd94dfa60474d63d792367c95f93fe76290d400b02e5d49cbdd852603d7ca",
    "verified_classes": [
      "ErasureEpochNotSettled",
      "ErasureState"
    ],
    "verified_functions": [
      "recall",
      "forget_and_record"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "ErasureEpochNotSettled"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}