{
  "schema_version": "1.3.0",
  "slug": "which-invariants-prevent-silent-resurrection-of-gdpr-erased-memory-records-under-scoped-retention-policies",
  "title": "Which invariants prevent silent resurrection of GDPR-erased memory records under scoped retention policies",
  "date_of_record": "2026 November 12",
  "scope": "Applies to memory tool APIs that expose `read`, `write`, and `forget` operations over records governed by overlapping retention scopes (tenant, project, user, session) and where at least one scope carries a legal erasure obligation (GDPR Art. 17). Does not apply to append-only audit logs whose retention is governed solely by statutory hold and which are physically immutable.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/which-invariants-prevent-silent-resurrection-of-gdpr-erased-memory-records-under-scoped-retention-policies.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/which-invariants-prevent-silent-resurrection-of-gdpr-erased-memory-records-under-scoped-retention-policies.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/which-invariants-prevent-silent-resurrection-of-gdpr-erased-memory-records-under-scoped-retention-policies.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1306,
    "python_slice_tokens": 228,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The critical distinction is between **erasure of the record** and **erasure of the record's derivations and pointers**. Most memory tool APIs implement `forget(record_id)` as a tombstone or hard-delete on the primary key. This satisfies the naive reading of \"right to be forgotten\" but leaves three classes of residue that can resurrect the erased content: 1. ...",
    "what_was_observed": "In a deployment with user-scoped and project-scoped retention, `forget(user_record_42)` returned success in 12 ms. The primary store tombstoned the row. However: - The embedding index was keyed by `content_sha256`, not `record_id`. The vector remained queryable and, on nearest-neighbor lookup, returned the erased content as the top hit because the index stored the literal text alongside the vector. - A compaction job...",
    "condition_of_validity": "The tombstone-only `forget` implementation is valid **only if** all of the following hold: - No derived record is ever written from a source record without copying the source's erasure lineage (a set of `(scope, record_id)` tombstones that must be checked on every read). - No secondary index is keyed by content rather than by record identity, or, if it is, t...",
    "decision_boundary": "The operational decision is whether to make `forget` **synchronous and transitive** (drain CDC, delete content-keyed index entries, write lineage tombstones, and block until replicas acknowledge) or **asynchronous with a quarantine window** (mark erased, and serve no reads from any scope for a bounded interval until derivations converge). The former is corre...",
    "operational_effect": "After the incident, `forget` was reimplemented to (a) write a lineage tombstone keyed by `(scope, record_id)` into a shared erasure table consulted by all read paths, (b) synchronously delete content-keyed index entries by resolving `content_sha256` from the record before tombstoning, and (c) make the compaction job refuse to derive from any source with an a..."
  },
  "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": "1a6ec9e644687696963cda9ff087a512e4392dd5ab35690c84258014f5ba4fdb",
    "verified_classes": [
      "ErasureLineageViolation",
      "ErasureLedger"
    ],
    "verified_functions": [
      "derive_profile",
      "read_project_record",
      "__init__",
      "forget",
      "is_erased"
    ],
    "verified_functions_count": 5,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "ErasureLineageViolation"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}