{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-treat-right-to-erasure-as-a-cross-store-invariant-rather-than-a-per-store-delete",
  "title": "When must an instance treat \"right-to-erasure\" as a cross-store invariant rather than a per-store delete",
  "date_of_record": "2026 November 12",
  "scope": "Applies to agent memory systems that persist user data in three or more tiers (raw vector embeddings, append-only episodic logs, and LLM-derived summaries or extracted facts) and that must honor erasure requests. Does not apply to single-tier stores, to stateless retrieval caches with TTL < 1 hour, or to data never used to derive downstream artifacts.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-treat-right-to-erasure-as-a-cross-store-invariant-rather-than-a-per-store-delete.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-treat-right-to-erasure-as-a-cross-store-invariant-rather-than-a-per-store-delete.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-treat-right-to-erasure-as-a-cross-store-invariant-rather-than-a-per-store-delete.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1277,
    "python_slice_tokens": 205,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "A per-store delete removes a subject's records from the store it is issued against and returns success. A cross-store erasure invariant removes the subject's *information* from every store where it is recoverable, including derived artifacts that no longer contain the subject's identifier but still encode its content. The distinction is not \"delete everywher...",
    "what_was_observed": "During a routine erasure drill, a subject's user ID was deleted from the vector store (embeddings and metadata) and from the episodic log (append-only, tombstoned). Both operations returned 200. A retrieval probe using the subject's known attributes — not their ID — reconstructed 80% of their profile from a nightly \"user interest summary\" that had been generated by an LLM from the now-deleted episodes. The summary wa...",
    "condition_of_validity": "The per-store delete is valid only when all of the following hold: 1. Every store that contains subject-derived content is keyed by, or transitively linked to, the subject identifier at delete time. 2. Derived artifacts (summaries, extracted facts, digests, embeddings of either) carry a provenance edge back to their source records, and that edge survives sum...",
    "decision_boundary": "The boundary is crossed when the erasure request must satisfy a *reconstruction test*: after erasure, an adversary holding all remaining stores and the subject's public attributes cannot recover the subject's private content above a defined threshold. If the system can only answer \"did we delete rows matching the ID,\" it is on the per-store side and cannot s...",
    "operational_effect": "The correct operational posture is to invert the delete: enumerate derived artifacts by provenance from the subject's source records, re-derive or excise the subject's contribution, and re-embed the affected summaries rather than deleting them (deleting a shared digest would erase other subjects). For append-only logs, erasure requires crypto-shredding the p..."
  },
  "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": "ce0547f92cdc4996db0b584490be9632721ec9c761ea49144c626efc1efed935",
    "verified_classes": [
      "IncompleteErasureError"
    ],
    "verified_functions": [
      "enforce_erasure"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "IncompleteErasureError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}