{
  "schema_version": "1.3.0",
  "slug": "what-structural-signals-indicate-a-retention-scoped-memory-write-has-silently-outlived-its-scope",
  "title": "What structural signals indicate a retention-scoped memory write has silently outlived its scope",
  "date_of_record": "2026 November 11",
  "scope": "Applies to read/write/forget memory tool APIs that attach a retention scope (TTL, session, or principal-bound lifetime) to a stored record and expose a separate delete/forget operation. Does not apply to append-only logs where deletion is physically impossible, nor to memory backends where scope is enforced solely at read time by a query filter with no independent storage lifetime.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-a-retention-scoped-memory-write-has-silently-outlived-its-scope.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-a-retention-scoped-memory-write-has-silently-outlived-its-scope.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-a-retention-scoped-memory-write-has-silently-outlived-its-scope.warrant.json"
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  "token_profile": {
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  "remnant_summary": {
    "core_distinction": "The failure mode is not \"the record was not deleted.\" It is \"the record was deleted from the namespace the caller can observe, while a scope-shadowed copy remained readable through a different access path.\" Read/write/forget APIs typically implement retention as a *visibility attribute* on a single physical record: the write sets `retention_scope`, the reade...",
    "what_was_observed": "A memory tool exposed `write(content, scope=..., ttl=...)`, `read(query, scope=...)`, and `forget(record_id)`. A record written under `scope=session:abc` with a 1-hour TTL was forgotten at T+10min via its returned `record_id`. A subsequent `read` under `scope=session:abc` returned nothing, as expected. However, a `read` under a *broader* scope (`scope=principal:user-42`, the parent scope) returned the full content at...",
    "condition_of_validity": "The invariant \"forget under scope S removes content from all read paths reachable by holders of S\" holds only when: - Every physical artifact derived from a write is addressable by the identifier returned to the caller, **or** - Forget is defined over content identity rather than address identity, and the store enforces that definition transactionally across...",
    "decision_boundary": "An agent should treat a `forget` as **not having occurred** — and must not report to a user that content was deleted — unless it can confirm at least one of: - The forget response includes a count of physical artifacts removed and the store documents that this count covers all tiers and derived artifacts. - A post-forget read under every scope that could rea...",
    "operational_effect": "The practical consequence is that retention and deletion are not inverses. Retention bounds *when* content becomes unreachable via a given scope; forget bounds *which address* becomes unreachable immediately. A caller that conflates them will under-report deletion, will believe TTLs are shorter than they are, and will leave content readable across scope tran..."
  },
  "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": "1ee8dcfda032175b0e856673c515631c0797f8c0db4fac6b03e9be6296d42e0b",
    "verified_classes": [
      "ScopedForgetUnverifiedError"
    ],
    "verified_functions": [
      "forget_and_verify"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "ScopedForgetUnverifiedError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}