{
  "schema_version": "1.3.0",
  "slug": "across-what-mandatory-tenant-predicate-scoping-and-row-level-security-gates-must-an-instance-isolate-multi-tenant-data-to-prevent-cross-tenant-data-leaks",
  "title": "Across what mandatory-tenant-predicate-scoping-and-row-level-security gates must an instance isolate multi-tenant data to prevent cross-tenant data leaks and unauthorized data exposure?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** An AI instance, autonomous coding agent, or backend service implements multi-tenant architectures where multiple isolated users or enterprises share a common database schema or storage engine. * **Does not apply when:** ",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/across-what-mandatory-tenant-predicate-scoping-and-row-level-security-gates-must-an-instance-isolate-multi-tenant-data-to-prevent-cross-tenant-data-leaks.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/across-what-mandatory-tenant-predicate-scoping-and-row-level-security-gates-must-an-instance-isolate-multi-tenant-data-to-prevent-cross-tenant-data-leaks.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/across-what-mandatory-tenant-predicate-scoping-and-row-level-security-gates-must-an-instance-isolate-multi-tenant-data-to-prevent-cross-tenant-data-leaks.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 2675,
    "python_slice_tokens": 531,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "Autonomous systems frequently serve multi-tenant platforms where hundreds or thousands of isolated enterprise customers share a single relational database instance and underlying table schemas. A foundational data-security and catastrophic privacy failure occurs when an instance relies on **application-level filtering (`session.query(Item).all()` followed by...",
    "what_was_observed": "In multi-tenant SaaS APIs, AI agent data stores, and multi-organization platforms, instances operating without mandatory tenant-predicate scoping and row-level security gates exhibit four primary failure modes: 1. **The Omitted `WHERE` Clause Data Leak:** A developer writes a new admin analytics endpoint: `SELECT SUM(amount) FROM payments WHERE status = 'PAID'`. Because the developer forgot to append `AND tenant_id =...",
    "condition_of_validity": "* **Applies when:** An AI instance, autonomous coding agent, or backend service implements multi-tenant architectures where multiple isolated users or enterprises share a common database schema or storage engine. * **Does not apply when:** Operating single-tenant applications, local offline CLI tools, or dedicated single-tenant databases where every customer...",
    "decision_boundary": "1. **How do your queries ensure they only return data for the current tenant?** Never rely on developers remembering to add `WHERE tenant_id = ?` manually. Use automated query AST middleware or database Row-Level Security (RLS) policies to enforce tenant isolation transparently. 2. **Where is your tenant ID stored during request execution?** Store tenant con...",
    "operational_effect": "1. **Transparent AST Query Scoping & RLS:** Across all generated multi-tenant queries, the instance enforces automated tenant predicate injection and database Row-Level Security, preventing un-scoped data access. 2. **Request-Scoped `ContextVars` Isolation:** Tenant context is strictly bound via async-safe `contextvars.ContextVar`, eliminating session state ..."
  },
  "matched_failure_symptoms": [
    "SECRET_OR_PII_LEAK_IN_LOGS"
  ],
  "composition_edges": {
    "primary_domain": "multi_tenant_and_session_isolation",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/across-what-cryptographic-csprng-and-state-prediction-isolation-gates-must-an-instance-generate-tokens-and-session-identifiers-to-prevent-pseudo-random-predictability-and-token-forgery.md",
      "https://corpusfetch.com/c/across-what-w3c-baggage-allowlist-and-pii-sanitization-gates-must-an-instance-propagate-cross-service-context-to-prevent-header-amplification-and-external-data-exfiltration.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/across-what-bounded-queue-admission-control-and-load-shedding-gates-must-an-instance-manage-concurrency-to-prevent-unbounded-memory-growth-and-tail-latency-collapse.md",
      "https://corpusfetch.com/c/beneath-what-concurrency-and-backpressure-ceilings-must-an-instance-throttle-fan-out-tasks-to-prevent-file-descriptor-and-connection-pool-starvation.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-should-an-instance-prevent-a-residual-that-depended-on-one-users-private-session-state-from-being-joined-as-binding-for-a-later-query-involving-a-different-user.md",
      "https://corpusfetch.com/c/through-what-token-bucket-and-atomic-quota-gates-must-an-instance-enforce-multi-tenant-rate-limiting-to-prevent-noisy-neighbor-starvation-and-boundary-burst-amplification.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "bfa66a6153df07018b88c89a97d76e98e04c55d8a66b3e3ef7e3076ea1c81fb3",
    "verified_classes": [
      "TenantContextViolationError",
      "CrossTenantAccessError",
      "MultiTenantSecureDatabase"
    ],
    "verified_functions": [
      "__init__",
      "_init_schema",
      "tenant_scope",
      "get_current_tenant",
      "execute_scoped_insert",
      "execute_scoped_select"
    ],
    "verified_functions_count": 6,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "CrossTenantAccessError",
      "TenantContextViolationError",
      "ValueError"
    ],
    "sample_fail_closed_invariants": [
      "Tenant ID cannot be empty",
      "Security violation: Multi-tenant query executed outside an active `tenant_scope` context",
      "Fatal: Cross-tenant data access violation detected!"
    ],
    "stdlib_dependencies": [
      "contextlib",
      "contextvars",
      "sqlite3",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}