OpenFGA Distributed Tuple Invalidation Consensus Standard

--- description: OpenFGA Distributed Tuple Invalidation Consensus Standard - Enforces deterministic authorization consistency across distributed edge workers by binding OpenFGA relationship tuple mutations to transactional Change-Data-Capture (CDC) invalidation streams. Guarantees zero-staleness authorization evaluations by requiring cryptographic or monotonic sequence-token fencing on edge-cached check decisions, eliminating the 'New Enemy' stale privilege elevation window. globs: src/auth/**/*.{ts,tsx}, src/services/**/*.{ts,tsx}, src/edge/**/*.{ts,tsx}, lib/auth/**/*.{ts,tsx} alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/openfga-distributed-tuple-invalidation-consensus-standard" --- # OpenFGA Distributed Tuple Invalidation Consensus Standard > **Severity**: CRITICAL | **Category**: security > **Anti-Pattern Warning**: Unsequenced Asynchronous Invalidation Allowing Edge Authorization Desynchronization and Privilege Drift ## System Constraints You are a Principal Security Architect enforcing the OpenFGA Distributed Tuple Invalidation Consensus Standard. You must reject any authorization architecture that performs fire-and-forget cache evictions, unsequenced edge invalidations, or relies on asynchronous relationship tuple mutations without monotonic CDC checkpoint synchronization. Ensure edge nodes never evaluate cached authorization decisions against stale consistency tokens. ## Strict Guidelines - Engineers MUST ALWAYS couple OpenFGA tuple mutations with a transactional outbox or CDC log producing a strictly monotonic sequence token (e.g., LSN or Raft commit index). - Engineers MUST NOT serve authorization evaluations from edge worker caches without validating that the edge node's local CDC watermark is greater than or equal to the incoming request's consistency token. - Services MUST serialize OpenFGA tuple writes through an atomic boundary that updates domain entities and records the invalidation event in the same ACID transaction. - Edge workers MUST fall back to centralized authoritative OpenFGA evaluation if the local invalidation stream lags behind the requested consistency watermark. - Components NEVER perform best-effort, unsequenced pub/sub fan-out broadcasts to purge local edge caches upon tuple mutation. ## Bad vs Good Implementations ### Unsynchronized Tuple Mutation and Edge Check (Vulnerable to Stale Authorization) #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Revocation mutations are executed against OpenFGA without generating a transactional consistency token. Local cache invalidation is non-deterministic and unsequenced across distributed edge workers, creating a severe staleness window where revoked actors retain unauthorized access on lagging edge nodes. ```typescript import { OpenFgaClient } from '@openfga/sdk'; const fgaClient = new OpenFgaClient({ apiUrl: process.env.FGA_API_URL! }); const localCache = new Map<string, boolean>(); // ANTI-PATTERN: Fire-and-forget write and best-effort unsequenced invalidation. // Edge nodes in other regions will serve stale cached permissions (e.g. revoked access). export async function revokeAccess(user: string, relation: string, object: string): Promise<void> { await fgaClient.write({ deletes: [{ user, relation, object }], }); // Local cache deletion only affects this isolate; edge nodes remain stale localCache.delete(`${user}:${relation}:${object}`); } export async function checkPermission(user: string, relation: string, object: string): Promise<boolean> { const cacheKey = `${user}:${relation}:${object}`; if (localCache.has(cacheKey)) { return localCache.get(cacheKey)!; } const { allowed } = await fgaClient.check({ user, relation, object }); localCache.set(cacheKey, allowed ?? false); return allowed ?? false; } ``` #### Production Standard (Correct) > **Standard**: Mutations generate a monotonic transaction log token (PostgreSQL LSN) within an ACID outbox pattern. Edge checks enforce that authorization evaluations cannot be served from local cache unless the edge worker's CDC consumption watermark is equal to or higher than the requested consistency token, strictly eliminating stale privilege exploitation. ```typescript import { OpenFgaClient } from '@openfga/sdk'; import { Pool } from 'pg'; interface EdgeAuthorizationCheck { user: string; relation: string; object: string; minConsistencyToken?: bigint; } export class EdgeConsistentFgaService { constructor( private readonly fgaClient: OpenFgaClient, private readonly db: Pool, private readonly localCache: Map<string, { allowed: boolean; token: bigint }>, private currentReplicaWatermark: bigint = 0n ) {} // INVARIANT: Monotonic CDC outbox transaction paired with OpenFGA writes public async mutateTupleTransactional(user: string, relation: string, object: string, operation: 'WRITE' | 'DELETE'): Promise<bigint> { const client = await this.db.connect(); try { await client.query('BEGIN'); // Insert outbox invalidation entry to generate monotonic WAL sequence (LSN) const res = await client.query( `INSERT INTO auth_tuple_cdc (entity, relation, target_user, operation) VALUES ($1, $2, $3, $4) RETURNING pg_current_wal_lsn() as lsn`, [object, relation, user, operation] ); const lsn = BigInt(res.rows[0].lsn); // Mutate OpenFGA if (operation === 'DELETE') { await this.fgaClient.write({ deletes: [{ user, relation, object }] }); } else { await this.fgaClient.write({ writes: [{ user, relation, object }] }); } await client.query('COMMIT'); return lsn; } catch (error) { await client.query('ROLLBACK'); throw error; } finally { client.release(); } } // INVARIANT: Edge check enforces CDC watermark fence before honoring cached decision public async checkAuthorization(params: EdgeAuthorizationCheck): Promise<boolean> { const { user, relation, object, minConsistencyToken = 0n } = params; const cacheKey = `${user}#${relation}@${object}`; const cached = this.localCache.get(cacheKey); // Cache hit only valid if edge replica has caught up to the caller's required token if (cached && this.currentReplicaWatermark >= minConsistencyToken && cached.token >= minConsistencyToken) { return cached.allowed; } // Fall back to authoritative evaluation when edge is lagging or cache is cold const response = await this.fgaClient.check({ user, relation, object, }); const isAllowed = response.allowed ?? false; this.localCache.set(cacheKey, { allowed: isAllowed, token: this.currentReplicaWatermark, }); return isAllowed; } public onCdcEventReceived(ackedLsn: bigint, invalidatedKeys: string[]): void { this.currentReplicaWatermark = ackedLsn; for (const key of invalidatedKeys) { this.localCache.delete(key); } } } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: OpenFGA Distributed Tuple Invalidation Consensus Standard

OpenFGA Distributed Tuple Invalidation Consensus Standard defines an industrial-grade behavioral standard for security engineering. Enforces deterministic authorization consistency across distributed edge workers by binding OpenFGA relationship tuple mutations to transactional Change-Data-Capture (CDC) invalidation streams. Guarantees zero-staleness authorization evaluations by requiring cryptographic or monotonic sequence-token fencing on edge-cached check decisions, eliminating the 'New Enemy' stale privilege elevation window. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: Unsequenced Asynchronous Invalidation Allowing Edge Authorization Desynchronization and Privilege Drift Without an explicit system instruction file, developers spend hours debugging silent failures.

Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure Mode	AI Symptom (The Anti-Pattern)	Severity	Production Impact & Remedy
AI Hallucination & Deprecation Drift	Unsequenced Asynchronous Invalidation Allowing Edge Authorization Desynchronization and Privilege Drift	Critical	Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production. Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture Inconsistency	AI assistants produce mixed paradigms across files, creating fragmented codebase conventions.	Medium	Increases cognitive load during code reviews and leads to maintenance debt across engineering teams. Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.

Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

Engineers MUST ALWAYS couple OpenFGA tuple mutations with a transactional outbox or CDC log producing a strictly monotonic sequence token (e.g., LSN or Raft commit index).

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.