OpenFGA Real-Time Vector Clock Barrier for Causal Revocation Invalidation

Q: How does adopting this rule prevent AI hallucinations?

This rule explicitly declares what the AI must avoid (Stale ReBAC Evaluation on Stale Replicas Without Causal Horizon Fencing) and prescribes verified positive examples. Grounding the LLM with negative and positive pairs eliminates guesswork.

Q: Which AI coding environments are supported?

This specification is multi-platform compatible: Cursor (.cursor/rules/*.mdc & .cursorrules), Anthropic Claude Code (CLAUDE.md), Windsurf (.windsurfrules), Codex / Cline (AGENTS.md), and GitHub Copilot (.github/copilot-instructions.md).

Q: Can I combine this rule with other technology stacks?

Yes. Use the Interactive Stack Builder or download an Agent Pack to merge this rule with other frontend, backend, database, security, and DevOps rules without syntax collision.

OpenFGA Real-Time Vector Clock Barrier for Causal Revocation Invalidation

--- description: OpenFGA Real-Time Vector Clock Barrier for Causal Revocation Invalidation - Enforces causal consistency across geo-distributed OpenFGA ReBAC policy evaluation nodes using vector clock barriers. Guarantees that read-heavy edge nodes block or divert requests when their local replica's causal state lags behind the client's causal horizon, preventing authorization bypasses via stale revocation states. globs: src/auth/**/*.ts, src/security/**/*.ts, src/rebac/**/*.ts, src/middleware/**/*.ts alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/openfga-vector-clock-causal-invalidation-barrier" --- # OpenFGA Real-Time Vector Clock Barrier for Causal Revocation Invalidation > **Severity**: CRITICAL | **Category**: security > **Anti-Pattern Warning**: Stale ReBAC Evaluation on Stale Replicas Without Causal Horizon Fencing ## System Constraints You are a Principal Security Architect and Distributed Systems Engineer enforcing real-time tuple invalidation and causal consistency across OpenFGA ReBAC evaluation nodes. Mandate that every authorization evaluation check evaluates and satisfies incoming causal vector clock tokens before inspecting local caches or read-replica tuple stores. Forbid bare check queries that disregard client causal horizons (New Enemy Problem). ## Strict Guidelines - Engineers MUST ALWAYS extract and validate causal consistency tokens (vector clocks or zookies) from incoming request context before evaluating relation tuples. - Engineers MUST NOT serve authorization decisions from local L1/L2 caches or read-replicas whose vector clock state is strictly older than the client's incoming causal barrier. - Services MUST route check requests to authoritative leader nodes or initiate bounded synchronous catch-up if the local node's vector clock lags behind the request barrier. - Components NEVER drop or asynchronously batch tuple revocation invalidation events without advancing and fencing the monotonic local vector clock barrier. - Code SHOULD include the newly advanced vector clock state in downstream response headers to propagate the causal horizon back to the client or gateway. ## Bad vs Good Implementations ### Causal Vector Clock Barrier Enforcement in OpenFGA Check Middleware #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Directly evaluates authorization on a local read-replica without inspecting or comparing the client's causal vector clock barrier. In geo-distributed clusters with read replication lag, recently revoked access remains permissible until the replica catches up asynchronously. ```typescript import { OpenFgaClient } from '@openfga/sdk'; import { Request, Response, NextFunction } from 'express'; const fgaClient = new OpenFgaClient({ apiUrl: process.env.FGA_EDGE_REPLICA_URL!, storeId: process.env.FGA_STORE_ID!, }); export async function authorizeUser(req: Request, res: Response, next: NextFunction) { const { user, relation, object } = req.body; // CRITICAL VULNERABILITY: Evaluates against a local geo-replica without validating // causal vector clocks. If an admin revoked access 10ms ago on the primary node, // replication lag allows the user to retain unauthorized access (New Enemy Problem). const { allowed } = await fgaClient.check({ user, relation, object, }); if (!allowed) { return res.status(403).json({ error: 'Forbidden' }); } next(); } ``` #### Production Standard (Correct) > **Standard**: Validates the incoming vector clock causal token against local replication progress. If the edge node lags behind the client's causal horizon, it attempts a sub-millisecond barrier sync and automatically degrades to authoritative leader evaluation if unsynchronized, preventing revocation bypasses. ```typescript import { OpenFgaClient, ConsistencyPreference } from '@openfga/sdk'; import { Request, Response, NextFunction } from 'express'; interface VectorClock { [nodeId: string]: number; } interface NodeState { getClock(): VectorClock; waitForBarrier(clientClock: VectorClock, timeoutMs: number): Promise<boolean>; } declare const localNodeState: NodeState; const fgaEdgeClient = new OpenFgaClient({ apiUrl: process.env.FGA_EDGE_REPLICA_URL!, storeId: process.env.FGA_STORE_ID! }); const fgaPrimaryClient = new OpenFgaClient({ apiUrl: process.env.FGA_PRIMARY_LEADER_URL!, storeId: process.env.FGA_STORE_ID! }); function isLagging(clientClock: VectorClock, localClock: VectorClock): boolean { return Object.entries(clientClock).some(([node, seq]) => (localClock[node] ?? 0) < seq); } export async function authorizeUser(req: Request, res: Response, next: NextFunction) { const { user, relation, object } = req.body; const rawClock = req.headers['x-causal-vector-clock']; const clientClock: VectorClock = rawClock ? JSON.parse(rawClock as string) : {}; let clientToUse = fgaEdgeClient; let consistency = ConsistencyPreference.MinimizeLatency; if (isLagging(clientClock, localNodeState.getClock())) { const caughtUp = await localNodeState.waitForBarrier(clientClock, 50); if (!caughtUp) { // Local node lags behind causal barrier; fail-safe by routing to primary leader clientToUse = fgaPrimaryClient; consistency = ConsistencyPreference.HigherConsistency; } } const { allowed } = await clientToUse.check( { user, relation, object, }, { consistency } ); if (!allowed) { return res.status(403).json({ error: 'Access revoked under causal barrier' }); } res.setHeader('x-causal-vector-clock', JSON.stringify(localNodeState.getClock())); next(); } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: OpenFGA Real-Time Vector Clock Barrier for Causal Revocation Invalidation

OpenFGA Real-Time Vector Clock Barrier for Causal Revocation Invalidation defines an industrial-grade behavioral standard for security engineering. Enforces causal consistency across geo-distributed OpenFGA ReBAC policy evaluation nodes using vector clock barriers. Guarantees that read-heavy edge nodes block or divert requests when their local replica's causal state lags behind the client's causal horizon, preventing authorization bypasses via stale revocation states. 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: Stale ReBAC Evaluation on Stale Replicas Without Causal Horizon Fencing 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	Stale ReBAC Evaluation on Stale Replicas Without Causal Horizon Fencing	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 extract and validate causal consistency tokens (vector clocks or zookies) from incoming request context before evaluating relation tuples.

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.