OpenFGA Relationship-Based Access Control Traversal Circuit Breaker

Q: How does adopting this rule prevent AI hallucinations?

This rule explicitly declares what the AI must avoid (Executing unbounded OpenFGA checks with raw contextual tuples without depth limits or latency circuit breakers.) 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.

--- description: OpenFGA Relationship-Based Access Control Traversal Circuit Breaker - Enforces strict resolution depth invariants, cyclic graph detection, and sub-graph memoization on OpenFGA Check and Expand operations. Prevents graph traversal denial-of-service (Graph DoS) and cascading latency blow-ups caused by unbounded recursive relation trees and unvetted contextual tuples. globs: src/authz/**/*.ts, src/services/auth/**/*.ts, src/lib/fga/**/*.ts, src/middleware/authorization/**/*.ts alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/openfga-rebac-depth-circuit-breaker" --- # OpenFGA Relationship-Based Access Control Traversal Circuit Breaker > **Severity**: CRITICAL | **Category**: security > **Anti-Pattern Warning**: Executing unbounded OpenFGA checks with raw contextual tuples without depth limits or latency circuit breakers. ## System Constraints You are a Principal Security Architect enforcing ReBAC safety invariants on OpenFGA integrations. Mandate hard resolution timeouts, strict cardinality bounds on contextual tuples, cycle breakers, and sub-graph memoization on all permission checks. ## Strict Guidelines - Engineers MUST ALWAYS enforce strict cardinality bounds (maximum 25 items) and schema validation on contextual tuples injected into authorization checks. - Engineers MUST ALWAYS bound OpenFGA Check and Expand API calls with explicit AbortSignal deadlines (recommended <= 150ms-250ms) to halt recursive graph traversal blow-ups. - Engineers MUST NOT evaluate authorization models containing recursive self-referential relations (e.g., nested parent/child groups) without verifying server-side cycle detection or passing depth constraints via gateway headers. - Code SHOULD implement deterministic in-memory sub-graph memoization for high-fanout subject relations within the scope of a single request context. - Services MUST default to fail-closed (denied authorization) if the circuit breaker trips, graph recursion times out, or the traversal budget is exhausted. ## Bad vs Good Implementations ### Vulnerable vs. Circuit-Breaker Guarded OpenFGA Check #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Contextual tuples are passed directly without cardinality validation, allowing clients to inject cycle-inducing graphs. The API check has no timeout or depth deadline, causing catastrophic thread starvation and authorization latency if recursive relations (e.g., nested groups or parent folders) loop. ```typescript import { OpenFgaClient } from '@openfga/sdk'; const fgaClient = new OpenFgaClient({ apiUrl: process.env.FGA_API_URL! }); // ANTI-PATTERN: Raw check accepting unbounded contextual tuples without timeout, depth protection, or memoization export async function checkPermission( userId: string, relation: string, objectId: string, contextualTuples?: Array<{ user: string; relation: string; object: string }> ): Promise<boolean> { const response = await fgaClient.check({ user: `user:${userId}`, relation, object: objectId, contextualTuples: contextualTuples ?? [], }); return Boolean(response.allowed); } ``` #### Production Standard (Correct) > **Standard**: Enforces a hard limit on contextual tuples, wraps execution in an AbortSignal deadline circuit breaker (200ms), utilizes memoization for repeated relation checks, and guarantees fail-closed behavior on timeout or traversal exhaustion. ```typescript import { OpenFgaClient, ClientCheckRequest } from '@openfga/sdk'; const MAX_CONTEXTUAL_TUPLES = 20; const CHECK_TIMEOUT_MS = 200; export interface GuardedCheckOptions { signal?: AbortSignal; correlationId?: string; } export class GuardedRebacEvaluator { constructor( private readonly fgaClient: OpenFgaClient, private readonly subGraphCache: Map<string, { allowed: boolean; expiresAt: number }> ) {} public async checkWithCircuitBreaker( req: ClientCheckRequest, options: GuardedCheckOptions = {} ): Promise<boolean> { if (req.contextualTuples && req.contextualTuples.length > MAX_CONTEXTUAL_TUPLES) { throw new Error(`Contextual tuple cardinality of ${req.contextualTuples.length} exceeds limit (${MAX_CONTEXTUAL_TUPLES})`); } const memoKey = `${req.user}#${req.relation}@${req.object}`; const cached = this.subGraphCache.get(memoKey); if (cached && cached.expiresAt > Date.now()) { return cached.allowed; } const timeoutController = new AbortController(); const timer = setTimeout(() => timeoutController.abort(), CHECK_TIMEOUT_MS); const combinedSignal = options.signal ? AbortSignal.any([options.signal, timeoutController.signal]) : timeoutController.signal; try { const response = await this.fgaClient.check( { user: req.user, relation: req.relation, object: req.object, contextualTuples: req.contextualTuples, }, { signal: combinedSignal, headers: { 'X-FGA-Traversal-Limit': '15' }, } ); const allowed = Boolean(response.allowed); this.subGraphCache.set(memoKey, { allowed, expiresAt: Date.now() + 5000 }); return allowed; } catch (error) { if (combinedSignal.aborted) { // Fail-closed invariant on traversal exhaustion or timeout return false; } throw error; } finally { clearTimeout(timer); } } } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: OpenFGA Relationship-Based Access Control Traversal Circuit Breaker

OpenFGA Relationship-Based Access Control Traversal Circuit Breaker defines an industrial-grade behavioral standard for security engineering. Enforces strict resolution depth invariants, cyclic graph detection, and sub-graph memoization on OpenFGA Check and Expand operations. Prevents graph traversal denial-of-service (Graph DoS) and cascading latency blow-ups caused by unbounded recursive relation trees and unvetted contextual tuples. 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: Executing unbounded OpenFGA checks with raw contextual tuples without depth limits or latency circuit breakers. 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	Executing unbounded OpenFGA checks with raw contextual tuples without depth limits or latency circuit breakers.	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 enforce strict cardinality bounds (maximum 25 items) and schema validation on contextual tuples injected into authorization checks.

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.