OpenFGA 1.6+ CDC Consistency Token Synchronization Standard

Multi-region authorization architectures suffer from replication lag anomalies where transactional database state propagates faster than asynchronous OpenFGA tuple projections. This standard mandates propagating and binding change-data-capture (CDC) transaction tokens (e.g., PostgreSQL LSN, CockroachDB HLC, or OpenFGA continuation/transaction IDs) into OpenFGA Check and Contextual Tuple evaluations. Enforcing this invariant eliminates stale read authorization vulnerabilities (e.g., revoked access lingering during propagation windows).

--- description: OpenFGA 1.6+ CDC Consistency Token Synchronization Standard - Multi-region authorization architectures suffer from replication lag anomalies where transactional database state propagates faster than asynchronous OpenFGA tuple projections. This standard mandates propagating and binding change-data-capture (CDC) transaction tokens (e.g., PostgreSQL LSN, CockroachDB HLC, or OpenFGA continuation/transaction IDs) into OpenFGA Check and Contextual Tuple evaluations. Enforcing this invariant eliminates stale read authorization vulnerabilities (e.g., revoked access lingering during propagation windows). globs: src/auth/**/*.ts, src/services/**/*.ts, src/security/**/*.ts, src/middleware/**/*.ts alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/openfga-cdc-consistency-token-synchronization" --- # OpenFGA 1.6+ CDC Consistency Token Synchronization Standard > **Severity**: CRITICAL | **Category**: security > **Anti-Pattern Warning**: Decoupled Check Queries Tolerating Asynchronous CDC Replication Lag Vulnerabilities ## System Constraints You are a Principal Engineer enforcing the OpenFGA 1.6+ CDC Consistency Token Synchronization Standard. Mandate that all authorization checks occurring in the write-after-read consistency envelope bind change data capture (CDC) state tokens or contextual tuples to evaluate permissions deterministically. Never permit raw fgaClient.check calls following state mutations without explicit consistency verification or transactional sequencing barriers. ## Strict Guidelines - Engineers MUST ALWAYS bind the database transaction identifier or CDC log sequence number (LSN) into authorization checks when querying state affected by recent writes. - Engineers MUST NOT rely on default eventual consistency OpenFGA check evaluations when executing sensitive post-mutation reads, updates, or revocations. - Services MUST pass contextual tuples containing the active session's write sequence or transient mutations to OpenFGA check calls if the CDC pipeline has not confirmed ingestion up to the target token. - Components NEVER assume an asynchronous CDC consumer has written relation tuples to OpenFGA before returning a write confirmation to the caller. - Code SHOULD leverage OpenFGA 1.6+ consistency parameters (e.g., MINIMIZE_LATENCY vs HIGHER_CONSISTENCY) combined with transactional version checkpoints across multi-region read replicas. ## Bad vs Good Implementations ### Naive Eventual Consistency Check vs CDC Token Synchronized Authorization #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: The check executes directly against OpenFGA without CDC sequence awareness. In multi-region deployments, if user permissions were revoked in the primary OLTP store, a race window exists where an adversary can execute unauthorized operations before CDC processes and propagates the revocation tuple to OpenFGA. ```typescript import { OpenFgaClient } from '@openfga/sdk'; interface AuthorizeRequest { userId: string; documentId: string; action: 'read' | 'write' | 'delete'; } export async function authorizeDocumentAccess( fga: OpenFgaClient, req: AuthorizeRequest ): Promise<boolean> { // VULNERABLE: Direct check against OpenFGA without verification of CDC replication lag. // If a membership revocation occurred in the database milliseconds ago, OpenFGA's // read replica may evaluate against stale authorization tuples. const response = await fga.check({ user: `user:${req.userId}`, relation: req.action, object: `document:${req.documentId}`, }); return response.allowed ?? false; } ``` #### Production Standard (Correct) > **Standard**: Enforces CDC sequence token alignment against the local sync watermark. If replication lag is detected, it falls back to contextual tuples with HIGHER_CONSISTENCY, eliminating stale authorization anomalies deterministically. ```typescript import { OpenFgaClient, ConsistencyPreference } from '@openfga/sdk'; interface AuthorizeRequest { userId: string; documentId: string; action: 'read' | 'write' | 'delete'; requiredLsn?: string; } interface ConsistencyStore { getLatestProcessedLsn(partitionKey: string): Promise<string>; } export async function authorizeDocumentAccess( fga: OpenFgaClient, consistencyStore: ConsistencyStore, req: AuthorizeRequest ): Promise<boolean> { const partitionKey = `document:${req.documentId}`; // Invariant: Verify CDC projection synchronization before evaluation if (req.requiredLsn) { const processedLsn = await consistencyStore.getLatestProcessedLsn(partitionKey); if (BigInt(processedLsn) < BigInt(req.requiredLsn)) { // Fallback: If CDC lags, contextual tuples guarantee zero-stale authorization return fga.check({ user: `user:${req.userId}`, relation: req.action, object: partitionKey, consistency: ConsistencyPreference.HigherConsistency, contextualTuples: [ // Explicitly supply contextual state to guarantee isolation { user: `user:${req.userId}`, relation: 'blocked', object: partitionKey, } ], }).then((res) => res.allowed ?? false); } } const response = await fga.check({ user: `user:${req.userId}`, relation: req.action, object: partitionKey, consistency: ConsistencyPreference.HigherConsistency, }); return response.allowed ?? false; } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: OpenFGA 1.6+ CDC Consistency Token Synchronization Standard

OpenFGA 1.6+ CDC Consistency Token Synchronization Standard defines an industrial-grade behavioral standard for security engineering. Multi-region authorization architectures suffer from replication lag anomalies where transactional database state propagates faster than asynchronous OpenFGA tuple projections. This standard mandates propagating and binding change-data-capture (CDC) transaction tokens (e.g., PostgreSQL LSN, CockroachDB HLC, or OpenFGA continuation/transaction IDs) into OpenFGA Check and Contextual Tuple evaluations. Enforcing this invariant eliminates stale read authorization vulnerabilities (e.g., revoked access lingering during propagation windows). 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: Decoupled Check Queries Tolerating Asynchronous CDC Replication Lag Vulnerabilities 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	Decoupled Check Queries Tolerating Asynchronous CDC Replication Lag Vulnerabilities	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 bind the database transaction identifier or CDC log sequence number (LSN) into authorization checks when querying state affected by recent writes.

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.