langchain-enterprise-rbac

# LangChain Enterprise RBAC ## Overview Role-based access control for multi-tenant LangChain applications: permission models, model access gating, tenant-scoped vector stores, usage quotas, and FastAPI middleware integration. ## Permission Model ```typescript // permissions.ts enum Permission { CHAIN_INVOKE = "chain:invoke", CHAIN_STREAM = "chain:stream", MODEL_GPT4O = "model:gpt-4o", MODEL_GPT4O_MINI = "model:gpt-4o-mini", MODEL_CLAUDE = "model:claude-sonnet", TOOLS_EXECUTE = "tools:execute", ADMIN_CONFIG = "admin:config", ADMIN_USERS = "admin:users", } interface Role { name: string; permissions: Permission[]; } const ROLES: Record<string, Role> = { viewer: { name: "viewer", permissions: [Permission.CHAIN_INVOKE, Permission.MODEL_GPT4O_MINI], }, user: { name: "user", permissions: [ Permission.CHAIN_INVOKE, Permission.CHAIN_STREAM, Permission.MODEL_GPT4O_MINI, Permission.TOOLS_EXECUTE, ], }, power_user: { name: "power_user", permissions: [ Permission.CHAIN_INVOKE, Permission.CHAIN_STREAM, Permission.MODEL_GPT4O_MINI, Permission.MODEL_GPT4O, Permission.MODEL_CLAUDE, Permission.TOOLS_EXECUTE, ], }, admin: { name: "admin", permissions: Object.values(Permission), }, }; ``` ## User and Tenant Models ```typescript interface Tenant { id: string; name: string; monthlyTokenLimit: number; tokensUsed: number; allowedModels: string[]; }...