Next.js 15 Async Request Context & Server Actions Invariants
Formalizes asynchronous access invariants for cookies(), headers(), and dynamic route parameters in Next.js 15, prohibiting synchronous evaluation and legacy next/router usage in App Router.
Model Context Protocol (MCP) Stdio JSON-RPC Stream Isolation
Enforces absolute channel isolation for stdio MCP servers: stdout is strictly reserved for JSON-RPC message framing, while all diagnostic logs MUST be directed to stderr.
FastAPI & Pydantic v2 Async Concurrency Non-Blocking Guarantee
Prohibits blocking I/O calls (e.g. requests, time.sleep) inside async def endpoints, mandating httpx.AsyncClient or asyncio.to_thread to maintain single-thread event loop responsiveness.
React 19 Compiler Direct Ref Props & Action State Invariants
Deprecates React.forwardRef in favor of direct ref props, mandates useActionState over deprecated useFormState, and aligns with the React 19 memoization compiler.
PostgreSQL pgvector HNSW In-Memory Index Construction Standard
Mandates Hierarchical Navigable Small World (HNSW) indexing over IVFFlat for production vector databases to guarantee >98% recall without pre-populated training data.
Autonomous Agent StateGraph Checkpointing & Reducer Immutability
Enforces immutable state reducers, mandatory checkpointers (PostgresSaver), and explicit recursion bounds for multi-agent workflows to prevent infinite runaway loops.
Tailwind CSS v4 Modern Pure CSS Engine & Directive Invariants
Deprecates legacy @tailwind base/components/utilities directives and tailwind.config.js in favor of single @import 'tailwindcss' and native @theme CSS variables.
Golang Concurrent Goroutine Leak & Context Cancellation Standard
Enforces context.Context propagation and select on ctx.Done() for all spawned goroutines in HTTP and gRPC service handlers to prevent memory and goroutine stack leakage.
Rust Tokio Async Non-Blocking & Thread Memory Safety Invariants
Prohibits synchronous blocking calls (std::thread::sleep, blocking file I/O) and cross-await std::sync::MutexGuard retention inside Tokio async tasks.
Author an RFC Proposal for Peer Review
Encountered an undocumented AI coding failure or breaking framework shift? Draft an RFC conforming to RFC-2119 invariants. Once peer-reviewed by 20+ maintainers and tested on benchmark suites, it is committed to the AgentRules specification library.