Quantum-safe security platforms must serve diverse engineering teams across multiple programming languages, yet maintaining consistent threat detection semantics while respecting language-native idioms presents significant design challenges. We present a cross-language SDK architecture for QCrypton that delivers five production SDKs—Go, Python, Java, Ruby, and Rust—each exposing 12 threat scanners, a unified threat callback mechanism, and concurrent batch scanning, while following language-specific best practices: functional options in Go, kwargs in Python, overloaded constructors in Java, keyword arguments in Ruby, and the builder pattern in Rust. All SDKs share a standardized response schema (ScanResult with findings, riskScore, and verdict) and a common authentication model (Bearer token), ensuring that security policies are enforced identically regardless of client language. We evaluate the SDK suite across consistency (100% API parity), concurrency models (goroutines, ThreadPoolExecutor, CompletableFuture, Ruby Threads, tokio::join!), and threat callback type safety, demonstrating that language-native patterns reduce integration time by eliminating impedance mismatch without sacrificing cross-language behavioral consistency.