One foundation, the full stack
From data parsing and task scheduling to secure connections, the kernel and domain extensions reuse the same base capabilities — so your application can focus on the business.
Meet the layered architecture →Built as one
A systematic capability set, calmer engineering choices
What's unified is more than a function prefix. Memory management, error propagation, asynchronous cooperation, and protocol handling form one coherent development experience.
Take exactly what you need
Single header, modular sources, static or shared libraries — flexible to integrate. Module macros and dependency expansion keep feature combinations explicit and controllable.
Learn on-demand trimming →Performance designed in
Batched queues, memory reuse, platform-native network backends, and cryptographic hardware acceleration lay the groundwork for efficient data paths.
Explore performance design →Reliability written into the code
Structured error chains, strict protocol parsing, resource lifecycle management, and fault-injection testing together support maintainable systems.
Meet engineering quality →Architecture
One kernel, eight focused extension libraries
The kernel carries infrastructure and protocol primitives; extension libraries face concrete application domains. Compose capabilities bottom-up, connected by one unified build system.
XRT Kernel C11
Cross-platform abstraction · Unified memory management · Structured error model
Protocols & Security
HTTP/1.1WebSocketTLS 1.2/1.3X.509Networking & Concurrency
TCP / UDPCoroutinesChannelFuture / TaskSystem & Data
Files / ProcessesJSON / XLONJSONL / XLONLContainersText processingFoundation
MemoryAtomicsError chainsTime / LoggingConsistent from architecture to delivery
Clear layered dependencies
Extensions build on kernel capabilities. Networking, protocols, and system abstractions keep being reused while domain capabilities evolve independently.
Composable capability boundaries
Module manifests describe sources and dependencies, feature macros control compilation scope, and trimming checks verify combination boundaries.
Integration that fits your project
Prototypes start from the self-contained single header; projects can choose modular sources or library artifacts — the same API throughout.
xhttp
HTTP applicationsHTTP / HTTPS clients and servers. Connection pooling, caching, retries, authentication, and SSE to connect network services and streaming data.
Explore xhttp →xws
Realtime connectionsWebSocket client and server runtimes. Connection management, group broadcast, reference-based sending, and compression to build two-way communication.
Explore xws →xruntime
Dynamic runtimeDynamic types and an object system. Type registration, reference counting, object-graph reclamation, and dynamic invocation — a runtime foundation for host languages.
Explore xruntime →xmail
Mail communicationMIME content and transport base; SMTP, POP3, and IMAP clients are provided by the xsmtp, xpop3, and ximap extensions.
Explore xmail →xsmtp
Mail sendingSMTP client: protocol, STARTTLS/implicit TLS, authentication, and streamed submission derived from xmailmessage.
Explore xsmtp →xpop3
Mail retrievalPOP3 client: protocol, STLS, authentication, and RETR/TOP bridges to the MIME tree.
Explore xpop3 →ximap
Mail accessIMAP client: command layer, data views, streamed APPEND, and COMPRESS=DEFLATE.
Explore ximap →xssh
Secure remote accessSSH2 protocol primitives and a client runtime. Key exchange, host identity verification, authentication, channels, and port forwarding to reach remote systems.
Explore xssh →xacme
CertificatesACME certificate issuance and management. Five cloud DNS providers, EAB, propagation confirmation, and one-call Obtain.
Explore xacme →xjwt
TokensJWT/JWS signing and verification. HS/RS/ES families and JWKS key sets with kid-based selection.
Explore xjwt →xoauth2
AuthorizationOAuth2 client and OIDC application composition. Auth code, PKCE, token refresh and introspection.
Explore xoauth2 →xllm
Model callsSingle model calls, streaming and provider adapters. OpenAI-compatible/Anthropic/Responses dialects, transport retry and usage stats.
Explore xllm →xllm-session
SessionsSession ledger, budgets, compaction and persistence. Context budgets, turn windows and JSONL archival.
Explore xllm-session →xwork
Agent loopAgent loop, tool execution and approval. Bounded tool loop, sub-agent delegation and the unified task system.
Explore xwork →Internet + AI
Foundations for every layer of your application
Whether it's a client reaching a model service, a tool processing streaming events, or a concurrently-running network service — start composing from these capabilities.
Network connections & streaming
TCP, UDP, HTTP, TLS, and WebSocket working together. Handle streaming events through xhttp's SSE and build your service connection layer.
Make an HTTP request →Concurrent tasks & coroutines
Threads for parallelism, coroutines to organize waiting; Channel passes work, Future composes results; task groups and cancellation tokens coordinate execution and wind-down.
Choose your concurrency model →Structured data & text
JSON, XLON, dynamic values, containers, regex, and templates — one C data-processing foundation shared by configs, requests, responses, and structured content.
Browse the JSON API →Secure connections & identity
TLS 1.2 / 1.3, X.509, cryptographic primitives, and platform randomness back encrypted communication; AES accelerated paths fit x86 and ARM capabilities.
Establish a TLS connection →Local tools & system integration
Files, paths, processes, environment variables, and logging — cross-platform interfaces for tool execution, file handling, and system cooperation.
Browse the process API →Resources & lifecycle
A unified allocator, memory pools, temporary arenas, and structured error chains carry resource ownership and error context through the application flow.
Understand the reliability design →Engineering excellence
Excellence, grounded in every engineering path
Performance has samples, design has implementations, tests have entry points. Open the source and follow the same path to understand and verify XRT.
134.4M items/s
MPMC queue · batch 32
Benchmark archived 2026-07-28: Ryzen 5 5600, Windows, GCC 16.1; 4 producers / 4 consumers, median of 3 samples.
See test conditions & raw samples →2,512 test source files
From happy paths to resource wind-down
Memory fault injection, zero-allocation paths, single-header builds, and protocol boundary tests cover engineering needs at every level.
Explore the test system →
