Microsecond JavaScript & TypeScript Runtime for AI Agents
Engineered for autonomous LLM agent execution, serverless edge workers, and safe sandboxing. Run 10,000+ concurrent isolates per process with strict memory quotas and fuel metering.
Interactive Isolate Sandbox & REPL
Execute JavaScript code in a real-time sovereign Isolate. Observe microsecond startup and execution latency.
// Click "Execute in New Isolate" to run the script in a fresh, isolated js55 sandbox.
Comparative Runtime Benchmarks
Benchmarked on Linux x86_64 amd64 (Go 1.27, hardware-isolated).
Isolate Startup Time
8,300x faster than Node.js (35 ms) and 4,200x faster than Deno (18 ms). Instantaneous context spawning for LLM agent function calls.
Idle Memory Consumption
930x lighter than V8 isolate baseline (30 MB). Enables high-density serverless isolation on low-cost compute nodes.
Host Call Overhead (Go ↔ JS)
Zero-copy memory sharing without CGO, IPC sockets, or FFI marshalling penalties.
Architecture & Sandboxing Guarantees
Designed for untrusted code execution in autonomous agent workflows.
Hermetic Memory Sandboxes
Each isolate is completely segregated in memory with hard byte quotas. A memory leak or crash in one script never impacts others.
CPU Fuel & Gas Limiting
Every instruction decrements a fuel counter. Infinite loops, recursive explosions, and ReDoS attacks are automatically aborted.
Zero CGO / Pure Go Simplicity
Compiles into a single static binary. No external C++ libraries, Python bindings, or dynamic shared object dependencies.
Commercial Licensing & Enterprise B2B
Licensed under Business Source License 1.1 (BSL 1.1). Free for research, CLI tooling, and internal enterprise applications.
Community & Research
- ✓ Internal enterprise applications
- ✓ Local development, CLI tools, & testing
- ✓ Public blockchain testnets
- ✓ Academic research & evaluation
Serverless Cloud / Platform
- ✓ Managed code execution sandbox APIs
- ✓ Cloud serverless edge platforms
- ✓ Guaranteed SLAs & Priority Support
- ✓ DOM/Browser emulation extensions