hindurable/nurl repository overview

⁠NURL - Neural Unified Representation Language

Self-hosted compiler for the NURL programming language, packaged with a pure-NURL HTTP API server, a Monaco-based browser playground, and a Model Context Protocol (MCP) server — all in one image. No Python; the playground server itself is a NURL program (nurlapi/main.nu).

NURL is a terse prefix-notation systems language that lowers to LLVM IR. See github.com/nurl-lang/nurl⁠ for the language reference.

⁠What's inside

• nurlc — the self-hosted NURL compiler (bootstrapped nurlc_lastgood.ll → nurlc_lastgood.bin → nurlc_self → nurlc_self2; clang-only, no Python).
• Cross-compilation toolchains, all preinstalled:
  • Linux x86_64 ELF — clang-16 + glibc, full FFI (HTTP / sqlite / canvas)
  • Linux cross — zig cc: x86_64 / aarch64 / riscv64 musl (static), aarch64 glibc. libc only; no HTTP/canvas/audio
  • macOS Mach-O — zig cc, Intel and Apple Silicon (libSystem only; no Cocoa/AudioToolbox)
  • Windows .exe — mingw-w64 + statically-linked libcurl (Schannel TLS, no DLLs to ship)
  • WebAssembly — WASI SDK 24 + wasm-opt (binaryen) for Asyncify
• Pure-NURL HTTP API (nurlapi/main.nu, compiled to a native binary at image-build time) with /build, /build_wasm, /build_windows, /build_macos, /build_target build endpoints and /targets (the cross-compile target registry the playground's dropdown is built from). HTTP server, router, JSON, MCP transport — all stdlib (stdlib/ext/http_*.nu, stdlib/ext/json.nu, stdlib/ext/mcp_*.nu).
• Browser playground at / — Monaco editor, examples dropdown, build+run in-page via @bjorn3/browser_wasi_shim⁠.
• MCP server at /mcp (Streamable HTTP) — tools, resources, prompts for Claude Desktop, Cursor, Windsurf, Zed.
• Bundled assets: stdlib, examples, compiler test suite, EBNF grammar, README, ROADMAP, GOTCHAS.
• OpenAPI 3.1 at /openapi.json, Swagger UI at /docs.

⁠Quick start

docker run --rm -p 8000:8000 <your-namespace>/nurl:latest

Then open:

• http://localhost:8000/⁠ — playground
• http://localhost:8000/docs⁠ — Swagger UI
• http://localhost:8000/health⁠ — liveness probe
• http://localhost:8000/mcp⁠ — MCP endpoint

⁠Build a binary via HTTP

curl -s -X POST http://localhost:8000/build_wasm \
  -H 'Content-Type: application/json' \
  -d '{"source":"@ main → i { ^ 0 }\n","return_format":"binary"}' \
  -o main.wasm
wasmtime main.wasm

⁠MCP client config

{
  "mcpServers": {
    "nurl": {
      "url": "http://localhost:8000/mcp",
      "transport": "streamable-http"
    }
  }
}

⁠Image details

⁠Environment variables

Common overrides — full list in nurlapi/main.nu (search for env_var_or):

⁠Tags

• latest — latest stable release
• vX.Y.Z — pinned release (matches NURL vX.Y.Z)

⁠Source & license

• Source: https://github.com/nurl-lang/nurl⁠
• License: dual-licensed MIT OR Apache-2.0