Lambda Jube Runtime

Lambda has one host executable: lambda.exe (or lambda in a release bundle). Jube is the native-module system used to add hosted languages without recompiling a different runtime.

Hosted Python

Python is the first hosted language. The full bundle contains:

lambda
modules/lang-python/
module.json
  lang-python.dylib | lang-python.so | lang-python.dll

The build writes a platform-specific SHA-256 for the native library into module.json; the host verifies it before loading the library.

The standard bundle contains the same host binary plus a manifest-only lang-python descriptor, but omits the Python grammar and native library. When a Python source or py command is selected, the host discovers the module, validates its ABI, hosted API version, build ID, and descriptor before activating it. A missing or incompatible module produces a generic hosted language diagnostic; it is never parsed as Lambda source.

lambda py app.py
lambda run --lang python app.py
lambda app.py

The compatibility name lambda-jube.exe is a symlink/launcher to lambda.exe; it is not an independently compiled runtime.

Build and package commands

make build                 # standard host
make build-lang-python     # external debug Python module
make build-jube            # host + Python module + compatibility link

make release               # release host
make release-lang-python   # release Python module
make package-standard      # standard distribution staging
make package-jube          # full distribution staging
make verify-jube-package   # identical-host hash plus hosted Python smoke test

release-standard/lambda and release-jube/lambda must be byte-identical. Only the full bundle carries the lang-python native library and resources; the standard bundle carries its small manifest-only descriptor.

JIT compilation

Supported builds use only the MIR Direct path:

Lambda AST -> transpile-mir.cpp -> MIR API -> native code

The retired C2MIR implementation in transpile.cpp and transpile-call.cpp remains as legacy reference source. It is excluded from the host and CLI build configurations and from generated test projects; supported binaries do not expose --c2mir.

Boundary and ownership

The host owns Jube discovery, lifecycle, capability/build negotiation, rooting, runtime-import registration, and generic CLI/source dispatch. Python owns Python syntax, AST policy, scope rules, object/class semantics, runtime helpers, imports, and lowering decisions. Python must not call JavaScript runtime symbols; cross-language module loading goes through the host's import-time language bridge.

Lambda and JavaScript evaluator/JIT paths do not consult hosted-language descriptors. Module discovery happens only at CLI or import fallback points.

The detailed hosted-language architecture and Python implementation sequence are maintained in vibe/Lambda_Design_Jube_Lang_Hosting.md and vibe/Lambda_Impl_Hosted_Python.md.