deepseek-harness/packages/code-runtime

code-runtime/ — code-execution capability family

The code-execution capability seam (see capability seams): an abstract runtime interface for executing one model-written program against host-provided async bindings, capturing what it printed and returned. The consumer is the tool registry's Code Mode (tools: { mode: code } — the run_code tool and the generated TypeScript SDK); design in the Code Mode RFC. Product packages.

Package	Role	ctx key
code-runtime/	Abstract code-execution seam (interface + vocabulary)	ctx.codeRuntime
code-runtime-worker/	Worker-thread backend: fresh worker per run, TypeScript via host-side type-strip (annotations advisory, never type-checked), port-bridged bindings, budget/heap containment	registers ctx.codeRuntime

The interface lives at code-runtime/code-runtime/; the shipped backend at code-runtime/code-runtime-worker/. Backends differ by execution substrate (worker thread, process, container) and by source language — both readonly descriptors on the service — and register ctx.codeRuntime without touching the interface or its consumer; that split is what makes a hardened backend a drop-in later.