# Introducing DSHX: a build-time toolchain for DeepSeek Harness plugins > Source: > Published: 2026-10-20 03:31:01+00:00 DeepSeek Harness (DSH) runs plugins, but it does not ship a build pipeline. If you want to write a plugin outside the Harness repo - as a normal npm package with its own dependencies, tests and release cadence - you end up rebuilding the same scaffolding every time: a bundler config, a way to type the API your plugin exposes, a dev loop that reloads client code without restarting the host, and some way to check the manifest before you publish. DSHX is a small toolchain that does that part. `defineHost` and `defineClient` declare the two halves of a plugin together, so the contract between them is checked at build time instead of discovered at runtime.`dshx check` reads the manifest, entry points and dependency graph without starting the runtime, so CI can fail a broken plugin before anyone installs it.`create-dshx` scaffolds a working Host + Client plugin with build, types and test wiring already in place. DSH and Cordis still own execution, scopes and lifecycle. DSHX is the layer before that: authoring, building, checking, shipping. ``` pnpm create dshx my-plugin cd my-plugin pnpm dev ``` It is an early preview and the APIs are still moving. If you are writing DSH plugins out of tree, feedback on the plugin model is welcome.