dsh-cxas

A DeepSeek Harness (DSH) tool plugin that wraps the CX Agent Studio Scripting API (CXAS SCRAPI) command-line tool (cxas) as structured, model-facing tools. It lets a DSH agent list apps, pull/push apps, run and export evaluations, list deployments, inspect conversations/traces, and interact with tools/callbacks/variables — directly through the cxas CLI.

DeepSeek Harness plugin · category: Tools & Capabilities · license: Apache-2.0 · install with the dsp CLI: dsp install dsh-cxas

What it does

Each registered tool builds an cxas <command> argv, runs the binary as a subprocess on the host, and returns a canonical result with exitCode, stdout, stderr, and command so the model can reason about failures and continue.

Prerequisites

1. cxas-scrapi installed and on PATH:

   pip install cxas-scrapi
   cxas --help      # verify it runs

2. Google Cloud application-default credentials (or a service-account key via the SDK):

   gcloud auth application-default login
   gcloud config set project <your-project>

Mounting the plugin

Restart required. If a DSH web session is already running at http://127.0.0.1:3080, you must stop it and relaunch with the overlay for the new tools to appear. A running server does not pick up a new --patch.

Option A — quick overlay (--patch)

From the directory that contains dsh-cxas (e.g. the workspace root):

pnpm dsh web --patch C:/Users/yashk/Downloads/nvidia/NVIDIA-Nexus/dsh-cxas/cordis.yml
# or, if `dsh` is installed (not run-from-source):
dsh web --patch C:/Users/yashk/Downloads/nvidia/NVIDIA-Nexus/dsh-cxas/cordis.yml

Open http://127.0.0.1:3080 and ask the agent to, for example, “Use cxas_apps_list to list the apps in my project.” If port 3080 is taken by another instance, add --port 3090 --no-open.

The plugin name in cordis.yml is a file:// URL — on Windows the ESM loader rejects bare absolute paths like C:/.... If you move the plugin, update name to point at its src/index.ts as a file:// URL.

Option B — install into a profile (bundle)

The package also declares dsh.bundle, so it can be installed permanently:

dsh plugin --profile demo add ./dsh-cxas
dsh --profile demo

See Publishing a bundle for the build-script / prepare allowance notes if you install from git.

Verification

A standalone smoke test drives apply() with a stub tools registry and checks that the plugin registers all tools and that execute() successfully invokes the real cxas binary (no DSH boot or credentials required):

# from the deepseek-harness checkout root:
node --import tsx/esm C:/Users/yashk/Downloads/nvidia/NVIDIA-Nexus/dsh-cxas/test-load.mjs

Expected: registered 24 tools, cxas_help exitCode=0, and correct argv for cxas_apps_list, cxas_lint, and the cxas passthrough.

Configuration

Set values in the config: block of your cordis.yml / cordis.patch.yml.

Notes & limitations

• The plugin shells out to the host cxas binary; it does not bundle or authenticate to Google Cloud itself.
• Tool parameter sets are a curated subset. For an unmapped command, use the cxas passthrough tool (its args array is passed through verbatim), or call cxas_help first to confirm exact flags.
• Mapped flag names are best-effort against the current CLI surface; if a flag is rejected, consult cxas_help and use the passthrough tool.

Model Experience

Indirectly, through the tool schemas it registers: every tool contributes its name, description, and parameter schema to the assembled system prompt, and its output.render produces the model-facing result text. No additional prompt sections are injected beyond the tool catalog itself.

KV Cache effect

Does not invalidate a reusable prefix. The plugin adds no request-prefix content at boot; the only model-visible text is per-call tool description and result content, which is data-dependent and independent of prior requests.