dsh-micromamba-env

A DeepSeek Harness plugin that lets you view your micromamba environments without leaving the app, and select one environment per workspace. The environment/package catalog is strictly read-only; the only write is the workspace's own selection file.

What it does

• Sidebar panel — a new Micromamba entry in the global panel list opens a main panel listing every environment with its name, absolute path, base / default / external / selected flags, package count, and Python/R version when present. The panel also shows the current workspace's selected environment and offers a name/path filter.
• Package browser — click an environment to expand a filterable list of its installed packages (name, version, build, channel).
• Per-workspace selection — an Environment picker in the composer (left of the input box) remembers one micromamba environment per workspace in <workspace>/.context/micromamba-environment.json, so switching workspaces restores each project's own environment.
• Agent tools:
  • micromamba_list_envs — environments, flags, counts, interpreters
  • micromamba_list_packages — packages in one environment, optional filter
  • micromamba_info — binary path, version, root prefix, platform
  • micromamba_workspace_environment — read/persist the active workspace's selection
  • micromamba_run — run a command line with the selected environment

All micromamba invocation happens on the Host half. The browser half only reads same-origin JSON routes (/dsh-micromamba-env/envs, /packages, /environments, and /selection) and never runs a shell command.

Execution policy

When a workspace has a selected environment and enforcePythonTool is true (the default), the Host denies Python commands submitted through Bash and directs the model to micromamba_run. The detector unwraps the usual wrappers — sudo, env, xargs, nohup, nice, timeout, strace, bash -c, pip, pytest, ipython, uv run python, and friends — and it also inspects terminal_send. Non-Python Bash commands are unaffected, and clearing the selection lifts the restriction.

micromamba_run executes through the same sandboxing shell executor as the Bash tool: it resolves the session's sandboxPolicy and passes it to the shell, so read-only and workspace-write sessions confine it identically. Without a sandboxing executor it falls back to executing the parsed argv directly.

The Python detector is best-effort: it inspects the command text of shell-like tool calls. A determined caller can always find a new wrapper, so treat it as a guardrail for the model rather than a hard security boundary — the sandbox policy on micromamba_run is the enforced boundary.

Install

Author the bundle in this directory, then install it in the current profile with the Harness Plugin Manager (install_bundle), or let the agent do it. The bundle patch inserts one Host row, micromamba-env, and the dsh.client declaration loads client.js in the browser.

Configuration

The row config (in cordis.patch.yml) accepts:

Field	Default	Meaning
micromambaPath	""	Absolute path to micromamba. Empty auto-detects: $MICROMAMBA / $MAMBA_EXE, then $HOME/bin, $HOME/.local/bin, /opt/homebrew/bin, /usr/local/bin, then PATH.
rootPrefix	""	micromamba root prefix (-r). Empty uses $MAMBA_ROOT_PREFIX, then micromamba's own default.
extraEnvPaths	[]	Extra environment paths to show even when micromamba env list omits them.
maxDetailEnvs	25	How many environments get a package summary on the list call.
maxPackages	20000	Hard cap on packages returned by one package-list call.
timeoutMs	30000	Per-command timeout for every micromamba invocation.
enforcePythonTool	true	Deny Python commands through Bash while a workspace has a selected environment.
cacheTtlMs	30000	How long an environment listing is reused. The panel's refresh button bypasses the cache.

Example:

- insert:
    - id: micromamba-env
      name: 'dsh-micromamba-env'
      config:
        rootPrefix: /Users/you/.local/share/mamba

Repository layout

index.js          plugin entry: tools, HTTP routes, system-prompt section
lib/config.js     configuration schema
lib/micromamba.js executable discovery and micromamba reads
lib/selection.js  per-workspace selection, execution, and the policy guard
client.js         sidebar panel + composer picker
test/             unit tests (`npm test`)

Notes

• The default flag comes from micromamba info --json's env location, i.e. the environment micromamba uses by default in the Harness process. It is not a live view of a terminal you may have activated elsewhere. selected is the current workspace's own choice.
• Environments outside the root prefix (for example a project-local ~/micromamba/envs/...) are labelled external.
• The bundle has no static dependencies outside Node's standard library. Its config schema prefers @deepseek-ai/schemastery when the profile can supply it (loaded by absolute path, because a symlinked checkout cannot resolve the profile's node_modules), and otherwise falls back to a small built-in Standard Schema with the same defaults and type checks.
• micromamba_run maps python/python3/python.exe and Rscript onto the selected environment's interpreters, and sets PYTHONNOUSERSITE=1.