Install Hermes Plugins

Hermes plugins extend the Hermes runtime inside a NemoClaw-managed sandbox. They are different from NemoClaw skills and from OpenClaw plugins, so install them through the Hermes plugin path instead of skill install.

How Hermes Loads Plugins

NemoClaw sets HERMES_HOME to /sandbox/.hermes when it starts the Hermes gateway. Hermes plugin directories live under /sandbox/.hermes/plugins/<plugin-name>. NemoClaw uses the same mechanism for its built-in Hermes integration, which the sandbox image bakes into /sandbox/.hermes/plugins/nemoclaw.

The built-in NemoClaw Hermes plugin provides sandbox status tools, skill reload support, managed-tool broker patches, and runtime grounding for the OpenShell sandbox. Do not replace or remove /sandbox/.hermes/plugins/nemoclaw when you add your own plugin.

Choose an Install Path

Today, the supported path for custom Hermes plugins is to bake the plugin into a custom sandbox image and onboard from that Dockerfile. Use this path when the plugin adds Python code, runtime hooks, or dependencies that Hermes must see at gateway startup.

nemohermes <name> skill install <path> is only for SKILL.md agent skills. It uploads skill instructions and refreshes skill discovery, but it does not install Hermes runtime plugins.

Prepare a Build Directory

Put the custom Dockerfile and everything it needs to COPY in one directory. nemohermes onboard --from <Dockerfile> sends the Dockerfile’s parent directory as the Docker build context.

my-hermes-plugin-sandbox/
├── Dockerfile
└── my-hermes-plugin/
    ├── __init__.py
    └── requirements.txt

If you start from the stock NemoClaw Hermes Dockerfile, keep the NemoClaw Hermes image contract intact. The image must still include the generated Hermes config, NemoClaw Hermes plugin, blueprint files, and nemoclaw-start entrypoint.

Install the Plugin in the Image

Add your plugin after the Dockerfile has created /sandbox/.hermes. The example below shows the layer that copies a plugin directory into the Hermes plugin tree.

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COPY my-hermes-plugin/ /opt/my-hermes-plugin/
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USER root
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RUN mkdir -p /sandbox/.hermes/plugins/my-hermes-plugin \
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    && cp -a /opt/my-hermes-plugin/. /sandbox/.hermes/plugins/my-hermes-plugin/ \
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    && if [ -f /opt/my-hermes-plugin/requirements.txt ]; then \
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        /opt/hermes/.venv/bin/python -m pip install --no-cache-dir -r /opt/my-hermes-plugin/requirements.txt; \
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    fi \
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    && chown -R sandbox:sandbox /sandbox/.hermes/plugins/my-hermes-plugin \
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    && chmod -R a+rX /sandbox/.hermes/plugins/my-hermes-plugin
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USER sandbox
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WORKDIR /sandbox

Keep plugin code and dependency files inside the build directory. Avoid copying host credentials, local caches, or broad home-directory contents into the image.

Create the Sandbox

Run onboarding with the custom Dockerfile and an explicit sandbox name. NemoClaw requires a name for --from builds so a custom image cannot silently replace the default sandbox.

$
nemohermes onboard --name my-hermes-build --from ./my-hermes-plugin-sandbox/Dockerfile

For non-interactive onboarding, set the same values through environment variables.

$
NEMOCLAW_NON_INTERACTIVE=1 \
>
NEMOCLAW_SANDBOX_NAME=my-hermes-build \
>
NEMOCLAW_FROM_DOCKERFILE=./my-hermes-plugin-sandbox/Dockerfile \
>
nemohermes onboard

If you resume an interrupted onboarding run, use the same Dockerfile path that started the session. NemoClaw records the custom Dockerfile path and rejects a resume that points at a different image source.

Network Access

Hermes plugins still run inside the OpenShell sandbox boundary. If a plugin calls an external API at runtime, add a policy preset for the required hostnames and binaries before you recreate the sandbox.

Hermes uses Python for plugin execution, so policy entries usually need to allow the Hermes Python runtime, such as /opt/hermes/.venv/bin/python, in addition to any command-line wrapper your plugin starts. For package downloads during sandbox runtime, use the pypi preset or a custom preset that allows the package hosts you need.

For policy concepts, see Network Policies. For custom preset workflows, see Customize Network Policy.

Common Mistakes

These are the most common places where Hermes plugin installation gets mixed up with other NemoClaw extension paths.

• Do not use skill install for Hermes runtime plugins.
• Do not install Hermes plugins into /sandbox/.openclaw/extensions; that path is for OpenClaw plugins.
• Do not remove /sandbox/.hermes/plugins/nemoclaw; NemoClaw depends on that plugin for managed Hermes behavior.
• Do not put the Dockerfile in a broad directory unless you intend to send that whole directory as the Docker build context.
• Do not assume Python package downloads during runtime are allowed by default; sandbox egress still follows OpenShell policy.

Next Steps

• Review NemoHermes Command Reference for nemohermes onboard --from details.
• Review Customize Network Policy if the plugin needs runtime network egress.
• Review Runtime Controls before changing shields or mutability settings for a plugin-enabled sandbox.