About plugins

Learn what a plugin is, how it differs from other catalog artifacts, and how a plugin moves from a git repository into a running harness agent.

A plugin is a versioned bundle of agent capabilities, including skills, MCP server declarations, lifecycle hooks, and sub-agent definitions, that you publish to the catalog as a single unit. Plugins follow the same packaging format that coding harnesses like Claude Code use to distribute and install reusable agent extensions.

Plugins are specifically designed for harness agents that run inside a pre-built coding harness runner, such as Claude Code or OpenClaw. The harness provides the model loop, tool execution, and session management. At deploy time, it pulls the plugins you specify, assembles their files into the layout it expects, and loads them into the running session. The registry’s role is to version, index, and govern which plugins are approved for use within your organization.

Lifecycle

When you publish a plugin to the registry catalog, the registry connects to the Git repository where the plugin is hosted and resolves the branch to a commit SHA that is stored with the plugin. During an agent deployment, the registry fetches the plugin bundle from the repository by using the commit SHA. Then, the bundle is deployed into a harness runner container in your connected deployment runtime.

Review the following diagram to learn more about the lifecycle of a plugin.

    sequenceDiagram
    actor Author
    actor Platform
    participant Registry
    participant Git
    participant AgentCore

    Author->>Git: Push plugin bundle (plugin.json + skills)
    Author->>Registry: Publish plugin to catalog
    Registry-->>Author: Plugin created
    Registry->>Git: Resolve branch to commit SHA
    Registry->>Registry: Store commit SHA in <br/>status.resolvedSource.commit

    Platform->>Registry: Publish harness agent that references <br/>the plugin
    Registry-->>Platform: Harness agent created
    Platform->>Registry: Create agent deployment
    Registry->>Git: Fetch pinned commit bundle
    Git-->>Registry: Return bundle content 
    Registry->>AgentCore: Deploy harness runner with bundle
    AgentCore-->>Platform: Agent ready

Note

Because the plugin is resolved to a specific commit SHA when you add the plugin to the catalog, any updates that the plugin author makes to the Git repository are not automatically picked up by the registry. You must re-publish the plugin for the latest plugin bundle content to be included in the commit SHA. Note that when you update the plugin catalog entry, existing deployments that use this plugin are not updated and continue using the previous version of the plugin. You must re-deploy the agent to pick up the plugin changes.

Limitations

Review the limitations of using plugins in Solo Enterprise for agentregistry.

Public repositories only: Your plugin bundle must be stored in a public repository. GitHub (github.com) and GitLab, including self-hosted GitLab instances, are supported. Private repositories and OCI artifact sources are not supported.
Plugin content remains in source: The registry does not store the bundle content. Instead, it resolves the URL that points to the bundle when you publish the plugin to the catalog and when you deploy a harness agent that references the plugin. If the source repository is not available, the registry cannot perform these actions.
No scaffolding support: Solo Enterprise for agentregistry does not currently support scaffolding for plugins. You must manually create the plugin definition.

Next steps

Publish a plugin Write a plugin definition and publish it to the registry catalog. Create a harness agent Compose a harness agent from plugins, skills, and instructions.

Publish a plugin