Extensions
Add tools, reusable instructions, and automation. Organize them into profiles for different kinds of work.
Use extensions to connect services, add agents, or teach Clarvis a repeatable task. An Extension Profile saves the plugins and skills you want to use together: one set just for research, another for coding, another for review. You can create profiles for other purposes too, and switch between them in the same project. You can review their contents before activating them.
The guided profile editor separates installation from activation. The Plugins browser also offers an explicit install-and-activate action. Both let you inspect the package first.
Understand the four layers
| Layer | What it does |
|---|---|
| Marketplace | A catalog that helps you discover plugin packages. It does not activate anything. |
| Plugin | An installed package that can contribute agents, skills, MCP servers, hooks, or capability backends. |
| Standalone skill | A reusable instruction package installed independently of a plugin. |
| Extension Profile | A complete allow-list that selects exact installed plugins and standalone skills. |
A plugin is selected as a whole, with all of its declared contents. A standalone skill can be selected on its own. An Extension Profile never chooses a model or agent profile, changes tool grants or sandbox policy, stores credentials, or pins package versions.
Follow the activation flow
Open /extensions and press Enter to use the guided editor:
- choose whether the definition belongs globally or to this workspace;
- edit a profile, clone the active snapshot, or start with an empty allow-list;
- search marketplace listings, installed plugins, and standalone skills together;
- inspect the agents, skills, MCP servers, hooks, and programs included in the set;
- review what will be added and removed, approve project-owned code when required, then apply and reconnect.
In this editor, installing a marketplace item adds it to your draft. It becomes active after you approve the final preview. Changes apply to new runs; work in progress keeps its original set.
Choose the default or an isolated profile
builtin:default is a virtual, immutable starting point. It uses the normal plugin activation list and makes all standalone skill roots available with their standard precedence.
Create a custom Extension Profile to keep separate sets of extensions for different purposes. For example, your research profile can include only browser and documentation extensions, leaving coding extensions in another profile. Global profiles can be reused across workspaces.
Each custom profile lists its full set of extensions. It does not add to builtin:default or inherit from other profiles.
Keeping unnecessary plugins out also keeps their tool definitions out of the model's context. That reduces input tokens and can lower usage costs. See how profiles affect token use.
Keep activation local and auditable
Profile definitions may be global or workspace-scoped. A workspace definition can be committed and shared, but the selected profile is machine-local state: cloning a repository cannot activate executable content by itself.
Workspace plugins require approval for their exact executable inventory. Clarvis fingerprints the resolved contribution bytes and trust state, records the profile id and fingerprint with runs and sessions, and fails closed if selected content changes. Use /reconnect after an intentional change so the next run receives a fresh snapshot.
Choose the right extension guide
| You want to… | Read |
|---|---|
| compose and select an exact capability set | Extension Profiles |
| give agents reusable, on-demand instructions | Skills |
| connect an external tool or prompt server | MCP servers |
| run automation around lifecycle events | Hooks |
| package several contributions together | Plugins |
| publish or consume plugin catalogs | Marketplaces |
| inspect file formats, limits, and status states | Extensions reference |
| understand scope and executable approval | Scopes and workspace trust |