Autonomous Agents Agent Plugin Catalog — Knowledge Module

Agent Plugin Catalog

Plugins are small packages the SideButton MCP server loads from ~/.sidebutton/plugins/ and exposes as extra MCP tools. The catalogue lives in agent-runners/plugins.json (validated against plugins.schema.json) and is vendored by the portal to label the plugin chips it shows per agent.

How plugins are installed

• Each plugins.json entry maps a slug → public git repo (+ ref, submodules, system_deps).
• At provision time the portal forwards SIDEBUTTON_PLUGINS = a profile's default_plugins ∪ any provision-request override (see [[runners]] for profiles).
• base/19b-plugins.sh runs after 19-secrets.sh, clones the requested slugs into ~/.sidebutton/plugins/, then systemctl restart sidebutton so the server loads the new plugins together with the now-populated ~/.agent-env.
• Plugins only apply to variants that ship a server (ext, noext) — never the bare variant.
• The agent reports loaded plugins on GET /health (plugins[]); the portal fleet list + agent detail render those chips.

Known plugins

Slug	What it adds	Notes
screen-record	Screen-recording MCP tools (start_recording, stop_recording, list_recordings)	Default plugin for the swe-full-stack, qa-generalist, swe-native profiles. Installed at ~/.sidebutton/plugins/screen-record/ with shell handlers under handlers/
writing-quality	check_writing_quality MCP tool — scores text against the writing/writing-quality pack rules	Reads ANTHROPIC_API_KEY from ~/.agent-env at runtime (the post-secrets restart in 19b is what makes the key available)

Plugin layout (plugin.json + handlers)

A plugin folder contains a plugin.json manifest plus handler scripts the server shells out to (e.g. screen-record/handlers/{start,stop,list}_recording.sh). Tools surface in MCP tools/list once the server restarts.

Gotchas

• A plugin that needs a secret (e.g. writing-quality → ANTHROPIC_API_KEY) is useless until 19b restarts the server after secrets land — order matters.
• system_deps in a plugin entry are apt packages installed before the clone; a missing dep makes the tool load but fail at call time.
• The bare (ubuntu-claude-code) variant has no server, so SIDEBUTTON_PLUGINS is ignored there.
• Code-first module — verify the live catalogue against plugins.json at the pinned RUNNERS_REF before relying on a specific slug.

See [[runners]] for how SIDEBUTTON_PLUGINS is wired through profiles and the provisioning pipeline.