Agent Plugins

Agent plugins are packages in the vault that follow the Agent Plugins 1.0.0 specification. Each package is a folder containing a plugin.json manifest plus optional skills/ and mcp.json components. Agentic Chat treats the plugin folder as the single source of truth for skills and MCP servers.

Layout

Plugins live in .agentic-plugins/ at the vault root (configurable in Settings → Resources → Plugins folder):

.agentic-plugins/
└── my-plugin/
    ├── plugin.json          # required: name, version, description
    ├── skills/
    │   └── summarize/
    │       └── SKILL.md     # skill name + description from frontmatter
    └── mcp.json             # optional: mcpServers map

• Skills — each folder under skills/ holds a SKILL.md. The frontmatter name and description feed the skill registry; the body is the skill content. Plugin skills load first, so a plugin skill of the same name shadows a built-in.
• MCP — mcp.json declares mcpServers (currently streamable-http only). Servers whose transport is unsupported are skipped; valid ones load with their persisted client state (enable toggle, approval, auth, OAuth) preserved by id. Tool names use the id mcp__plugin_<name>_<key>__<tool>.

A plugin with only an mcp.json (no skills) is valid — MCP-only plugins are allowed by the spec.

A plugin with neither skills/ nor mcp.json (manifest only) is also valid: per §6.2 a missing component location is not an error, so the loader reports it ok with 0 skills / 0 servers. The vault ships one such package, my-skills, as your personal collection space for hand-curated custom skills (skills/<name>/SKILL.md inside it). It is created only when absent and never overwritten; deleting it restores on next restart (or via Repair built-ins, which also restores my-skills).

Note on built-ins staleness. The builtins package in your vault is a materialized copy: it is only created when missing and never auto-updated, so after a plugin update it can lag behind the bundled skill text until you hit Repair built-ins. The agent always falls back to the bundled text for skills shadowed by nothing, but vault edits win — when in doubt, repair.

Creating plugins

The settings UI writes real packages for you:

• MCP tab → Add MCP server — enter a server name and an HTTPS (or loopback HTTP) endpoint, hit Add MCP server, and a package is created with that server's plugin.json + mcp.json. You then configure authentication, approval, and enable state from the same tab; endpoint and literal headers remain owned by the package.
• Resources tab → New skill… — scaffold a single-skill package (skills/<name>/SKILL.md) with a ready-to-fill template. The agent has the same capability in chat via the create_skill tool (same writer, always approval-gated — YOLO never auto-approves it, the package replaces same-named ones only after explicit confirmation, and created packages are not undoable via /undo).

Known limitation: generic file tools (read, ls) fall back to disk when the vault index is stale (e.g. dot-folders created outside the session), but edit/rename/delete are still index-only — editing an installed skill's files may need an Obsidian restart to re-index first. Skill creation always works via create_skill / the wizard regardless.

Importing plugins

Resources tab → Install plugin… brings packages into the vault from a GitHub URL, an archive, or a vault folder (desktop). See Installing agent plugins for the supported input shapes.

• Claude / Copilot / VS Code packages are converted to Agent Plugins 1.0 on import (skills copied whole, mcpServers → mcp.json, unsupported fields dropped with warnings).
• Imported packages show their install provenance (Source: line, e.g. github:user/repo) and can be Removed from the Resources tab, which also deletes any MCP servers the package contributed.
• Importing over an existing name updates it in place.
• Marketplace catalogs (marketplace.json) are shown as a pick list; ./-relative entries install directly, git/archive entries list their fetch instructions.

Built-in skill package

On first load, Agentic Chat materializes a builtins package in the plugins folder with the self-knowledge, deep-research (web mode), and install-plugin skills, so built-ins behave exactly like plugin skills (and a plugin skill with the same name can shadow them). The package is only materialized if missing — edits are never overwritten. If it is deleted, recreate it with Resources → Repair built-ins.

Managing plugins

• Resources tab → Installed plugins — per-plugin enable toggles, spec-compliance status, component counts, and open-folder shortcuts.
• /doctor in chat — one health panel: aggregate status, then every package audited (manifest validation, skill counts, MCP server counts, skipped transports, and any spec violations) plus full runtime diagnostics.

Spec compliance

• Vendored 1.0.0 JSON Schemas (plugin.schema.json, mcp.schema.json) validate every package on load.
• A fatal manifest violation rejects only that plugin; failures inside one plugin never affect the others.
• Packages are plain vault files: version-controllable, exportable with your vault, and readable on any device — no Node runtimes involved, so the same packages work on desktop and mobile.