Capacities MCP Server

An MCP server for Capacities: search, property-based object lookup, object CRUD, save weblinks, and daily notes from any MCP-compatible client.

⚠️ Upgrade to 2.x. Version 2.x runs on the Capacities v2 REST API. Version 1.x used the Capacities Beta API, which Capacities discontinues on September 1, 2026. On that date, 1.x builds (and any .dxt packaged before v2.0.0) stop working. Reinstall the current capacities-desktop-extension.dxt (v2.x) to keep the integration working. See the Capacities API notice.

Prerequisites

• A Capacities account with API access

• An API token (Capacities Desktop App → Settings → API → Generate token)

Related MCP server: Capacities-MCP-Plus

Installation

Choose the option that fits your setup:

Option 1: Claude Desktop Extension (Easiest)

1. Download capacities-desktop-extension.dxt

2. In Claude Desktop: Settings → Extensions → Import Extension

3. Select the .dxt file and enter your API token when prompted

All dependencies are bundled; no additional setup needed.

Option 2: Run from Source

git clone https://github.com/inconceivablelabs/capacitiesMCP.git
cd capacitiesMCP
npm install
npm run build

Then add to your MCP client config (e.g. Claude Desktop's claude_desktop_config.json):

{
  "mcpServers": {
    "capacities": {
      "command": "node",
      "args": ["/path/to/capacitiesMCP/server/dist/index.js"],
      "env": {
        "CAPACITIES_API_TOKEN": "your_token_here"
      }
    }
  }
}

Option 3: Docker Container

For running as a persistent service (e.g. behind an MCP gateway):

# Build from the repo root: the Dockerfile copies from both src/ and server/.
docker build -f server/Dockerfile -t capacities-mcp .
docker run -d \
  -e CAPACITIES_API_TOKEN=your_token_here \
  capacities-mcp

The Docker image uses server/, which contains only the runtime package and compiled output, with no source or dev dependencies.

Available tools

Single-space per token. A v2 API token is scoped to exactly one space; list_spaces returns that one space. To work with multiple spaces, use multiple tokens.

The object model: properties vs. body

Objects in Capacities hold two kinds of content, and the tools treat them differently:

• Properties — the object's typed fields: title, text, dates, numbers, labels (e.g. a task's Status, a weblink's Category), and entity relations (tags, a meeting's attendees). Set these with the properties / labels / relations inputs on create_object / update_object, keyed by property name or id (get them, plus label options and relation targets, from get_space_info). Relations and labels are set by name and resolved strictly: an unknown name is an error, never a guess; pass create_missing_relations: true to auto-create unmatched relation targets.

• Body — freeform Markdown, set via the body / notes / content / markdown parameter.

Rule of thumb: set structured things as properties, prose as body. A tag is a property (a relations entry), not a [[link]] typed into the text. One tool call completes one object (all its properties and its body); several distinct, standalone objects take several calls.

Markdown conventions (body)

Any body/notes field supports Capacities' inline conventions:

Use [[Name]] to reference something that already exists; use () / # when you intend to create the task/tag.

Weblinks & media objects (current API limitation)

save_weblink creates a Weblink from a URL and auto-fetches the page's title and description; you can override title and description at save time. Those are the only properties settable on a weblink. The Capacities API currently treats media objects (weblinks, PDFs, images, audio, files) as create-only: they cannot be updated after creation, so tags, Category, and Topic cannot be set on a weblink through the API. To tag a weblink today, put a #tag in its notes (this associates a Tag via the body).

This is an upstream Capacities API limitation, not a limitation of this server. As soon as the Capacities API allows updating media objects, this server will add full weblink property support (tags / Category / Topic via save_weblink). Until then, #tag-in-notes is the available path.

Configuration

Project structure

capacitiesMCP/
├── src/                  # TypeScript source (single source of truth)
├── server/               # Runtime packaging
│   ├── Dockerfile        # Container build
│   ├── package.json      # Runtime dependencies only
│   └── dist/             # Compiled output (built from root src/)
├── tsconfig.json         # Builds src/ → server/dist/
├── manifest.json         # DXT extension manifest
└── *.dxt                 # Pre-built extension packages

npm run build compiles src/ directly into server/dist/. There is one source, one build step, and one output location used by all three installation methods.

Development

npm install
npm run build        # Compile TypeScript
npm run dev          # Watch mode
npm run inspector    # MCP Inspector for debugging
npm test             # Run tests

See CLAUDE.md for architecture details.

License

MIT. See LICENSE.