Populi MCP Server

populi-mcp

MCP server for the Populi API v2. It lets Claude, Codex, Cursor and any other Model Context Protocol client look up people, admissions, academics and billing data in your Populi instance, and, if you opt in, make changes.

Package: @kisasa/populi-mcp on npm. Command: populi-mcp. Transport: stdio.

How it works

Populi's API has 697 routes across 180 models. Exposing each as its own tool would flood a model's context, so this server gives the model a small toolset plus the API reference itself:

Together they cover the whole API: all 492 documented GET routes, all 205 write routes, file uploads and file downloads. Routes that aren't in the bundled catalog work too, since the tools take any path.

A typical exchange: the model searches for the route, reads its parameters, then calls populi_get with a server-side filter.

The catalog is generated from the public API docs and ships inside the package, so searching and describing work offline and cost no API requests.

Configuration

The key's Populi roles decide what it can see. A route the key cannot reach returns a 403 naming the problem; populi_describe_api lists the roles each route needs.

Sandbox first

Populi issues separate sk_sandbox_... keys that only work against sandbox instances (live keys only work on live). Point this server at a sandbox while you evaluate it.

Read-only by default

With no POPULI_ALLOW_WRITES, the write tool is not registered at all, so the model cannot even attempt a change. When you enable it, populi_write is marked destructive, so clients that prompt for approval will ask before each call. DELETE in Populi is permanent.

Install

Requires Node.js 20 or newer. Every client below runs npx -y @kisasa/populi-mcp, so there is nothing to install by hand.

Claude Code

claude mcp add populi \
  -e POPULI_BASE_URL=https://yourschool.populiweb.com \
  -e POPULI_API_KEY=sk_sandbox_... \
  -- npx -y @kisasa/populi-mcp

Claude Desktop

Edit claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\):

{
  "mcpServers": {
    "populi": {
      "command": "npx",
      "args": ["-y", "@kisasa/populi-mcp"],
      "env": {
        "POPULI_BASE_URL": "https://yourschool.populiweb.com",
        "POPULI_API_KEY": "sk_sandbox_..."
      }
    }
  }
}

On Windows, if Claude Desktop cannot find npx, use "command": "cmd" with "args": ["/c", "npx", "-y", "@kisasa/populi-mcp"].

Codex

codex mcp add populi \
  --env POPULI_BASE_URL=https://yourschool.populiweb.com \
  --env POPULI_API_KEY=sk_sandbox_... \
  -- npx -y @kisasa/populi-mcp

or in ~/.codex/config.toml:

[mcp_servers.populi]
command = "npx"
args = ["-y", "@kisasa/populi-mcp"]

[mcp_servers.populi.env]
POPULI_BASE_URL = "https://yourschool.populiweb.com"
POPULI_API_KEY = "sk_sandbox_..."

Cursor

In .cursor/mcp.json (project) or ~/.cursor/mcp.json (global). Cursor expands ${env:NAME}, which keeps the key out of the file:

{
  "mcpServers": {
    "populi": {
      "command": "npx",
      "args": ["-y", "@kisasa/populi-mcp"],
      "env": {
        "POPULI_BASE_URL": "https://yourschool.populiweb.com",
        "POPULI_API_KEY": "${env:POPULI_API_KEY}"
      }
    }
  }
}

Any other MCP client

Run npx -y @kisasa/populi-mcp as a stdio server with POPULI_BASE_URL and POPULI_API_KEY in its environment.

More than one instance

Add one entry per instance under different names (populi-sandbox, populi-live), each with its own key.

API behaviors worth knowing

• Rate limits. 50 requests/min per key from 3AM-7PM PST, 100/min overnight, plus per-IP and per-school limits. On HTTP 429 the call returns an error with how long to wait, and later calls fail fast with the remaining wait instead of hammering a limited key. Prefer one filtered call over many unfiltered ones.
• One request at a time. Populi allows a single "heavy" call (Data Slicer, big exports) at once, so the server runs requests sequentially even if the client sends several in parallel.
• Pages. Lists return at most 200 records. all_pages follows every page up to 500 pages, stopping once max_records (default 500, up to 1,000,000) is reached. The page that crosses the limit is kept whole, so nothing is dropped. The result says whether it completed and otherwise gives a next_page to resume from. If a rate limit or timeout hits part-way, the pages already fetched are returned, not thrown away.
• Filters. Populi ignores filter field names it does not know and returns the whole list, which looks like "everyone matches". populi_describe_api lists the valid condition names for a route; populi_find_people uses the right ones for people.
• GET parameters. filter, expand, page and limit travel in a parameters query value, because most HTTP clients cannot send a GET body. If that would make the URL longer than about 7 KB (for example a filter listing thousands of ids), the request is sent as a GET with a JSON body instead, which Populi documents as the normal form. POST/PUT/DELETE send a JSON body.
• Large responses from populi_get are truncated at max_chars (default 40,000, up to 1,000,000) with a note on how to narrow the request. Use populi_download to save the whole thing to a file instead.
• File downloads. Routes that return a file (PDF/XLS/CSV exports, transcripts, Data Slicer results, file downloads) are fetched with populi_download, which writes into the files folder. It never overwrites (an existing name gets -1, -2, ...), and only uses names, never paths, so it can't write outside the folder. populi_get describes a file response but can't show it.
• File uploads. populi_write takes files, each either a path inside the files folder or content_base64. They are sent as multipart/form-data with the file as file and the other fields as a JSON parameters part, which is how Populi's upload routes (/people/{id}/upload_file, /people/{id}/update_profile_picture, /libraryresources/{id}/update_image, /libraryresources/{id}/digitalresources/upload) expect them. As a safety cap, this server refuses files over 100 MB.
• The files folder is a boundary. A model can only read uploads from, and save downloads to, POPULI_FILES_DIR. Paths that leave it, including through symlinks, are refused, so a prompt-injected "upload my SSH key" has nothing to read. Point it at a broader folder only if you want that.
• Timeouts. Populi publishes no timeout, and reports such as Data Slicer can be slow, so the default is two minutes. Your MCP client may enforce its own tool timeout as well, which this server can't raise; check its settings if a long report is cut off.
• Student data is sensitive. Records can include SSNs, birthdates, grades and financial aid. The server never logs request or response bodies, and the key is never echoed in errors, but whatever a tool returns goes to your model provider. Use the narrowest key role and expand you need.

Development

git clone https://github.com/kisasa/populi-mcp.git
cd populi-mcp
npm install
npm run build      # compile to dist/
npm test           # unit + in-memory MCP tests, no network

Try it against a real instance:

POPULI_BASE_URL=https://yourschool.populiweb.com POPULI_API_KEY=sk_sandbox_... \
  npx @modelcontextprotocol/inspector node dist/index.js

Refreshing the API catalog

data/catalog.json is scraped from the rendered API docs (Populi publishes no OpenAPI file):

npm run build:catalog

Review and commit the diff when Populi ships API changes.

Releasing

Publishing is automated by .github/workflows/publish.yml on every push to main, and only acts when the version is new. To release:

1. Bump version in package.json and both version fields in server.json.
2. Merge to main. The workflow publishes to npm (with provenance), the MCP Registry as io.github.kisasa/populi-mcp, and creates a GitHub release.

npm authentication uses trusted publishing if configured for this repo, otherwise the NPM_TOKEN repository secret.

License

MIT. Not affiliated with Populi. "Populi" is a trademark of its owner.