Egnyte Large File Manager

A local MCP server that fills the binary / large-file gap in Egnyte's hosted MCP connector.

Egnyte's official connector only returns extracted text (get_file_content) into agent context — it never hands you the real file bytes. So you can't pandas.read_excel() / openpyxl a workbook, parse a native PDF, or re-package a .msg. This server adds the missing piece: sign in with OAuth, then download the actual binary to local disk (and chunk-upload large files back).

It is meant to run alongside the official Egnyte connector, not replace it:

Where it runs. This is a local stdio MCP server (and .mcpb bundle). The download→disk→load flow only works where the MCP server shares a filesystem with code execution:

• Claude Code (CLI): ✅ fully works — server and your code run on the same machine.

• Claude Cowork / sandboxes: ⚠️ Cowork runs your code in an isolated VM whose filesystem is separate from the host where the MCP server runs, so a file the MCP downloads isn't visible to the VM's Python. Use the bundled python/egnyte_fetch.py inside the sandbox instead (see Claude Cowork / cloud sandbox).

• claude.ai web chat: ❌ remote connectors only; no local MCP, no Python filesystem.

Tools

The model gets a path, not the bytes — so a 200 MB workbook never bloats the context. Your code then does pd.read_excel("/path/from/tool").

Auth — simple OAuth sign-in

Uses the OAuth 2.0 authorization-code flow over an HTTPS localhost loopback redirect. Egnyte does not support PKCE / public clients, so this is a confidential client: a client_secret is required and is stored as a sensitive config field (never logged).

1. On first tool call (or egnyte_login) the server opens your browser to Egnyte's sign-in page.

2. You log in as yourself — including via your company's SSO/SAML.

3. Egnyte redirects to https://localhost:<port>/callback (a self-signed loopback listener — accept the one-time browser cert warning); the server captures the code and exchanges it (with the client_secret) for a token.

4. The token is cached locally (0600-permission file in your config dir) and reused; it auto-refreshes, falling back to a browser re-auth only when the refresh token is gone.

Because you sign in as yourself, the server only sees what your Egnyte permissions allow — same access model as the official connector. No shared service account, no flattened ACLs.

Headless / SSH: set EGNYTE_NO_BROWSER=1 — the server prints the authorize URL instead of launching a browser; open it on any machine that can reach your Egnyte domain, and it will redirect back to the loopback.

Prerequisites

• Node.js ≥ 18

• An Egnyte API key + secret. Register an app at https://developers.egnyte.com → "Get an API Key". Register https://localhost:53682/callback as the allowed redirect (Egnyte requires HTTPS).

• Your Egnyte domain (e.g. acme.egnyte.com).

Configure

Local dev: copy .env.example → .env and fill in EGNYTE_DOMAIN, EGNYTE_CLIENT_ID, and EGNYTE_CLIENT_SECRET (all required — Egnyte is a confidential client).

Installed .mcpb bundle: the host (Claude Desktop) prompts for these via the bundle's user_config — client_secret is stored as a sensitive field.

Run / develop

npm install
npm run login     # one-time browser sign-in, caches token
npm run dev       # run the stdio server locally
npm run build     # compile to dist/
npm run pack      # build + package into egnyte-large-file-manager.mcpb

Use with Claude Code

claude mcp add egnyte-large-file-manager --transport stdio -- node /abs/path/to/dist/server.js

(or install the packed .mcpb in Claude Desktop)

Claude Cowork / cloud sandbox

In Cowork your code runs in an isolated VM whose filesystem is separate from the host where an MCP server runs — so the MCP's download wouldn't be visible to the VM's Python. For these environments use the bundled, dependency-free python/egnyte_fetch.py, which runs inside the sandbox and pulls bytes straight from the Egnyte API.

1. Pre-seed a token (interactive browser OAuth can't reach a headless VM):

• Run npm run login once on a machine with a browser, then inject the resulting token into the sandbox — either copy ~/.config/egnyte-mcp/tokens.json, or set EGNYTE_ACCESS_TOKEN as a sandbox secret.

• Per-user ACLs are preserved only if each user injects their own token (not a shared one).

2. Use it in the sandbox (EGNYTE_DOMAIN + the token in env):

python egnyte_fetch.py download "/Shared/Docs/report.xlsx"   # prints {"path": "...", ...}

from egnyte_fetch import download
import pandas as pd
path = download("/Shared/Docs/report.xlsx")["path"]
df = pd.read_excel(path, sheet_name=None)   # real binary, loaded in-VM

Same hardening as the MCP: *.egnyte.com host lock, .. path rejection, download-dir confinement, SHA-512 verify, single + chunked upload.

Security

• Per-user OAuth — no shared service token; Egnyte ACLs are enforced per signed-in user.

• Client secret — Egnyte requires a confidential client; the client_secret is stored as a sensitive config field and is never logged or returned to the model. OAuth state guards the callback against CSRF.

• Token cache is a 0600 file; it is git-ignored and must never be committed.

• Least privilege — request only the scopes you need (filesystem read; add write only if you upload).

• Paths, not bytes — file contents are written to disk and referenced by path, never echoed through the model.

• Download confinement — downloads are restricted to the configured download directory; a model-supplied dest cannot escape it (no ../ or absolute-path writes).

• Host locked to *.egnyte.com — the API host is validated, so a bad EGNYTE_DOMAIN can't exfiltrate the token/secret to another server. .. segments in Egnyte paths are rejected.

License

Apache-2.0. See LICENSE.