Nextcloud authenticates app passwords against the *loginName*, which differs from the UID for OIDC-provisioned users (e.g. user_oidc makes the UID the display name: UID "Ada Lovelace", loginName "ada@example.com"). The runtime consumers of stored app passwords bound the UID as the BasicAuth username, so every Notes/Files/Shares/CalDAV call returned HTTP 401. PR #818 fixed only the provisioning endpoint; the consuming paths were missed. Observed on a login_flow tenant (NC's own OIDC app as IdP): the background-sync scan loop never started ("Credential validation failed ... HTTP 401") and semantic search returned 0 results because the ACL shared_with_me lookup 401'd and degraded to a self-only owner filter. Root cause: NextcloudClient / CalendarClient conflated two identities — the DAV/URL path identity (the user_id the whole system keys on = NC UID) and the auth-credential username (the loginName). Decouple them: - Thread a keyword-only auth_username through NextcloudClient -> CalendarClient (defaults to username, so single-user / OAuth where UID == loginName is unchanged). - get_user_client_basic_auth (background sync + the /api/v1/vector-viz/search endpoint) authenticates as the stored loginName, UID for paths. - _get_client_from_login_flow (the get_client(ctx) MCP-tool path) does the same. - cleanup_invalid_app_passwords validates with the loginName, so it no longer 401s and wrongly deletes a valid OIDC user's password. The loginName is already persisted in app_passwords.username and returned by get_app_password_with_scopes. Adds unit tests covering the UID != loginName split for both client builders, the calendar credential/path split, and the cleanup validation. Also genericises the example user in the #818 comment/test (real name/email -> Ada Lovelace / ada@example.com). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Nextcloud MCP Server
A production-ready MCP server that connects AI assistants to your Nextcloud instance.
Enable Large Language Models like Claude, GPT, and Gemini to interact with your Nextcloud data through a secure API. Create notes, manage calendars, organize contacts, work with files, and more - all through natural language conversations.
This is a dedicated standalone MCP server designed for external MCP clients like Claude Code and IDEs. It runs independently of Nextcloud (Docker, VM, Kubernetes, or local) and provides deep CRUD operations across Nextcloud apps.
Note
Looking for AI features inside Nextcloud? Nextcloud also provides Context Agent, which powers the Assistant app and runs as an ExApp inside Nextcloud. See docs/comparison-context-agent.md for a detailed comparison of use cases.
Tip
Don't want to self-host? Astrolabe Cloud is a managed hosting service for this MCP server, aimed at users and teams who want advanced features like background sync and semantic search without operating the infrastructure themselves. The service is currently under development — sign up on the landing page to join the early-adopter list.
Quick Start
Run the server locally with uvx (no installation required):
NEXTCLOUD_HOST=https://your.nextcloud.instance.com \
NEXTCLOUD_USERNAME=your_username \
NEXTCLOUD_PASSWORD=your_app_password \
uvx nextcloud-mcp-server run --transport stdio
Or add it directly to your MCP client configuration (e.g. claude_desktop_config.json or .claude/settings.json):
{
"mcpServers": {
"nextcloud": {
"command": "uvx",
"args": ["nextcloud-mcp-server", "run", "--transport", "stdio"],
"env": {
"NEXTCLOUD_HOST": "https://your.nextcloud.instance.com",
"NEXTCLOUD_USERNAME": "your_username",
"NEXTCLOUD_PASSWORD": "your_app_password"
}
}
}
}
Tip
Generate an app password in Nextcloud under Settings > Security > Devices & sessions instead of using your login password.
Docker
For full features including semantic search, run with Docker:
docker run -p 127.0.0.1:8000:8000 --rm \
-e NEXTCLOUD_HOST=https://your.nextcloud.instance.com \
-e NEXTCLOUD_USERNAME=your_username \
-e NEXTCLOUD_PASSWORD=your_app_password \
ghcr.io/cbcoutinho/nextcloud-mcp-server:latest
Then connect your MCP client (Claude Desktop, IDEs, mcp dev, etc.) to http://127.0.0.1:8000/mcp.
For Kubernetes, see cbcoutinho/helm-charts. For other deployment options and Compose profiles, see docs/installation.md.
Key Features
- 110+ MCP Tools - Comprehensive API coverage across 10 Nextcloud apps
- MCP Resources - Structured data URIs for browsing Nextcloud data
- Semantic Search (Experimental) - Optional vector-powered search for Notes, Files, News items, and Deck cards (requires Qdrant + Ollama)
- Document Processing - OCR and text extraction from PDFs, DOCX, images with progress notifications
- Flexible Deployment - Docker, Kubernetes (Helm chart), VM, or local installation
- Production-Ready Auth - Basic Auth with app passwords; multi-user via Login Flow v2 — MCP clients authenticate via OAuth, the server handles Nextcloud app passwords transparently
- Tag-Based File Exclusion - Hide sensitive files/folders from MCP file tools by tagging them with a configured Nextcloud system tag (
EXCLUDED_TAGS). See docs/configuration.md - Multiple Transports - streamable-http (default) and stdio
Supported Apps
| App | Tools | Capabilities |
|---|---|---|
| Notes | 7 | Full CRUD, keyword search, semantic search |
| Calendar | 20+ | Events, todos (tasks), recurring events, attendees, availability |
| Contacts | 8 | Full CardDAV support, address books |
| Files (WebDAV) | 12 | Filesystem access, OCR/document processing |
| Deck | 15 | Boards, stacks, cards, labels, assignments |
| Cookbook | 13 | Recipe management, URL import (schema.org) |
| Tables | 5 | Row operations on Nextcloud Tables |
| Sharing | 10+ | Create and manage shares |
| News | 8 | Feeds, folders, items, feed health monitoring |
| Collectives | 16 | Full CRUD on collectives, pages, and tags |
| Talk (spreed) | 6 | List conversations, read/post messages, mark as read, list participants |
| Semantic Search | 2+ | Vector search for Notes, Files, News items, and Deck cards (experimental, opt-in, requires infrastructure) |
Want to see another Nextcloud app supported? Open an issue or contribute a pull request!
Authentication
The MCP server authenticates to Nextcloud using app-specific passwords (Basic Auth). Three deployment modes are supported:
| Mode | Best for |
|---|---|
| Single-User (BasicAuth) | Personal use, development, single-user deployments |
| Multi-User (BasicAuth pass-through) | Multi-user setups where clients send credentials via Authorization header |
| Multi-User (Login Flow v2) | Multi-user / hosted deployments — clients authenticate to the MCP server via OAuth, and the server obtains a per-user app password from Nextcloud and uses it transparently |
OAuth-direct-to-Nextcloud is no longer supported (it required upstream patches to user_oidc that were never merged). Login Flow v2 replaces it for multi-user deployments and works with stock Nextcloud.
See docs/authentication.md for setup instructions.
Semantic Search
An experimental RAG pipeline that lets MCP clients find Nextcloud content by meaning rather than keywords — a query for "car" also surfaces notes about "vehicle" or "transportation". Disabled by default (ENABLE_SEMANTIC_SEARCH=false); requires a vector database and embedding service. See docs/semantic-search-architecture.md and docs/configuration.md.
Tip
Don't want to run Qdrant and an embedding service? Astrolabe Cloud (under development) provides semantic search and background sync as a managed service.
Documentation
- Installation — Docker, Compose profiles, local, VM
- Configuration — Environment variables, document processing, semantic search setup
- Authentication — Basic Auth, Login Flow v2
- Running the Server — Start, manage, troubleshoot
- App Documentation — Per-app guides (Notes, Calendar, Contacts, WebDAV, Deck, Cookbook, Tables)
- Semantic Search Architecture + Vector Sync UI
- Login Flow v2 — recommended multi-user setup (architecture, env vars, scope reference, troubleshooting)
- Troubleshooting · Comparison with Context Agent
Contributing
Contributions are welcome!
- Report bugs or request features: GitHub Issues
- Submit improvements: Pull Requests
- Development guidelines: CLAUDE.md
Security
Found a security issue? Do not open a public GitHub issue. Use GitHub's private vulnerability reporting, or email security@astrolabecloud.com if you can't use GitHub. See SECURITY.md for details.
License
This project is licensed under the AGPL-3.0 License. See LICENSE for details.
