Chris CoutinhoandClaude Opus 4.7
d153e96520
Fix issues raised by reviewer on PR #743: - troubleshooting.md: renumber "Getting Help" steps (4→3, 5→4) after earlier consolidation left a gap - installation.md: drop stale "OIDC app" prerequisite; admin access is now optional under Login Flow v2 (works on stock Nextcloud 16+) - semantic-search-architecture.md: rename VECTOR_SYNC_ENABLED to ENABLE_SEMANTIC_SEARCH in the Status callout (renamed in v0.58.0) - configuration.md: remove Quick Start references to deprecated oauth-multi-user / oauth-advanced templates and point to login-flow-v2.md; update "OAuth, Multi-User BasicAuth" label to "Login Flow v2, Multi-User BasicAuth" - auth-flows.md: fix background-sync diagram so Encrypt+persist step no longer crosses into the Nextcloud column Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
12 KiB
Authentication Flows by Deployment Mode
This document provides a unified reference for the auth flows in each supported deployment mode. For configuration details, see Authentication. For Login Flow v2 architecture and setup, see Login Flow v2.
Quick Reference Matrix
| Mode | Client → MCP → NC | Background Sync | Astrolabe → MCP |
|---|---|---|---|
| Single-User BasicAuth | Embedded credentials | Same credentials | N/A |
| Multi-User BasicAuth | Header pass-through | Stored app password (optional) | OAuth Bearer token |
| Login Flow v2 | OAuth → MCP, app pwd → NC | Stored app password | OAuth Bearer token |
Communication Patterns
This document covers three distinct communication patterns:
- MCP Client → MCP Server → Nextcloud: Interactive tool calls initiated by users through MCP clients (Claude Desktop, claude.ai, custom clients).
- MCP Server → Nextcloud: Background operations like vector sync that run without user interaction.
- Astrolabe → MCP Server: Astrolabe app backend communication for settings UI and unified search.
Deployment Modes
1. Single-User BasicAuth
Use Case: Personal Nextcloud instance, local development, single-user deployments.
MCP Client → MCP Server → Nextcloud
MCP Client MCP Server Nextcloud
│ │ │
│── MCP Request ─────────────▶│ │
│ (no auth required) │ │
│ │── HTTP + BasicAuth ───────▶│
│ │ Authorization: Basic │
│ │ (embedded credentials) │
│ │◀── API Response ───────────│
│◀── Tool Result ─────────────│ │
Key characteristics:
- Credentials embedded in server configuration (
NEXTCLOUD_USERNAME,NEXTCLOUD_PASSWORD) - Single shared
NextcloudClientcreated at startup - No MCP-level authentication required (server trusts local clients)
- All requests use the same Nextcloud user
Implementation: context.py — returns the shared client from lifespan context
Background Sync
Uses the same embedded credentials as interactive requests. The background job accesses Nextcloud with the configured username/password.
Astrolabe Integration
Not applicable — Astrolabe is only used in multi-user deployments where users need personal settings and per-user state.
2. Multi-User BasicAuth
Use Case: Internal deployment where users provide their own Nextcloud credentials via HTTP headers.
MCP Client → MCP Server → Nextcloud
MCP Client MCP Server Nextcloud
│ │ │
│── MCP Request ─────────────▶│ │
│ Authorization: Basic │ │
│ (user credentials) │ │
│ │── BasicAuthMiddleware ────▶│
│ │ Extracts credentials │
│ │ │
│ │── HTTP + BasicAuth ───────▶│
│ │ (pass-through) │
│ │◀── API Response ───────────│
│◀── Tool Result ─────────────│ │
Key characteristics:
BasicAuthMiddlewareextracts credentials from theAuthorization: Basicheader- Credentials passed through to Nextcloud (not stored)
- Client created per-request from extracted credentials
- Stateless — no credential storage between requests
Background Sync (Optional)
If users provision an app password (via Astrolabe or nc_auth_provision_access), the server can run background jobs on their behalf:
Astrolabe MCP Server Nextcloud
│ │ │
│── Store app password ──────▶│ │
│ (via management API) │ │
│ │ [Encrypt + persist locally]│
│ │ (SQLite, Fernet) │
│◀── Confirmation ────────────│ │
│ │ │
│ [Background job] │ │
│ │── Retrieve app password ──▶│
│ │── HTTP + BasicAuth ───────▶│
│ │◀── API Response ───────────│
Requirements: TOKEN_ENCRYPTION_KEY, TOKEN_STORAGE_DB.
Astrolabe → MCP Server
Astrolabe MCP Server Nextcloud OIDC
│ │ │
│── OAuth Flow ──────────────▶│◀── Token from IdP ────────▶│
│ (user initiates) │ │
│ │ │
│── Bearer Token ────────────▶│ │
│ (management API calls) │ │
│ │── Validate via JWKS ──────▶│
│ │ (or introspection) │
│◀── API Response ────────────│ │
Key characteristics:
- Astrolabe has its own OAuth client registered in Nextcloud
- Tokens are validated by the MCP server using Nextcloud OIDC JWKS
- Authorization check:
token.sub == requested_resource_owner
3. Login Flow v2
Use Case: Hosted multi-user deployments, OAuth-based MCP clients (claude.ai, Astrolabe Cloud), production. Recommended for any setup where MCP clients shouldn't handle Nextcloud credentials directly.
This mode replaces the previously-supported "OAuth Single-Audience" and "OAuth Token Exchange" modes, both of which required upstream Nextcloud patches that were never merged. See ADR-022 for the rationale.
MCP Client → MCP Server → Nextcloud (steady state)
MCP Client MCP Server Nextcloud
│ │ │
│── Bearer Token ────────────▶│ │
│ (issued by MCP server, │ │
│ mcp:* scopes) │ │
│ │── Validate scopes ─────────│
│ │ (@require_scopes) │
│ │ │
│ │── Lookup user's │
│ │ stored app password │
│ │ │
│ │── HTTP + BasicAuth ───────▶│
│ │ Authorization: Basic │
│ │ (per-user app password) │
│ │◀── API Response ───────────│
│◀── Tool Result ─────────────│ │
Key characteristics:
- MCP client authenticates to MCP server via OAuth 2.1 + PKCE
- MCP server is the OAuth authorization server (DCR via RFC 7591)
mcp:*scopes (e.g.mcp:notes.read,mcp:notes.write) gate tool access- Per-user app password obtained via Login Flow v2 and stored encrypted in SQLite
- App passwords appear in Nextcloud's Settings → Security → Devices & Sessions and are user-revocable
First-Use Provisioning (one-time per user)
MCP Client MCP Server Nextcloud
│ │ │
│── Bearer Token + request ──▶│ │
│ │ No stored app password │
│ │ │
│◀── Elicit URL or 401 ───────│ │
│ "Visit <login-url>" │ │
│ │── POST /index.php/login/v2▶│
│ │◀── login_url, poll_token ──│
│ │ │
│ User opens login_url in browser, authenticates, "Grant"│
│ ──────────────────────────────────────────────────────▶│
│ │ │
│ │── Poll endpoint (bg) ─────▶│
│ │◀── loginName, appPassword ─│
│ │ │
│ │── Encrypt + store │
│ │ in tokens.db │
│ │ │
│── Retry request ───────────▶│── Basic Auth as above ────▶│
Background Sync
Uses the same per-user app password retrieved from encrypted storage. No token refresh needed — Nextcloud app passwords don't expire (until the user revokes them).
MCP Server Nextcloud
│ │
[Background job starts] │ │
│── Retrieve app password ──▶│
│ (per user, from SQLite) │
│ │
│── HTTP + BasicAuth ───────▶│
│◀── API Response ───────────│
Astrolabe → MCP Server
Same as Multi-User BasicAuth — see Astrolabe → MCP Server above.
Configuration Quick Reference
Single-User BasicAuth
NEXTCLOUD_HOST=https://nextcloud.example.com
NEXTCLOUD_USERNAME=admin
NEXTCLOUD_PASSWORD=<app-password>
Multi-User BasicAuth
NEXTCLOUD_HOST=https://nextcloud.example.com
ENABLE_MULTI_USER_BASIC_AUTH=true
# Optional: app-password storage for background sync
TOKEN_ENCRYPTION_KEY=<fernet-key>
TOKEN_STORAGE_DB=/app/data/tokens.db
Login Flow v2
NEXTCLOUD_HOST=https://nextcloud.example.com
ENABLE_LOGIN_FLOW=true
# Required for app-password storage
TOKEN_ENCRYPTION_KEY=<fernet-key>
TOKEN_STORAGE_DB=/app/data/tokens.db
# Public URLs (for browser redirects)
NEXTCLOUD_MCP_SERVER_URL=https://mcp.example.com
NEXTCLOUD_PUBLIC_ISSUER_URL=https://nextcloud.example.com
See Login Flow v2 for full setup, scope reference, and troubleshooting.
Related Documentation
- Authentication — mode comparison and selection
- Login Flow v2 — multi-user setup details
- Configuration — environment variable reference
- ADR-022 — design rationale for mode consolidation