This ADR documents the architectural decision to support both OAuth and
AppAPI (ExApp) deployment modes in a single codebase with 90%+ code sharing.
Key additions:
- Comprehensive analysis of AppAPI limitations and challenges
- Feature parity matrix comparing OAuth vs AppAPI modes
- Resolution of critical open questions via research:
* Non-browser client authentication (app passwords/OAuth)
* Streaming transport compatibility (buffered, not real-time)
* Callbacks/webhooks (MCP notifications not possible in AppAPI)
- Detailed implementation plan with 4 phases (10 days)
- Mode-aware architecture with abstraction layer
Critical findings:
- AppAPI mode does NOT support MCP sampling (RAG features)
- No real-time progress updates (use Nextcloud notifications)
- Buffered streaming only (Streamable HTTP works, WebSocket doesn't)
- Requires app password support in AppAPI proxy
Deployment mode selection:
- OAuth: Multi-tenant, external clients, sampling/RAG, real-time updates
- AppAPI: Single-tenant, simplified install, native UI, admin-controlled
Related to investigation of ~/Software/app_api/ and ~/Software/nc_py_api/
for AppAPI integration patterns.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
