Documents the architectural flaw in current implementation where
session tokens and background tokens are not properly separated.
Key issues identified:
- Session tokens should be exchanged on-demand (RFC 8693)
- Background tokens should use separate refresh token grant
- Current implementation reuses refresh tokens incorrectly
- No separation between foreground and background operations
This is a P0 blocker that must be fixed before production use.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
Implements Progressive Consent architecture with dual OAuth flows:
- Flow 1: Direct client authentication (aud: "mcp-server")
- Flow 2: Resource provisioning with refresh tokens
Components added:
- Client registry with validation (client_registry.py)
- Progressive token verifier (progressive_token_verifier.py)
- Token broker service integration
- Provisioning decorator for MCP tools
- OAuth provisioning tools (provision_nextcloud_access, etc.)
Configuration:
- Progressive Consent enabled by default (ENABLE_PROGRESSIVE_CONSENT=true)
- Client validation with pre-registered clients
- Audience separation framework
KNOWN ISSUE - Token Exchange Pattern Incorrect:
The current implementation does NOT properly implement token exchange.
MCP session tokens should be EXCHANGED for delegated Nextcloud tokens
during tool calls, not stored/reused. Critical corrections needed:
1. Session tokens: Flow 1 token → exchange → ephemeral Nextcloud token
- Generated on-demand per tool call
- Short-lived, not stored
- Scopes limited to tool requirements
2. Background tokens: Flow 2 refresh token → background Nextcloud token
- Only for offline/background jobs
- Potentially different scopes than session tokens
- Must NOT be used for MCP session tool calls
The token exchange mechanism needs to be implemented to properly
separate session-time delegation from background job authorization.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
