Security

Threat Model

The bridge operates as a localhost-only process communicating with the Super Productivity desktop app on 127.0.0.1:3876.

What the bridge can do

Read all tasks, projects, and tags
Create, update, complete, archive, and restore tasks
Start and stop time tracking
Modify host config files (when configure is run)

What the bridge cannot do

Delete tasks — task.delete is intentionally excluded
Access the network — only connects to localhost
Modify SP settings — only uses the task/project/tag APIs
Persist credentials — no auth tokens or secrets are stored

Data Flow

MCP Host → stdin/stdout → sp-local-bridge → HTTP localhost → Super Productivity

All communication is local. No data leaves your machine via the bridge.

MCP Host Trust

Your MCP host (VS Code Copilot, Claude Desktop, Codex) decides when to invoke bridge tools. Review your host's:

Data handling policy — the host sees your task data in tool responses
Tool approval settings — some hosts auto-approve, others ask per-call
Context window — task data may be sent to the host's AI model

Config File Safety

The configure command:

Creates a backup (.bak) before modifying any config file
Uses atomic writes (temp file + rename) to prevent corruption
For JSON configs, parses the existing file before modification
For TOML configs (Codex), applies a structural guard and creates a backup before surgical edits; this is not a full TOML parser
Validates structure before writing

Recommendations

Back up SP data before heavy automation use
Use --dry-run before first configure to preview changes
Review host privacy — your task data flows through the host
Keep the binary updated — install from tagged releases
Restrict binary permissions — standard user install to ~/.local/bin