Deciduum

A time-based decision and cognition log that captures decisions and their reasoning — forming a foundation for future thinking and action.

Deciduum (decide + continuum) — the ongoing journey of decisions over time.

Philosophy

• No productivity scoring or gamification — Just honest tracking
• Time is the primary organizing principle — Everything is anchored to when it happened
• Decisions are intentional events — Not habits, not tasks, but conscious choices
• Manual state transitions only — No automation; you decide when to move forward

Why Deciduum?

• Human-first: Clean CLI for daily use
• Agent-compatible: AI can follow your reasoning chain
• Future-oriented: Build reasoning chains for better decisions
• 100% local: Your data stays with you

Core Concepts

Concept	Description
Decision	A conscious choice with a date. The anchor point for reasoning.
DecisionLog	Append-only reasoning and reflections — the reasoning chain behind a decision.
Memo	An unstructured thought, observation, or cognitive note.
Direction	An optional long-term grouping that provides context for related decisions.

Installation

pipx install deciduum

Verify installation:

deciduum --help

Usage Examples

# Create a new decision
deciduum decisions create "My decision"

# List all decisions
deciduum decisions list

# Add reasoning to a decision
deciduum decisions log "decision-id" "My reasoning"

# Create a memo (unstructured thought)
deciduum memos create "My thought"

# View today's activity
deciduum today

# Create a new session (separate database)
deciduum session create work

Development Installation

For local development, install in editable mode:

pip install -e cli/

• -e (editable): Changes to source code take effect immediately without reinstalling

Architecture

Deciduum is built with a CLI-first, offline-first approach:

• Local SQLite — All data lives in your local database
• Session-based multi-database — Switch contexts by creating new sessions
• Optional server — Add FastAPI backend for multi-device access (not required)

Sessions are stored at ~/.deciduum/sessions/{session_id}.db. The default session is default.

Project Structure

deciduum/
├── cli/           # Python CLI (Typer + SQLAlchemy)
├── backend/       # FastAPI server (optional)
├── frontend/      # React frontend (optional)
└── docs/          # Documentation

Quick Reference

Command	Description
deciduum decisions create "text"	Create a decision
deciduum decisions list	List all decisions
deciduum decisions log <id> "text"	Add reasoning to a decision
deciduum memos create "text"	Create a memo
deciduum memos list	List all memos
deciduum today	Show today's activity
deciduum session create <name>	Create a new session
deciduum session list	List all sessions

Use DECIDUUM_SESSION=<name> to switch sessions:

DECIDUUM_SESSION=work deciduum decisions list