contextium
100% Open Source MIT

A way of working
that holds up.

Most AI sessions start from zero, then drift halfway through a long thread. Contextium is the methodology that fixes that. Give your AI an operating system.

terminal
$ curl -sSL contextium.ai/install | bash

You can see what AI should be.

A genuine multiplier across everything you build. But every session starts from zero. You re-explain your preferences, the AI makes a plausible guess, drifts halfway through a long thread, and tomorrow you start over. The gap between AI's promise and your reality never closes.

A pile of prompts

Snippets you paste, a memory feature that's a flat list of facts, rules nobody enforces. No structure that survives a long thread. Day 1,000 looks like day 1.

A sticky note.

Contextium

A way of working: a thinking-and-doing loop with fresh context between them, rules backed by hooks that actually fire, and memory written down every session. Each session builds on the last.

An operating system.

The core

Three verbs. Fresh context
between thinking and doing.

The Loop is one command per verb. The boundary between them is the point: a session that wrote the plan and grew attached to its choices is the wrong one to also judge the work.

Think

/project

Plan the work and write a short SPEC of what success looks like. No code yet, just a clear target.

Do

/implement

Execute the SPEC with self-validation, starting from a clean context. A new session catches what the invested one defends.

Wrap

/close

Journal what happened and why, one file for the day, then commit. Tomorrow's session reads it and picks up where you left off.

Plus /implement-audit for adversarial review, /explain for deep investigation, and a few more. Eight skills in Claude Code; the Loop verbs ship as native commands in Gemini, Codex, Cursor, and Copilot too.

commit-gate hook fires at commit
destructive-git guard hook fires at commit
memory-write guard hook fires at edit
your own rules wire as you grow
Not suggestions

Rules backed by
real mechanisms.

A rule that lives only in a document gets forgotten in the exact moment it was written to cover. Contextium's rules that matter are wired to hooks that actually fire: a commit gate, a destructive-git guard, a memory-write guard.

Advisory prose is allowed, but it's honest about being advisory. When a correction recurs, you write it down once and give it a mechanism. The layer becomes yours.

Accountability

Memory in two layers.
What and why.

The git log records what changed. The journal records why, one file per day, written by /close at the end of a session.

Reconstructing an old decision needs both, so the system keeps both. Six months from now you can see what you chose, what you rejected, and the reasoning, instead of re-exploring the same dead ends.

$ git log --oneline journal/
a3f2c1d Chose Postgres over DynamoDB — relational fit
8b1e4a7 Rejected the daemon — a 30-line script did it
c7d9f2e Split the parser — boundary cases were leaking
1e5a3b8 Reverted the cache — staleness beat the speed
f4c8d1a Picked MIT over Apache — simpler for a template
# Every "why" preserved, one file per day.
Claude
Today
Codex
Tomorrow
Gemini
Next year
Your Contextium
Same context. Zero migration.
No lock-in

Your context. Your data. Forever.

It's plain markdown in a git repo that you own. No platform holds it hostage. If a tool raises prices or pivots, your accumulated context doesn't vanish with it.

Model-agnostic by design. Pick your tools at install time and each gets its own native config from one source: a full .claude/ layer for Claude Code, GEMINI.md for Gemini, AGENTS.md for Codex, plus Cursor and Copilot. Same Loop, same rules, no drift.

One command. You're in.

The installer asks which AI tools you use, your name, and how autonomous you want the AI, then writes each tool's native config (.claude/, GEMINI.md, AGENTS.md, and the rest) and leaves your data alone on re-runs.

terminal
$ curl -sSL contextium.ai/install | bash
1

The installer asks

Which tools you use, your name, and how autonomous the AI should be. It writes the native config for each tool you pick from one portable source.

2

Open and run /project

Open the repo in Claude Code, Gemini, Codex, Cursor, or Copilot and start the Loop. The rules, commands, and hooks are already in place.

3

It starts compounding

Each session journals its reasoning and commits. Re-run bash install.sh anytime to refresh the layer without touching your data.

What's inside

The full .claude/ layer for Claude Code, shown here, plus empty data directories that grow as you work. Gemini, Codex, Cursor, and Copilot get the same methodology, rules, and Loop commands projected into their own native config.

.claude/skills/

8 Skills

The Loop verbs (project, spec, implement, close) plus implement-audit, explain, debate, and author. One keystroke each.

.claude/rules/

8 Principles

Always-loaded and kept short on purpose: voice, depth, boundaries, simplicity, no-deferral, mechanisms, journal format, and how to write your own.

.claude/hooks/

Wired Hooks

Mechanisms that fire: a commit gate, a destructive-git guard, a memory-write guard, a session checklist. Not documentation. Infrastructure.

.claude/agents/

3 Review Agents

Fresh-context sub-reviewers the Claude skills dispatch when they need a second set of eyes: implement-audit, research, spirit-check.

knowledge/ · journal/

Your Data Layer

Empty skeletons to start: people, goals, business context, daily logs, multi-session projects. They grow richer every session.

templates/integrations/

14 Connector Starters

Docs-only templates for wrapping external services (GitHub, Google, Todoist, and more). Configure only what you need.

Grow into it

Lean on purpose.

This ships as a methodology, not a pile of features. The heavy machinery, orchestration platforms, large reconcilers, multi-model SPEC review, per-session worktrees, is documented as advanced patterns you can grow into.

You start with the way of working and add weight where your own work demands it. Nothing you don't use is wired in.

100% Open Source

Free forever. No catch.

Contextium is MIT licensed. No premium tier. No hosted service. No data collection. Just a git repo of markdown files that you own completely.

MIT License Plain Markdown Git-Versioned No Telemetry

Stop starting from zero.

Run one command, then try /project. Then every session compounds.

$ curl -sSL contextium.ai/install | bash

MIT · Plain markdown · No lock-in