> ## Documentation Index > Fetch the complete documentation index at: https://docs.contextaco.com/llms.txt > Use this file to discover all available pages before exploring further. # What Contextaco is > A shared layer for carrying context across people, agents, conversations and tools. A valuable session with an agent produces a durable state of understanding — the decisions made, the constraints that forced them, the approaches that failed, the questions still open. That state normally dies when the session ends, and the next session starts by reconstructing it from scratch. Contextaco makes it persistent. You capture it in a **taco** — one address holding the notes for one line of work — and any human or agent can pick it up later. ## The loop Your agent writes down what it worked out as the work happens — not afterwards, and not into a second system you have to maintain. That is the point: you never file anything. A later session opens the same taco and starts from that understanding instead of rebuilding it. It reads the shape first, then only the notes it actually needs. When the work branches into a different intention, fork it. The copy is independent, and it records where it came from. Checkpoints record what changed and why, so whoever picks the work up next can see how it moved. ## What it is not Contextaco is deliberately **not** a note-taking app, a knowledge base, or a research library. You are not meant to visit it, tidy it, or maintain it. It is infrastructure your agent writes to and reads from; the web app exists so a human can review, trust and share what was written. It also makes no model calls of its own. It stores and serves — your agent does the reasoning. ## Where things live One address, and the setup for clients that cannot open a browser. Taco, note, note type, overview, checkpoint, fork, visibility. What a rejection means and what to do about it. Short answers to the questions that come up first.