> ## Documentation Index > Fetch the complete documentation index at: https://docs.fapost.in/llms.txt > Use this file to discover all available pages before exploring further. # Introduction > What FaPost Core is, and who each part of this documentation is for. **This documentation is being written.** Self-hosting, Developers and Reference are current and describe the platform as it stands. **The user guide is not written yet** — it covers the admin screens and the flow canvas, and describing an interface from the outside is how documentation drifts from the product. It follows once each screen can be walked through. **FaPost Core is a platform for building conversational assistants.** An assistant connects to messaging channels such as Telegram and WhatsApp, holds conversations with contacts, and runs them through flows designed on a visual canvas — with contacts, segments, broadcasts, and conversation history around it. This repository is Core: the platform itself, without vertical product packages. A flow is a directed graph, stored as JSON, that describes a conversation. Each node does one thing — send a message, wait for a reply, branch on a condition, call an HTTP endpoint, query a knowledge base — and edges connect a node's outcomes to whatever comes next. At runtime an engine walks that graph for one contact, resolving each node's handler by the pair `(type, version)` and keeping the conversation's state between steps. A node handler never decides which node runs next: it reports which outcome occurred, and the graph decides where that leads. That separation is what makes a flow editable by someone who does not write code, and a node reusable in flows its author never saw. ## What you can build Most installations start as a bot that answers questions on one channel. The platform is not limited to that: an assistant can qualify leads, run a multi-step intake form, notify a team, look up records in another system through an HTTP call, or broadcast to a segment of contacts on a schedule. Tenancy is not a layer bolted on top — it is a coordinate of the runtime. One installation serves many independent organisations, each with its own assistants, contacts, channels, and data, isolated in its own schema. ## Where to go Build an assistant, design flows, manage contacts and broadcasts. For the people who run it day to day. Install, run, and upgrade FaPost on your own infrastructure. For whoever keeps the servers. Build a Solution or Plugin, or work on Core itself — including the local development environment and what the platform is made of. Contracts, schemas, queues, commands. ## What happens when someone writes A contact sends a message. The assistant looks up which flow should handle it and starts a **session** — one contact moving through one flow. The session runs from node to node until the flow ends or reaches a node that waits for a reply. While it waits, the session stays open. When the contact answers, it picks up exactly where it stopped, with everything collected so far still in place. Two consequences are worth knowing before you build anything: **A published flow is a snapshot.** A session holds the version of the flow it started with. Publishing a change affects the next conversation, not the ones already in progress — so nobody finds the questions changing underneath them mid-conversation. **A broadcast never delays a reply.** Large sends are paced separately from conversation traffic, so a mailout to fifty thousand contacts does not put the person who just asked a question behind a queue. ## Status The platform is pre-1.0 and in active development. Where a feature is not finished, these pages say so rather than describing an intention as a fact — and the user guide names the screens it has not been written for yet.