Glossary
This page defines the terms used across the guide, in alphabetical order.
Access token. The random secret in the part of the address after #. Anyone who has the full address can use your service. See Security and privacy.
Address. The URL the launcher prints, such as http://127.0.0.1:52395/#<token>: your machine, a random port, and the access token.
Agent. The program that works toward your request by calling a model and using tools to read files, edit them and run commands. In pi-webapp that is Pi.
Background launcher. The pi-webapp command and the service it keeps running after you close the terminal. Also called the web launcher.
Business package. In the desktop app, the pi-webapp version that runs inside the app shell. It updates separately from the shell. See Desktop app.
Compact. A command that shortens a session's history to free up context. Run it from the + menu or /compact.
Data folder. Pi's folder (~/.pi/agent by default) with your sessions, credentials, settings and pi-webapp's own pi-web/ state. See Files and directories.
Extension. Code that adds capabilities to Pi, such as commands and tools. See Packages, skills and plugins.
Handoff. Moving a running shared service to the current desktop app's launcher, without changing its address. It waits for idle chats and never force-stops.
Model provider. The company or server that hosts a model: Anthropic, OpenAI, your own gateway. You connect one in Pi Settings → Models.
Package. A bundle of extensions and skills installed from npm, Git or a folder.
Pause / Continue. Pause stops a chat's current execution and keeps its progress. Continue starts a new request that carries on from it. See Conversations.
Pi. The coding agent that pi-webapp is an interface for. Its package is @earendil-works/pi-coding-agent.
Pi SDK. Pi as a library. The npm package of pi-webapp is pinned to one exact SDK version that it was tested with.
Plugin. A pi-webapp feature with its own screen: the built-in Files, Terminal and Git tools, and optional ones such as Excalidraw. Managed under Plugins in the sidebar.
Hosted plugin. The kind of plugin that is downloaded and runs in its own process and browser frame, such as Excalidraw. The term shows up in some logs and messages.
Preview channel. The update option that follows the newer of npm's latest and alpha versions. Stable follows latest only. See Updates.
Queue. Messages you send while Pi is working; Pi handles them when the current task finishes. See Conversations.
Service. The local program that serves the page and drives Pi. It listens on 127.0.0.1 only.
Session. One saved chat with Pi in a workspace, stored as a file under sessions/.
Shell (desktop). The installed desktop app itself, as opposed to the pi-webapp version it runs.
Skill. A SKILL.md file or folder of guidance that Pi can load for a task. Skills appear as skill:<name> commands.
Steer. Sending a message to a working Pi so it reaches Pi at its next opportunity, without waiting for the task to finish. Use Ctrl/Cmd+Enter.
Tool call. One action the agent took, such as reading a file or running a command. Shown collapsed in the conversation and listed in the Trajectory tab.
Trajectory. The tab that lists every message, tool call and reply of a session with timing and token details.
Turn. One user message and everything Pi did in response.
Workspace. A project folder, where the agent starts and where chats are grouped. Not a security boundary.