Configuration reference

Configure PI WEB where your agents work.

PI WEB configuration covers the machine-local and project-local settings you usually need: bind address, trusted development-host settings, UI preferences, plugin enablement, file-explorer path access, upload limits, and session-daemon tools.

Config files

PI WEB uses a global config file for machine-local settings and a project-local file for repository settings.

  • Global config: $PI_WEB_CONFIG, or $XDG_CONFIG_HOME/pi-web/config.json, or ~/.config/pi-web/config.json.
  • Project config: <project>/.pi-web/config.json for commit-able project settings.

Each PI WEB machine has its own config. When using Fleet/machine federation, edit a remote machine's config by opening that machine directly or changing files on that machine.

If you installed services with a custom config path, rerun pi-web install --config /path/to/config.json after changing that path or after upgrading from a version that only applied the custom path to the web service. This regenerates service files so the web/API and session daemon use the same PI_WEB_CONFIG.

Precedence and reloads

Runtime values are resolved in this order:

defaults → config file → environment overrides

Environment overrides include PI_WEB_HOST, PI_WEB_PORT / PORT, PI_WEB_ALLOWED_HOSTS, PI_WEB_MAX_UPLOAD_BYTES, PI_WEB_SPAWN_SESSIONS, and PI_WEB_SUBSESSIONS.

  • host / port: restart the web/API service or process.
  • maxUploadBytes: restart both the web/API process and the session daemon.
  • spawnSessions / subsessions: restart the session daemon.
  • pathAccess: applies on the next request; existing file views may need a browser refresh.
  • plugins: reload the browser tab after changing plugin enablement.
  • shortcuts: saved settings apply in the browser after config refresh/save.

Global config example

pi-web install creates the initial file. You can also save settings from Settings → General, Settings → Plugins, Settings → Keyboard, and Settings → Session daemon.

Example config.json
{
  "host": "127.0.0.1",
  "port": 8504,
  "pathAccess": {
    "allowedPaths": ["~/SDKs", "/opt/reference"]
  },
  "maxUploadBytes": 67108864,
  "spawnSessions": true,
  "subsessions": false,
  "plugins": {
    "workspace-tasks": { "enabled": true },
    "updates": { "enabled": true },
    "info": { "enabled": false }
  },
  "shortcuts": {
    "core:view.chat": "mod+1",
    "core:session.stop": null
  }
}

Project-local config

Project-local config lives at <project>/.pi-web/config.json. Use it for settings that should follow a repository. When a project config defines pathAccess, PI WEB merges it after the global path list.

.pi-web/config.json
{
  "version": 1,
  "pathAccess": {
    "allowedPaths": ["~/SDKs", "/opt/reference"]
  }
}

Project-local pathAccess.allowedPaths entries must still be host-absolute or ~-prefixed; relative roots are not supported. Plugins may own separate project files, such as .pi-web/tasks.json for the built-in Workspace Tasks plugin.

Config matrix

Use this table as the quick reference for where a setting can live, which environment variable overrides it, and whether project-local config overrides or merges with global config. Rows with JSON key are runtime-only environment variables, not config-file keys.

Config JSON key Env var Scope Project-local behavior Applies / restart
Config-file keys
Web/API bind host host PI_WEB_HOST Global Not supported locally Restart web/API
Web/API port port PI_WEB_PORT, PORT Global Not supported locally Restart web/API
Dev-server allowed hosts allowedHosts PI_WEB_ALLOWED_HOSTS Global Not supported locally Restart dev web/UI
External filesystem roots pathAccess.allowedPaths Global + project Merges: global roots first, then project roots; duplicates removed Next file request; refresh existing views if needed
Upload/body limit maxUploadBytes PI_WEB_MAX_UPLOAD_BYTES Global Not supported locally Restart web/API and session daemon
Agent can spawn sessions spawnSessions PI_WEB_SPAWN_SESSIONS Global/session daemon Not supported locally Restart session daemon
Tracked subsessions (beta) subsessions PI_WEB_SUBSESSIONS Global/session daemon Not supported locally; also requires spawnSessions Restart session daemon
Plugin enablement/settings plugins.<id>.enabled, plugins.<id>.settings Global Not core local config; plugins may read their own project files Reload browser tab
Keyboard shortcuts shortcuts.<actionId> Global Not supported locally Applies after settings save/config refresh
Project config version version Project Project-local only; must be 1 when present Next project-config read
Runtime-only environment variables
Global config file path PI_WEB_CONFIG (XDG_CONFIG_HOME affects the default path) Process/env Selects the global config file; not a project config Restart services/processes after changing env
Managed data directory PI_WEB_DATA_DIR Process/env Not supported locally Restart services before changing; moves managed state location
Session daemon socket PI_WEB_SESSIOND_SOCKET Web/API + session daemon env Not supported locally Restart daemon and web/API; both must match
Session daemon TCP port PI_WEB_SESSIOND_PORT Session daemon env Not supported locally Restart session daemon; set PI_WEB_SESSIOND_URL for web/API too
Session daemon TCP host PI_WEB_SESSIOND_HOST Session daemon env Not supported locally Restart session daemon
Web-to-daemon URL PI_WEB_SESSIOND_URL Web/API env Not supported locally Restart web/API
Projects storage file PI_WEB_PROJECTS_FILE Web/API + session daemon env Not supported locally Restart services; advanced state override
Remote machines storage file PI_WEB_MACHINES_FILE Web/API env Not supported locally Restart web/API; advanced state override
Pi session storage directory PI_CODING_AGENT_SESSION_DIR Pi/session daemon env Not supported locally Restart session daemon; follows Pi session priority
Pi agent config directory PI_CODING_AGENT_DIR Pi/Web/API/session daemon env Not supported locally Restart services
Skip update checks PI_WEB_SKIP_VERSION_CHECK, PI_WEB_OFFLINE, PI_SKIP_VERSION_CHECK, PI_OFFLINE Web/API env Not supported locally Restart web/API after env changes

External path access

pathAccess.allowedPaths grants PI WEB's file explorer and absolute @ path completions access to specific filesystem roots outside the current workspace. By default, workspace-relative file reads stay inside the workspace and absolute paths are denied.

Accepted root forms:

  • Unix absolute paths, for example /opt/reference.
  • Home-relative paths, for example ~/SDKs.
  • Windows absolute paths on Windows hosts, for example C:\Users\dev\SDKs.

When an absolute request is served, PI WEB expands ~, canonicalizes configured roots with realpath, requires roots to be existing directories, and rejects symlink escapes outside the allowed roots.

This is not a sandbox for the underlying Pi Coding Agent or your OS user. It only controls PI WEB UI/API file exposure outside a workspace. Add only roots you trust PI WEB to list and read through the browser UI.

Session daemon tools

spawnSessions

Boolean. Controls whether agents receive the spawn_session tool. Defaults to true. Set it to false if you do not want an agent to start independent PI WEB sessions.

Environment override: PI_WEB_SPAWN_SESSIONS=0|1|true|false.

subsessions

Boolean. Beta. Controls whether agents receive the tracked-subsession tools: spawn_subsession, list_subsessions, check_subsession, and read_subsession. Defaults to false and also requires spawnSessions to be enabled.

Tracked subsessions let an agent delegate work to child sessions, get notified when children stop working, and inspect their transcripts. Restart the session daemon after changing this setting.

Environment override: PI_WEB_SUBSESSIONS=0|1|true|false.

Optional completion tools

File and path @ completions work without extra tools. If fzf is available on the PI WEB server's PATH, PI WEB uses it to improve completion filtering and ranking; otherwise it falls back to built-in ranking.