pi-web/docs/config.md

PI WEB configuration reference

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

This file is the markdown reference for agents and package consumers. The website page is https://pi-web.dev/config.

Config files

PI WEB uses two config files:

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

Each PI WEB machine has its own config. When using Fleet/machine federation, Settings uses the selected machine for config that affects work running there: session daemon tools, PI WEB plugin enablement, external path access, and upload defaults. Gateway/browser-only settings stay local to the gateway: keyboard shortcuts, remote machine registry/tokens, and gateway host/port/allowed-hosts. Remote servers that do not advertise selected-machine settings support report those settings as unavailable instead of silently falling back to the gateway.

Pi package settings are separate from PI WEB config. They live in Pi's package-manager settings on the target machine and are managed by Pi (pi install, pi remove, pi update) or Settings → Pi packages. In a federated setup, Settings → Pi packages targets the currently selected machine. The PI WEB plugins config key only enables or disables discovered PI WEB browser plugins on the machine whose config you are editing; it does not install, remove, or update Pi packages.

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.

Reverse-proxy deployment paths

The deployment path is not a PI WEB config-file key or environment setting. The published client is portable: one build works at / and at canonical trailing-slash prefixes such as /ai/ or /test/ai/.

For a nested deployment, redirect the slashless prefix to the trailing-slash URL, strip the prefix before forwarding to PI WEB, and proxy authenticated HTTP and WebSocket traffic through the same location. Relative browser and PWA URLs then stay within that prefix. See the reverse proxy installation guide for a complete Nginx example.

Precedence and reloads

Machine-global runtime values are resolved as:

defaults → global config file → environment overrides

Supported project-local settings are then applied for that project's workspaces. For upload defaults, <project>/.pi-web/config.json overrides the global value.

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.

Process restarts depend on the key:

• host / port: restart the gateway web/API service or process.
• maxUploadBytes: restart both the web/API process and the session daemon on that machine.
• spawnSessions / subsessions: restart the session daemon on that machine.
• pathAccess: applies on the next request; existing file views may need a browser refresh.
• uploads.defaultFolder: applies to newly opened Files upload dialogs and new direct drag/drop batches after config/workspace refresh.
• plugins: reload the browser tab after changing PI WEB plugin enablement.
• Pi package install/remove/update: not a PI WEB config key; after a mutation, type /reload in each idle PI WEB session on the target machine to refresh Pi runtime resources such as extensions, skills, prompt templates, themes, and context/system prompt files as supported by Pi. Reload the browser page separately for PI WEB browser plugin changes. A routine session daemon restart is not required.
• shortcuts: saved settings apply in the browser after config refresh/save.

Global config example

{
  "host": "127.0.0.1",
  "port": 8504,
  "pathAccess": {
    "allowedPaths": ["~/SDKs", "/opt/reference"]
  },
  "uploads": {
    "defaultFolder": ".pi-web/uploads"
  },
  "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.

{
  "version": 1,
  "pathAccess": {
    "allowedPaths": ["~/SDKs", "/opt/reference"]
  },
  "uploads": {
    "defaultFolder": "manual/uploads"
  }
}

Project-local pathAccess.allowedPaths entries are merged after the global list and deduplicated. Paths must still be host-absolute or ~-prefixed; relative roots are not supported.

Project-local uploads.defaultFolder overrides the global upload destination for workspaces in that project. Current PI WEB servers include this workspace-effective value on the existing workspace responses used locally and through machine federation. Older remote servers may omit the optional field; the browser falls back to the global/default upload folder.

Plugins may own separate project files, such as .pi-web/tasks.json for the built-in Workspace Tasks plugin.

Configuration matrix

Rows with JSON key — are runtime-only environment variables, not config-file keys. Global means machine-global. In Settings, selected-machine-safe global keys (pathAccess, uploads, maxUploadBytes, spawnSessions, subsessions, and plugins) are edited for the selected machine; gateway host/port/allowed-hosts, keyboard shortcuts, and machine registry/tokens stay local.

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
Manual file upload default folder	uploads.defaultFolder	—	Global + project	Overrides: project value wins for workspaces in that project; otherwise global/default applies	New Upload dialogs and direct drag/drop batches after config/workspace refresh
Upload/body limit	maxUploadBytes	PI_WEB_MAX_UPLOAD_BYTES	Global	Not supported locally	Restart web/API and session daemon on that machine
Agent can spawn sessions	spawnSessions	PI_WEB_SPAWN_SESSIONS	Global/session daemon	Not supported locally	Restart session daemon on that machine
Tracked subsessions (beta)	subsessions	PI_WEB_SUBSESSIONS	Global/session daemon	Not supported locally; also requires spawnSessions	Restart session daemon on that machine
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 web/API and session daemon
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

Key details

Managed data directory

PI_WEB_DATA_DIR sets the root for PI WEB-managed runtime state and defaults to ~/.pi-web. Unless a more specific path override is configured, PI WEB stores its project and machine registries, locally discovered plugins, default session-daemon socket, and session archives beneath this root.

This setting does not change the PI WEB config file selected by PI_WEB_CONFIG or Pi-owned state such as the active session files selected by PI_CODING_AGENT_SESSION_DIR.

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. Add only roots you trust PI WEB to list and read through the browser UI.

Accepted root forms:

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

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

In Settings → General, external filesystem roots are saved on the selected machine. Gateway host, port, and allowed-hosts fields stay on the gateway config.

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.

Manual upload defaults

The Files panel can upload one or more files in two ways:

• Drop files onto the Files panel to upload immediately to the workspace-effective default folder.
• Use the toolbar Upload button to open the review dialog, edit the destination, and opt into upload options.

uploads.defaultFolder sets the workspace-effective default destination. The built-in default is .pi-web/uploads; a global config value applies to every project unless <project>/.pi-web/config.json sets a project-local override.

{
  "uploads": {
    "defaultFolder": "manual/uploads"
  }
}

The value must be a non-empty workspace-relative folder. PI WEB normalizes repeated separators and backslashes to /, and rejects absolute paths or .. traversal. In the upload dialog only, clearing the destination field uploads that batch to the workspace root.

Manual uploads use the workspace file-write path: paths stay workspace-relative, parent folder creation is enabled by default, and overwrite is disabled by default. Direct drag/drop always keeps overwrite off; the review dialog lets you explicitly enable overwrite when needed. Browser-owned XHR progress is shown per batch/file, conflicts and errors stay visible in the upload progress UI, and the final file-write response is the source of truth.

For machine federation, Settings saves the global upload default on the selected machine. Current remote PI WEB servers also return workspace.effectiveConfig.uploads.defaultFolder on the existing workspace-list response. Older remote servers can omit that optional field without breaking clients; the Files panel falls back to the global/default upload folder.

The per-request size limit is still controlled by maxUploadBytes / PI_WEB_MAX_UPLOAD_BYTES on the machine serving the upload.

Session daemon tools

spawnSessions controls whether agents receive the spawn_session tool. It defaults to true; set it to false if you do not want an agent to start independent PI WEB sessions.

subsessions is beta and controls whether agents receive the tracked-subsession tools: spawn_subsession, list_subsessions, check_subsession, read_subsession, and yield_to_subsessions. It defaults to false and also requires spawnSessions to be enabled.

Tracked subsessions are join-oriented. Calling spawn_subsession returns immediately, so the parent can continue independent work while the child runs. Work whose result the parent does not need to join belongs in the fire-and-forget spawn_session tool instead.

At a join point, after finishing its independent work, the parent calls yield_to_subsessions alone as the final action in its tool batch. Pi ends a tool batch early only when every result in that batch is terminating. If any tracked child is still working, the action ends the current agent run so the parent becomes idle. If none are working, it does not end the run and clearly reports that there is nothing to wait for.

A completion notice automatically wakes an idle parent. If the parent is busy, the notice queues until the current turn ends rather than interrupting in-flight work. When multiple children finish at different times, the parent handles each completion and calls yield_to_subsessions again while another child is still working.

list_subsessions, check_subsession, and read_subsession never yield or change control flow and are not completion-polling mechanisms. They remain available for deliberate inspection or recovery. While a child is working, agent-facing check_subsession and read_subsession withhold partial output and transcript entries and instead direct the parent to continue independent work or yield at the join point. Once the child is no longer working, its output and transcript are available. Completion notifications, rather than polling inspection tools, are the normal synchronization mechanism.

In Settings → Session daemon, these keys are saved on the selected machine. Restart the session daemon on that machine after changing them.

Plugin config

The plugins key is only for PI WEB browser plugin enablement/settings on the machine whose config you are editing. It does not install, remove, or update Pi packages; use Settings → Pi packages or Pi's package manager for package operations. In a federated setup, Settings → PI WEB plugins and Settings → Pi packages both target the currently selected machine, and each panel labels where changes will be saved or run.

Plugins are enabled by default. Set plugins.<id>.enabled to false to remove a plugin from that machine's /pi-web-plugins/manifest.json before the browser imports it. Settings lists discovered plugins from the selected machine, including disabled entries exposed by that machine.

{
  "plugins": {
    "workspace-tasks": { "enabled": true, "settings": {} },
    "updates": { "enabled": false }
  }
}

Reload the browser tab after changing plugin enablement. Already-loaded plugin JavaScript is not unloaded from the current page.

Shortcut config

Shortcut values are keyed by action id. Values are shortcut strings such as mod+k or mod+g p; null disables that action's shortcut.

{
  "shortcuts": {
    "core:view.chat": "mod+1",
    "core:session.stop": null
  }
}

Prefer Settings → Keyboard for editing shortcuts interactively.

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/ranking; otherwise it falls back to built-in ranking.