nvim-pi

Neovim plugin with a bundled Pi extension.

This package works in two modes:

• install it as a Neovim plugin and let it launch Pi with the bundled extension
• install it with pi install git:github.com/aliou/nvim-pi and use the extension directly in terminal Pi sessions

When Neovim is not running, the extension still loads cleanly and degrades gracefully.

What it provides

Pi extension

Tool / Command	Description
nvim_context	Query the connected Neovim instance for focused buffer, splits, diagnostics, or current function
/neovim:settings	Configure Neovim integration settings for the Pi extension
/neovim:undotree [file]	Inspect a Neovim persistent undo tree for a file
@vim: autocomplete	Type @vim: in Pi’s input to autocomplete file paths from visible Neovim splits

Additional disabled-by-default behavior:

• extensions/undo can update matching Neovim persistent undo files after successful Pi edit and write tool calls.

Behavior provided by hooks:

• automatically discovers and connects to a matching Neovim instance on session start
• injects visible editor state into the system prompt on each turn (configurable)
• reloads files in Neovim after successful write and edit tool calls
• sends LSP diagnostics for modified files after the turn ends

Neovim plugin

• starts a Neovim RPC server and writes lockfiles Pi can discover
• opens Pi in a terminal split or float
• passes through selected Pi CLI flags
• runs a periodic checktime timer while Pi is open to detect external file changes
• provides a context picker (<C-Space> by default) to send editor context to Pi
• exposes :PiNvimStatus

Setup

As a Neovim plugin

Install this repo as a Neovim plugin. The lua/ directory is runtimepath-compatible.

Example with vim.pack:

vim.pack.add({ { name = "nvim-pi", src = "https://github.com/aliou/nvim-pi" } })
require("pi-nvim").setup()

Use an existing Pi git install as a Neovim plugin:

pi install git:github.com/aliou/nvim-pi

vim.opt.runtimepath:append(vim.fn.expand("~/.pi/agent/git/github.com/aliou/nvim-pi"))
require("pi-nvim").setup()

If you installed it into project settings with pi install -l, use that project’s .pi/git/github.com/aliou/nvim-pi path instead.

Local checkout setup for development:

vim.opt.runtimepath:append(vim.fn.expand("/absolute/path/to/nvim-pi"))
require("pi-nvim").setup()

Requirements:

• pi must be on PATH
• nvim must support serverstart() and --remote-expr

When you open Pi through pi-nvim, the plugin launches:

pi --extension /absolute/path/to/nvim-pi

The extension then injects runtime editor state through hooks. By default (load_extension = "auto"), the plugin checks whether nvim-pi is installed globally in Pi and skips --extension if so — this avoids loading the extension twice when you already installed it with pi install.

As a Pi extension

You can also install it directly in Pi:

pi install git:github.com/aliou/nvim-pi

This is useful if you want the extension available in terminal Pi sessions too. If no Neovim instance is running, the extension still loads and simply reports that no instance was found when needed.

Configuration

Pi extension config

/neovim:settings currently exposes:

Setting	Default	Description
Connection status messages	on	Show nvim: connected / no instance found style messages in the Pi session
Editor state injection	off	Inject current Neovim editor state (open splits, cursor position) into each prompt automatically
@vim: autocomplete	enabled	Enable autocomplete for open Neovim splits
Persistent undo tools	disabled	Update Neovim persistent undo files after successful Pi edit and write tool calls

Feature toggles are shown as unavailable if Pi did not load that extension entry point.

Neovim plugin config

require("pi-nvim").setup({
  auto_start = true,
  data_dir = nil,

  -- Pi CLI flags
  models = nil,
  provider = nil,
  model = nil,
  thinking = nil,
  load_extension = "auto", -- "auto": skip --extension if installed globally; true: always pass; false: never pass
  extra_args = nil,

  -- Window configuration
  win = {
    layout = "auto",
    width_threshold = 150,
    width = 80,
    height = 20,
    focus_source_on_stopinsert = true, -- switch to source window on exiting terminal mode
    keys = {
      close = { "<C-q>", mode = "n", desc = "Close Pi" },
      stopinsert = { "<C-q>", mode = "t", desc = "Exit terminal mode" },
      suspend = { "<C-z>", mode = "t", desc = "Suspend Neovim" },
      picker = { "<C-Space>", mode = "t", desc = "Open context picker" },
    },
  },
})

Keymaps

The plugin does not create global leader mappings by default.

Example mappings:

vim.keymap.set("n", "<leader>po", require("pi-nvim").open, { desc = "Open Pi" })
vim.keymap.set("n", "<leader>pc", require("pi-nvim").close, { desc = "Close Pi" })
vim.keymap.set("n", "<leader>pp", require("pi-nvim").toggle, { desc = "Toggle Pi" })

Terminal/window-local keys are configured under setup({ win = { keys = ... } }).

Usage

From Pi

The nvim_context tool supports these actions:

• focused_buffer - focused file, cursor position, selection, filetype
• splits - all visible splits with metadata
• diagnostics - diagnostics for the current buffer
• current_function - treesitter info for the symbol at the cursor

If multiple matching Neovim instances are found, Pi prompts you to choose one when UI is available.

From Neovim

Commands and API:

• :PiNvimStatus - show RPC and terminal state
• require("pi-nvim").open() - open the Pi terminal
• require("pi-nvim").close() - close the Pi terminal
• require("pi-nvim").toggle() - toggle the Pi terminal
• require("pi-nvim").start() - start the RPC server manually
• require("pi-nvim").stop() - stop the RPC server manually
• require("pi-nvim").status() - get the current RPC state
• require("pi-nvim").is_open() - check if the Pi terminal is open

Pi extension commands:

• /neovim:settings - configure connection messages, @vim: autocomplete, and persistent undo integration
• /neovim:undotree [file] - open a persistent undo tree overlay for a file; when no file is provided, Pi shows a picker if UI is available

Troubleshooting

Pi cannot find Neovim

Check:

• :PiNvimStatus shows the RPC server as running
• pi and nvim are both on PATH
• lockfiles exist under Neovim’s data dir, usually ~/.local/share/nvim/pi-nvim/

Discovery prefers:

1. exact cwd matches
2. Neovim instances whose cwd is a child of Pi’s cwd

Multiple Neovim instances found

Pi will prompt for selection in interactive mode. In non-interactive mode, the tool returns an error instead of guessing.

RPC server errors

Check:

• <stdpath('log')>/pi-nvim/rpc.log (typically ~/.local/state/nvim/pi-nvim/rpc.log)
• :PiNvimStatus

Healthcheck

:checkhealth pi-nvim

Architecture

Neovim plugin (Lua)                            Pi extension (TypeScript)
-------------------                            ------------------------
require("pi-nvim").setup()                    pi --extension /path/to/nvim-pi
          |                                                   |
          v                                                   v
   rpc.start()                                     extensions/nvim/index.ts registers:
   lockfile.create()                               - hooks (editor state, lifecycle)
          |                                      - tool (nvim_context)
          v                                      - command (/neovim:settings)
~/.local/share/nvim/pi-nvim/                       - renderers (connection, diagnostics)
<cwd-hash>-<pid>.json                                           |
          |                                          session_start discovers lockfile
          |                                          before_agent_start queries splits
          |                                          tool_result reloads files
          |                                          turn_end requests diagnostics
          v                                                   |
   nvim --server <socket> --remote-expr <luaeval(...)> <------+

Core (src/) has zero Pi dependencies:
  nvim.ts          lockfile discovery + RPC
  types.ts         domain types + type guards
  format.ts        shared formatting helpers

Additional extensions:
  splits-autocomplete/       @vim: autocomplete for open splits
  undo/                       /neovim:undotree plus disabled-by-default persistent undo update hooks

Additional Lua features:
  cli/terminal     open/close/toggle Pi in a split or float
  cli/picker       <C-Space> context picker to send info to Pi
  cli/watch        periodic checktime timer while Pi is open

The TypeScript extension discovers Neovim instances through lockfiles, then queries the running editor through nvim --remote-expr, which evaluates require("pi-nvim").query(...) inside Neovim.