A bidirectional communication bridge between Neovim and a terminal coding agent (pi or Claude Code).

Shannon opens a floating window in Neovim where you type a prompt. When you save (:w or :x), it delivers the prompt to a running agent session in a sibling tmux pane, along with file and cursor context. Close without sending using :fclo or :q!.

With the companion Pi skill or Claude Code plugin installed, communication flows in both directions — the agent can annotate your code with virtual text, open files, and jump to lines.

• Neovim 0.9+
• tmux
• A supported agent (pi or Claude Code) running in a sibling tmux pane

With lazy.nvim:

{ 'wincent/shannon', config = true }

With packer.nvim:

use {
  'wincent/shannon',
  config = function()
    require('wincent.shannon').setup()
  end,
}

With mini.deps:

add('wincent/shannon')
require('wincent.shannon').setup()

Manual: clone into your pack/ directory, run :packadd shannon, and call require('wincent.shannon').setup().

require('wincent.shannon').setup()

This creates the default keymaps with <Leader>s as the prefix:

require('wincent.shannon').setup({
  keymaps = true,              -- set to false to suppress default keymaps
  prefix = '<Leader>s',        -- keymap prefix
  agents = { 'pi', 'claude' }, -- process names to search for, in priority order
})

Shannon locates the target pane by running pgrep -x <name> for each entry in agents and walking up the process tree until it reaches a sibling tmux pane's shell. The first match wins, so order the list by preference.

Defaults to { 'pi', 'claude' }. Override to pin a single agent, reorder priority, or add others:

-- pi only
require('wincent.shannon').setup({ agents = { 'pi' } })

-- prefer claude over pi
require('wincent.shannon').setup({ agents = { 'claude', 'pi' } })

-- add a custom agent
require('wincent.shannon').setup({ agents = { 'pi', 'claude', 'aider' } })

• :Shannon — open the floating prompt window. In visual mode, the selected range is included as context.
• :ShannonNextMark / :ShannonPreviousMark — jump between Shannon annotations (extmarks).
• :ShannonClearMarks — clear all Shannon annotations in the current buffer.

While the floating window is open, CTRL-Y and CTRL-E scroll the parent window.

If the prompt starts with /btw, the prompt text is placed before the context line.

For bidirectional communication with the agent, install the shannon Claude Code plugin from the wincent-claude-plugins marketplace:

claude plugin marketplace add wincent/wincent-claude-plugins
claude plugin install shannon

This teaches Claude Code to annotate code, open files, and navigate your Neovim session via RPC.

Equivalently, a "neovim" Pi skill exists in the marketplace repo under pi/skills/. If you want to share the marketplace repo with both Claude and Pi, you can configure Pi to read from the marketplace repo by add the following in ~/.pi/agent/settings.json:

{
  "skills": [
    "~/.claude/plugins/marketplaces/wincent-claude-plugins/pi"
  ]
}

See LICENSE.md.