pi-ghost-text

Ghost-text prompt suggestions for the pi coding agent — like Claude Code's inline autocomplete for the prompt box.

As you type (or after the agent finishes and the input is empty), a dimmed prediction of the likely next prompt appears after the cursor. Accept it, cycle alternatives, or keep typing.

Requirements

• Interactive TUI mode. Suggestions are an editor feature and only appear in the interactive terminal (pi with no mode flag). They do not run in -p/--print, --mode json, or --mode rpc.
• A model with a configured API key. With the default "model": "auto", the extension scans the available models for a fast/cheap one, in priority order: haiku, then gpt-*mini, then flash, then nano. If none match — or if an explicit provider/model-id isn't found — it falls back to the active session model. Set a specific model with /suggest-model.

Install

pi install npm:pi-ghost-text

Remove it:

pi remove npm:pi-ghost-text

Using it

| Key | Action | |-----|--------| | Tab | Cycle to the next candidate; accept when it's the last (or only) one | | → (right arrow, cursor at end) | Accept the current suggestion | | Esc | Dismiss the ghost, keeping what you've typed | | Move the cursor away from the end | Dismiss | | Keep typing | Shrink the ghost while it still matches, otherwise regenerate |

Tab only applies to the ghost when the file/command autocomplete dropdown is not open. Accepting inserts the suggestion into the editor for you to edit; press Enter to send it.

When candidates is 1 (the default), Tab simply accepts. Set candidates to 2 or 3 to fetch alternatives and cycle them.

Commands

| Command | What it does | |---------|--------------| | /suggest | Choose mode: both, while-typing, after-turn, or off | | /suggest-model | Pick the suggestion model (or auto to prefer a fast, cheap one) | | /suggest-context | Set the context window (messages × chars per message) |

Configuration

Stored as JSON, resolved defaults ← global ← project:

• global: ~/.pi/agent/prompt-suggestions.json
• project: .pi/prompt-suggestions.json

{
  "model": "auto",
  "mode": "both",
  "candidates": 1,
  "streaming": true,
  "contextMessages": 8,
  "contextChars": 600,
  "maxPerTurn": 0,
  "debug": false
}

| Key | Default | Description | |-----|---------|-------------| | model | "auto" | "auto" (prefer a fast, cheap model) or an explicit provider/model-id | | mode | "both" | "both", "while-typing", "after-turn", or "off" | | candidates | 1 | Alternatives to fetch (1–3); Tab cycles them | | streaming | true | Stream the single suggestion token-by-token (ignored when candidates > 1) | | contextMessages | 8 | Recent messages included in the suggestion prompt (0 = none) | | contextChars | 600 | Chars kept per message | | maxPerTurn | 0 | Max suggestions shown per agent turn (0 = unlimited) | | debug | false | Append diagnostic lines to ~/.pi/agent/prompt-suggestions.log |

mode, model, contextMessages, and contextChars are settable from the commands above; candidates, streaming, maxPerTurn, and debug are JSON-only. Commands write to the global scope, so a project override in .pi/prompt-suggestions.json takes precedence over a command-set value.

Privacy

When enabled, the suggestion model receives only:

• the text you have typed so far, and
• the last contextMessages user/assistant messages, each trimmed to contextChars characters.

It is never sent:

• the full conversation transcript,
• tool outputs,
• file contents,
• project or session metadata.

Suggestions are advisory and best-effort; failures are never surfaced in the UI. With "debug": true they are logged to ~/.pi/agent/prompt-suggestions.log with a stable category (timeout / error / no-suggestion).

Troubleshooting

If no suggestion appears:

1. Confirm the mode is not off — run /suggest.
2. Confirm the suggestion model has an API key configured (or, for auto, that one of the fast/cheap models does). /suggest-model shows what's available. An explicit model that isn't found silently falls back to the active session model, so check the spelling as provider/model-id.
3. While-typing suggestions need ≥4 chars of plain text (not starting with / or !, not an @file completion in progress), a ~700ms pause, and the agent must be idle (not mid-response).
4. After-turn suggestions only appear when the editor is empty right after the agent settles.
5. If maxPerTurn is set, you may have hit the per-turn cap.
6. Set "debug": true and check ~/.pi/agent/prompt-suggestions.log for [prompt-suggestions] lines — they state the reason (timeout, error, no-suggestion).
7. If the ghost flakes with streaming enabled, set "streaming": false to force the non-streaming path.

Development

npm test   # node --test, no dependencies (requires Node ≥ 23.6)

Prior art

Inspired by supi-prompt-suggestions. This adds inline while-typing autocomplete (prefix-anchored, shrink-on-type), multi-candidate cycling, streaming ghost text, scoped global/project config, and explicit modes on top of the empty-box next-prompt suggestion.