@8monkey/pi-context-history

Pi extension that manages conversation context: trims old history, strips stale tool calls, and keeps a rolling summary fed back into the system prompt. Each feature toggles independently.

Packages

Package details

extension

Install @8monkey/pi-context-history from npm and Pi will load the resources declared by the package manifest.

npm repohome report
$ pi install npm:@8monkey/pi-context-history
Package
@8monkey/pi-context-history
Version
0.3.0
Published
Jul 9, 2026
Downloads
849/mo · 52/wk
Author
heiwen
License
MIT
Types
extension
Size
16.3 KB
Dependencies
0 dependencies · 1 peer
Pi manifest JSON
{
  "extensions": [
    "./src/index.ts"
  ]
}

Security note

Pi packages can execute code and influence agent behavior. Review the source before installing third-party packages.

README

pi-context-history

A Pi extension that keeps long-running conversations lean and focused.

In long sessions, the context window fills with old messages and tool output the model no longer needs. This extension removes what's stale and keeps a rolling summary so earlier context isn't lost.

Everything is on by default and works once installed. Each feature can be disabled independently.

Install

pi install npm:@8monkey/pi-context-history

Features

  • Trim history. Drops messages older than PI_HISTORY_DAYS (60 by default) on each context rebuild.
  • Strip tool history. Removes tool calls and results from turns before the current one, leaving the in-progress turn untouched.
  • Compact. Keeps a rolling summary of each session in ~/.pi/agent/compact/<session-id>.md and folds it into that session's system prompt, so the model continues with prior context. The summary regenerates during session start when you resume a session after it has gone stale. Run /compact-session to regenerate on demand.
  • Append message. Adds a user or assistant message to the end of the history with /add-user-message and /add-assistant-message.

Commands

Command What it does
/compact-session Write a fresh summary of the current session now, ignoring the staleness window.
/add-user-message <text> Add a message to the conversation as if you had typed it.
/add-assistant-message <text> Add a message as if the assistant had said it. Requires a selected model.

Appended messages are persisted immediately but only enter the live context on the next rebuild (resume or branch).

Configuration

All configuration is via environment variables, and all of it is optional.

Feature toggles

Each feature is on by default. Set its variable to false to disable it.

Variable Feature
PI_TRIM_HISTORY Trim history
PI_STRIP_TOOL_HISTORY Strip tool history
PI_COMPACT Compact (generation and injection)
PI_APPEND_MESSAGE The append-message commands

Settings

Variable Default Description
PI_HISTORY_DAYS 60 Maximum age, in days, of messages kept in context.
PI_COMPACT_STALENESS_DAYS 3 How old the summary may get before it's regenerated on resume.

Compact prompt

Override the built-in prompt with a file at prompts/compact.md, read from the project .pi/ first, then ~/.pi/. It must contain the {conversation_history} placeholder.

Development

No runtime dependencies. Pi loads the TypeScript directly, so there's no build step, and it runs under Node or Bun.

node --test        # run tests
npm run typecheck

License

MIT