Pi

@db0-ai/pi is an extension that gives the Pi coding agent persistent, cross-session memory. Preferences, project patterns, and solutions survive compaction and session resets.

npm · GitHub

Install

npx @db0-ai/pi init

This creates the extension at ~/.pi/agent/extensions/db0/, installs dependencies, and writes the entry point. No other configuration needed.

What it does

The extension registers tools and lifecycle hooks with Pi's extension API:

Tools

The agent gets three memory tools:

Tool	Description
`db0_memory_write`	Store a fact with scope and optional tags
`db0_memory_search`	Search memories by query
`db0_memory_list`	List memories, optionally filtered by scope

Lifecycle hooks

Hook	Behavior
`before_agent_start`	Packs relevant memories into context
`turn_end`	Extracts facts from the assistant's response
`session_start`	Creates a fresh harness (memories carry over)
`session_shutdown`	Runs reconciliation and closes cleanly

Memory extraction happens automatically after every turn. The agent doesn't need to be told to remember — it just does.

What gets remembered

With the coding-assistant profile (default), the extension captures:

Tool and language preferences ("use bun", "single quotes", "functional style")
Project patterns and architecture decisions
Solutions to problems encountered across sessions
User corrections and feedback

Facts are scoped: user-scope memories persist forever, session-scope ones expire with the session.

Storage

Default: ~/.pi/agent/db0.sqlite

Override with the DB0_STORAGE environment variable or pass dbPath in the extension config:

export DB0_STORAGE=postgresql://user:pass@host:5432/db

Uninstall

# Remove extension and database
npx @db0-ai/pi uninstall

# Remove extension, keep memories
npx @db0-ai/pi uninstall --keep-data

Configuration

The extension accepts these options:

Option	Default	Description
`dbPath`	`~/.pi/agent/db0.sqlite`	Storage path or PostgreSQL URL
`profile`	`coding-assistant`	Memory profile
`tokenBudget`	`1500`	Tokens for context injection