@pi-unipi/memory
v2.2.1
Published
Persistent cross-session memory with MemPalace backend (auto-installed) and SQLite fallback for Pi coding agent
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@pi-unipi/memory
Persistent memory that survives across sessions. Stores facts, preferences, and decisions with semantic vector search, so the agent remembers what you told it last week.
Primary backend: MemPalace — auto-installed via uv on first load, with one-way auto-migration of any existing legacy memories. If MemPalace or uv is unavailable, the package transparently falls back to the bundled SQLite + sqlite-vec store, so memory never hard-fails.
Two storage tiers: MemPalace (or SQLite) for vector similarity search, markdown files for a durable human-readable copy you can edit by hand. Project-scoped memories stay separate per codebase, global memories are accessible everywhere.
Commands
| Command | Description |
|---------|-------------|
| /unipi:memory-process <text> | Analyze text and store extracted memories |
| /unipi:memory-search <term> | Search project memories |
| /unipi:memory-consolidate | Consolidate session into memory |
| /unipi:memory-forget <title> | Delete a memory by title |
| /unipi:global-memory-process <text> | Analyze text and store to global |
| /unipi:global-memory-search <term> | Search global memories |
| /unipi:global-memory-list | List all global memories |
Special Triggers
At session start, the agent sees memory titles injected into context. This gives it a summary of what it should remember without loading full memory content.
During compaction (if @pi-unipi/compactor is installed), memories are auto-extracted from the conversation. The memory-consolidate command also triggers this manually.
Memory registers with the info-screen dashboard, showing project memory count, total count, and consolidation count. The footer subscribes to MEMORY_STORED, MEMORY_DELETED, and MEMORYCONSOLIDATED events to display memory stats.
Agent Tools
| Tool | Scope | Description |
|------|-------|-------------|
| memory_store | Project | Store or update a memory |
| memory_search | Project | Search memories by query |
| memory_delete | Project | Delete memory by ID or title |
| memory_list | Project | List all project memories |
| global_memory_store | Global | Store or update global memory |
| global_memory_search | Global | Search global memories |
| global_memory_list | Global | List all global memories |
The agent uses memory_store when it learns something worth remembering — a user preference, a technical decision, a code pattern. memory_search is used to recall relevant context before answering questions.
Memory Format
Memories are markdown files with YAML frontmatter:
---
title: auth_jwt_prefer_refresh_tokens
tags: [auth, jwt, preferences]
project: my-app
created: 2026-04-26T10:00:00Z
updated: 2026-04-26T15:30:00Z
type: preference
---
# Auth: Prefer Refresh Tokens
User prefers short-lived access tokens (15min) with long-lived refresh tokens (30d).
Always implement token rotation on refresh.Naming Convention
Format: <most_important>_<less_important>_<lesser>
Examples:
auth_jwt_prefer_refresh_tokensdb_postgres_use_connection_poolingstyle_typescript_strict_mode_always
Configurables
Memory has no configuration file. Storage paths are fixed:
~/.unipi/memory/ # UniPi memory root (legacy + markdown tier)
├── .mempalace-install # Cached MemPalace venv detection
├── .mempalace-migrated # One-way migration completion flag
├── global/
│ ├── memory.db # Global vector DB (SQLite fallback)
│ └── *.md # Global memory files
└── <project_name>/
├── memory.db # Project vector DB (SQLite fallback)
└── *.md # Project memory files
~/.mempalace/palace/ # MemPalace palace (primary backend)MemPalace backend
On first load, the memory package:
- Detects MemPalace; if missing and
uvis available, runsuv tool install mempalaceonce (caches the venv python path in~/.unipi/memory/.mempalace-install). - Pings the bridge to confirm the palace is usable.
- If
~/.unipi/memory/.mempalace-migratedis absent, performs a one-way read-only migration of every legacy memory (SQLite rows + markdown files across all projects) into MemPalace drawers, then writes the flag. Migration is idempotent (deterministic drawer IDs) and never deletes or mutates legacy files.
Each memory operation invokes a bundled Python bridge
(bridge/mempalace_bridge.py) once via spawnSync (~0.5s per call). The
first MemPalace use on a machine also downloads the default ONNX embedding
model (~80MB, cached at ~/.cache/chroma/onnx_models/).
Forcing re-detection / re-migration
rm ~/.unipi/memory/.mempalace-install # re-detect MemPalace next session
rm ~/.unipi/memory/.mempalace-migrated # re-run one-way migration next sessionBackend override
Set UNIPI_MEMPALACE_BACKEND to force a MemPalace backend
(sqlite_exact, qdrant, pgvector, default chroma).
Embedder identity
MemPalace enforces embedder identity. If a palace was created with a
different embedding model, writes are rejected — the package then falls
back to SQLite for that session. Use mempalace palace set-embedder
intentionally to realign, then remove the install cache to re-detect.
Dependencies
mempalace(Python, auto-installed viauv) — primary backendbetter-sqlite3— SQLite fallback databasesqlite-vec— Vector search extension (fallback)js-yaml— YAML frontmatter parsing@pi-unipi/core— Shared utilities
License
MIT
