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Polypack Memory

MCP server exposing Polypack as persistent adaptive memory

Open source Open in the app JSON README (API)

About

MCP server exposing Polypack as persistent adaptive memory

Details

Kind
MCP servers
Topic
AI, RAG & memory
Publisher
imattau
Origin
official
Category
ferramentas
Transport
local
Version
0.1.31
Last push
2026-09-06T05:29:46Z
Repository state
ativo
Language
Python
Added
2026-08-29 04:00:10
Updated
2026-09-06 06:00:46
Origin id
io.github.imattau/polypack-mcp

README

<p align="center">
  <picture>
    <source media="(prefers-color-scheme: dark)" srcset="docs/assets/logo-lockup-dark.svg">
    <img src="docs/assets/logo-lockup.svg" alt="polypack-mcp" height="64">
  </picture>
</p>

<p align="center">Persistent, adaptive memory for MCP clients.</p>

<!-- mcp-name: io.github.imattau/polypack-mcp -->

An MCP server that exposes Polypack as persistent adaptive memory. MCP-specific
tools live here; the database remains an independent dependency.

## Install and run

The simplest installation is from PyPI:

```sh
python3 -m pip install 'polypack-mcp[polypack]'
```

For one MCP client, use the default stdio server configuration. For Claude and
Codex sharing the same durable memory, install once and create a long-running
user service:

```sh
polypack-mcp setup --store ~/.local/share/polypack-mcp
```

This starts a stateless Streamable HTTP server at `http://127.0.0.1:8765/mcp/`, restarts it after a
failure, and prints client configuration snippets. The setup command uses
`systemd --user`; on systems without systemd, start the server directly:

```sh
polypack-mcp --transport streamable-http --port 8765 --store ~/.local/share/polypack-mcp
```

In shared Streamable HTTP mode, configure both clients with the URL. Do not configure them
with a `command` and `--store`, since that starts two processes competing for
the same durable store.

Codex (`~/.codex/config.toml`):

```toml
[mcp_servers.polypack]
  url = "http://127.0.0.1:8765/mcp/"
```

Claude Desktop:

```json
{
  "mcpServers": {
    "polypack": { "url": "http://127.0.0.1:8765/mcp/" }
  }
}
```

### Debian package

The Debian package installs and starts a system-level `polypack-mcp` service
automatically. It runs as the dedicated `polypack` user, stores data in
`/var/lib/polypack-mcp`, and exposes the same local Streamable HTTP endpoint:

```sh
sudo apt install ./polypack-mcp_<version>_amd64.deb
```

After installation, point Claude and Codex at
`http://127.0.0.1:8765/mcp/`. The default port can be changed in
`/etc/default/polypack-mcp`, followed by a service restart. The service can be
managed with:

```sh
sudo systemctl status polypack-mcp
sudo systemctl restart polypack-mcp
```

The PyPI installation remains user-managed and uses `polypack-mcp setup` to
create a per-user service instead.

### Optional semantic retrieval

The default installation uses Polypack's local graph, activation, and lexical
retrieval without downloading an AI model. To enable local Qwen semantic
retrieval, run:

```sh
sudo polypack-mcp embeddings setup qwen3 --system --store /var/lib/polypack-mcp
```

This creates a managed localhost helper, downloads Qwen once into the store's
embedding cache, and reindexes existing memories. The model is not bundled in
the Debian/RPM package.

The helper loads Qwen3-Embedding-0.6B in bfloat16 (~1GB resident once loaded,
versus ~2.4GB in fp32) and unloads it after 15 minutes of inactivity,
reloading automatically on the next request. `memory_recall` results include
a `semantic` entry in `scoreComponents` whenever the helper is reachable,
alongside `lexical` and `activation` — the three sum to the reported `score`.
If the helper is stopped or errors, recall falls back to lexical + activation
scoring automatically. Check or disable it with:

```sh
polypack-mcp embeddings status
sudo polypack-mcp embeddings disable --system --store /var/lib/polypack-mcp
```

For a PyPI user service, omit `sudo --system` and use the user store:

```sh
polypack-mcp embeddings setup qwen3
```

### APT repository

The latest Debian package is also published to the public APT repository at
`https://imattau.github.io/polypack-mcp`. Configure it with the repository's
signing key, then install and update normally:

```sh
curl -fsSL https://imattau.github.io/polypack-mcp/gpg.key \
  | sudo gpg --dearmor -o /usr/share/keyrings/polypack-mcp.gpg
echo "deb [signed-by=/usr/share/keyrings/polypack-mcp.gpg] https://imattau.github.io/polypack-mcp stable main" \
  | sudo tee /etc/apt/sources.list.d/polypack-mcp.list
sudo apt update
sudo apt install polypack-mcp
```

The repository is updated automatically for each `v*.*.*` release tag. See
`docs/apt-repository.md` for maintainer setup instructions.

### RPM package

RPM-based distributions can install from the public RPM repository:

```sh
sudo rpm --import https://imattau.github.io/polypack-mcp/rpm/RPM-GPG-KEY-polypack-mcp
sudo tee /etc/yum.repos.d/polypack-mcp.repo >/dev/null <<'EOF'
[polypack-mcp]
name=Polypack MCP
baseurl=https://imattau.github.io/polypack-mcp/rpm/
enabled=1
gpgcheck=1
gpgkey=https://imattau.github.io/polypack-mcp/rpm/RPM-GPG-KEY-polypack-mcp
EOF
sudo dnf install polypack-mcp
```

The matching `.rpm` asset is also attached to the
[GitHub release](https://github.com/imattau/polypack-mcp/releases):

```sh
sudo dnf install ./polypack-mcp-<version>-1.x86_64.rpm
```

The RPM package provides the same systemd service, store location, localhost
Streamable HTTP endpoint, and Python 3.12 requirement as the Debian package.

## Run manually

```sh
pip install -e '.[polypack]'
polypack-mcp --store ./polypack-data
```

The server exposes seventeen focused tools: `memory_store`, `memory_get`,
`memory_update`, `memory_list_contexts`, `memory_delete`, `memory_recall`,
`memory_context`, `memory_feedback`, `memory_suppress`, `memory_supersede`,
`memory_consolidate`, `memory_link`, `memory_unlink`, `memory_thread`,
`memory_store_batch`, `memory_link_batch`, and `graph_query`. It also publishes context,
active-memory, schema, stats, and agent workflow guidance resources under
`polypack://`.

Memory classes are `entity`, `episodic`, `procedural`, and `semantic`. Store
project or user preferences as `procedural` memories; `preference` is not a
separate memory class.

When using a durable Polypack store, mutating operations checkpoint immediately
and the server flushes the store during shutdown.

Retrieval tools return `{items, metadata}`. Metadata includes candidate and
excluded counts, context matches, score components, fallback behavior, the
retrieval version, and selection statistics. `memory_context` uses estimated
tokens (`ceil(content characters / 4)`, minimum one) as its `token_budget`.
An item is never returned if it would exceed the remaining budget; budgets less
than or equal to zero are rejected. Context is a soft preference: matching
memories are preferred and unscoped global memories may be used as fallback.
Pass `strict_context: true` for isolation. An empty isolated result reports
`reason: "no_context_match"` and the searched context.

`memory_recall` can optionally hydrate related graph memories in the same call:

```json
{
  "query": "identity cache fix",
  "context": "cross-agent",
  "include_neighbors": true,
  "edge_types": ["RESPONDS_TO"],
  "depth": 2,
  "neighbor_limit": 3,
  "limit": 20,
  "token_budget": 4000
}
```

Neighbor traversal is opt-in and bounded. `limit` caps the total response and
`neighbor_limit` caps hydrated neighbors; metadata reports
`moreNeighborsAvailable` when additional eligible neighbors were found. Neighbor
items include their distance and connecting relationship metadata. Use
`memory_link` with the default
`RESPONDS_TO` relationship for handoffs, reviews, and fixes that address an
earlier memory. Graph edges are authoritative for relationships; use
`graph_query(operation="relationship_diagnostics")` to find legacy
`provenance.responds_to` values that are not backed by edges. See
`polypack://help/workflow` for the agent-facing workflow.

Feedback is activation feedback: `useful=true` reinforces a memory and
`useful=false` provides negative retrieval feedback. Responses expose activation
before and after plus whether learned weights changed. Supersession and
consolidation materialize `SUPERSEDES`, `SUPERSEDED_BY`, and
`CONSOLIDATED_FROM` graph edges.

Use `memory_get` for exact ID lookup and `memory_update` for mutable fields
(context, confidence, provenance, and metadata). Content changes should use
`memory_supersede` so history remains intact. Use `memory_unlink` to correct a
relationship and `memory_list_contexts` to discover namespaces. `memory_delete`
is permanent, requires `confirm=true`, and supports an optional revision check;
prefer `memory_suppress` when retaining history is useful.

Pass `--store` to open a durable Polypack directory. Without it, the server uses
the in-memory reference backend, which is convenient for smoke tests.
The `polypack` extra requires `polypack-db>=3.3.1` and uses its native
`ActivationEngine.working_memory` selector for context assembly.

## Development

```sh
pip install -e '.[dev]'
pytest
```

The test suite includes an MCP client/server protocol smoke test covering tool
discovery, memory storage, recall, and resource reads.

## Documentation

- [Getting started](docs/getting-started.md)
- [Operations and configuration](docs/operations.md)
- [Troubleshooting](docs/troubleshooting.md)

More