Willow

PyPI License: MIT MCP

Agent-neutral MCP server with persistent memory and task execution. Works with any MCP client: Claude Code, Claude Desktop, Cursor, or any custom agent that speaks stdio MCP.

Three storage backends in one server:

• SOIL store — SQLite-backed local key/value store with full-text search and soft delete
• Postgres knowledge base — multi-keyword searchable knowledge graph
• Kart task queue — sandboxed task executor for shell commands and scripts

Every tool call is authorized via SAP/1.0 — a filesystem-based identity gate with no ACL database.

Install

pip install willow-mcp

Requires Python 3.11+. Postgres is optional — SOIL store works standalone.

Tools

Tool	Description
store_put	Write record (JSON object) to SQLite store
store_get	Read record by record_id
store_list	List all records in a collection
store_update	Update an existing record
store_search	Multi-keyword AND search in a collection
store_delete	Soft-delete a record by record_id
store_search_all	Search across all collections
knowledge_ingest	Add to Postgres knowledge base
knowledge_search	Multi-keyword search in Postgres knowledge base
task_submit	Submit task to Kart queue
task_status	Check task status
task_list	List pending tasks

Every tool requires an app_id param. Authorization is checked via SAP/1.0.

MCP config

{
  "mcpServers": {
    "willow": {
      "command": "python3",
      "args": ["-m", "willow_mcp"]
    }
  }
}

You can also run the full willow-1.9 server directly — the tool API is identical, apps work against both transparently.

Configuration

Env var	Default	Description
WILLOW_PG_DB	willow	Postgres database name
WILLOW_PG_USER	$USER	Postgres user (Unix socket auth)
WILLOW_STORE_ROOT	~/.willow/store	SQLite store directory — set to willow-1.7's store root to share data
WILLOW_APP_ID	willow-mcp	Default app_id if not passed per-call
SAP_SAFE_ROOT	~/.sap/Applications	SAFE folder root
SAP_PGP_FINGERPRINT	(empty)	Pinned GPG fingerprint

Authorization

Uses openclaw-sap-gate (SAP/1.0). If openclaw-sap-gate is not installed, all calls are permitted (open mode).

License

MIT — Sean Campbell 2026