pce-memory

PCE Memory - MCP Server for Process-Context Engine

Overview

PCE Memory is the official MCP server implementation of Process-Context Engine (PCE).
It provides context memory, retrieval, and integration capabilities for agents and LLM applications.

MCP Configuration

> Note: Replace your-project with your actual project name to keep databases separate per project.

$3

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

``json
{
"mcpServers": {
"pce-memory": {
"command": "npx",
"args": ["-y", "pce-memory"],
"env": {
"PCE_DB": "~/.pce/your-project.db"
}
}
}
}
`

$3

Add to .mcp.json in your project root:

`json
{
"mcpServers": {
"pce-memory": {
"command": "npx",
"args": ["-y", "pce-memory"],
"env": {
"PCE_DB": "~/.pce/your-project.db"
}
}
}
}
`

$3

Add to VS Code settings (settings.json):

`json
{
"cline.mcpServers": {
"pce-memory": {
"command": "npx",
"args": ["-y", "pce-memory"],
"env": {
"PCE_DB": "~/.pce/your-project.db"
}
}
}
}
`

Features

- MCP Protocol Support: Model Context Protocol (MCP) v1.0.4 compliant
- Pace Layering: Three-tier scope management (session / project / principle)
- Boundary-First Security: Scope-based boundary management with Redact-before-send
- Hybrid Search: Full-text search + Vector similarity search
- DuckDB Storage: Fast local storage with embedded DuckDB
- Local Embeddings: Local embedding generation via transformers.js

Quick Start

`bash


Run directly with npx

npx pce-memory

Or install globally

npm install -g pce-memory
pce-memory
`

Commands

| Command | Description |
| ------------------ | ------------------------------- |
| pce-memory | MCP client (auto-starts daemon) |
| pce-daemon | Standalone daemon process |
| pce-memory-stdio | Direct stdio mode (no daemon) |

MCP Tools

$3

Apply policy (initialization)

`typescript
{
yaml?: string // Policy YAML (uses default if omitted)
}
`

$3

Register a claim (knowledge fragment)

`typescript
{
text: string, // Claim content
kind: "fact" | "preference" | "task" | "policy_hint",
scope: "session" | "project" | "principle",
boundary_class: "public" | "internal" | "pii" | "secret",
content_hash: string, // Format: sha256:...
provenance: { // Origin info (required)
at: string, // ISO 8601 timestamp
actor?: string,
url?: string,
note?: string
}
}
`

$3

Build active context (AC)

`typescript
{
scope: string[], // Target scopes
allow: string[], // Allowed boundary classes
q?: string, // Search query
top_k?: number // Number of results (default: 10)
}
`

$3

Pre-generation boundary check

`typescript
{
payload: string, // Text to validate
scope?: string,
allow?: string[]
}
`

$3

Update critic (adopt/reject/stale/duplicate)

`typescript
{
claim_id: string,
signal: "helpful" | "harmful" | "outdated" | "duplicate",
score?: number // -1.0 to 1.0
}
`

$3

Get current state

`typescript
// Returns: { state: "Uninitialized" | "PolicyApplied" | "HasClaims" | "Ready" }
`

State Machine

`
Uninitialized
│
│ policy_apply
▼
PolicyApplied
│
│ upsert
▼
HasClaims
│
│ activate
▼
Ready ◄──┐
│ │
└──────┘ (activate/upsert/feedback)
`

Pace Layering (Scope)

| Scope | Change Rate | Use Case |
| ----------- | ----------- | --------------------------------------- |
| session | Fast | Session-specific temporary information |
| project | Medium | Project-specific patterns and decisions |
| principle` | Slow | Universal principles and best practices |

Requirements

- Node.js >= 22.18.0

License

MIT