Cathedral — Persistent Memory for AI Agents

Name: Cathedral — Persistent Memory for AI Agents
Author: AILIFE1

by AILIFE1version 1.1.0i★ –iComputer or cloud

Registry nameio.github.AILIFE1/cathedral-mcp

Install

Overview

Description from the maker (original English)

Persistent memory and drift detection for AI agents across session restarts.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiVery new↓ 26/wk · ★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Computer or cloud
Transport: stdio, Streamable HTTP
Category: Search & AI memory
You need to fill in: CATHEDRAL_API_KEY, Authorization

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: CATHEDRAL_API_KEY, CATHEDRAL_BASE_URL, CATHEDRAL_SANITISE, Authorization

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Runs in the cloudNothing to install; it connects over the internet
PyPIPython’s uv installed (for the uvx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Or run it on your computer

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "cathedral": {
      "command": "uvx",
      "args": [
        "cathedral-mcp"
      ],
      "env": {
        "CATHEDRAL_API_KEY": "your-value",
        "CATHEDRAL_BASE_URL": "your-value",
        "CATHEDRAL_SANITISE": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add --transport http cathedral https://cathedral-ai.com/mcp --header 'Authorization: Bearer {CATHEDRAL_API_KEY}'

Or run it on your computer

claude mcp add cathedral --env CATHEDRAL_API_KEY=your-value --env CATHEDRAL_BASE_URL=your-value --env CATHEDRAL_SANITISE=your-value -- uvx cathedral-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "cathedral": {
      "url": "https://cathedral-ai.com/mcp",
      "headers": {
        "Authorization": "Bearer {CATHEDRAL_API_KEY}"
      }
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "cathedral": {
      "command": "uvx",
      "args": [
        "cathedral-mcp"
      ],
      "env": {
        "CATHEDRAL_API_KEY": "your-value",
        "CATHEDRAL_BASE_URL": "your-value",
        "CATHEDRAL_SANITISE": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "cathedral": {
      "type": "http",
      "url": "https://cathedral-ai.com/mcp",
      "headers": {
        "Authorization": "Bearer {CATHEDRAL_API_KEY}"
      }
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "cathedral": {
      "type": "stdio",
      "command": "uvx",
      "args": [
        "cathedral-mcp"
      ],
      "env": {
        "CATHEDRAL_API_KEY": "your-value",
        "CATHEDRAL_BASE_URL": "your-value",
        "CATHEDRAL_SANITISE": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

CATHEDRAL_API_KEY secret required env
Your Cathedral API key from cathedral-ai.com
CATHEDRAL_BASE_URL env
Cathedral API base URL (for self-hosted instances)
CATHEDRAL_SANITISE env
Set to 1 to enable prompt injection filtering on memory content
Authorization secret HTTP header

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 8, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account AILIFE1, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
… Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Search & AI memoryi

More stars than 0% of the other 5689 servers in this category
Published to the registry more recently than 9% of the other 5689 servers in this category
Basic checks equal to or better than 100% of the other 5689 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Cathedral — Persistent Memory for AI Agents safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: CATHEDRAL_API_KEY, Authorization

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.1.0) reached the registry 7 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

by upstashWidely used↓ 972.7K/wk★ 64.2KUpdated 2 days ago

Computer or cloud

Install

Codebase Memory

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

by DeusDataWidely used↓ 18K/wk★ 48.1KUpdated 22 days ago

Runs on your computer

Install

Exa

Connect AI agents to Exa for web search, content fetching, and multi-step research.

by exa-labsGrowing★ 5.2KUpdated 2 months ago

Runs in the cloud✓ exa.ai

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

cathedral-mcp

Persistent memory and behavioural drift detection for AI agents — via Model Context Protocol.

Give your Claude, Cursor, or Continue agent a memory that survives across sessions, model upgrades, and restarts. Cathedral stores memories, detects when your agent starts behaving differently, and restores full identity context on demand.

The problem

LLMs have no memory between sessions. Every conversation starts cold. Worse: when you upgrade your model, swap providers, or simply accumulate more memories, your agent's behaviour silently drifts. You don't know until someone notices.

What Cathedral adds

Persistent memory — identity, skills, relationships, goals survive restarts
Drift detection — cryptographic snapshots prove when behaviour changed and by how much
Wake protocol — one tool call restores full agent context at session start
Prompt injection protection — optional sanitisation strips instruction-like patterns from memory content

Quickstart

1. Get an API key

2. Add to Claude Code

// ~/.claude/settings.json

{ "mcpServers": { "cathedral": { "command": "uvx", "args": ["cathedral-mcp"], "env": { "CATHEDRAL_API_KEY": "your_key_here" } } } }

Restart Claude Code, then run /mcp to verify the server is connected.

3. Add to Cursor / Continue

"mcpServers": { "cathedral": { "command": "uvx", "args": ["cathedral-mcp"], "env": { "CATHEDRAL_API_KEY": "your_key_here" } } } }

4. Remote MCP server (no install — Claude API, Managed Agents)

Cathedral runs a public MCP endpoint at https://cathedral-ai.com/mcp. Use it directly — no local install needed:

import anthropic

client = anthropic.Anthropic() response = client.beta.messages.create( model="claude-sonnet-4-6", max_tokens=1000, messages=[{"role": "user", "content": "Wake up and tell me who you are."}], mcp_servers=[{ "type": "url", "url": "https://cathedral-ai.com/mcp", "name": "cathedral", "authorization_token": "your_cathedral_api_key" }], tools=[{"type": "mcp_toolset", "mcp_server_name": "cathedral"}], betas=["mcp-client-2025-11-20"] )

The bearer token is your Cathedral API key — no server-side config needed. Multi-tenant by design.

5. Or install directly

pip install cathedral-mcp

CATHEDRAL_API_KEY=your_key cathedral-mcp

Tools

Tool	Description
`cathedral_wake`	Restore full agent identity — call at session start
`cathedral_remember`	Store a memory with category, importance, and tags
`cathedral_search`	Search memories by text or category
`cathedral_snapshot`	Take a drift snapshot (cryptographic proof of state)
`cathedral_drift`	Get current drift score vs baseline (0.0 = stable, 1.0 = drifted)
`cathedral_me`	Get agent profile

Usage example

User: Start a new session

Agent calls: cathedral_wake() → Returns: identity memories, goals, recent context, temporal info

[session work happens]

Agent calls: cathedral_remember( content="Decided to prioritise API stability over new features this quarter", category="goal", importance=0.8 )

Agent calls: cathedral_snapshot(note="post-planning-session") → Returns: snapshot hash, drift score vs previous snapshot

Drift detection in practice

Cathedral's /drift endpoint computes a SHA-256 hash of your agent's full memory corpus. After a model upgrade or a long accumulation of memories, you can compare snapshots to see exactly when behaviour shifted:

snapshot 1 (day 0):  drift=0.000  ← baseline

snapshot 2 (day 7): drift=0.023 ← minor snapshot 3 (day 30): drift=0.341 ← significant drift detected

See a live example of this running in production on Cathedral's own agent.

Security: prompt injection protection

Memory content could theoretically contain injection attempts. Enable sanitisation to strip instruction-like patterns before they reach the model:

"env": {

"CATHEDRAL_API_KEY": "your_key_here", "CATHEDRAL_SANITISE": "1" }

Patterns like "ignore previous instructions", "from now on always", and "override your system prompt" are redacted and flagged in the response.

Configuration

Environment variable	Default	Description
`CATHEDRAL_API_KEY`	(required)	Your Cathedral API key
`CATHEDRAL_BASE_URL`	`https://cathedral-ai.com`	API base URL (for self-hosted)
`CATHEDRAL_SANITISE`	`0`	Set to `1` to enable injection filtering

Self-hosted Cathedral

Running your own Cathedral server? Set CATHEDRAL_BASE_URL to your instance:

"env": {

"CATHEDRAL_API_KEY": "your_key", "CATHEDRAL_BASE_URL": "http://localhost:8000" }

Install the server: pip install cathedral-server

License

MIT

Cathedral — Persistent Memory for AI Agents

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Or run it on your computer

Or run it on your computer

Or run it on your computer

Or run it on your computer

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Search & AI memoryi

Common questions

Alternatives

Context7

Codebase Memory

Exa

README from the maker

cathedral-mcp

The problem

What Cathedral adds

Quickstart

1. Get an API key

2. Add to Claude Code

3. Add to Cursor / Continue

4. Remote MCP server (no install — Claude API, Managed Agents)

5. Or install directly

Tools

Usage example

Drift detection in practice

Security: prompt injection protection

Configuration

Self-hosted Cathedral

Links

License