Montycat MCP - Shared Memory for AI Agents
Shared, persistent memory for AI agents, with semantic recall and live updates.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
montycat-mcpclaude mcp add montycat-mcp-shared-memory-for-ai-agents -e 'MONTYCAT_URI=<your montycat_uri>' -e 'MONTYCAT_TLS=<MONTYCAT_TLS>' -e 'MONTYCAT_TLS_CERTIFICATE_PATH=<MONTYCAT_TLS_CERTIFICATE_PATH>' -e 'MONTYCAT_TLS_VERIFY=<MONTYCAT_TLS_VERIFY>' -e 'MONTYCAT_TLS_CERTIFICATE_FINGERPRINT=<MONTYCAT_TLS_CERTIFICATE_FINGERPRINT>' -- uvx montycat-mcp==1.1.6
{
"mcpServers": {
"montycat-mcp-shared-memory-for-ai-agents": {
"command": "uvx",
"args": [
"montycat-mcp==1.1.6"
],
"env": {
"MONTYCAT_URI": "<your montycat_uri>",
"MONTYCAT_TLS": "<MONTYCAT_TLS>",
"MONTYCAT_TLS_CERTIFICATE_PATH": "<MONTYCAT_TLS_CERTIFICATE_PATH>",
"MONTYCAT_TLS_VERIFY": "<MONTYCAT_TLS_VERIFY>",
"MONTYCAT_TLS_CERTIFICATE_FINGERPRINT": "<MONTYCAT_TLS_CERTIFICATE_FINGERPRINT>"
}
}
}
}
Environment variables
MONTYCAT_URIsecret Optional Montycat engine URI: montycat://user:password@host:port/storeMONTYCAT_TLSSet to true when connecting to a TLS-enabled remote Montycat engineMONTYCAT_TLS_CERTIFICATE_PATHOptional PEM certificate path for exact TLS certificate pinningMONTYCAT_TLS_VERIFYSet to true to verify TLS with the platform trust storeMONTYCAT_TLS_CERTIFICATE_FINGERPRINTOptional SHA-256 TLS certificate fingerprint
docker.io/montygovernance/montycat-mcp:1.1.6claude mcp add montycat-mcp-shared-memory-for-ai-agents -e 'MONTYCAT_URI=<your montycat_uri>' -e 'MONTYCAT_TLS=<MONTYCAT_TLS>' -e 'MONTYCAT_TLS_CERTIFICATE_PATH=<MONTYCAT_TLS_CERTIFICATE_PATH>' -e 'MONTYCAT_TLS_VERIFY=<MONTYCAT_TLS_VERIFY>' -e 'MONTYCAT_TLS_CERTIFICATE_FINGERPRINT=<MONTYCAT_TLS_CERTIFICATE_FINGERPRINT>' -- docker run -i --rm docker.io/montygovernance/montycat-mcp:1.1.6
{
"mcpServers": {
"montycat-mcp-shared-memory-for-ai-agents": {
"command": "docker",
"args": [
"run",
"-i",
"--rm",
"docker.io/montygovernance/montycat-mcp:1.1.6"
],
"env": {
"MONTYCAT_URI": "<your montycat_uri>",
"MONTYCAT_TLS": "<MONTYCAT_TLS>",
"MONTYCAT_TLS_CERTIFICATE_PATH": "<MONTYCAT_TLS_CERTIFICATE_PATH>",
"MONTYCAT_TLS_VERIFY": "<MONTYCAT_TLS_VERIFY>",
"MONTYCAT_TLS_CERTIFICATE_FINGERPRINT": "<MONTYCAT_TLS_CERTIFICATE_FINGERPRINT>"
}
}
}
}
Environment variables
MONTYCAT_URIsecret Optional Montycat engine URI: montycat://user:password@host:port/storeMONTYCAT_TLSSet to true when connecting to a TLS-enabled remote Montycat engineMONTYCAT_TLS_CERTIFICATE_PATHOptional PEM certificate path for exact TLS certificate pinningMONTYCAT_TLS_VERIFYSet to true to verify TLS with the platform trust storeMONTYCAT_TLS_CERTIFICATE_FINGERPRINTOptional SHA-256 TLS certificate fingerprint
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
Montycat MCP - Shared Memory for AI Agents
A self-hosted MCP server that gives AI agents persistent, searchable memory. Claude, Codex, Cursor, and any Model Context Protocol client write to one memory and read each other's.
- Memory that survives the chat. Decisions, preferences, and project context carry into the next session.
- One memory, many agents. Every MCP client you use works from the same facts.
- Recall by meaning, keyword, or both. Vector search finds a memory when the wording differs, BM25 nails exact identifiers, and hybrid mode fuses the two. Exact-key and metadata lookup too.
- Yours. Server, engine, and embeddings run on your machine. No hosted memory service, no cloud embedding API.
Install
Claude Desktop — download
montycat-mcp.mcpb
and drag it into Claude Desktop. No Python needed. That link always serves the
current release; every release
also carries a version-named copy and a .sha256 to check it against.
Claude Code — install uv, then:
/plugin marketplace add MontyGovernance/montycat-mcp
/plugin install montycat-mcp@montygovernance
/mcp confirms the montycat server is connected.
Codex, Cursor, other MCP clients — point your client's stdio config at
uvx montycat-mcp (Python 3.10+). For Codex:
codex mcp add montycat -- uvx montycat-mcp
The engine
Memory lives in a Montycat Semantic engine. Montycat MCP starts a local one for you, so most people can stop reading here.
Point it at an engine you already run:
export MONTYCAT_URI="montycat://memory-agent:password@localhost:21210/memories"
export MONTYCAT_TLS=true # remote engines only
Or start one yourself with Docker:
docker run -d --name montycat -p 21210:21210 -p 21211:21211 \
-e MONTYCAT_SUPEROWNER=admin -e MONTYCAT_PASSWORD=change-me \
-v montycat_data:/var/lib/.montycat \
montygovernance/montycat:semantic
On Apple Silicon use the arm64-semantic tag instead — semantic is the amd64
image, and it crashes under emulation. Port 21211 carries live memory watches.
Use it
Talk to your agent normally; it picks the tool.
Remember that the team chose PostgreSQL for the billing service.
What did we decide about the billing database?
Save this to the shared
engineeringscope.
scope decides where a memory lives — alice for private, engineering for a
team, shared for common. It is a namespace, not a security boundary: for real
isolation, give each MCP server its own least-privilege Montycat credential.
Tools
| Need | Tools |
|---|---|
| Store | montycat_remember, montycat_remember_bulk, montycat_update, montycat_forget |
| Recall | montycat_semantic_search, montycat_recall, montycat_list_memories |
| Inspect schemas | montycat_list_enforced_schemas — check field names and data types before structured writes or filtered retrieval |
| Collaborate | montycat_await_memory_change — wait for another agent's write, no polling |
| Namespaces | montycat_list_keyspaces, montycat_create_keyspace, montycat_update_cache, montycat_remove_keyspace |
| Admin | semantic index, snapshot, and policy tools — see the plugin guide |
For persistent namespaces, cache is a capacity in MB and compression is
chosen by montycat_create_keyspace. Compression cannot be changed after the
keyspace is created; migrate into a new keyspace to use a different setting.
Cache capacity can be changed later with montycat_update_cache.
Destructive tools are declared as such, so your client's confirmation prompts apply.
Configuration
| Variable | Purpose |
|---|---|
MONTYCAT_URI | Connection string: montycat://user:password@host:port/store |
MONTYCAT_TLS | true for a remote TLS engine |
MONTYCAT_TLS_VERIFY | Optional: true to verify with the platform trust store |
MONTYCAT_TLS_CERTIFICATE_PATH | Optional PEM certificate path for exact certificate pinning |
MONTYCAT_TLS_CERTIFICATE_FINGERPRINT | Optional SHA-256 certificate fingerprint as an alternative pin |
All three verification settings are optional. With only MONTYCAT_TLS=true,
MCP retains the historical encrypted-but-unverified behavior; with TLS unset or
false, existing plaintext configurations are unchanged.
| MONTYCAT_DEFAULT_KEYSPACE | Memory namespace; memory by default |
| MONTYCAT_SCOPE | Default scope when a call omits one |
| MONTYCAT_AUTO_PROVISION | Create a permitted scope on first use; true by default |
| MONTYCAT_AUTOSTART | off to require an already-running engine |
Compose setup and the full variable list: compose.yaml and the plugin guide.
More
Changelog · Privacy · Issues · Docs · Docker Hub
Existing MemoCat installs keep working: memocat-mcp, MEMOCAT_*, and
memocat:// are still supported. New setups should use the Montycat names.
MIT
Frequently asked questions
What is Montycat MCP - Shared Memory for AI Agents?
Shared, persistent memory for AI agents, with semantic recall and live updates.
How do I install Montycat MCP - Shared Memory for AI Agents?
It runs on your machine. In Claude Code: claude mcp add montycat-mcp-shared-memory-for-ai-agents -e 'MONTYCAT_URI=<your montycat_uri>' -e 'MONTYCAT_TLS=<MONTYCAT_TLS>' -e 'MONTYCAT_TLS_CERTIFICATE_PATH=<MONTYCAT_TLS_CERTIFICATE_PATH>' -e 'MONTYCAT_TLS_VERIFY=<MONTYCAT_TLS_VERIFY>' -e 'MONTYCAT_TLS_CERTIFICATE_FINGERPRINT=<MONTYCAT_TLS_CERTIFICATE_FINGERPRINT>' -- uvx montycat-mcp==1.1.6. For other clients, paste the JSON configuration from this page into their MCP settings.
Does Montycat MCP - Shared Memory for AI Agents need an API key?
Yes. It expects MONTYCAT_URI, which you set in its configuration.
Is Montycat MCP - Shared Memory for AI Agents open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains Montycat MCP - Shared Memory for AI Agents?
It is published by MontyGovernance. AI.tn lists it but does not maintain or endorse it.
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