durable-mcp 0.2.0

Durable Model Context Protocol (MCP) helpers for building resumable MCP servers on top of Reboot durable workflows.

Reboot Durable MCP

A framework for building durable MCP servers.

• Takes advantage of the protocols ability to resume after disconnection, e.g., due to the server getting rebooted.

• Any existing requests will be retried safely using Reboot workflows.

• Using Reboot you can run multiple replicas of your server, and session messages will always be routed to the same replica.

Requirements

• Linux and macOS
• Python >= 3.12
• Docker

Install

Using uv:

uv add durable-mcp

Using pip:

pip install durable-mcp

Run your application

Activate the venv (set up either via uv or python -m venv venv):

source .venv/bin/activate

Make sure you have Docker running:

docker ps

And run your app:

rbt dev run --python --application=path/to/your/main.py

If you want the application to be restarted when you modify your files you can add one or more --watch=path/to/**/*.py to the above command line.

To simplify you can move all command line args to a .rbtrc.

# This file will aggregate all of the command line args
# into a single command line that will be run when you
# use `rbt`.
#
# For example, to add args for running `rbt dev run`
# you can add lines that start with `dev run`. You can add
# one or more args to each line.

dev run --python
dev run --application=path/to/your/main.py
dev run --watch=path/to/**/*.py --watch=different/path/to/**/*.py

Supported client --> server requests:

• initialize
• tools/call
• tools/list
• prompts/get
• prompts/list
• resources/list
• resources/read
• resources/templates/list
• resources/subscribe
• resources/unsubscribe
• completion/complete
• logging/setLevel

Supported client --> server notifications:

• notifications/initialized
• notifications/progress (for server initiated requests, e.g., elicitation)
• notifications/roots/list_changed

Supported client <-- server requests:

• elicitation/create
• roots/list
• sampling/createMessage

Supported client <-- server notifications:

• notifications/progress
• notifications/message
• notifications/prompts/list_changed
• notifications/resources/list_changed
• notifications/tools/list_changed
• notifications/resources/updated

Supported client <--> server notifications:

• notifications/cancelled

TODO:

• EventStore support for resumability
• Auth
• Docs
• yapf
• Push to durable-mcp in pypi.org
• Pydantic state for each session

Contributing

First grab all dependencies:

uv sync

Activate the venv:

source .venv/bin/activate

Generate code:

rbt generate

Make sure you have Docker running:

docker ps

Make your changes and run the tests:

pytest tests