Cratis Chronicle MCP server

Chronicle.MCP

The Chronicle MCP server connects an AI agent to a running Cratis Chronicle event-sourcing database over the Model Context Protocol. Point your agent at a Chronicle server and it can explore the domain, operate observers and jobs, and turn plain-language requests into Chronicle artifacts — always grounded in the store's real schema.

Because the server talks to Chronicle directly, it works no matter which Chronicle client language your application uses — .NET, TypeScript, Kotlin/Java, or Elixir. Any MCP-capable tool can use it. See the Documentation for the full guide.

Using

The Chronicle MCP server leverages Stdio and is packaged as a container. In your tool, configure it using that.

Releases are also listed in the official MCP Registry as io.github.Cratis/chronicle-mcp, using the same versioned Docker Hub image. The listing starts the server in the read-only profile; job control needs the Mutation profile and an authorization policy.

Note: You must have a Chronicle server running.

Example: VSCode

In VSCode you would do this by adding a tool to your agent. This can done either by adding it to the global user settings or through an mcp.json file in the .vscode folder of your project.

For the global user settings, you simply do the following:

"mcp": {
    "servers": {
        "Chronicle": {
            "type": "stdio",
            "command": "docker",
            "args": [
                "run",
                "-i",
                "--rm",
                "-eCratis__Chronicle__Mcp__ConnectionString=chronicle://host.docker.internal:35000",
                "cratis/chronicle-mcp"
            ]
        }
    }
}

Note: To configure the connection string for Chronicle you pass it an environment variable; CratisChronicleMcp__ConnectionString

running locally - on MacOS and Windows the host machine is found at host.docker.internal.

For a local mcp.json file, its almost the same:

{
    "servers": {
        "Chronicle": {
            "type": "stdio",
            "command": "docker",
            "args": [
                "run",
                "-i",
                "--rm",
                "-eCratis__Chronicle__Mcp__ConnectionString=chronicle://host.docker.internal:35000",
                "cratis/chronicle-mcp"
            ]
        }
    }
}

You can see this in action in the mcp.json in this repository.

Note: The cratis/chronicle-mcp is a multi CPU architecture image supporting both x64 and arm64 automatically.

Configuration

Configuration is optional. The MCP server works out of the box with sensible defaults suitable for local development:

• Connection String: chronicle://host.docker.internal:35000
• Credentials: Development client ID (chronicle-dev-client) and secret (chronicle-dev-secret)
• Profile: ReadOnly — mutating tools are not listed or callable.

Shortened. The full README is on GitHub.