johnreitano/daisy

MCP Datastore Server

An MCP (Model Context Protocol) server for Google Cloud Datastore that provides simple query capabilities.

Features

• List Kinds: Get all available entity kinds (tables) in your Datastore
• Get Entity: Retrieve a specific entity by key
• Query Entities: Basic querying with pagination
• Filter Entities: Simple equality filtering on any field (including key fields)
• Count Entities: Count entities in a kind with optional filtering

Setup

1. Install dependencies:

npm install

2. Set up authentication:

   • Set GOOGLE_CLOUD_PROJECT environment variable
   • Set GOOGLE_APPLICATION_CREDENTIALS to point to your service account key file
   • Or use Application Default Credentials (ADC)

3. Build the project:

npm run build

4. Run the server:

npm start

Available Tools

datastore_list_kinds

Lists all available entity kinds in the Datastore.

datastore_get

Gets an entity by its key.

• kind: Entity kind
• key: Entity key (name or ID)
• parent: Parent key (optional)

datastore_query

Queries entities with optional pagination.

• kind: Entity kind to query
• limit: Maximum results (default: 100)
• offset: Results to skip (default: 0)

datastore_filter

Filters entities by field equality.

• kind: Entity kind to query
• field: Field name to filter on (including __key__ or key)
• value: Value to match exactly
• limit: Maximum results (default: 100)

datastore_count

Counts entities in a kind with optional filtering.

• kind: Entity kind to count
• field: Field name to filter on (optional)
• value: Value to match exactly (required if field is provided)

Examples

// List kinds
{"name": "datastore_list_kinds", "arguments": {}}

// Get entity
{"name": "datastore_get", "arguments": {"kind": "User", "key": "12345"}}

// Query with pagination
{"name": "datastore_query", "arguments": {"kind": "User", "limit": 10}}

// Filter by field
{"name": "datastore_filter", "arguments": {"kind": "User", "field": "status", "value": "active"}}

// Filter by key
{"name": "datastore_filter", "arguments": {"kind": "User", "field": "__key__", "value": "12345"}}

// Count all entities
{"name": "datastore_count", "arguments": {"kind": "User"}}

// Count with filter
{"name": "datastore_count", "arguments": {"kind": "User", "field": "status", "value": "active"}}