aggregate
Perform read-only aggregation on MongoDB collections to filter, group, sort, join, and reshape data using a safe pipeline, ensuring data integrity and efficiency.
Instructions
Execute a read-only aggregation pipeline on a collection.
Supported Stages:
$match: Filter documents
$group: Group documents by a key
$sort: Sort documents
$project: Shape the output
$lookup: Perform left outer joins
$unwind: Deconstruct array fields
Unsafe/Blocked Stages:
$out: Write results to collection
$merge: Merge results into collection
$addFields: Add new fields
$set: Set field values
$unset: Remove fields
$replaceRoot: Replace document structure
$replaceWith: Replace document
Example - User Statistics by Role: use_mcp_tool with server_name: "mongodb", tool_name: "aggregate", arguments: { "collection": "users", "pipeline": [ { "$match": { "active": true } }, { "$group": { "_id": "$role", "count": { "$sum": 1 }, "avgAge": { "$avg": "$age" } }}, { "$sort": { "count": -1 } } ], "limit": 100 }
Example - Posts with Author Details: use_mcp_tool with server_name: "mongodb", tool_name: "aggregate", arguments: { "collection": "posts", "pipeline": [ { "$match": { "published": true } }, { "$lookup": { "from": "users", "localField": "authorId", "foreignField": "_id", "as": "author" }}, { "$unwind": "$author" }, { "$project": { "title": 1, "authorName": "$author.name", "publishDate": 1 }} ] }
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| collection | Yes | Collection name | |
| database | No | Database name (optional if default database is configured) | |
| limit | No | Maximum number of documents to return (optional) | |
| pipeline | Yes | MongoDB aggregation pipeline stages (read-only operations only) |