googleapis--mcp-toolbox/docs/en/integrations/mongodb/tools/mongodb-aggregate.md

title, type, weight, description

title	type	weight	description
mongodb-aggregate	docs	1	A "mongodb-aggregate" tool executes a multi-stage aggregation pipeline against a MongoDB collection.

About

The mongodb-aggregate tool is the most powerful query tool for MongoDB, allowing you to process data through a multi-stage pipeline. Each stage transforms the documents as they pass through, enabling complex operations like grouping, filtering, reshaping documents, and performing calculations.

The core of this tool is the pipelinePayload, which must be a string containing a JSON array of pipeline stage documents. The tool returns a JSON array of documents produced by the final stage of the pipeline.

A readOnly flag can be set to true as a safety measure to ensure the pipeline does not contain any write stages (like $out or $merge).

Compatible Sources

{{< compatible-sources >}}

Example

Here is an example that calculates the average price and total count of products for each category, but only for products with an "active" status.

kind: tool
name: get_category_stats
type: mongodb-aggregate
source: my-mongo-source
description: Calculates average price and count of products, grouped by category.
database: ecommerce
collection: products
readOnly: true
pipelinePayload: |
  [
    {
      "$match": {
        "status": {{json .status_filter}}
      }
    },
    {
      "$group": {
        "_id": "$category",
        "average_price": { "$avg": "$price" },
        "item_count": { "$sum": 1 }
      }
    },
    {
      "$sort": {
        "average_price": -1
      }
    }
  ]
pipelineParams:
  - name: status_filter
    type: string
    description: The product status to filter by (e.g., "active").

Reference

field	type	required	description
type	string	true	Must be mongodb-aggregate.
source	string	true	The name of the mongodb source to use.
description	string	true	A description of the tool that is passed to the LLM.
database	string	true	The name of the MongoDB database containing the collection.
collection	string	true	The name of the MongoDB collection to run the aggregation on.
pipelinePayload	string	true	A JSON array of aggregation stage documents, provided as a string. Uses {{json .param_name}} for templating.
pipelineParams	list	true	A list of parameter objects that define the variables used in the pipelinePayload.
canonical	bool	false	Determines if the pipeline string is parsed using MongoDB's Canonical or Relaxed Extended JSON format.
readOnly	bool	false	If true, the tool will fail if the pipeline contains write stages ($out or $merge). Defaults to false.