> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adriel.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Data reference

> Metrics, breakdowns, refresh cadence, and limits for the Mailchimp data source in Adriel.

## Introduction

Mailchimp is an email-marketing and automation platform built around the Audience → Campaign → Member model. An audience (formerly a "list") groups subscribers, a campaign is a single send to one or more audience segments, and a member is a contact within an audience with their own engagement history. When Mailchimp is connected to an online store, it also captures e-commerce attribution, enabling revenue-per-campaign reporting.

The connector exposes send-level and engagement-level data for each campaign through the Mailchimp Marketing API (v3). Typical use cases include comparing open and click performance across campaigns, tracking deliverability and unsubscribes, and measuring e-commerce revenue attributed to email sends.

As an email-marketing connector, campaign, send, and engagement metrics are standardized so widgets can aggregate alongside other sources without additional configuration.

To connect this data source, see [How to connect Mailchimp to Adriel](/data-sources/g-n/mailchimp/how-to-connect).

## Data refresh strategy

### Architecture data

The audience and campaign catalog is fetched on demand when a dashboard loads. New audiences, segments, and campaigns created in Mailchimp become available immediately, with no daily refresh cycle.

### Reports data

Report data is fetched from the Mailchimp Marketing API on demand; there is no daily cache. Each dashboard visit triggers a fresh read for the requested date range, so opens, clicks, bounces, and unsubscribes reflect the current state in Mailchimp. Because reads happen on demand, engagement events (opens and clicks) that arrive days after the original send continue to update the counts against the historical send date rather than the day the event occurred.

## Architecture levels

Account → Audience → Campaign

Reporting is campaign-level: each row corresponds to a campaign send within an authorized account. Audience is the Mailchimp grouping that a campaign is sent to; member- and event-level engagement is not exposed as a separate reporting level.

## Metrics

<Note>
  **How to read the columns**
  **Data type** uses this vocabulary: Number, Currency, Percentage, Ratio, Duration, Date, Text, URL, Array, Boolean.
  **API Key** in code style like `emails_sent` is the literal Mailchimp Marketing API v3 field. *Italic text* describes how a value is produced when it doesn't map cleanly to a single API field.
</Note>

### Campaigns & sends

| Metric        | Description                                    | Data type | API Key                             |
| ------------- | ---------------------------------------------- | --------- | ----------------------------------- |
| Email sent    | Total emails dispatched in the campaign.       | Number    | `emails_sent`                       |
| Hard bounces  | Permanent delivery failures.                   | Number    | `detailReport.bounces.hard_bounces` |
| Soft bounces  | Temporary delivery failures.                   | Number    | `detailReport.bounces.soft_bounces` |
| Unsubscribed  | Recipients who unsubscribed from the campaign. | Number    | `detailReport.unsubscribed`         |
| Abuse reports | Recipients who marked the campaign as spam.    | Number    | `detailReport.abuse_reports`        |

### Email engagement

| Metric                   | Description                                                | Data type  | API Key                                        |
| ------------------------ | ---------------------------------------------------------- | ---------- | ---------------------------------------------- |
| Opens                    | Total opens, including repeat opens by the same recipient. | Number     | `report_summary.opens`                         |
| Unique opens             | Distinct recipients who opened the email.                  | Number     | `report_summary.unique_opens`                  |
| Open rate                | Unique opens as a proportion of successful deliveries.     | Percentage | `report_summary.open_rate`                     |
| Link clicks              | Total link clicks, including repeat clicks.                | Number     | `report_summary.clicks`                        |
| Unique clicks            | Distinct clicks on any tracked link.                       | Number     | `detailReport.clicks.unique_clicks`            |
| Unique subscriber clicks | Distinct recipients who clicked any link.                  | Number     | `detailReport.clicks.unique_subscriber_clicks` |
| Click rate               | Unique clicks as a proportion of successful deliveries.    | Percentage | `report_summary.click_rate`                    |
| Forwards count           | Times recipients forwarded the campaign.                   | Number     | `detailReport.forwards.forwards_count`         |
| Forwards opens           | Opens generated by forwarded copies of the campaign.       | Number     | `detailReport.forwards.forwards_opens`         |

### Revenue & ecommerce

<Note>
  E-commerce metrics are populated only for accounts where Mailchimp's e-commerce tracking is connected to a store. Campaigns sent from accounts without an attached store report zero for these metrics.
</Note>

| Metric  | Description                                                           | Data type | API Key                                  |
| ------- | --------------------------------------------------------------------- | --------- | ---------------------------------------- |
| Orders  | Orders attributed to the campaign.                                    | Number    | `report_summary.ecommerce.total_orders`  |
| Revenue | Revenue attributed to the campaign.                                   | Currency  | `report_summary.ecommerce.total_revenue` |
| Spent   | Total amount spent by recipients, as tracked by Mailchimp e-commerce. | Currency  | `report_summary.ecommerce.total_spent`   |

## Breakdowns

### Campaign

| Breakdown    | Description                                                         | API Key       |
| ------------ | ------------------------------------------------------------------- | ------------- |
| Campaign ID  | Group by campaign identifier.                                       | `campaignId`  |
| Title        | Group by campaign title (the default grouping).                     | `title`       |
| Subject      | Group by email subject line.                                        | `subject`     |
| From name    | Group by the sender name on the campaign.                           | `fromName`    |
| Type         | Group by campaign type (Regular, Plain-text, A/B, RSS, Automation). | `type`        |
| Content type | Group by campaign content type.                                     | `contentType` |
| Status       | Group by campaign status.                                           | `status`      |
| Send time    | Group by the date and time the campaign was sent.                   | `sendTime`    |

### General

<Note>
  These groupings are provided by Adriel rather than returned by Mailchimp.
</Note>

| Breakdown       | Description                                   |
| --------------- | --------------------------------------------- |
| No Grouping     | Do not break down; return one aggregated row. |
| Datasource Name | Group by the Adriel data source name.         |

## Limitations

* **Field schema locked to Mailchimp Marketing API v3** — metric and breakdown keys follow the v3 response shape. Fields added by Mailchimp in newer API versions are not surfaced until the connector is updated.
* **E-commerce metrics require a connected store** — Orders, Revenue, and Spent report zero for accounts without Mailchimp e-commerce tracking connected to a store.
* **Late opens and clicks update historical sends** — because report data is read on demand, opens and clicks that arrive after a send update the original send-date counts rather than appearing on the day the event occurred.
* **Rate metrics use median aggregation** — Open rate and Click rate are aggregated using the median across campaigns; the other metrics are summed. Rates are not recomputed as a weighted total across a date range.
* **No token refresh** — Mailchimp issues an access token that does not expire and provides no refresh token ([Mailchimp OAuth 2 guide](https://mailchimp.com/developer/marketing/guides/access-user-data-oauth-2/)). If the token is revoked inside Mailchimp, subsequent reads fail and the data source disconnects.
* **Campaign-level reporting only** — audience-, segment-, and member-level engagement is not exposed as breakdowns or metrics.

## API references

* [Mailchimp Marketing API](https://mailchimp.com/developer/marketing/api/)
* [Campaign reports (Reports endpoint)](https://mailchimp.com/developer/marketing/api/reports/)
* [Campaigns endpoint](https://mailchimp.com/developer/marketing/api/campaigns/)
* [Audiences (Lists) endpoint](https://mailchimp.com/developer/marketing/api/lists/)

## See also

* [How to connect Mailchimp to Adriel](/data-sources/g-n/mailchimp/how-to-connect) (paired how-to)
* [Active Campaign data reference](/data-sources/a-f/active-campaign/data-reference) — alternative email-marketing platform
* [Klaviyo data reference](/data-sources/g-n/klaviyo/data-reference) — email-marketing platform with deeper e-commerce attribution