Gibbon is an API wrapper for MailChimp's API.

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Important Notes

Please read MailChimp's Getting Started Guide.

Gibbon 3.0.0+ returns a Gibbon::Response instead of the response body directly. Gibbon::Response exposes the parsed response body and headers.


$ gem install gibbon


A MailChimp account and API key. You can see your API keys here.


First, create a one-time use instance of Gibbon::Request:

gibbon = "your_api_key")

Note Only reuse instances of Gibbon after terminating a call with a verb, which makes a request. Requests are light weight objects that update an internal path based on your call chain. When you terminate a call chain with a verb, a request instance makes a request and resets the path.

You can set an individual request's timeout and open_timeout like this:

gibbon.timeout = 30
gibbon.open_timeout = 30

You can read about timeout and open_timeout in the Net::HTTP doc.

Now you can make requests using the resources defined in MailChimp's docs. Resource IDs are specified inline and a CRUD (create, retrieve (or get), update, upsert, or delete) verb initiates the request. upsert lets you update a record, if it exists, or insert it otherwise where supported by MailChimp's API.

Note upsert requires Gibbon version 2.1.0 or newer!

You can specify headers, params, and body when calling a CRUD method. For example:

gibbon.lists.retrieve(headers: {"SomeHeader": "SomeHeaderValue"}, params: {"query_param": "query_param_value"})

Note get can be substituted for retrieve as of Gibbon version 3.4.1 or newer!

Of course, body is only supported on create, update, and upsert calls. Those map to HTTP POST, PATCH, and PUT verbs respectively.

You can set api_key, timeout, open_timeout, faraday_adapter, proxy, symbolize_keys, logger, and debug globally:

Gibbon::Request.api_key = "your_api_key"
Gibbon::Request.timeout = 15
Gibbon::Request.open_timeout = 15
Gibbon::Request.symbolize_keys = true
Gibbon::Request.debug = false

For example, you could set the values above in an initializer file in your Rails app (e.g. your_app/config/initializers/gibbon.rb).

Assuming you've set an api_key on Gibbon, you can conveniently make API calls on the class itself:


You can also set the environment variable MAILCHIMP_API_KEY and Gibbon will use it when you create an instance:

gibbon =

Note Substitute an underscore if a resource name contains a hyphen.

Pass symbolize_keys: true to use symbols (instead of strings) as hash keys in API responses.

gibbon = "your_api_key", symbolize_keys: true)

MailChimp's resource documentation is a list of available resources.

Debug Logging

Pass debug: true to enable debug logging to STDOUT.

gibbon = "your_api_key", debug: true)

Custom logger

Ruby is used by default, but it can be overrided using:

gibbon = "your_api_key", debug: true, logger:

Logger can be also set by globally:

Gibbon::Request.logger =



Fetch first page of lists:


Retrieving a specific list looks like:


Retrieving a specific list's members looks like:



Get first page of subscribers for a list:


By default the Mailchimp API returns 10 results. To set the count to 50:

gibbon.lists(list_id).members.retrieve(params: {"count": "50"})

And to retrieve the next 50 members:

gibbon.lists(list_id).members.retrieve(params: {"count": "50", "offset": "50"})

And to retrieve only subscribed members

gibbon.lists(list_id).members.retrieve(params: {"count": "50", "offset": "50", "status": "subscribed"})

Subscribe a member to a list:

gibbon.lists(list_id).members.create(body: {email_address: "", status: "subscribed", merge_fields: {FNAME: "First Name", LNAME: "Last Name"}})

If you want to upsert instead, you would do the following:

gibbon.lists(list_id).members(lower_case_md5_hashed_email_address).upsert(body: {email_address: "", status: "subscribed", merge_fields: {FNAME: "First Name", LNAME: "Last Name"}})

You can also unsubscribe a member from a list:

gibbon.lists(list_id).members(lower_case_md5_hashed_email_address).update(body: { status: "unsubscribed" })

Get a specific member's information (open/click rates etc.) from MailChimp:


Permanently delete a specific member from a list:



Tags are a flexible way to organize (slice and dice) your list: for example, you can send a campaign directly to one or more tags.

Add tags to a subscriber:

  body: {
    tags: [{name:"referred-from-xyz", status:"active"},{name:"pro-plan",status:"active"}]

Batch Operations

Any API call that can be made directly can also be organized into batch operations. Performing batch operations requires you to generate a hash for each individual API call and pass them as an Array to the Batch endpoint.

# Create a new batch job that will create new list members
gibbon.batches.create(body: {
  operations: [
      method: "POST",
      path: "lists/#{ list_id }/members",
      body: "{...}" # The JSON payload for PUT, POST, or PATCH

This will create a new batch job and return a Batch response. The response will include an id attribute which can be used to check the status of a particular batch job.

Checking on a Batch Job
Response Body (i.e. response.body)

Note This response truncated for brevity. Reference the MailChimp API documentation for Batch Operations for more details.


Only retrieve ids and names for fetched lists:

gibbon.lists.retrieve(params: {"fields": ","})

Only retrieve emails for fetched lists:

gibbon.lists(list_id).members.retrieve(params: {"fields": "members.email_address"})


Get first page of campaigns:

campaigns = gibbon.campaigns.retrieve

Fetch the number of opens for a campaign

email_stats = gibbon.reports(campaign_id).retrieve["opens"]

Create a new campaign:

recipients = {
  list_id: list_id,
  segment_opts: {
    saved_segment_id: segment_id
settings = {
  subject_line: "Subject Line",
  title: "Name of Campaign",
  from_name: "From Name",
  reply_to: ""

body = {
  type: "regular",
  recipients: recipients,
  settings: settings

  gibbon.campaigns.create(body: body)
rescue Gibbon::MailChimpError => e
  puts "Houston, we have a problem: #{e.message} - #{e.raw_body}"

Add content to a campaign:

(Please note that Mailchimp does not currently support dynamic replacement of mc:edit areas in their drag-and-drop templates using their API. Custom templates can be used instead.)

body = {
  template: {
    id: template_id,
    sections: {
      "name-of-mc-edit-area": "Content here"

gibbon.campaigns(campaign_id).content.upsert(body: body)

Send a campaign:


Schedule a campaign:

body = {
  schedule_time: "2016-06-27 20:00:00"
gibbon.campaigns(campaign_id).actions.schedule.create(body: body)


Interests are a little more complicated than other parts of the API, so here's an example of how you would set interests during at subscription time or update them later. The ID of the interests you want to opt in or out of must be known ahead of time so an example of how to find interest IDs is also included.

Subscribing a member to a list with specific interests up front:

gibbon.lists(list_id).members.create(body: {email_address: user_email_address, status: "subscribed", interests: {some_interest_id: true, another_interest_id: true}})

Updating a list member's interests:

gibbon.lists(list_id).members(member_id).update(body: {interests: {some_interest_id: true, another_interest_id: false}})

So how do we get the interest IDs? When you query the API for a specific list member's information:


The response body (i.e. response.body) looks someting like this (unrelated things removed):

{"id"=>"...", "email_address"=>"...", ..., "interests"=>{"3def637141"=>true, "f7cc4ee841"=>false, "fcdc951b9f"=>false, "3daf3cf27d"=>true, "293a3703ed"=>false, "72370e0d1f"=>false, "d434d21a1c"=>false, "bdb1ff199f"=>false, "a54e78f203"=>false, "c4527fd018"=>false} ...}

The API returns a map of interest ID to boolean value. Now we to get interest details so we know what these interest IDs map to. Looking at this doc page, we need to do this:


To get a list of interest categories. That gives us something like (again, this is the response.body):

{"list_id"=>"...", "categories"=>[{"list_id"=>"...", "id"=>"0ace7aa498", "title"=>"Food Preferences", ...}] ...}

In this case, we're interested in the ID of the "Food Preferences" interest, which is 0ace7aa498. Now we can fetch the details for this interest group:


That response gives the interest data, including the ID for the interests themselves, which we can use to update a list member's interests or set them when we call the API to subscribe her or him to a list.

Error handling

Gibbon raises an error when the API returns an error.

Gibbon::MailChimpError has the following attributes: title, detail, body, raw_body, status_code. Some or all of these may not be available depending on the nature of the error. For example:

  gibbon.lists(list_id).members.create(body: body)
rescue Gibbon::MailChimpError => e
  puts "Houston, we have a problem: #{e.message} - #{e.raw_body}"


Overriding Gibbon's API endpoint (i.e. if using an access token from OAuth and have the api_endpoint from the metadata):

Gibbon::Request.api_endpoint = ""
Gibbon::Request.api_key = your_access_token_or_api_key

You can set an optional proxy url like this (or with an environment variable MAILCHIMP_PROXY):

gibbon.proxy = ''

You can set a different Faraday adapter during initialization:

gibbon = "your_api_key", faraday_adapter: :net_http)

Migrating from Gibbon 1.x

Gibbon 2.x+ exposes a different API from version 1.x. This is because Gibbon maps to MailChimp's API and because version 3 of the API is quite different from version 2. First, the name of the primary class has changed from API to Request. And the way you pass an API key during initialization is different. A few examples below.


Gibbon 1.x:

gibbon ="your_api_key")

Gibbon 2.x+:

gibbon = "your_api_key")

MailChimp API 3 is a RESTful API, so Gibbon's syntax now requires a trailing call to a verb, as described above.

Fetching Lists

Gibbon 1.x:


Gibbon 2.x+:


Fetching List Members

Gibbon 1.x:

gibbon.lists.members({:id => list_id})

Gibbon 2.x+:


Subscribing a Member to a List

Gibbon 1.x:

gibbon.lists.subscribe({:id => list_id, :email => {:email => ""}, :merge_vars => {:FNAME => "Bob", :LNAME => "Smith"}})

Gibbon 2.x+:

gibbon.lists(list_id).members.create(body: {email_address: "", status: "subscribed", merge_fields: {FNAME: "Bob", LNAME: "Smith"}})


Thanks to everyone who has contributed to Gibbon's development.

  • Copyright (c) 2010-2022 Amro Mousa. See LICENSE.txt for details.
  • MailChimp (c) 2001-2022 The Rocket Science Group.