A long-lived project that still receives updates
Client library for accessing the EasyPost shipping API via Ruby.


~> 13.0
~> 0.14
~> 3.12
~> 1.49
~> 0.22
~> 5.4
~> 6.5
~> 2.7.5
~> 1.4.0
~> 6.1
~> 3.18
 Project Readme

EasyPost Ruby Client Library

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EasyPost, the simple shipping solution. You can sign up for an account at


gem install easypost
# Require the library in your project:
require 'easypost'


A simple create & buy shipment example:

require 'easypost'


shipment = client.shipment.create(
  from_address: {
    company: 'EasyPost',
    street1: '118 2nd Street',
    street2: '4th Floor',
    city: 'San Francisco',
    state: 'CA',
    zip: '94105',
    phone: '415-456-7890',
  to_address: {
    name: 'Dr. Steve Brule',
    street1: '179 N Harbor Dr',
    city: 'Redondo Beach',
    state: 'CA',
    zip: '90277',
    country: 'US',
    phone: '310-808-5243',
  parcel: {
    width: 15.2,
    length: 18,
    height: 9.5,
    weight: 35.1,

bought_shipment =, rate: shipment.lowest_rate)

puts bought_shipment

Custom Connections

Pass in a lambda function as custom_client_exec when initializing a client that responds to call(method, uri, headers, open_timeout, read_timeout, body = nil) where:

  • uri is the fully-qualified URL of the EasyPost endpoint, including query parameters (Uri object)
  • method is the lowercase name of the HTTP method being used for the request (e.g. :get, :post, :put, :delete)
  • headers is a hash with all headers needed for the request pre-populated, including authorization (Hash object)
  • open_timeout is the number of seconds to wait for the connection to open (integer)
  • read_timeout is the number of seconds to wait for one block to be read (integer)
  • body is a string of the body data to be included in the request, or nil (e.g. GET or DELETE request) (string or nil)

The lambda function should return an object with code and body attributes, where:

  • code is the HTTP response status code (integer)
  • body is the response body (string)


require 'faraday'

custom_connection = lambda { |method, uri, headers, _open_timeout, _read_timeout, body = nil|
  conn = uri.to_s, headers: headers) do |faraday|
    faraday.adapter Faraday.default_adapter
  conn.public_send(method, uri.path) { |request|
    request.body = body if body
  }.yield_self do |response| response.status, body: response.body)

my_client =
  api_key: ENV['EASYPOST_API_KEY'],
  custom_client_exec: custom_connection,


require 'typhoeus'

custom_connection = lambda { |method, uri, headers, _open_timeout, _read_timeout, body = nil|
    headers: headers,
    body: body,
  ).yield_self do |response| response.code, body: response.body)

my_client =
  api_key: ENV['EASYPOST_API_KEY'],
  custom_client_exec: custom_connection,

HTTP Hooks

Users can audit HTTP requests and responses being made by the library by subscribing to request and response events. To do so, pass a block to the subscribe_request_hook and subscribe_response_hook methods of an instance of EasyPost::Client:

require 'easypost'


# Returns a randomly-generated symbol which you can use to later unsubscribe the request hook
client.subscribe_request_hook do |request_data|
  # Your code goes here
# Returns a randomly-generated symbol which you can use to later unsubscribe the response hook
client.subscribe_response_hook do |response_data|
  # Your code goes here

You can also name your hook subscriptions by providing an optional parameter to the methods above:

require 'easypost'


request_hook = client.subscribe_request_hook(:my_request_hook) do |request_data|
  # Your code goes here
response_hook = client.subscribe_response_hook(:my_response_hook) do |response_data|
  # Your code goes here

puts request_hook  # :my_request_hook
puts response_hook # :my_response_hook

Keep in mind that subscribing a hook with the same name of an existing hook will replace the existing hook with the new one. A request hook and a response hook can share the same name.

Custom HTTP Connections with HTTP Hooks

If you're using a custom HTTP connection, keep in mind that the response_data parameter that a response hook receives will not be hydrated with all the response data. You will have to inspect the client_response_object property in response_data to inspect the response code, response headers and response body.


API documentation can be found at:

Library documentation can be found on the web at: or by building them locally via the make docs command.

Upgrading major versions of this project? Refer to the Upgrade Guide.


New features and bug fixes are released on the latest major release of this library. If you are on an older major release of this library, we recommend upgrading to the most recent release to take advantage of new features, bug fixes, and security patches. Older versions of this library will continue to work and be available as long as the API version they are tied to remains active; however, they will not receive updates and are considered EOL.

For additional support, see our org-wide support policy.


# Install dependencies
make install

# Install style guide (Unix only)
make install-style

# Lint project
make lint
make lint-fix

# Run tests (coverage is generated on a successful test suite run)

# Run security analysis
make scan

# Generate library documentation
make docs

# Update submodules
make update-examples-submodule


The test suite in this project was specifically built to produce consistent results on every run, regardless of when they run or who is running them. This project uses VCR to record and replay HTTP requests and responses via "cassettes". When the suite is run, the HTTP requests and responses for each test function will be saved to a cassette if they do not exist already and replayed from this saved file if they do, which saves the need to make live API calls on every test run. If you receive errors about a cassette expiring, delete and re-record the cassette to ensure the data is up-to-date.

Sensitive Data: We've made every attempt to include scrubbers for sensitive data when recording cassettes so that PII or sensitive info does not persist in version control; however, please ensure when recording or re-recording cassettes that prior to committing your changes, no PII or sensitive information gets persisted by inspecting the cassette.

Making Changes: If you make an addition to this project, the request/response will get recorded automatically for you. When making changes to this project, you'll need to re-record the associated cassette to force a new live API call for that test which will then record the request/response used on the next run.

Test Data: The test suite has been populated with various helpful fixtures that are available for use, each completely independent from a particular user with the exception of the USPS carrier account ID (see Unit Test API Keys for more information) which has a fallback value of our internal testing user's ID. Some fixtures use hard-coded dates that may need to be incremented if cassettes get re-recorded (such as reports or pickups).

Unit Test API Keys

The following are required on every test run:


Some tests may require an EasyPost user with a particular set of enabled features such as a Partner user when creating referrals. We have attempted to call out these functions in their respective docstrings. The following are required when you need to re-record cassettes for applicable tests:

  • USPS_CARRIER_ACCOUNT_ID (eg: one-call buying a shipment for non-EasyPost employees)
  • PARTNER_USER_PROD_API_KEY (eg: creating a referral customer)
  • REFERRAL_CUSTOMER_PROD_API_KEY (eg: adding a credit card to a referral customer)