Outkit API Client View Source

This is the official Elixir client for the Outkit API.


First, add Outkit to your mix.exs dependencies:

def deps do
  [{:outkit, "~> 0.0.3"}]

Then, update your dependencies:

$ mix deps.get

Add :outkit to your list of applications if using Elixir 1.3 or lower.

defp application do
  [applications: [:outkit]]


In one of your configuration files, include your Outkit API credentials like this:

config :outkit,
  key: "OUTKIT_API_KEY",
  secret: "OUTKIT_API_SECRET",



All functions of the API client take an %Outkit.Client{} struct as the first argument. This struct contains auth info and options. If you don’t supply a client as the first argument, the library will auto-build one from the configuration and use it automatically. So in the following example the two methods are identical, provided that you have specified the same settings in your configuration files as those passed to the Outkit.Client.new function:

# Method one

# Method two
client = Outkit.Client.new(key: "my-key", secret: "my-secret", passphrase: "my-passphrase")
Outkit.Message.create(client, message)

This gives you complete flexibility in terms of how you want to use Outkit - one static configuration for your entire app or several clients that can be dynamically configured at runtime.

Submitting a message

Submitting a message for rendering and/or delivery will return a message record with the Outkit ID and the status set to received (as well as a few other properties that can be determined at creation time). The API call returns as soon as the message is saved on our servers, it does not wait for rendering or delivery to take place (by default - see the section on synchronous processing below). You can retrieve the status of a message at any time. We also support webhook notifications on status changes.

# Create a message
{:ok, message} = Outkit.Message.create(%{
  type: "email",                   # Message type - 'email' and 'sms' currently supported
  project: "my-project",           # Outkit project identifier (managed through our web UI)
  template: "my-template",         # Template identifier (managed through our web UI)
  subject: "Welcome, Jane!",       # Email subject (optional, can also be set in the template or omitted for SMS messages)
  to: "some.name@example.com",     # Recipient address (and optional name)
  from: "other.name@example.com",  # Sender address (and optional name)
  data: %{
    name: "John Doe",
    # ...
    # Add the values for any variables used in the template here

Retrieving a message

You can retrieve the status and data of a message at any time. After the message has been rendered, we will also return the applicable rendered fields (subject, html_body and text_body for emails, text_body for SMS messages) so that you can see exactly what was/will be sent.

{:ok, message} = Outkit.Message.get("some-id")

Return values

The return value for all API functions in this library is always a tuple:

# Either
{:ok, some_data}

# or
{:error, error_message}

The data part of the tuple will (by default) contain only the actual data returned from the API, converted to Elixir data structures. So both Outkit.Message.get/1 and Outkit.Message.create/1 return an %Outkit.Message{} struct, like so

  type: "email"
  project: "acme-project", 
  template: "welcome", 
  html_body: "... rendered HTML ...",
  text_body: "... rendered plain text ...",
  backend_response: %{             # Note that child Maps are regular maps with string keys
    "normalized_id" => "abc123",

If you need access to the full response from our API (including HTTP headers, HTTP status code etc.), you can set the return_response in the opts key on the client, like so:

client = Outkit.Client.new(opts: [return_response: true])   # Or you could do the same in your configuration
{:ok, response} = Outkit.Message.create(client, message)

The response variable will contain something like this:

  body: %{...}, 
  raw_body: "...",
  headers: %{...},
  status_code: 200,

You’d find the actual data in response.body["data"]. Note that the data is just regular Lists or Maps with string keys - no structs.

Rendering a message

To support the use case of rendering a message using the Outkit infrastructure, but sending it yourself, you can specify render_only: true in the message record. You may also want to set sync: true in these cases - see the next section.

Once the message has been rendered, its data will contain a text_body field (all types), and subject and html_body fields for emails. These can then be fed directly to, say, a Mailgun client or SMTP server. See details below.

Synchronous processing

For some use cases (sending emails from scripts, using Outkit as a renderer etc.), it can be desirable to have the API calls operate synchronously - ie. perform rendering/delivery immediately instead of queueing messages, and return the rendered message and (optionally) its delivery status in the data from the API call. This can be accomplished by setting sync: true in the submitted message.

Note that this will incur additional costs (see our pricing page for details), and that each Outkit customer is only allowed a limited number of such requests (currently 100.000 per month), since they are more difficult and costly for us to scale. Customers that need additional synchronous requests can contact support to have their monthly limit raised. We expect to raise the default limit significantly when we have more usage data.

Message lifecycle

Submitted messages typically go through the following stages, which are reflected in the status field:

  • received - The message has been received and saved in our datastore, where it awaits further processing
  • queued_for_rendering - The message has been queued for rendering
  • rendered - The subject and HTML/text of the template have been rendered and merged with the submitted data
  • queued_for_delivery - The message has been queued for delivery
  • delivered - Message has been successfully delivered to the backend

Typically, a message will go through all stages in a matter of milliseconds, but it can sometimes take a little longer.

Note that different message can have different statuses. For example, a message with the render_only flag set will never be queued for delivery or delivered. Messages that supply their own text_body and html_body instead of using a template will never be rendered, only delivered.

Note that the delivered status does not necessarily mean that the message has been delivered to the end user. Once the backend has accepted the message, it’s up to the backend to perform final delivery. Most backends offer webhooks if you need confirmation of the actual delivery.

There are some additional statuses your message can have, in case of errors and problems:

  • render_error - We were unable to render the template with the submitted data
  • backend_error - We encountered an error when trying to submit the message to the configured backend
  • internal_error - There was an unrecoverable problem on our end (should be very rare)

If the message has any of these statuses, there will be more information in the status_message field. Also, you can inspect the full backend response in the response field.

All messages have a done flag (true or false) which indicate whether we have finished processing it. Nothing more will happen to a message once it is done, regardless of its status.

A note on function names

The functions names for messages (get and create) are deliberately generic, to align them with future expansions of the API (say, Outkit.Project.create). So even though you might feel like you are submitting or sending a message (and we often use terms like that in our own docs), in API terms you are always just create-ing it.

You’ll probably wrap our functions in your own MyApp.send_sms or MyApp.enqueue_email or whatever anyway, so it shouldn’t be much of an issue. We feel that when dealing with APIs and their clients, consistency trumps linguistic precision.


  • Write proper tests with mocks (the current tests run "live" against our dev servers)