The Atlas API follows the principles of the REST architectural style to expose a number of internal resources which enable programmatic access to Atlas’s features.

As with changes made through the Atlas web interface, changes made through the API are subject to Atlas billing. If you incur charges, you must have a valid credit card on file with Atlas or risk having your account locked.

The API has the following features:

  • JSON entities - All entities are expressed in JSON.
  • Digest authentication - To ensure that your API key is never sent over the network, API requests are authenticated using HTTP Digest Authentication.
  • Browsable interface - Using a consistent linking mechanism, you can browse the entire API by starting at the root resource and following links to related resources.
  • Security - In addition to Digest Authentication, the API is only accessible via HTTPS, and certain calls requiring even more security are protected by user-defined whitelists. Further, an API user’s capabilities are restricted by their assigned role(s). For example, a user with the Read Only role within a particular group is not allowed to modify any resources within that group.

HTTP Methods

All resources support a subset of these common HTTP Methods:

  • GET - Retrieve the JSON representation of a resource.
  • POST - Create a new resource using the provided JSON representation.
  • PUT - Replace a resource with the provided JSON representation.
  • PATCH - Update the specified fields in a resource using the provided JSON representation.
  • DELETE - Remove a resource.
  • HEAD - Returns the response header without the JSON representation of the resource.


All entities are represented in JSON. The following rules and conventions apply:

  • Content Type Request Header

    When sending JSON to the server via POST or PUT, make sure to specify the correct content type request header: Content-Type: application/json

  • Invalid Fields

    Invalid fields are rejected rather than ignored. If, for example, you attempt to create a new entity and misspell one of the fields, or if you attempt to update an existing entity and include a field that cannot be modified, the server responds with a 400 status code and an error message stating which field was invalid.

  • ISO-8601-Formatted Dates

    All dates are returned as ISO-8601-formatted strings designated in UTC. When sending dates to the server (i.e., as query parameters or fields in POST or PATCH request entities), use ISO-8601-formatted dates. If you do not specify a time zone, UTC is assumed. However, it is highly recommended that you include a time zone designator to avoid any ambiguity.

  • BSON Timestamps

    In some cases, a timestamp is returned as a BSON timestamp, most notably in the backup resources. These are represented in JSON documents as an object with two fields: date, which is an ISO-8601-formatted date string in UTC with granularity to the second, and increment a 32-bit integer.

  • Field Names for Fields with Numbers

    Fields that contain numeric values in a particular unit will be named so as to disambiguate the unit being used.

  • Empty Fields

    Fields that do not have a current value are returned with an appropriate default value.

    Fields that do not have a sensible default value are omitted from the entity.

  • Field Order

    The fields in the JSON documents returned by the server are in no particular order, and the order may change. Do not depend on the order of the fields.


Each resource includes one or more links to sub-resources and/or related resources. Links are placed in the links field of an entity, which is an array of link relation objects. Each link relation has two fields:

  • rel - Name (or type) of the relation. Many of these are considered Extension Relation Types and are prefixed by
  • href - The target URL.

All entities include at least one link relation called self, which is simply its own URL. When an entity is part of a list, then it only includes the self link relation.

For more information, refer to the Web Linking Specification. Note that although the specification describes a format for including links in the HTTP response headers, doing so is not a requirement. To make the API easily browsable, it includes the links in the response body rather than in the response headers.


Some resources return a list of entities. When a list of entities is expected in a response, the results are returned in batches bounded by two query parameters:

  • pageNum - Page number (1-based). Defaults to 1 if not specified.
  • itemsPerPage - Maximum number of items to return, up to a maximum of 100. Defaults to 100 if not specified.

The response entity contains three fields:

  • totalCount - The total number of items in the entire result set.
  • results - The result set, which is an array of entity documents.
  • links - Contains one to three link relations: previous for the previous page of results (omitted for the first page); next for the next page of results (omitted for the last page); and self for the current page (always present).

If you make a request for a list of entities and there are no results, then the API responds with a 200 status code and the results array is empty. It does not respond with a 404 in this case, since the list of entities may not be empty at some point in the future. However, if you request a list of entities in a context that does not exist (e.g., the list of hosts for a non-existent group), then this does result in a 404 response status.


Some clients might not be able to access the HTTP response headers and/or status code. In that case, you can request that the response include an “envelope,” which is simply an extra layer of information in the JSON document and contains any relevant details that would normally be in the response headers. By default, the API does not include the response in an envelope. To request one, simply add the query parameter envelope=true.

For responses that contain a single entity, the envelope contains two fields:

  • status - The HTTP status code.
  • content - The requested entity.

For responses that contain a list of entities, there is already an envelope that wraps the results, so specifying envelope=true only adds the status field to the existing envelope.

Pretty Printing

By default, extraneous whitespace is stripped from the JSON returned by the server. To ask for pretty-printed JSON, simply append the pretty=true query parameter to any request:

curl -u "username:apiKey" --digest -i ""

Response Codes

Responses use the standard HTTP response codes, including:

Code Meaning Notes
200 OK The request was successful. This is typically the response to a successful GET request.
201 Created A new resource was created. This is typically the response to a successful POST request.
202 Accepted A request for an asynchronous operation was accepted.
400 Bad Request Something was wrong with the client request.
401 Unauthorized Authentication is required but was not present in the request. Typically this means that the digest authentication information was omitted from the request, the provided credentials are incorrect, or the user associated with the given API key is not allowed to access the requested resource.
403 Forbidden Access to the specified resource is not permitted.
404 Not Found The requested resource does not exist.
405 Method Not Allowed The HTTP method is not supported for the specified resource. Keep in mind that each resource may only support a subset of HTTP methods. For example, you are not allowed to DELETE the root resource.
409 Conflict This is typically the response to a request to create or modify a property of an entity that is unique when an existing entity already exists with the same value for that property.
5xx Various server errors Something unexpected went wrong. Try again later and consider notifying Atlas Support.


When a request results in an error, the response body contains a document with additional details about what went wrong. The document contains three fields:

  • error - The error code, which is simply the HTTP status code.
  • reason - A short description of the error, which is simply the HTTP status phrase.
  • detail - A more detailed description of the error.

Group ID

Many resources are tied to a group and require the Group ID. You can retrieve the group ID through the Atlas interface. Click Settings, then Group Settings. The ID appears at the top of the page.


As previously mentioned, the Atlas API uses HTTP Digest Authentication. The details of digest authentication are beyond the scope of this document, but it essentially requires a username and a password which are hashed using a unique server-generated value called a nonce. The username is the username of a registered Atlas account, and the password is an API key associated with that account.

Keep the following points in mind:

  • The server-generated nonce is used by the client to hash the username and password before sending them back to the server to authenticate a request. The nonce is only valid for a short amount of time as per the digest authentication specification. This is to prevent replay attacks, so you can’t cache a nonce and use it forever.
  • Using digest authentication in combination with HTTPS provides an extra layer of security by ensuring that a password is never transmitted back to the server.
  • Some resource methods require even more security and are additionally protected by user API whitelists that allow access to the resource only from the IP addresses listed. Each user configures their own API whitelist of IP addresses that allow them access to the resource, in combination with their API keys. A user can access a whitelisted resource only when the API key and whitelisted IP address come from the same Atlas user account.
  • Atlas roles allow more fine-grained control of the operations a user is allowed to perform. The API resources enforce the same authorization rules, so the resources and methods that can be accessed by an API key are governed by the roles granted to the associated user.
  • Many resources are tied to a group, as evidenced by URLs of the form .../api/atlas/v1.0/groups/<GROUP-ID>/.... For these resources, the user tied to the API key must be a member of the group. Otherwise the server will respond with a 401 error.

Rate Limiting

Certain resources are subject to rate limiting.

For resources that are rate limited, Atlas allows up to 100 requests per minute per group. Keep in mind that an API key is assigned to a user, but that user may access multiple groups. Consider two users: A and B. User A belongs to group X, and user B belongs to groups X and Y. At 1:00:00pm, User A makes 50 requests to a rate limited resource in group X, all of which are complete by 1:00:20pm. At 1:00:30pm, User B attempts to make 60 requests to a rate limited resource in group X. Since User A has already used up 50 requests within the 1:00pm minute for group X, the last 10 requests User B attempts to make are rejected. However, User B can make requests to a rate limited resource in group Y, since each group maintains a separate request counter. At 1:01pm, requests to group X may proceed, because the request counter used for rate limiting resets each minute.

If you exceed the rate limit, the API returns a 429 Too Many Requests response code.