Protocols

Encoding

All API calls are made over HTTPS, receive JSON input, and return JSON output. For information about what JSON is, please refer to RFC 4627 and JSON (Wikipedia).

Any timestamps that appear in the response from or as input for an API method are always given as numbers signifying the millisecond count since the Unix Epoch. For example, "Tue, 31 Jan 2012 00:02:30 GMT" is represented as the number 1327968150000.

Input

Each API method has a distinct corresponding URL. Calls to this URL are made with HTTP POST. The body of the message is expected to contain valid JSON (as described in RFC4627). The Content-Type must either be absent or set to application/json, otherwise a MalformedJSON (400) error will be issued. Query parameters in the URL are ignored.

An optional header "DNAnexus-API" may also be provided to indicate which version of the API should be used. This document describes the API with version string "1.0.0". If the header is not given, it is assumed that the most recent version should be used.

NOTE: Certain API methods do not require any input. However, for compatibility with the future, JSON parsing will still be performed, so valid JSON must still be provided in the body, but that JSON will only be checked syntactically, not semantically.

CORS support

All URLs corresponding to API methods have some support for CORS (cross-origin resource sharing), based on the 27 July 2010 W3C Working Draft. More specifically:

  • If a POST request to the URL of an API method includes the "Origin" header, its contents will be propagated into the "Access-Control-Allow-Origin" header of the response.
  • Preflight requests (OPTIONS requests to the URL of an API method, with appropriate extra headers as defined in the CORS draft) will be accepted if the value of the "Access-Control-Request-Method" header is "POST". The values of "Origin" and "Access-Control-Request-Headers" (if any) of the request, will be propagated to "Access-Control-Allow-Origin" and "Access-Control-Allow-Headers" respectively in the response. The "Access-Control-Max-Age" of the response is set to 1 year.

Output

Successful results are always returned as JSON in the response body, with response code 200. All responses are UTF-8 encoded. A header called "DNAnexus-API" will also be provided with value equal to the version number of the API used to fulfill the query. For errors please refer to the "Errors" paragraph.

Errors

Non-successful invocations of the API return an error. Errors are represented with an HTTP error code, and the response body contains a JSON object with the following structure:

{
    "error": {
        "type": "MalformedJSON",
        "message": "Problems parsing JSON"
    }
}

The object contains a single key, "error". Its value is an object with two keys, "type" and "message". They value of "type" is a string with a DNAnexus-defined error type, and the message contains a short description of the error in English.

Error type General meaning HTTP Code
MalformedJSON The input could not be parsed as JSON 400
InvalidAuthentication The provided OAuth2 token is invalid 401
PermissionDenied Insufficient permissions to perform this action 401
SpendingLimitExceeded The spending limit has been reached for the account that would be billed for this action 403
ResourceNotFound A specified entity or resource could not be found 404
InvalidInput The input is syntactically correct (JSON), but semantically incorrect (for example, a JSON array is provided where a hash was required; or a required parameter was missing, etc.) 422
InvalidState The operation is not allowed at this object state 422
InvalidType An object specified in the request is of invalid type 422
RateLimitConditional Too many invalid requests 429
InternalError The server encountered an internal error 500
ServiceUnavailable Some service was temporarily unavailable 503

Some errors may also choose to provide additional details in another field called "details". The documentation for the route will describe when such detailed information will be provided and what subfields can be expected. An example of such an error is after attempting to run an applet with invalid input for one of the applet’s input fields:

{
    "error": {
        "type": "InvalidInput",
        "message": "i/o value for fieldname is not int",
        "details": {
            "field": "fieldname",
            "reason": "class",
            "expected": "int"
        }
    }
}

Errors in execution environments

See the Execution Environment Reference for more information on how errors are propagated during app and applet execution on the platform.

Request retries

Each request receives an HTTP response code from the server. Some responses indicate that the request should be retried. For example, any 5xx response code should be retried (up to some limit). See the HTTP retry section in the client documentation, for more information.

Last edited by Ohad Rodeh, 2016-02-10 18:34:37

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