Overview of the REST API

The REST API uses a resource to perform HTTP operations. A resource is an object with a type, associated data, relationships to other resources, and a set of methods that operate on it. Actions can be performed on the following resources:

• An entry on a form
• A field on a form
• A menu on a form

Example API call

The following example shows how a client creates a POST call and passes the user name, password, and authString in the Request headers using the /x-www-form-urlencoded content type:

POST /api/jwt/login HTTP/1.1
host: www.example.com
 
username=SomeUser&password=mysecret&authString=authenticationstring

BMC Helix ITSM performs the normal authentication mechanisms to validate the credentials. If the credentials are valid, the AR Server generates a JSON Web Token (JWT). You can attempt a REST API call if you have a token. A single JWT token is valid for an hour. You can use a single token across multiple AR System servers that are in the same server group.

// comments not actually included, added for clarity
{
    // the username
    "sub" : "SomeUser",
    // the Server-Connect-Name of the AR Server who issued the token
    "iss" : "www.example.com",
    // the UNIX time when the token was issued
    "iat" : 1408774310,
    // 2 minutes before "iat", to account for clock skew between servers
    "nbf" : 1408777790,
    // the UNIX time when the token expires, the duration being a configurable value (probably between 1 minute and 12 hours)
    "exp" : 1408777910,
    // a custom claim, the cache ID
    "_cacheId" : 13
}

The JWT is signed and base64 encoded string, and is sent back as a response body to the HTTP request:

HTTP/1.1 200 OK
 
eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ.dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

The client receives the token and uses it in all subsequent REST API calls through the Authorization header using the AR-JWT schema:

GET /api/arsys/v1/entry/SomeForm HTTP/1.1
Authorization: AR-JWT eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ.dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

Supported resources

The following table lists comment resources for REST operations.

Supported operations

The following table displayed common parameters for REST operations: 

For more information about these operations, see the same table in  Overview of the REST API in the AR System documentation.

HTTP status codes

When responding to requests, the REST API uses some of the HTTP status codes. The following table gives a summary of the status codes that are returned. Each operation specifies the response code you receive on successful calls or errors. 

For a list of error codes, see  Error handling for the REST API  in the AR System documentation.