A DeveloperKey object looks like:

{
  // The ID should match the Developer Key ID in canvas
  "id": 1000000000040,
  // true the tool is a lti key, null is not a lti key
  "is_lti_key": true,
  // Controls if the tool is visable
  "visible": true,
  // The name of the account associated with the tool
  "account_name": "The Academy",
  // The public key in jwk format
  "public_jwk": "{
  	"kty":"RSA",
  	"e":"AQAB",
  	"n":"ufmgt156hs168mgdhy168jrsydt168ju816rtahesuvdbmnrtd87t7h8ser",
  	"alg":"RS256",
  	"use":"sig",
  	"kid":"Se68gr16s6tj_87sdr98g489dsfjy-547a6eht1",
  }",
  // The code of the vendor managing the tool
  "vendor_code": "fi5689s9avewr68",
  // The date and time the tool was last used
  "last_used_at": "2019-06-07T20:34:33Z",
  // The number of active access tokens associated with the tool
  "access_token_count": 0,
  // redirect uris description
  "redirect_uris": "https://redirect.to.here.com",
  // redirect uri description
  "redirect_uri": "https://redirect.to.here.com",
  // Api key for api access for the tool
  "api_key": "sd45fg648sr546tgh15S15df5se56r4xdf45asef456",
  // Notes for use specifications for the tool
  "notes": "Used for sorting graded assignments",
  // Display name of the tool
  "name": "Tool 1",
  // ID of the user associated with the tool
  "user_id": "tu816dnrs6zdsg148918dmu",
  // The time the jwk was created
  "created_at": "2019-06-07T20:34:33Z",
  // The user name of the tool creator
  "user_name": "johnsmith",
  // Email associated with the tool owner
  "email": "johnsmith@instructure.com",
  // True if the tool has required permissions, null if there are no needed
  // permissions
  "require_scopes": true,
  // Icon to be displayed with the name of the tool
  "icon_url": "null",
  // Specified permissions for the tool
  "scopes": "https://canvas.instructure.com/lti/public_jwk/scope/update",
  // The current state of the tool
  "workflow_state": "active"
}