From Facebook Developer Wiki

Contents 1 Description 2 Parameters 3 Error Codes 4 Notes 5 See Also

Description

Lets your application invite users to an event in one of the following ways:

• The user who has created an event can invite friends to that event, if they have granted your application create_event extended permission. The user may have created the event directly on Facebook, through your application, or through another application.
• Your application can create an event using events.create and invite your application users to it.

This method does not require a session key. However, if you call this method without an active user session, then you can invite only your application users to events that were created through your application.

Parameters

Required	Name	Type	Description
required	api_key	string	The application key associated with the calling application. If you specify the API key in your client, you don't need to pass it with every call.
	call_id	float	The request's sequence number. Each successive call for any session must use a sequence number greater than the last. We suggest using the current time in milliseconds, such as PHP's microtime(true) function. If you specify the call ID in your client, you don't need to pass it with every call.
	sig	string	An MD5 hash of the current request and your secret key, as described in the How Facebook Authenticates Your Application. Facebook computes the signature for you automatically.
	v	string	This must be set to 1.0 to use this version of the API. If you specify the version in your client, you don't need to pass it with every call.
optional	session_key	string	The session key of the logged in user. The session key is automatically included by our PHP client. If you call this method without an active user session, then you can invite only your application users to events that were created through your application.
	format	string	The desired response format, which can be either XML or JSON. (Default value is XML.)
	callback	string	Name of a function to call. This is primarily to enable cross-domain JavaScript requests using the <script> tag, also known as JSONP, and works with both the XML and JSON formats. The function will be called with the response passed as the parameter.
required	eid	int	The event ID.
	uids	array	An array of user IDs of the users who will receive the event invitation.
optional	personal_message	string	An optional message you can include with the invitation. Plain text only.

Error Codes

Code	Description
1	An unknown error occurred. Please resubmit the request.
2	The service is not available at this time.
4	The application has reached the maximum number of requests allowed. More requests are allowed once the time window has completed.
5	The request came from a remote address not allowed by this application.
100	One of the parameters specified was missing or invalid (e.g. missing location, etc.)
101	The API key submitted is not associated with any known application.
102	The session key was improperly submitted or has reached its timeout. Direct the user to log in again to obtain another key.
103	The submitted call_id was not greater than the previous call_id for this session.
104	Incorrect signature.

Notes

You can call this method using a session secret, and not the application secret (for example, for a Facebook Connect site or desktop application).

See Also

• events.cancel
• events.create
• events.edit
• events.get
• events.getMembers
• events.rsvp