How to identify missing parameter on placeOrder?

[mojovski2]

Hey guys,
I am trying to place an order via the API but receive a message that some of the required parameters is missing.
Here is what I send:

{'params': {'instructions': [{'orderType': 'LIMIT', 'selectionId': 4030151.0, 'side': 'BACK', 'limitOrder': {'persistenceType': 'LAPSE', 'price': 100.5, 'size': 3.0}}], 'marketId': 1.120831103}, 'jsonrpc': '2.0', 'method': 'SportsAPING/v1.0/placeOrders', 'id': 1}

And here is the response:

{u'jsonrpc': u'2.0', u'id': 1, u'error': {u'message': u'DSC-0018', u'code': -32602}}

As far the docs about placeOrder tell, I filled out the required fields.

What do I miss?

Thanks alot in advance!

[ForeTwo]

This bet is failing on selectionId (needs to be an int, not float).

It would then fail on an invalid price (incorrect increment).

[mojovski2]

This bet is failing on selectionId (needs to be an int, not float).

It would then fail on an invalid price (incorrect increment).

Thank you!

Actually, I still dont get how the price increments work. Is there some explanation out there?

[jptrader]

https://api.developer.betfair.com/se...ice+Increments

[mojovski2]

Sorry, still have difficulties to place an order.

I call now
https://gist.github.com/mojovski/fbd99d3b8c0404479401

And receive no exception, but a response like this:
https://gist.github.com/mojovski/d533c83ca3942d8221bc


The market data details can be found here:
https://gist.github.com/mojovski/c87be771a56dd53a7121

What do I miss here?