RingCT coinbase transactions dont have ecdhInfo fields with mask, outPk and amount. For example, this is how ringct coinbase txs looks like (look at json representation):

https://explorer.xmr.my/tx/b3630cecf07e3db8a3bad74f9e3ec29451148ec3a0cce1475d73549576bbc773/1

Notice that ringct fields are empty

"rct_signatures": {
"type": 0
}

Now compare with normal ringct tx: https://explorer.xmr.my/tx/91870fad32873d8e01f1e1328540dd9d997a042343664aec4e5a1ace58d4554a/1

rct_signatures structure is field. Of special interest is ecdhInfo:

"ecdhInfo": [ {
"mask": "ea3f55ede33a6500cbaf8209494f98f47c8e2c392ae1c4829ca2b6e56fa7a80a",
"amount": "0aeff00281a107ae87a1d36d15d935a5af4bb42386feccb0913e98deeb67ee09"
}, {
"mask": "4238c9f9cdc40045e79970ad9481af1fa1f2141e9dedc58a13adfb3dec21f607",
"amount": "826a729c9bf014af4af3b801b195c3787566b89d28a887f6c0262ed26237ba09"
}],
"outPk": [ "8d58a7e35b866bcb8f3fc14dd44d7190a8b8057917d8b1362a36562bf5466aef", "6bcb6810dcf18c4f6480c695b619e3302c92ab1642ce6b263bfdbbd935d18649"]
},

Normal txs have outPk, mask and amount provided and avaliable in the blockchain. Those values are not available for coinbase ringct txs. My guess is that they are created in flight when spending ringct coinbase txs? But how? Cant find this information. They are needed for spending coinbase ringct txs from what I understand.

Any info appreciated.

RingCT coinbase transactions don't have ecdhInfo fields with mask, outPk and amount. For example, this is how ringct coinbase transactions looks like (look at JSON representation):

https://explorer.xmr.my/tx/b3630cecf07e3db8a3bad74f9e3ec29451148ec3a0cce1475d73549576bbc773/1

Notice that the ringct fields are empty:

"rct_signatures": {
"type": 0
}

Now compare this with a normal ringct transaction: https://explorer.xmr.my/tx/91870fad32873d8e01f1e1328540dd9d997a042343664aec4e5a1ace58d4554a/1

rct_signatures structure is field. Of special interest is ecdhInfo:

"ecdhInfo": [ {
"mask": "ea3f55ede33a6500cbaf8209494f98f47c8e2c392ae1c4829ca2b6e56fa7a80a",
"amount": "0aeff00281a107ae87a1d36d15d935a5af4bb42386feccb0913e98deeb67ee09"
}, {
"mask": "4238c9f9cdc40045e79970ad9481af1fa1f2141e9dedc58a13adfb3dec21f607",
"amount": "826a729c9bf014af4af3b801b195c3787566b89d28a887f6c0262ed26237ba09"
}],
"outPk": [ "8d58a7e35b866bcb8f3fc14dd44d7190a8b8057917d8b1362a36562bf5466aef", "6bcb6810dcf18c4f6480c695b619e3302c92ab1642ce6b263bfdbbd935d18649"]
},

Normal transactions have outPk, mask and amount provided and available in the blockchain. Those values are not available for coinbase ringct transactions. My guess is that they are created in flight when spending ringct coinbase transactions? But how? I can't find this information. They are needed for spending coinbase ringct transactions from what I understand.

Any info is appreciated.