How to connect two Candy Machines?

Question

I need to create a collection with a total of 100 NFTs, where the first 10 (IDs 0 to 9) will be minted to the same wallet from the start, and the remaining 90 will have the possibility to be minted through a web page.

I understand that the procedure would be as follows:

1. Create a CMv2 with a total of 10 assets.

2. Mint all of them (because the minting is random, it must be done before adding the remaining NFTs).

3. Create the second CMv2 with the remaining 90 assets. I must specify the address of the mint created in the first CMv2 (the "collection mint address") with the -m parameter.

However, I encounter several errors when doing this:

• Case 1:

private.json -> "number": 10
public.json -> "number": 90

assets
├── private
│   ├── 0.json
│   ├── 0.png
│   ├── ...
│   ├── 9.json
│   └── 9.png
└── public
    ├── 10.json
    ├── 10.png
    ├── ...
    ├── 99.json
    └── 99.png
config
├── private.json
└── public.json

• Case 2 (same file structure as above):

private.json -> "number": 10
public.json -> "number": 100

• Case 3:

private.json -> "number": 10
public.json -> "number": 90

assets
├── private
│   ├── 0.json
│   ├── 0.png
│   ├── ...
│   ├── 9.json
│   └── 9.png
└── public
    ├── 0.json
    ├── 0.png
    ├── ...
    ├── 89.json
    └── 89.png
config
├── private.json
└── public.json

• Case 4 (same file structure as above):

private.json -> "number": 10
public.json -> "number": 100

All 4 cases return the same error: Error Number: 6003. Error Message: Index greater than length!.

Answer 1

Using the Suger CLI you can combine 2 collections into 1.

First upload the public collection:

sugar upload assets/public -c config/public.json --cache .cache/public.json -k <WALLET KEYPAIR.json> -l debug -r <RPC ENDPOINT URL>

sugar deploy -c config/public.json --cache .cache/public.json -k <WALLET KEYPAIR.json> -l debug -r <RPC ENDPOINT URL>

Then do the same with the private collection.

Finally set the same collection using the Sugar CLI:

sugar collection set --cache .cache/public.json -k <WALLET KEYPAIR.json> --candy-machine <CANDY MACHINE ID> --collection-mint <COLLECTION ADDRESS> -r <RPC ENDPOINT URL>

Repeat for private collection. To index correctly, you manage that via the candy machine configuration.

Answer 2

After the mint you can close the Candy Machine, you don't need it anymore. So, it doesn't matter how many Candy Machines you use to mint your NFTs.

As the previous reply said, you have to use Metaplex Certified Collections to set the same collection for all the NFTs that were minted using different Candy Machines.

You can use many Candy Machines as you want and then combine all the NFT in the same Metaplex Certified Collections.