Metadata
Get any information required to construct a transaction for a specific network. Metadata returned here could be a recent hash to use, an account sequence number, or even arbitrary chain state. The request used when calling this endpoint is created by calling /construction/preprocess in an offline environment. You should NEVER assume that the request sent to this endpoint will be created by the caller or populated with any custom parameters. This must occur in /construction/preprocess. It is important to clarify that this endpoint should not pre-construct any transactions for the client (this should happen in /construction/payloads). This endpoint is left purposely unstructured because of the wide scope of metadata that could be required.
A ConstructionMetadataRequest is utilized to get information required to construct a transaction. The Options object used to specify which metadata to return is left purposely unstructured to allow flexibility for implementers. Options is not required in the case that there is network-wide metadata of interest. Optionally, the request can also include an array of PublicKeys associated with the AccountIdentifiers returned in ConstructionPreprocessResponse.
Some blockchains require different metadata for different types of transaction construction (ex: delegation versus a transfer). Instead of requiring a blockchain node to return all possible types of metadata for construction (which may require multiple node fetches), the client can populate an options object to limit the metadata returned to only the subset required.
POST /construction/metadata HTTP/1.1
Host:
Content-Type: application/json
Accept: */*
Content-Length: 258
{
"network_identifier": {
"blockchain": "bitcoin",
"network": "mainnet",
"sub_network_identifier": {
"network": "shard 1",
"metadata": {
"producer": "0x52bc44d5378309ee2abf1539bf71de1b7d7be3b5"
}
}
},
"options": {},
"public_keys": [
{
"hex_bytes": "text",
"curve_type": "secp256k1"
}
]
}{
"metadata": {
"account_sequence": 23,
"recent_block_hash": "0x52bc44d5378309ee2abf1539bf71de1b7d7be3b5"
},
"suggested_fee": [
{
"value": "1238089899992",
"currency": {
"symbol": "BTC",
"decimals": 8,
"metadata": {
"Issuer": "Satoshi"
}
},
"metadata": {}
}
]
}