Token metadata resolver API for Tezos-based FA1.2 and FA2 tokens

This microservice is used to provide ultimately simple API for fetching token metadata for FA1.2 and FA2 tokens. Metadata fetching algorithm relies on Taquito's TZIP-12/TZIP-16 libraries.

Configuration

The service can accept the following ENV variables:

Variable	Default	Description
PORT	3000	Expected server port
RPC_URL	"https://mainnet-tezos.giganode.io/"	RPC URL to be used
READ_ONLY_SIGNER_PK	edpkvWbk81uh1DEvdWKR4g1bjyTGhdu1mDvznPUFE2zDwNsLXrEb9K	Public key of account with balance used for dry-running
READ_ONLY_SIGNER_PK_HASH	tz1fVQangAfb9J1hRRMP2bSB6LvASD6KpY8A	Public key hash of account with balance used for dry-running

For default mainnet configuration, they might be left unchanged.

API

The following endpoints are currently available:

• /healthz

{ "message": "OK" }

• /metadata/:address/:tokenId, where :address is a token contract address (e.g. KT1A5P4ejnLix13jtadsfV9GCnXLMNnab8UT) and :tokenId is a token ID for FA2 or always 0 for FA1.2 tokens. Response is received in the following format:

{
  "decimals": 10,
  "symbol": "KALAM",
  "name": "Kalamint",
  "thumbnailUri": "ipfs://Qme9FX9M7o2PZt9h6rvkUbfXoLpQr1HsuMQi6sL5Y75g3A"
}

• [POST] /, where body structure looks like:

Request:

[
  "KT1VYsVfmobT7rsMVivvZ4J8i3bPiqz12NaH_0",
  "KT1XPFjZqCULSnqfKaaYy8hJjeY63UNSGwXg_0"
]

• is an array of token slugs: "{{token_contract_address}}_{{token_id}}" for tokens. For FA1.2 tokens token_id must be 0.

Response:

[
  {
    "decimals": 6,
    "symbol": "wXTZ",
    "name": "Wrapped Tezos"
  },
  {
    "decimals": 8,
    "symbol": "crDAO",
    "name": "Crunchy DAO"
  }
]

Running the service

• NodeJS and yarn:

yarn && yarn start

• Docker:

docker build -t tez-metadata .
docker run -p 3000:3000 tez-metadata