Following this tutorial: https://www.shawntabrizi.com/substrate/querying-substrate-storage-via-rpc/

we should have that a pallet named "Members" should have prefix "0xba7fb8745735dc3be2a2c61a72c39e78" (equals to TwoX128("Members"))

However when accessing the value of the running chain using the polkadot-ui I get "0x2ce461329fdf4be12bce01afc0af09bc"


  • pallet name from metadata is obtained from api.rpc.state.getMetadata() with api being of type ApiPromise
  • twox128 is computed via @polkadot/util-crypto xxhashAsHex

1 Answer 1


After some inspection for the api.rpc.state.getMetadata(..) in the latest version of the MetadataV* type (currently MetadataV14) you can get the string used for the prefix from metadata.asLatest.pallets.storage.unwrap().prefix.toString() (clearly provided that metadata.asLatest.pallets.storage is not None)

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