Blockflow - Ralph Studio

Alephium uses a sharding algorithm called BlockFlow. The chain is split into groups, and blocks are produced per group pair. Most blockflow endpoints require fromGroup and toGroup parameters, both can be 0, 1, 2, or 3.

Get chain info

Returns the current height of a specific chain shard.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/chain-info?fromGroup=0&toGroup=0" \
  -H "Authorization: Bearer API_KEY"

{
  "currentHeight": 12973
}

Get block hashes at height

Returns all block hashes at a given height for a chain shard.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/hashes?fromGroup=0&toGroup=0&height=12900" \
  -H "Authorization: Bearer API_KEY"

{
  "headers": ["00000000ab3c..."]
}

Get a block by hash

Returns full block data including transactions.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/blocks/{block-hash}" \
  -H "Authorization: Bearer API_KEY"

{
  "hash": "00000000ab3c...",
  "timestamp": 1748476800000,
  "chainFrom": 0,
  "chainTo": 0,
  "height": 12900,
  "deps": [...],
  "transactions": [...],
  "nonce": "...",
  "version": 0,
  "depStateHash": "...",
  "txsHash": "...",
  "target": "..."
}

Get blocks in a time range

Returns all blocks produced within a timestamp range. Timestamps are in milliseconds.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/blocks?fromTs=1748476800000&toTs=1748480400000" \
  -H "Authorization: Bearer API_KEY"

Get the main chain block at height

Returns the canonical block at a specific height for a chain shard.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/main-chain-block-by-height?fromGroup=0&toGroup=0&height=12900" \
  -H "Authorization: Bearer API_KEY"

Get blocks with events

Returns blocks along with the contract events emitted in those blocks. Useful for indexing contract activity.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/blocks-with-events?fromTs=1748476800000&toTs=1748480400000" \
  -H "Authorization: Bearer API_KEY"

Is a block in the main chain

Checks whether a given block hash is part of the canonical chain.

curl "https://rpc.ralphstudio.xyz/{slug}/blockflow/is-block-in-main-chain?blockHash={block-hash}" \
  -H "Authorization: Bearer API_KEY"

{
  "isInMainChain": true
}

Parameters reference

Parameter	Type	Description
fromGroup	integer	Source shard group (0–3)
toGroup	integer	Destination shard group (0–3)
height	integer	Block height
fromTs	integer	Start timestamp in milliseconds
toTs	integer	End timestamp in milliseconds
blockHash	string	Hex-encoded block hash

​Get chain info

​Get block hashes at height

​Get a block by hash

​Get blocks in a time range

​Get the main chain block at height

​Get blocks with events

​Is a block in the main chain

​Parameters reference