BlockX Clients

BlockX supports different clients in order to support Cosmos and Ethereum transactions and queries:
Default Port
Cosmos gRPC
Query or send BlockX transactions using gRPC
Cosmos REST (gRPC-Gateway)
Query or send BlockX transactions using an HTTP RESTful API
Ethereum JSON-RPC
Query Ethereum-formatted transactions and blocks or send Ethereum txs using JSON-RPC
Ethereum Websocket
Subscribe to Ethereum logs and events emitted in smart contracts.
Tendermint RPC
Subscribe to Ethereum logs and events emitted in smart contracts.
Tendermint Websocket
Query transactions, blocks, consensus state, broadcast transactions, etc.
Command Line Interface (CLI)
Query or send BlockX transactions using your Terminal or Console.

Cosmos gRPC

BlockX exposes gRPC endpoints for all the integrated Cosmos SDK modules. This makes it easier for wallets and block explorers to interact with the Proof-of-Stake logic and native Cosmos transactions and queries.

Cosmos gRPC-Gateway (HTTP REST)

gRPC-Gateway reads a gRPC service definition and generates a reverse-proxy server which translates RESTful JSON API into gRPC. With gRPC-Gateway, users can use REST to interact the Cosmos gRPC service.

Ethereum JSON-RPC

BlockX supports most of the standard JSON-RPC APIs to connect with existing Ethereum-compatible web3 tooling.

Ethereum Websocket

Then, start a websocket subscription with ws
# connect to tendermint websocet at port 8546 as defined above
ws ws://localhost:8546/
# subscribe to new Ethereum-formatted block Headers
> {"id": 1, "method": "eth_subscribe", "params": ["newHeads", {}]}
< {"jsonrpc":"2.0","result":"0x44e010cb2c3161e9c02207ff172166ef","id":1}

Tendermint Websocket

Tendermint Core provides a Websocket connection to subscribe or unsubscribe to Tendermint ABCI events.
For more info about the how to subscribe to events, please refer to the official Tendermint documentation.
"jsonrpc": "2.0",
"method": "subscribe",
"id": "0",
"params": {
"query": "tm.event='<event_value>' AND eventType.eventAttribute='<attribute_value>'"

List of Tendermint Events

The main events you can subscribe to are:
  • NewBlock: Contains events triggered during BeginBlock and EndBlock.
  • Tx: Contains events triggered during DeliverTx (i.e. transaction processing).
  • ValidatorSetUpdates: Contains validator set updates for the block.
The list of events types and values for each Cosmos SDK module can be found in the Modules Specification section. Check the Events page to obtain the event list of each supported module on BlockX .
List of all Tendermint event keys:
Event Type
Subscribe to a specific event
Subscribe to a specific transaction
Subscribe to transactions at a specific block height
Index BeginBlock and Endblock events
Subscribe to ABCI BeginBlock events
Subscribe to ABCI EndBlock events
Below is a list of values that you can use to subscribe for the tm.event type:
Event Value
New block
New block header
New Byzantine Evidence
New transaction
Validator set updated
Block sync status
New consensus round
State sync status
Timeout propose
Timeout wait
Block is valid
Consensus vote


ws ws://localhost:26657/websocket
> { "jsonrpc": "2.0", "method": "subscribe", "params": ["tm.event='ValidatorSetUpdates'"], "id": 1 }
Example response:
"jsonrpc": "2.0",
"id": 0,
"result": {
"query": "tm.event='ValidatorSetUpdates'",
"data": {
"type": "tendermint/event/ValidatorSetUpdates",
"value": {
"validator_updates": [
"address": "09EAD022FD25DE3A02E64B0FE9610B1417183EE4",
"pub_key": {
"type": "tendermint/PubKeyEd25519",
"value": "ww0z4WaZ0Xg+YI10w43wTWbBmM3dpVza4mmSQYsd0ck="
"voting_power": "10",
"proposer_priority": "0"


Users can use the blockxd binary to interact directly with an BlockX node though the CLI.
To use the CLI, you will need to provide a Tendermint RPC address for the --node flag. Look for a publicly available addresses for testnet and mainnet in the Establishing Connections page.
  • Transactions: blockxd tx
    The list of available commands, as of v3.0.0, are:
Available Commands:
authz Authorization transactions subcommands
bank Bank transaction subcommands
broadcast Broadcast transactions generated offline
crisis Crisis transactions subcommands
decode Decode a binary encoded transaction string
distribution Distribution transactions subcommands
encode Encode transactions generated offline
erc20 erc20 subcommands
evidence Evidence transaction subcommands
evm evm transactions subcommands
feegrant Feegrant transactions subcommands
gov Governance transactions subcommands
ibc IBC transaction subcommands
ibc-transfer IBC fungible token transfer transaction subcommands
multisign Generate multisig signatures for transactions generated offline
multisign-batch Assemble multisig transactions in batch from batch signatures
sign Sign a transaction generated offline
sign-batch Sign transaction batch files
slashing Slashing transaction subcommands
staking Staking transaction subcommands
validate-signatures validate transactions signatures
vesting Vesting transaction subcommands
Queries: blockxd query
The list of available commands, as of v3.0.0, are:
Available Commands:
account Query for account by address
auth Querying commands for the auth module
authz Querying commands for the authz module
bank Querying commands for the bank module
block Get verified data for a the block at given height
claims Querying commands for the claims module
distribution Querying commands for the distribution module
epochs Querying commands for the epochs module
erc20 Querying commands for the erc20 module
evidence Query for evidence by hash or for all (paginated) submitted evidence
evm Querying commands for the evm module
feegrant Querying commands for the feegrant module
feemarket Querying commands for the fee market module
gov Querying commands for the governance module
ibc Querying commands for the IBC module
ibc-transfer IBC fungible token transfer query subcommands
incentives Querying commands for the incentives module
inflation Querying commands for the inflation module
params Querying commands for the params module
recovery Querying commands for the recovery module
slashing Querying commands for the slashing module
staking Querying commands for the staking module
tendermint-validator-set Get the full tendermint validator set at given height
tx Query for a transaction by hash, "<addr>/<seq>" combination or comma-separated signatures in a committed block
txs Query for paginated transactions that match a set of events
upgrade Querying commands for the upgrade module
vesting Querying commands for the vesting module
When querying Ethereum transactions versus Cosmos transactions, the transaction hashes are different. When querying Ethereum transactions, users need to use event query. Here's an example with the CLI:
curl -X GET "http://localhost:26657/tx_search?query=ethereum_tx.ethereumTxHash%3D0x8d43464891fac6c113e809e14dff1a3e608eae124d629799e42ca0e36562d9d7&prove=false&page=1&per_page=30&order_by=asc" -H "accept: application/json"