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name: First Steps wih Ethereum JSON RPC category:

First steps with ethereum JSON-RPC

1. clone cpp-ethereum or install it

manual installation

git clone https://github.com/ethereumproject/cpp-ethereum
cd cpp-ethereum
mkdir build
cd build
cmake ..
make -j 4

automatic installation

build instructions are here

2. run eth (headless client)

eth -j

-j option will start ethereum node with jsonrpc http server at port 8080

etheruem should be ready to use now

type in console to check if everything is working fine

curl -X POST --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":83}' http://localhost:8080

3. mine and connect to the network

try running

eth -j -m true -f -b

where:

• -m true - to do anything in ethereum, you need some ethere, let's mine
• -f - mine with force, even if there are no transactions to mine
• -b - connect to ethereum network

with latest version of cpp-ethereum it may take some time to connect to network. If you see any delays with jsonrpc responses, or crashes contant us. We are probably aware of them, but it's good to know about any possible vulnerability

4. json-rpc methods, that you might be intrested in:

• eth_sendTransaction - used to send transaction / create contract
• eth_newBlockFilter - be notified any time there is new block on the chain
• eth_newFilter - create new custom filter and listen to blockchain events matching this filter
• eth_compileSolidity - used to compile solidity code