parMaster/ethtrx

Ethereum Transactions Explorer

Educational Project - Junior Golang Developer Test Problem

Prerequisites

Access to Mongo (database=etc, collection=transactions). Sandboxed demo is running docker container with Mongo 4.2 like this: docker run --name mongodb -p27018:27017 mongo:4.2
Set correct Mongo connection URI in configs/apiserver.toml
Set correct Etherscan API Key in configs/apiserver.toml

Using API

getTxList API provides a json-encoded transactions list

Basic request:

POST /getTxList HTTP/1.1

{
    "transactions": [
        {
            "hash": "0x4f65b92e705c450988557995b60b77978a9fde743a22efba07dd3206357e3c1d",
            "blockHash": "0xd1452f4505b203cbcfb897e03c5ad134f824fbb35ace4e83bb0a3722cd9e2c8b",
            "blockNumber": "0xd80d4f",
            "blockHeight": 14159183,
            "blockTime": "0x62011e67",
            "blockDate": "2022-02-07",
            "from": "0x00dee1f836998bcc736022f314df906588d44808",
            "to": "0x4a137fd5e7a256ef08a7de531a17d0be0cc7b6b6",
            "value": "0x10dd27a770322c",
            "valueNumber": "0.004746762009981484",
            "confirmations": 356,
            "type": "0x2",
            "chainId": "0x1"
        },
        {
            "hash": "0xd6e86d336ae817a85a9492f88d493edc9a9bd509fcd0fbdb4bea686df4905809",
            "blockHash": "0xd1452f4505b203cbcfb897e03c5ad134f824fbb35ace4e83bb0a3722cd9e2c8b",
            "blockNumber": "0xd80d4f",
            "blockHeight": 14159183,
            "blockTime": "0x62011e67",
            "blockDate": "2022-02-07",
            "from": "0xe92f359e6f05564849afa933ce8f62b8007a1d5d",
            "to": "0x9008d19f58aabd9ed0d60971565aa8510560ab41",
            "value": "0x0",
            "valueNumber": "0.",
            "confirmations": 356,
            "type": "0x2",
            "chainId": "0x1"
        }
    ]
}

Identical to the following request with page and limit parameters:

POST /getTxList -d '{"page":1, "limit":2}' HTTP/1.1

By default page and limit are set to 1 and 10 accordingly

Additional filters:

Filter transactions by hash

POST /getTxList -d '{"txhash":"0x90db94375b973f4046ba991e8a326968f3035ff12c53f4891d010ab2a3850c50"}' HTTP/1.1

{
    "transactions": [
        {
            "hash": "0x90db94375b973f4046ba991e8a326968f3035ff12c53f4891d010ab2a3850c50",
            "blockHash": "0xd1452f4505b203cbcfb897e03c5ad134f824fbb35ace4e83bb0a3722cd9e2c8b",
            "blockNumber": "0xd80d4f",
            "blockHeight": 14159183,
            "blockTime": "0x62011e67",
            "blockDate": "2022-02-07",
            "from": "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040",
            "to": "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040",
            "value": "0x0",
            "valueNumber": "0.",
            "confirmations": 356,
            "type": "0x2",
            "chainId": "0x1"
        }
    ]
}

Filter transactions by block number in decimal

POST /getTxList -d '{"blockheight":14159183}' HTTP/1.1

Identical to:

POST /getTxList -d '{"blocknumber":"0x62011e67"}' HTTP/1.1

{
    "transactions": [
        {
            "hash": "0x4f65b92e705c450988557995b60b77978a9fde743a22efba07dd3206357e3c1d",
            "blockHash": "0xd1452f4505b203cbcfb897e03c5ad134f824fbb35ace4e83bb0a3722cd9e2c8b",
            "blockNumber": "0xd80d4f",
            "blockHeight": 14159183,
            "blockTime": "0x62011e67",
            "blockDate": "2022-02-07",
            "from": "0x00dee1f836998bcc736022f314df906588d44808",
            "to": "0x4a137fd5e7a256ef08a7de531a17d0be0cc7b6b6",
            "value": "0x10dd27a770322c",
            "valueNumber": "0.004746762009981484",
            "confirmations": 356,
            "type": "0x2",
            "chainId": "0x1"
        },
... rest of response body ommited
}

Filter transactions by receiver

POST /getTxList -d '{"to":"0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040"}' HTTP/1.1

Filter transactions by sender

POST /getTxList -d '{"from":"0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040"}' HTTP/1.1

{
    "transactions": [
        {
            "hash": "0x90db94375b973f4046ba991e8a326968f3035ff12c53f4891d010ab2a3850c50",
            "blockHash": "0xd1452f4505b203cbcfb897e03c5ad134f824fbb35ace4e83bb0a3722cd9e2c8b",
            "blockNumber": "0xd80d4f",
            "blockHeight": 14159183,
            "blockTime": "0x62011e67",
            "blockDate": "2022-02-07",
            "from": "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040",
            "to": "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040",
            "value": "0x0",
            "valueNumber": "0.",
            "confirmations": 356,
            "type": "0x2",
            "chainId": "0x1"
        }
    ]
}

Filter transactions by date

POST /getTxList -d '{"date":"2022-02-07"}' HTTP/1.1

{
    "transactions": [
        {
            "hash": "0x90db94375b973f4046ba991e8a326968f3035ff12c53f4891d010ab2a3850c50",
            "blockHash": "0xd1452f4505b203cbcfb897e03c5ad134f824fbb35ace4e83bb0a3722cd9e2c8b",
            "blockNumber": "0xd80d4f",
            "blockHeight": 14159183,
            "blockTime": "0x62011e67",
            "blockDate": "2022-02-07",
            "from": "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040",
            "to": "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040",
            "value": "0x0",
            "valueNumber": "0.",
            "confirmations": 356,
            "type": "0x2",
            "chainId": "0x1"
        }
    ]
}

Filters can be combined

POST /getTxList -d '{"blockheight":14159183, "from":"0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040"}' HTTP/1.1

Will apply both conditions blockheight == 14159183 && from == "0x9162c9a00a8e4c3654a4e3f236e8e2bf097c9040"

Empty result

Looks like this

{
    "transactions": null
}

Errors

POST /getTxList -d '{"txhash":"0x9"}' HTTP/1.1

{
    "error": "Invalid 'txhash' parameter: hex string of odd length"
}

POST /getTxList -d '{"page":"q"}' HTTP/1.1

{
     "error": "Error decoding request: json: cannot unmarshal string into Go struct field request.page of type int"
}

POST /getTxList -d '{"to":"0xdb298285fe"}' HTTP/1.1

POST /getTxList -d '{"from":"0xdb298285fe"}' HTTP/1.1

{
    "error": "'to' parameter is not a valid hex address"
}

etc.

(!) Please, note:

Calculating transaction comission requires the Gas User value, which is provided by eth_getTransactionReceipt API for each transaction. Considering the fact Ethereum blockchain serves more that 1 million transactions per day, it would require to call the receipt API more than 11 times/sec, which is imposible within 5 calls/sec using a Free etherscan plan.

Anyway, commission formula is:

(Block Base Fee Per Gas + Max Priority Fee Per Gas) * Gas Used

parMaster / ethtrx