eth_fillTransaction

POST

/{apiKey}

Fills in default values for a transaction object. This method populates missing fields such as gas, gasPrice, nonce, and chainId based on the current network state and transaction parameters. It returns both the filled transaction object and the RLP-encoded raw transaction data.

This is useful for preparing transactions before signing, as it ensures all required fields are present with appropriate values.

Path Parameters

apiKeystringrequireddefaults to docs-demo

For higher throughput, create your own API key

Request

Transactionobjectrequired

The transaction object with optional fields to be filled. Fields like gas, gasPrice, nonce, and chainId will be populated if not provided.

Responses

200

An object containing the filled transaction and its RLP-encoded form.

POST/v2/{apiKey}

curl --request POST \  --url https://tempo-moderato.g.alchemy.com/v2/docs-demo \  --header 'Content-Type: application/json' \  --data '{  "jsonrpc": "2.0",  "id": 1,  "method": "eth_fillTransaction",  "params": [    {      "from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73",      "to": "0x627306090abab3a6e1400e9345bc60c78a8bef57",      "value": "0x1"    }  ]}'

200Success

{  "jsonrpc": "2.0",  "id": 1,  "result": {    "raw": "0xf86c808504a817c80082520894627306090abab3a6e1400e9345bc60c78a8bef570180808080",    "tx": {      "from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73",      "to": "0x627306090abab3a6e1400e9345bc60c78a8bef57",      "value": "0x1",      "gas": "0x5208",      "gasPrice": "0x4a817c800",      "nonce": "0x0",      "chainId": "0x1",      "input": "0x"    }  }}

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