getblockhash - Bitcoin

Example code for the getblockhash JSON-RPC method. Complete guide on how to use getblockhash JSON-RPC in GetBlock Web3 documentation.

This method returns the hash of the block at the specified height in the best-block-chain.

Parameters

Parameter	Type	Required	Description
height	number	Yes	The block height (index).

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "getblockhash",
    "params": [820000],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "000000000000000000046b9302e08c16ea186950f42a5498320ddd1bd7ab3428"
}

Response Parameters

Field	Type	Description
result	string	The block hash as a hex string.

Use Case

The getblockhash method is essential for:

• Looking up blocks by height

• Building block explorer navigation

• Iterating through the blockchain

• Fetching specific historical blocks

• Implementing chain traversal algorithms

• Building height-based block references

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid ACCESS-TOKEN.
-8	Block height out of range	The specified height doesn't exist.

Integration Notes

The getblockhash method helps developers:

• Navigate blockchain by height

• Build block explorers

• Implement chain scanning

• Create historical analysis tools

• Support height-based lookups