> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.chainstack.com/feedback

```json
{
  "path": "/reference/bitcoin-preciousblock",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# preciousblock | Bitcoin

The `preciousblock` method allows a node to mark a specific block as "precious," meaning the block is treated as if it were received earlier than other blocks with the same amount of work. This can influence the node's choice of the active chain, potentially causing a reorganization to prefer the chain that includes the precious block.

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## Parameters

* `block hash` (required): The hash of the block to be marked as precious.

## Response

* `result` — always `null`, indicating that the block has been successfully marked as precious.
* `error` — an object containing an error message if an error occurred, otherwise `null`.
* `id` — an integer representing the ID of the request.

## Use case

The `preciousblock` method is useful in scenarios where a blockchain network participant wants to influence the chain selection process in favor of a particular branch that includes the specified block. This can be relevant in testing, or in situations where network conditions lead to competing chains.


## OpenAPI

````yaml /openapi/bitcoin_node_api/preciousblock.json POST /788f110831fe13808302bd79796d55e8
openapi: 3.0.0
info:
  title: preciousblock example
  version: 1.0.0
  description: >-
    This is an API example for preciousblock, a method to treat a block as if it
    were received before others with the same work.
servers:
  - url: https://nd-202-842-353.p2pify.com
security: []
paths:
  /788f110831fe13808302bd79796d55e8:
    post:
      tags:
        - Blockchain Operations
      summary: preciousblock
      operationId: preciousBlock
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                jsonrpc:
                  type: string
                  default: '1.0'
                method:
                  type: string
                  default: preciousblock
                params:
                  type: array
                  items:
                    type: string
                    description: The hash of the block to be treated as precious
                  example: >-
                    000000000000000000011cefb2db6b82b6ae69b4ec06eedc81fc85d16f97865d
                  default:
                    - >-
                      000000000000000000011cefb2db6b82b6ae69b4ec06eedc81fc85d16f97865d
                id:
                  type: integer
                  default: 1
      responses:
        '200':
          description: Acknowledgement that the block has been marked as precious
          content:
            application/json:
              schema:
                type: object
                properties:
                  result:
                    type: string
                    description: >-
                      The result is always null, indicating the request was
                      processed. Actual type is 'null'.
                    nullable: true
                  error:
                    type: object
                  id:
                    type: integer

````