> ## Documentation Index
> Fetch the complete documentation index at: https://www.helius.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# isBlockhashValid
> Returns whether a blockhash is still valid or not.
## Request Parameters
Blockhash to check validity status for, as a base-58 encoded string.
The commitment level for the request.
* `confirmed`
* `finalized`
* `processed`
The minimum slot that the request can be evaluated at.
## OpenAPI
````yaml openapi/rpc-http/isBlockhashValid.yaml POST /
openapi: 3.1.0
info:
title: Solana RPC API
version: 1.0.0
description: >-
Transaction validity verification API for checking if a previously acquired
Solana blockhash is still within its usable lifetime window for new
transaction submissions.
license:
name: Apache 2.0
url: https://www.apache.org/licenses/LICENSE-2.0.html
servers:
- url: https://mainnet.helius-rpc.com
description: Mainnet RPC endpoint
- url: https://devnet.helius-rpc.com
description: Devnet RPC endpoint
security: []
paths:
/:
post:
tags:
- RPC
summary: isBlockhashValid
description: >
Verify whether a Solana blockhash is still valid for transaction
submission.
This essential transaction preparation API allows applications to
determine if a previously
acquired blockhash is still within its validity window (typically ~2
minutes or ~150 blocks).
Transactions constructed with expired blockhashes will be rejected by
the network, so checking
validity before submission helps prevent transaction failures and
timeout errors. Critical for
wallet applications, exchanges, payment processors, and any service that
prepares transactions
in advance or needs to check if a pending transaction can still be
submitted or needs to be
reconstructed with a fresh blockhash to avoid expiration rejections.
operationId: isBlockhashValid
requestBody:
required: true
content:
application/json:
schema:
type: object
properties:
jsonrpc:
type: string
enum:
- '2.0'
description: The JSON-RPC protocol version.
example: '2.0'
default: '2.0'
id:
type: string
description: A unique identifier for the request.
example: '45'
default: '1'
method:
type: string
enum:
- isBlockhashValid
description: The name of the RPC method to invoke.
example: isBlockhashValid
default: isBlockhashValid
params:
type: array
description: Parameters for evaluating blockhash validity.
default:
- J7rBdM6AecPDEZp8aPq5iPSNKVkU5Q76F3oAV4eW5wsW
- commitment: processed
items:
oneOf:
- type: string
description: >-
Blockhash to check validity status for, as a base-58
encoded string.
example: J7rBdM6AecPDEZp8aPq5iPSNKVkU5Q76F3oAV4eW5wsW
- type: object
description: Configuration options for the request.
properties:
commitment:
type: string
description: The commitment level for the request.
enum:
- confirmed
- finalized
- processed
example: processed
minContextSlot:
type: integer
description: >-
The minimum slot that the request can be evaluated
at.
example: 1000
examples:
default:
$ref: '#/components/examples/isBlockhashValidRequest'
responses:
'200':
description: Successfully evaluated blockhash validity.
content:
application/json:
schema:
type: object
properties:
jsonrpc:
type: string
description: The JSON-RPC protocol version.
enum:
- '2.0'
example: '2.0'
id:
type: string
description: Identifier matching the request.
example: '45'
result:
type: object
description: Blockhash validity result.
properties:
context:
type: object
description: Context of the response.
properties:
slot:
type: integer
description: Slot in which the data was fetched.
example: 2483
value:
type: boolean
description: >-
Boolean indicating if this blockhash is still within
its validity window and can be used in new
transactions.
example: false
examples:
default:
$ref: '#/components/examples/isBlockhashValidResponse'
'400':
description: Bad Request - Invalid request parameters or malformed request.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
example:
jsonrpc: '2.0'
error:
code: -32602
message: Invalid params
id: '1'
'401':
description: Unauthorized - Invalid or missing API key.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
example:
jsonrpc: '2.0'
error:
code: -32001
message: Unauthorized
id: '1'
'429':
description: Too Many Requests - Rate limit exceeded.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
example:
jsonrpc: '2.0'
error:
code: -32005
message: Too many requests
id: '1'
'500':
description: Internal Server Error - An error occurred on the server.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
example:
jsonrpc: '2.0'
error:
code: -32603
message: Internal error
id: '1'
'503':
description: Service Unavailable - The service is temporarily unavailable.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
example:
jsonrpc: '2.0'
error:
code: -32002
message: Service unavailable
id: '1'
'504':
description: Gateway Timeout - The request timed out.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
example:
jsonrpc: '2.0'
error:
code: -32003
message: Gateway timeout
id: '1'
security:
- ApiKeyQuery: []
components:
examples:
isBlockhashValidRequest:
value:
jsonrpc: '2.0'
id: '45'
method: isBlockhashValid
params:
- J7rBdM6AecPDEZp8aPq5iPSNKVkU5Q76F3oAV4eW5wsW
- commitment: processed
isBlockhashValidResponse:
value:
jsonrpc: '2.0'
id: '45'
result:
context:
slot: 2483
value: false
schemas:
ErrorResponse:
type: object
properties:
jsonrpc:
type: string
description: The JSON-RPC protocol version.
enum:
- '2.0'
example: '2.0'
error:
type: object
properties:
code:
type: integer
description: The error code.
example: -32602
message:
type: string
description: The error message.
data:
type: object
description: Additional data about the error.
id:
type: string
description: Identifier matching the request.
example: '1'
securitySchemes:
ApiKeyQuery:
type: apiKey
in: query
name: api-key
description: >-
Your Helius API key. You can get one for free in the
[dashboard](https://dashboard.helius.dev/api-keys).
````