> ## 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.

# wallet/createspendauthsig | TRON

> TRON API method that creates a spending authorization signature for shielded TRC20 transactions. Available on TRON via Chainstack.

TRON API method that creates a spending authorization signature for shielded TRC20 transactions. This signature authorizes the spending of shielded notes and is a critical component of the privacy-preserving transaction protocol.

<Warning>
  All cryptographic parameters (`ask`, `alpha`, `tx_hash`) must be exactly 32 bytes (64 hexadecimal characters) provided as raw hex strings **without the 0x prefix**. Values that are shorter, longer, or include the 0x prefix will result in a "param length must be 32" error.
</Warning>

## Parameters

* `ask` — the authentication secret key used for signing (32 bytes, hex without 0x prefix)
* `alpha` — the alpha parameter for randomization (32 bytes, hex without 0x prefix)
* `tx_hash` — the transaction hash being authorized (32 bytes, hex without 0x prefix)

## Response

* `value` — the generated spending authorization signature (hex string without 0x prefix)

## Use case

The `wallet/createspendauthsig` method is used for:

* Authorizing the spending of shielded notes in privacy transactions
* Creating cryptographic signatures that prove spending authority without revealing identity
* Supporting the zero-knowledge proof system in shielded transactions
* Enabling secure authorization of shielded TRC20 transfers


## OpenAPI

````yaml openapi/tron_node_api/createspendauthsig.json post /95e61622bf6a8af293978377718e3b77/wallet/createspendauthsig
openapi: 3.0.0
info:
  title: wallet/createspendauthsig TRON API
  version: 1.0.0
  description: Create spending authorization signature for shielded transactions
servers:
  - url: https://tron-mainnet.core.chainstack.com
security: []
paths:
  /95e61622bf6a8af293978377718e3b77/wallet/createspendauthsig:
    post:
      tags:
        - Shielded Contract Methods
      summary: wallet/createspendauthsig
      operationId: createSpendAuthSig
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - ask
                - alpha
                - tx_hash
              properties:
                ask:
                  type: string
                  description: >-
                    Authentication secret key for signing (32 bytes, hex without
                    0x prefix)
                  example: >-
                    0f63eabdfe2bbfe08012f6bb2db024e6809c16e8ed055aa41a6095424f192005
                alpha:
                  type: string
                  description: >-
                    Alpha parameter for randomization (32 bytes, hex without 0x
                    prefix)
                  example: >-
                    d0f0768664f5c807f9e70d05993f029c71da529afaa5c037b44c63d6e13bc907
                tx_hash:
                  type: string
                  description: >-
                    Transaction hash being authorized (32 bytes, hex without 0x
                    prefix)
                  example: >-
                    7fb99e66df052f430d50e80a3f197c319a4e35184ed48a433d6219e025741337
      responses:
        '200':
          description: Successfully created spending authorization signature
          content:
            application/json:
              schema:
                type: object
                properties:
                  value:
                    type: string
                    description: >-
                      Generated spending authorization signature (hex string
                      without 0x prefix)
                    example: >-
                      66c806bc592a7599e65833bf25c3c7005c8b21b7895dd835a84c97d7bec49d0f1493d2c73a68eeb9b9699b92cae42406f9e44ebe19acaea3d5febfe28de57109

````