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

# Create Signing Request

> Create a transaction or message request for App or API ClientSigner signing.

## Endpoint

```protobuf theme={null}
rpc CreateSigningRequest(CreateSigningRequestRequest) returns (CreateSigningRequestResponse)
```

Messages are in `mpcvault.platform.v1`. Set exactly one supported transaction or message member of `type`; the [REST schema](https://docs.mpcvault.com/api-reference/rest/create-signing-request.md) shows all accepted members and nested fields. [Network guides](https://docs.mpcvault.com/api-reference/supported-networks) provide payload examples; gRPC uses the corresponding snake\_case field names and raw bytes.

The creation payload set is narrower than the queryable [SigningRequest payload set](https://docs.mpcvault.com/api-reference/signing-request.md#payload-fields). Existing swap, batch-payment, fiat, account-setup, management, Stellar message/authorization/challenge and Aptos whole-transaction requests cannot be created with this RPC.

## Request

| Field | Type | Required | Description |
| - | - | - | - |
| `type` | oneof | Yes | One supported transaction or message payload, including Solana/Sonic SVM and Stellar transaction members. |
| `notes` | google.protobuf.StringValue | No | Transaction notes. |
| `vault_uuid` | google.protobuf.StringValue | Depends on signing mode | Required when the callback ClientSigner key is set. For App signing it is optional or ignored according to the payload; see the [REST field rules](https://docs.mpcvault.com/api-reference/rest/create-signing-request.md). |
| `callback_client_signer_public_key` | google.protobuf.StringValue | Depends on wallet | Selects the callback ClientSigner. Omit for manual App signing; API wallets require a ClientSigner. |
| `broadcast_tx` | google.protobuf.BoolValue | No | Enables automatic broadcasting for supported standard transactions. Unsupported for messages, RawMessage and custom EVM networks. |

Omit `callback_client_signer_public_key` for manual App signing. A present wrapper containing an empty string selects the ClientSigner path and is rejected; it does not select App signing.

Output-only objects such as message `network`, Solana `jito` and EVM batch `batch_contract_address` cannot select creation parameters.

## Response

| Field | Type | Description |
| - | - | - |
| `signing_request` | SigningRequest | Created request with its shared payload; detail-only fields are unavailable here. |
| `error` | Error | Error information when returned. |

Use [Get Signing Request Details](https://docs.mpcvault.com/api-reference/grpc/get-signing-request-details) for inspection and approval progress. See [Introduction](https://docs.mpcvault.com/api-reference/overview.md#quickstart) for signing and confirmation.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.