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

# Execute Private Transaction

> Relay a proven apply_action transaction on-chain

## Overview

JSON-RPC method `paymaster_executeTransaction` with the `apply_action` type. The relayer submits the proven call on-chain and pays the gas; the pool fee (from the build step) reimburses it. No user signature is needed: the transaction settles straight from the proof. Use `invoke_and_apply_action` to also wrap a signed user call (with the `typed_data` returned by the build step).

The endpoint is the base URL itself (no path): `https://starknet.paymaster.avnu.fi` (mainnet) or `https://sepolia.paymaster.avnu.fi` (testnet).

## Headers

<ParamField header="x-paymaster-api-key" type="string" required>
  [Portal](https://portal.avnu.fi) API key. Required for the sponsored fee modes (`sponsored`, `sponsored_private`)
</ParamField>

## Body (JSON-RPC 2.0)

<ParamField body="method" type="string" required>
  `paymaster_executeTransaction`
</ParamField>

<ParamField body="params.transaction.type" type="string" required>
  `apply_action`, or `invoke_and_apply_action` when a signed user call is wrapped
</ParamField>

<ParamField body="params.transaction.apply_action.apply_actions_call" type="object" required>
  The proven call, as `{ to, selector, calldata }`
</ParamField>

<ParamField body="params.transaction.apply_action.proof" type="string" required>
  The zero-knowledge proof produced by the proving backend
</ParamField>

<ParamField body="params.transaction.apply_action.proof_facts" type="array" required>
  The proof facts (array of felt hex strings)
</ParamField>

<ParamField body="params.transaction.invoke" type="object">
  Only for `invoke_and_apply_action`: `{ user_address, typed_data, signature }`
</ParamField>

<ParamField body="params.parameters" type="object" required>
  Same shape as the build step: `{ version: '0x1', fee_mode, time_bounds? }`
</ParamField>

## Response

<ResponseField name="transaction_hash" type="string" required>
  The hash of the submitted transaction
</ResponseField>

<ResponseField name="tracking_id" type="string">
  Relayer tracking id
</ResponseField>

## Errors

| Code | Name                          | When                                                                             |
| ---- | ----------------------------- | -------------------------------------------------------------------------------- |
| 156  | `TRANSACTION_EXECUTION_ERROR` | On-chain execution failure                                                       |
| 159  | `PRIVACY_REQUIRES_SPONSORING` | Private transaction sent without a sponsored fee mode                            |
| 163  | `UNKNOWN_ERROR`               | Invalid API key, service unavailable, or blacklisted call                        |
| 165  | `MISSING_FEE_TRANSFER_TO`     | The private transaction calldata does not withdraw the pool fee to the paymaster |
| 166  | `CALLDATA_PARSING`            | The private transaction calldata could not be parsed                             |
| 167  | `POOL_FEE_TOO_LOW`            | The withdrawn pool fee is below the required amount                              |
| 168  | `PRIVACY_PROOF_MISSING`       | The proof is missing on a private transaction                                    |
| 169  | `MAX_L2_GAS_AMOUNT_EXCEEDED`  | The transaction exceeds the maximum L2 gas                                       |

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST "https://starknet.paymaster.avnu.fi" \
    -H "Content-Type: application/json" \
    -H "x-paymaster-api-key: $PAYMASTER_API_KEY" \
    -d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "paymaster_executeTransaction",
      "params": {
        "transaction": {
          "type": "apply_action",
          "apply_action": {
            "apply_actions_call": { "to": "0x04c9...pool", "selector": "0x02ac...", "calldata": ["0x1", "0x2"] },
            "proof": "base64-encoded-proof",
            "proof_facts": ["0x0123...", "0x0456..."]
          }
        },
        "parameters": {
          "version": "0x1",
          "fee_mode": {
            "mode": "sponsored_private",
            "pool_fee_token": "0x04718f5a0fc34cc1af16a1cdee98ffb20c31f5cd61d6ab07201858f4287c938d",
            "tip": "normal"
          }
        }
      }
    }'
  ```

  ```typescript TypeScript (SDK) theme={null}
  import { submitPrivateSwap } from '@avnu/avnu-sdk';

  const { transactionHash } = await submitPrivateSwap({
    callAndProof, // { call, proof } from the proving backend
    feeMode: { poolFeeToken: STRK, tip: 'normal' },
    paymasterApiKey: PAYMASTER_API_KEY,
  });
  ```
</RequestExample>

<ResponseExample>
  ```json Success theme={null}
  {
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
      "transaction_hash": "0x06f8...hash",
      "tracking_id": "0x0"
    }
  }
  ```
</ResponseExample>