pimlico_sendUserOperationNow

Sends a signed user operation in its own bundle right away and returns its receipt in the same response. There is no mempool wait and no receipt polling. From TypeScript, use sendUserOperationSync, which also handles the errors below. Its page has the latency benchmarks.

Available on Base, BSC and Robinhood, with EntryPoint 0.7 and 0.8.

Usage

The parameters are the same as eth_sendUserOperation: the user operation and the EntryPoint address.

A boosted user operation on Base with EntryPoint 0.8: maxFeePerGas and maxPriorityFeePerGas are 0 and every paymaster field is empty. The gas is billed to your Pimlico balance.

{
  "jsonrpc": "2.0",
  "method": "pimlico_sendUserOperationNow",
  "params": [
    {
      "sender": "0x1068D0C20CeFD20725035B90Eb0c32BFA4057c12",
      "nonce": "0x1",
      "callData": "0xb61d27f6000000000000000000000000000000000000000000000000000000000000dead000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000",
      "callGasLimit": "0x7530",
      "verificationGasLimit": "0x186a0",
      "preVerificationGas": "0xea60",
      "maxFeePerGas": "0x0",
      "maxPriorityFeePerGas": "0x0",
      "signature": "0xaae4efeb36210ec5111608edb88b81bec6d3e0d21f7666f3b93a9b709ff1bfab14fa4b2f84f37ad1af7f88d61a4cd8b6884c14db9b8c8a01f1ab7520ba46caf71b"
    },
    "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108"
  ],
  "id": 1
}

Returns

Type: RpcUserOperationReceipt

The user operation receipt, once the user operation is included: the same object eth_getUserOperationReceipt returns. Numbers are hex.

success: false means the user operation was included but its call reverted inside the account. Its nonce is used.

On Base, the receipt arrives before its block is sealed, so receipt.blockHash can be all zeros. Use blockNumber and transactionHash instead.

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "userOpHash": "0xaa7e6f2050bbd8e8fc0053f3646dac0e2c13c9830172ba06efcb9f49b1e8ca9f",
    "entryPoint": "0x4337084d9e255ff0702461cf8895ce9e3b5ff108",
    "sender": "0x1068D0C20CeFD20725035B90Eb0c32BFA4057c12",
    "nonce": "0x1",
    "actualGasUsed": "0x162e9",
    "actualGasCost": "0x0",
    "success": true,
    "logs": [],
    "receipt": {
      "transactionHash": "0x7cbfae4b823e5b08ab18913d165f56c65d52d30fd6c140646cf5e1c10a990b30",
      "transactionIndex": "0x18",
      "blockHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
      "blockNumber": "0x3289aeb",
      "from": "0x43370250bfc02C7F085cB105558DA41E9CDB2D79",
      "to": "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108",
      "cumulativeGasUsed": "0x19646c",
      "gasUsed": "0x104cb",
      "contractAddress": null,
      "logs": [
        {
          "logIndex": "0x1b",
          "transactionIndex": "0x18",
          "transactionHash": "0x7cbfae4b823e5b08ab18913d165f56c65d52d30fd6c140646cf5e1c10a990b30",
          "blockHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
          "blockNumber": "0x3289aeb",
          "address": "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108",
          "data": "0x",
          "topics": [
            "0xbb47ee3e183a558b1a2ff0874b079f3fc5478b7454eacf2bfc5af2ff5878f972"
          ]
        },
        {
          "logIndex": "0x1c",
          "transactionIndex": "0x18",
          "transactionHash": "0x7cbfae4b823e5b08ab18913d165f56c65d52d30fd6c140646cf5e1c10a990b30",
          "blockHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
          "blockNumber": "0x3289aeb",
          "address": "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108",
          "data": "0x00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000162e9",
          "topics": [
            "0x49628fd1471006c1482da88028e9ce4dbb080b815c9b0344d39e5a8e6ec1419f",
            "0xaa7e6f2050bbd8e8fc0053f3646dac0e2c13c9830172ba06efcb9f49b1e8ca9f",
            "0x0000000000000000000000001068d0c20cefd20725035b90eb0c32bfa4057c12",
            "0x0000000000000000000000000000000000000000000000000000000000000000"
          ]
        }
      ],
      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000008000000000000000000010000000000000000000000000000020000000800000000000000000000000000000002000000000000000000000000000000000000000000020000000000000000000800000000000020000000000000000000000000000800000000008000000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000002000000000000000000000000000001000000000000000000000000200000000010000020000000020000000000000000000000000000000000000000000000000000000800",
      "status": "0x1",
      "effectiveGasPrice": "0x5dd770"
    }
  }
}

Errors

Errors are standard JSON-RPC errors. error.data is only set when a bundle was sent, and holds userOpHash and transactionHash. If data.transactionHash is set, the user operation was sent: track it instead of resending.

Response	What happened	What to do
`-32602`, no `data`	Rejected, nothing was sent: invalid fields, gas limits too low, or a simulation failure such as `AA25 invalid account nonce`	Fix and resend
`-32602` "submitted but is not yet included", with `data`	Sent but not included in time. The bundler still tracks it and bumps its gas if it gets stuck	Don't resend. Poll `eth_getUserOperationReceipt` with `data.userOpHash`
`-32521` "reverted onchain", with `data`	The bundle landed but reverted, so it didn't execute the user operation. Another bundler may have included it first	Check `eth_getUserOperationReceipt`, and resend only if there is no receipt
`-32603`	The bundler couldn't send the bundle	Resend
No response (network error, client timeout, 5xx)	Unknown: it may have been sent	Resend

A signed user operation can execute at most once, because the EntryPoint checks its nonce. Resending never runs it twice: if the first send landed, the resend is rejected with AA25, and you can look up the receipt by userOpHash.

To avoid duplicate sends, set retryCount: 0 on your viem transport. By default viem resends up to 3 times on timeouts and internal errors.

{
    "jsonrpc": "2.0",
    "id": 1,
    "error": {
        "message": "bundle submission failed: FailedOp(0, AA25 invalid account nonce)",
        "code": -32602
    }
}

Not included yet

{
    "jsonrpc": "2.0",
    "id": 1,
    "error": {
        "message": "userOperation was submitted but is not yet included. Track it with eth_getUserOperationReceipt",
        "data": {
            "userOpHash": "0x…",
            "transactionHash": "0x…"
        },
        "code": -32602
    }
}

{
    "jsonrpc": "2.0",
    "id": 1,
    "error": {
        "message": "bundle transaction 0x64deb43595ad19c86d823081c8878117f2536413ec6e3dbad661e24d484791ee reverted onchain",
        "data": {
            "userOpHash": "0xbcebbcd851d2a455454d9fdfc2a698a67e69ccd44a582ced92f914bf58615d25",
            "transactionHash": "0x64deb43595ad19c86d823081c8878117f2536413ec6e3dbad661e24d484791ee"
        },
        "code": -32521
    }
}

Nonces

No queue: the user operation is simulated against the current chain state, so its nonce must be the account's current nonce for that key.
One at a time per key: a user operation with nonce N+1, sent while N is in flight, is rejected with AA25. The response comes after inclusion, so send them one after another.
Base, next nonce right after a receipt: the receipt arrives before its block is sealed, so nonce N+1 sent right after N's receipt can be rejected with AA25 invalid account nonce. Nothing is sent, so resend it after 1–2s.
Parallel sends: to send in parallel from one account, use different nonce keys.

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