<!-- source: https://secondlayer.tools/docs/api-reference#mempool-transaction-object -->

## The Mempool transaction object

A pending transaction: the transaction document before it has a block, so no height, index, status or result, plus when this instance first saw it.

| Field | Type | Description |
| --- | --- | --- |
| `cursor` | string | Opaque. Pass it back as `cursor` unchanged. |
| `tx_id` | string | Transaction id, `0x`-prefixed hex. |
| `received_at` | string · date-time · nullable | When this instance's node first saw it, ISO 8601 UTC. |
| `tx_type` | string | `token_transfer`, `contract_call`, `smart_contract`, `coinbase`, `tenure_change` or `poison_microblock`, decoded from the raw bytes. Falls back to the stored type when they do not decode. |
| `sender` | string | Sender principal. |
| `fee` | string · nullable | Fee in microSTX as a decimal string. `null` when the raw bytes do not decode. |
| `nonce` | string · nullable | Sender nonce as a decimal string. |
| `sponsored` | boolean · nullable | Whether a sponsor paid the fee. |
| `anchor_mode` | enum · nullable | Anchor mode from the raw bytes. Values: `on_chain_only`, `off_chain_only`, `any`. |
| `post_condition_mode` | enum · nullable | Post-condition mode from the raw bytes. Values: `allow`, `deny`. |
| `post_conditions` | array of PostCondition | Decoded post-conditions. Empty when there are none. |
| `token_transfer` | object | `token_transfer` only. |
| `coinbase` | object | `coinbase` only. |
| `tenure_change` | object | `tenure_change` only. |
| `contract_call` | object | `contract_call` only. No result yet. |
| `smart_contract` | object | `smart_contract` only. |

```json
{
  "cursor": "bToyNjg4Mjc0",
  "tx_id": "0x00a5cd852c25c5bb5cc7f97c60b88a6a635c001ad431e2133f366be85d5ce0f0",
  "tx_type": "token_transfer",
  "sender": "SM1Z09F6431EQT8GCTEF496TCT5JDTPJ3VFF9Q766",
  "received_at": "2026-09-23T15:11:05.629Z",
  "fee": "1732",
  "nonce": "37",
  "sponsored": false,
  "anchor_mode": "any",
  "post_condition_mode": "deny",
  "post_conditions": [],
  "token_transfer": {
    "recipient": "SMJWA5YRH2DRANX3V96Z6JJSFBE03Z9Y0WHN3XSQ",
    "amount": "79559850769",
    "memo": "572826509"
  }
}
```