# Decode a transaction

`POST https://api.rarebl.com/open/tx/decode`

Decodes a raw transaction (signed or unsigned) into the v1 Tx shape, with status `unsent`, so you can check what you are about to send.

**Rate class:** compute (2 requests per second, burst 10, per IP). **Available since:** Open API v2.

## Request

Send a JSON body (`Content-Type: application/json`). No API key is needed: `X-API-KEY` is reserved and ignored.

Example: `curl -X POST "https://api.rarebl.com/open/tx/decode" -H "Content-Type: application/json" -d '{"chain":"dash","hex":"0200000001139f6185036ea872d9e52bd7424ba9165f31b6479556b021fe4b8f3f42e8087a010000006a473044022047ac8e878352d3ebbde1c94ce3a10d057c24175747116f8288e5d794d12d482f0220217f36a485cae903c713331d877c1f64677e3622ad4010726870540656fe9dcb012103ad1d8e89212f0b92c74d23bb710c00662ad1470198ac48c43f7d6f93a2a26873ffffffff0240420f00000000001976a91454072845a9ca039a5b585f5fd994d88d38feb31c88ac189f3419000000001976a9147fb0a45f00c25ff1cb67753221326c7c420b8b2388ac00000000"}'`

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `chain` | string | Yes | The chain. One of: btc, ltc, bch, dash, eth, tron. |
| `hex` | string | No | The raw transaction hex. |
| `tx` | object | No | TRON only: the transaction JSON (use `tx` or `hex`). |

## Responses

### API200 (HTTP 200): OK

The decoded transaction, with `status: "unsent"`.

```json
{
  "status": 1,
  "code": "API200",
  "message": "success",
  "data": {
    "tx": {
      "chain": "dash",
      "hash": "8235cfafa0ef70d4a5135331c6889a7c15780b7aeb3bc20721571c2a4b51ffa7",
      "status": "unsent",
      "block": null,
      "blockHash": null,
      "time": null,
      "confirmations": 0,
      "value": "4.23879",
      "fee": "0.00000226",
      "utxo": {
        "size": 225,
        "vsize": 225,
        "weight": 900,
        "locktime": 0,
        "version": 2,
        "rbf": false,
        "coinbase": false,
        "inputs": [
          {
            "txid": "7a08e8423f8f4bfe21b0569547b6315f16a94b42d72be5d972a86e0385619f13",
            "vout": 1,
            "address": "XnL1FvTKqe6aWfB8NrvgbUMuWCEA3dNxfF",
            "value": "4.23879226",
            "scriptType": "pubkeyhash",
            "sequence": 4294967295,
            "coinbase": false
          }
        ],
        "outputs": [
          {
            "n": 0,
            "address": "XiM9Afap6UEb5LDkcWrg2YyA28hifkZZKM",
            "value": "0.01",
            "scriptType": "pubkeyhash",
            "opReturn": null,
            "spent": null
          },
          {
            "n": 1,
            "address": "XnL1FvTKqe6aWfB8NrvgbUMuWCEA3dNxfF",
            "value": "4.22879",
            "scriptType": "pubkeyhash",
            "opReturn": null,
            "spent": null
          }
        ]
      },
      "details": [
        {
          "key": "status",
          "label": "Status",
          "value": "Unsent",
          "kind": "text"
        }
      ]
    }
  },
  "go": null,
  "meta": {
    "requestid": "0123456789abcdef",
    "notices": []
  }
}
```

| Field | Type | Description |
| --- | --- | --- |
| `data.tx` | Tx | The v1 [Tx](https://docs.rarebl.com/data-types) shape. Prevout values are filled where the node knows them. |

### API400 (HTTP 400): Bad Request

A parameter is missing or malformed. `data.param` names it (here `hex`).

```json
{
  "status": 0,
  "code": "API400",
  "message": "hex is required.",
  "data": {
    "param": "hex"
  },
  "go": null,
  "meta": {
    "requestid": "0123456789abcdef",
    "notices": []
  }
}
```

### API429 (HTTP 429): Too Many Requests

Rate limited (compute class: 2 requests per second, burst 10, per IP). A `Retry-After` header says how long to wait, in seconds.

```json
{
  "status": 0,
  "code": "API429",
  "message": "Too many requests. Please retry shortly.",
  "data": null,
  "go": null,
  "meta": {
    "requestid": "0123456789abcdef",
    "notices": []
  }
}
```

### API502 (HTTP 502): Bad Gateway

The node is unavailable, still syncing or timed out. Retry later with a short back-off.

```json
{
  "status": 0,
  "code": "API502",
  "message": "The node is unavailable or timed out. Please try again.",
  "data": null,
  "go": null,
  "meta": {
    "requestid": "0123456789abcdef",
    "notices": []
  }
}
```

## Notes

- The reply is the same `Tx` shape as [Transaction](https://docs.rarebl.com/api/tx/get), with `status: "unsent"`, no block and 0 confirmations.
- Use it to double-check outputs and fees before you broadcast.