# Prepare to accept an offer

`POST /api/market/offers/{id}/accept/prepare`

Step 1 of accepting, for the UTXO's current holder only: checks the offer is active and the UTXO unspent at the same address and value, and returns the offer transaction with input 0 (your UTXO) ready for your wallet. It carries no bidder signature.

#### Path parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `id` | string | yes | The offer id (16 hex characters). |

#### Request body

`content-type: application/json`

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `seller_address` | string | yes | The address that holds the UTXO (the offer's `seller_address`). |
| `seller_public_key` | string | yes | Its public key, hex (Taproot: the internal key, x-only or compressed; SegWit: compressed). |

#### Example request

```bash title="cURL"
curl -X POST 'https://raresats.net/api/market/offers/dbf866a1e7e209e7/accept/prepare' \
  -H 'content-type: application/json' \
  -d '{
  "seller_address": "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr",
  "seller_public_key": "03cc8a4bc64d897bddc5fbc2f670f7a8ba0b386779106cf1223c6fc5d7cd6fc115"
}'
```
```js title="JavaScript"
const response = await fetch('https://raresats.net/api/market/offers/dbf866a1e7e209e7/accept/prepare', {
  method: 'POST',
  headers: { 'content-type': 'application/json' },
  body: JSON.stringify({
    "seller_address": "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr",
    "seller_public_key": "03cc8a4bc64d897bddc5fbc2f670f7a8ba0b386779106cf1223c6fc5d7cd6fc115"
  })
});
const data = await response.json();
```
```python title="Python"
import requests

data = requests.post("https://raresats.net/api/market/offers/dbf866a1e7e209e7/accept/prepare", json={
    "seller_address": "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr",
    "seller_public_key": "03cc8a4bc64d897bddc5fbc2f670f7a8ba0b386779106cf1223c6fc5d7cd6fc115"
}).json()
```

#### Response `200`

| Field | Type | Description |
| --- | --- | --- |
| `psbt` | string | The offer transaction, base64, with input 0 ready for your wallet. It carries no bidder signature (the server adds them). |
| `sign` | array of object | Input 0, your UTXO: sign it with your wallet's default sighash. |
| `sign[].index` | integer | The input to sign. |
| `sign[].address` | string | The address whose key signs it. |
| `sign[].sighash` | integer | The sighash type to sign with, when it is not the default: 131 (`0x83`, SIGHASH_SINGLE\|ANYONECANPAY) for listings. Absent on purchase inputs: sign with the default (SIGHASH_DEFAULT for Taproot, SIGHASH_ALL for SegWit v0). |
| `summary` | object | The trade you accept. |
| `summary.outpoint` | string | Your UTXO. |
| `summary.value` | integer | Its value in sats (it goes to the bidder). |
| `summary.price` | integer | What you receive, in sats (output 1, to your address). |
| `summary.platform_fee` | integer | The bidder's platform fee. |
| `summary.network_fee` | integer | The network fee, paid by the bidder. |
| `summary.total` | integer | What the bidder pays. |
| `summary.vsize` | integer | Estimated virtual size. |
| `summary.fee_rate` | number | sat/vB, fixed by the bidder. If it confirms slowly, you can speed it up by spending output 1 (CPFP). |
| `summary.unit_price` | number | `(price - value) / count`. |
| `summary.row` | string | The UTXO's own row. |
| `summary.count` | integer | Sats of `row` in the UTXO. |
| `summary.bidder_ordinals_address` | string | Where the UTXO goes. |
| `summary.listing_id` | string \| null | Your live listing of the UTXO, if any: accepting sells it (`sold` once confirmed). |

```json title="Response"
{
  "psbt": "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",
  "sign": [
    {
      "index": 0,
      "address": "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr"
    }
  ],
  "summary": {
    "outpoint": "24b3eedfdc210f4a5baa96a6c99db5a51d3b1286ab2f58cb0b16fc607e54107f:0",
    "value": 10000,
    "price": 110000,
    "platform_fee": 2750,
    "network_fee": 963,
    "total": 113713,
    "vsize": 321,
    "fee_rate": 3,
    "unit_price": 100000,
    "row": "decasat_alpha",
    "count": 1,
    "bidder_ordinals_address": "bc1p4qhjn9zdvkux4e44uhx8tc55attvtyu358kutcqkudyccelu0was9fqzwh",
    "listing_id": "5e1cb930f43354c3"
  }
}
```

#### Errors

`{error, code}`; see [Errors](https://raresats.net/docs/errors.md) for every code.

| Status | Code | Meaning |
| --- | --- | --- |
| 400 | `bad_address` | An address is not a mainnet address (or not one at all). |
| 400 | `bad_json` | The body is not valid JSON. |
| 400 | `bad_public_key` | A public key is not hex, or not a valid secp256k1 key of the right size. |
| 400 | `bad_request` | The body is not a JSON object, or the engine refused a malformed request (e.g. a purchase submitted without its signed setup PSBT). |
| 403 | `cross_origin` | A POST from a browser on another site (a foreign `Origin`, or `sec-fetch-site: cross-site`). Server-side clients send no `Origin` and are not affected. |
| 404 | `not_found` | No such listing or offer. In chat: no such message. A display name to remove that does not exist. |
| 405 | `method_not_allowed` | Wrong method for the route; the `allow` header lists the right ones. |
| 409 | `changed` | The UTXO's value is not what the PSBT says, or (wallet tools) a UTXO, its sats or the transaction being replaced changed since prepare: prepare again. |
| 409 | `config_changed` | The marketplace settings changed since this purchase or transfer was prepared (prepare it again), or since this offer was made (it is now `invalid`, reason `config_changed`). |
| 409 | `expired` | The prepared purchase, offer or transfer expired, or the offer itself has: prepare it again. |
| 409 | `not_active` | A listing (or offer) is not active: being bought (or accepted), sold, cancelled, moved, expired or invalid. Carries `id` and `status`. |
| 409 | `spent` | The UTXO (or a listing's UTXO) is spent or does not exist. |
| 413 | `too_large` | The body is over 256 KiB. |
| 415 | `not_json` | A POST without `content-type: application/json`. |
| 422 | `key_mismatch` | The public key does not control the address. |
| 422 | `legacy_address` | A legacy (P2PKH, `1…`) address: use Taproot or SegWit. |
| 422 | `not_owner` | The UTXO does not belong to the seller address, or (wallet tools) to the owner's addresses, or the transfer was made by another wallet. |
| 422 | `pubkey_mismatch` | The trade engine found the public key is not the address's key. |
| 422 | `unsupported_address` | An address type the marketplace does not trade (only Taproot, native SegWit and nested SegWit). |
| 422 | `unsupported_script` | The trade engine met a script type it does not support. |
| 429 | `rate_limited` | Over 30 POSTs a minute from your IPv4 address or IPv6 /64 (in chat, counted per IPv4 address or IPv6 /64: 30 writes and 20 login nonces a minute, 20 sign-ins and 10 display-name changes an hour; one message every 3 s and 20 a minute per address); wait `retry-after` seconds. With the AI moderation on, at most 6 messages and names a minute are checked per address and per IPv4 address or IPv6 /48. |
| 500 | `internal` | A server bug. Report it. |
| 503 | `bitcoind_unavailable` | bitcoind is not available. |
| 503 | `engine_unavailable` | The trade engine is not available. |
| 503 | `fork_unavailable` | The rare-sat index is not available. |
| 503 | `market_unavailable` | The marketplace is closed right now (its backends disagree on the network, or are unreachable). |
| 503 | `oracle_unavailable` | The ord oracle is not available. |

```json title="Error (422)"
{
  "error": "24b3eedfdc210f4a5baa96a6c99db5a51d3b1286ab2f58cb0b16fc607e54107f:0 is not held by bc1p4qhjn9zdvkux4e44uhx8tc55attvtyu358kutcqkudyccelu0was9fqzwh: only its holder can accept",
  "code": "not_owner",
  "outpoint": "24b3eedfdc210f4a5baa96a6c99db5a51d3b1286ab2f58cb0b16fc607e54107f:0"
}
```

Then sign input 0 with your wallet's default sighash and [accept](https://raresats.net/docs/accept-offer.md). You receive `price` at the address that holds the UTXO (output 1); the bidder pays the platform fee and the network fee.