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# Executions

**`Request — sent`**

```json title="Request — sent"
{
  "op": "subscribe",
  "reqId": "<string>",
  "params": {
    "topics": [
      "execution"
    ]
  }
}
```

**`Response — received`**

```json title="Response — received"
{
  "op": "subscribe",
  "reqId": "<string>",
  "success": true
}
```

**`execution · snapshot part — received`**

```json title="execution · snapshot part — received"
{
  "event": "execution",
  "msgType": "execution",
  "topic": "execution",
  "seq": "<string>",
  "seqTs": "<string>",
  "isSnapshot": true,
  "snapshotId": "<string>",
  "part": 0,
  "last": true,
  "data": [
    {
      "executionId": "<string>",
      "orderId": "<string>",
      "accountId": 0,
      "account": "<string>",
      "instrumentId": "<string>",
      "instrument": "<string>",
      "credentialId": 0,
      "side": "UNKNOWN",
      "kind": "UNKNOWN",
      "liquidity": "MAKER",
      "qty": "<string>",
      "px": "<string>",
      "fee": "<string>",
      "feeAssetId": 0,
      "feeAsset": "<string>",
      "fillTsNs": "<string>",
      "venueTsNs": "<string>",
      "venueTradeId": "<string>",
      "venueOrderId": "<string>",
      "notionalUsd": "<string>",
      "feeUsd": "<string>",
      "fxSource": "IDENTITY"
    }
  ]
}
```

**`execution · delta — received`**

```json title="execution · delta — received"
{
  "event": "execution",
  "msgType": "execution",
  "topic": "execution",
  "seq": "<string>",
  "seqTs": "<string>",
  "isSnapshot": false,
  "data": [
    {
      "executionId": "<string>",
      "orderId": "<string>",
      "accountId": 0,
      "account": "<string>",
      "instrumentId": "<string>",
      "instrument": "<string>",
      "credentialId": 0,
      "side": "UNKNOWN",
      "kind": "UNKNOWN",
      "liquidity": "MAKER",
      "qty": "<string>",
      "px": "<string>",
      "fee": "<string>",
      "feeAssetId": 0,
      "feeAsset": "<string>",
      "fillTsNs": "<string>",
      "venueTsNs": "<string>",
      "venueTradeId": "<string>",
      "venueOrderId": "<string>",
      "notionalUsd": "<string>",
      "feeUsd": "<string>",
      "fxSource": "IDENTITY"
    }
  ]
}
```

Each frame is its shape, read off the contract: `<string>` stands for a value, and a union shows its first form.

**URL** — No public environment serves this socket yet.

**Topic** `execution`

## Request parameters

| Parameter  | Type             | Required | Description                                                                                     |
| ---------- | ---------------- | -------- | ----------------------------------------------------------------------------------------------- |
| `op`       | string           | Yes      | `subscribe`                                                                                     |
| `reqId`    | string           | Yes      | Echoed byte-exact on the answer. Printable ASCII, escape-free; anything else answers MALFORMED. |
| `params`   | object           | Yes      |                                                                                                 |
| > `topics` | array of strings | Yes      | `execution`                                                                                     |

## Response parameters

| Parameter | Type    | Required | Description                                                                                     |
| --------- | ------- | -------- | ----------------------------------------------------------------------------------------------- |
| `op`      | string  | Yes      | One of `subscribe`, `unsubscribe`.                                                              |
| `reqId`   | string  | Yes      | Echoed byte-exact on the answer. Printable ASCII, escape-free; anything else answers MALFORMED. |
| `success` | boolean | Yes      | `true`                                                                                          |

## Push data parameters

`orderId` is null for a leg discovered at the venue before the platform bound it to an order; the row is restated with the id when attribution lands, and the upsert rule makes that a replacement rather than a duplicate.

**What the image holds.** Every execution leg of the organization this member retains, keyed by `executionId` — no window applies here, unlike `order`. A leg is retained as long as the order it belongs to is, so the set follows orders rather than time.

**How a row leaves.** With its order, when the platform releases that order under its own retention, and — as on `order` — **that release rides no wire**. Re-subscribe to rebuild. Nothing else removes a leg: a busted or corrected fill arrives as its own row with its own `kind`, never as a deletion of the one it corrects.

| Parameter        | Type              | Required | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| ---------------- | ----------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `event`          | string            | Yes      | `execution`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| `msgType`        | string            | Yes      | `execution`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| `topic`          | string            | Yes      | `execution`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| `seq`            | string            | Yes      | The stream position, as a decimal string — an int64 a JSON number would truncate.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| `seqTs`          | string            | Yes      | The stream timestamp, epoch-ns as a decimal string.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| `isSnapshot`     | boolean           | Yes      | One of `true`, `false`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| `snapshotId`     | string            | No       | **Present on a snapshot part only**, and the same on every part of one image; the next image of any topic carries a different one. **Opaque — compare it for equality and nothing else.** It is not a sequence, a version or a timestamp, and its shape may change; a client that ordered by it would be relying on how a member happens to mint it. Use it to keep two images apart. A repeat `subscribe` re-pushes the image — that is the resync, and there is no separate op — so a client can start image N+1 while N is still arriving, and without a name on each part it cannot tell which `last: true` closes which, nor stop a straggling part of N landing in the map N+1 just cleared. **Discard any part whose `snapshotId` is not the one you are currently applying.**                                                                                                            |
| `part`           | integer           | No       | Present on a snapshot part only; 1-based.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| `last`           | boolean           | No       | Present on a snapshot part only. The image is complete when true — including for an empty channel, which is still one part.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| `data`           | array of objects  | Yes      | One fill, keyed by `executionId`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| > `executionId`  | string            | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `orderId`      | string, nullable  | Yes      | Null for a leg discovered at the venue before the platform bound it to an order. The row is restated with the id when attribution lands, and the upsert rule makes that a replacement rather than a duplicate.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| > `accountId`    | integer           | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `account`      | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `instrumentId` | string            | Yes      | An instrument, by the platform's own id — an int64 as a decimal string, because a JSON number cannot hold one. **One id space across this wire and the HTTP lane**, and the same one both order doors take: the id you read here is the id you send, on `submitOrder` and on `POST /orders` alike. It is **the platform's own reference-data key and nothing else's**. It is not a venue symbol, and it is not an id from any other system — in particular it does **not** equal an immix-api v2 `Instrument.id`, and there is no arithmetic that maps between them. A client holding v2 ids resolves through the symbol, once, at cutover: `instrument` beside this field carries the platform symbol (`OKX@BTC/USDT`), which is what both systems can be joined on. The id is the stable address and the symbol is the convenience: a symbol is reference data's to change and this id is not. |
| > `instrument`   | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `credentialId` | integer           | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `side`         | string            | Yes      | One of `UNKNOWN`, `BUY`, `SELL`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| > `kind`         | string            | Yes      | One of `UNKNOWN`, `FILL`, `BUST`, `CORRECTION`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `liquidity`    | string, nullable  | Yes      | Null when the venue did not say. One of `MAKER`, `TAKER`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| > `qty`          | string            | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `px`           | string            | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `fee`          | string, nullable  | Yes      | Signed — a rebate is a negative fee. A fee is a fact once it names its asset, a stated zero included; only an unstated fee is null.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| > `feeAssetId`   | integer, nullable | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `feeAsset`     | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `fillTsNs`     | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `venueTsNs`    | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `venueTradeId` | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `venueOrderId` | string, nullable  | Yes      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| > `notionalUsd`  | string, nullable  | Yes      | qty x px converted at the quote asset's USD rate. Null where the platform holds no current rate — null is NEVER the un-converted amount.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| > `feeUsd`       | null              | Yes      | Always null in 1.0.0. The conversion is defined but the renderer for a signed 128-bit amount is not published yet, and a rounded fee would be a wrong number rather than a missing one. Read `fee` with `feeAsset`. When it starts carrying a value it will be a decimal string, which is an additive change to this type.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| > `fxSource`     | string, nullable  | Yes      | The route the QUOTE asset's USD rate took — the notional's provenance. Null where the platform holds no current rate, which is also when `notionalUsd` is null: null is NEVER the un-converted amount. One of `IDENTITY`, `DIRECT`, `CROSS`, `PEGGED`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |