# Search a collection

> Search by a selfie image OR a precomputed 512-d embedding. (POST /v1/collections/{id}/search)

Source: https://sightradar.com/docs/api/faces/search-a-collection

Search by a selfie image OR a precomputed 512-d embedding. Returns the
matching photo ids ranked by similarity.

### Example request

```bash
curl -X POST "https://api.sightradar.com/v1/collections/$ID/search" \
  -H "Authorization: Bearer $SR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com/photo.jpg"}'
```

### Parameters

| Name              | In     | Type     | Description                                                                                                                                                                                                                    |
| ----------------- | ------ | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `id` **required** | path   | `string` |                                                                                                                                                                                                                                |
| `Idempotency-Key` | header | `string` | Opt-in idempotency. A replay under the same key is never re-charged. For a selfie register it returns 200 with the stored result (Idempotent-Replay: true) when the registration identity matches; every other op returns 409. |

### Request body (application/json)

| Field       | Type       | Description                  |
| ----------- | ---------- | ---------------------------- |
| `embedding` | `number[]` |                              |
| `url`       | `string`   |                              |
| `gcsKey`    | `string`   |                              |
| `threshold` | `number`   | Min cosine similarity (0-1). |
| `limit`     | `integer`  | Max matches.                 |

Also accepts: `multipart/form-data`.

### Response body

| Field           | Type       | Description                                                                   |
| --------------- | ---------- | ----------------------------------------------------------------------------- |
| `collection_id` | `string`   |                                                                               |
| `matches`       | `object[]` |                                                                               |
| `photo_ids`     | `string[]` |                                                                               |
| `reason`        | `string`   | Present when no match: no\_face \| low\_quality\_selfie \| point\_not\_found. |
| `model_version` | `string`   |                                                                               |

### Status codes

| Status | Meaning                                                                |
| ------ | ---------------------------------------------------------------------- |
| `200`  | Search result.                                                         |
| `400`  | Cannot decode image, or no url/gcsKey/body provided.                   |
| `401`  | Missing or invalid API key.                                            |
| `402`  | Wallet balance too low for this operation.                             |
| `409`  | A request with this Idempotency-Key is in flight or already processed. |
| `429`  | Per-key RPS or per-customer concurrency limit exceeded.                |
| `502`  | Engine error (the credit hold is refunded automatically).              |