# Asynchronous mode
By default, Handl works in synchronous mode. You send a file for classification or recognition, wait for a response and only then send the next file. This mode is convenient for a low flow of documents and for testing purposes. In other cases, we recommend using the asynchronous mode. To enable it, specify **`async=true`** in the request parameters.
```bash
# asynchronous request for passport recognition from passport.jpg file, cloud version:
$ curl -X POST \
"https://latest.handl.io/recognize?doc_type=passport_main&quality=75&dpi=300&auto_pdf_raw_images=true&pdf_raw_images=true&async=true&token=ваш_ключ_лицензии" \
-H "accept: application/json" \
-H "Content-Type: multipart/form-data" \
-F "image=@passport.jpg;type=image/jpeg"
```
As a response to an asynchronous request Handl will return this HTTP-header:
```http
access-control-allow-credentials: true
access-control-allow-origin: https://latest.dbrain.io
content-length: 130
content-type: application/json
date: Tue08 Sep 2020 11:47:52 GMT
server: nginx/1.15.2
status: 200
```
The structure of the HTTP-message body is as follows:
```javascript
{
"detail": [],
"items": [],
"task_id": "5f576f68a3c2c6b689ff7a83",
"code": null,
"message": null,
"errno": null,
"traceback": null,
"fake": null
}
```
**`task_id`** must be specified for recognition or classification results, for example:
```bash
# use your license key instead of token parameter
$ curl -si \
"https://latest.handl.io/result/5f576f68a3c2c6b689ff7a83?token=xxx"
```
### **Possible responses to the results request**
{% tabs %}
{% tab title="Done" %}
If **`task_id`** is found and classification or recognition is completed, the response code is **200.**
{% code title="HTTP-header:" %}
```http
content-encoding: gzip
content-length: 896
content-type: application/json
date: Tue08 Sep 2020 11:26:22 GMT
server: nginx/1.15.2
status: 200
vary: Accept-Encoding
```
{% endcode %}
{% code title="Your possible request using Russian Passport as an example" %}
```javascript
{
"detail": [],
"items": [
{
"doc_type": "passport_main",
"fields": {
"date_of_birth": {
"text": "",
"confidence": 0,
"valid": null,
"coords": [
[
[
880,
1446
],
[
1187,
1446
],
[
1187,
1497
],
[
880,
1497
]
]
]
},
"date_of_issue": {
"text": "17.12.2004",
"confidence": 0.7422276735305786,
"valid": null,
"coords": [
[
[
233,
422
],
[
537,
419
],
[
537,
473
],
[
233,
476
]
]
]
},
"first_name": {
"text": "Adam",
"confidence": 0.998583197593689,
"valid": null,
"coords": [
[
[
748,
1289
],
[
972,
1289
],
[
972,
1340
],
[
748,
1340
]
]
]
},
"issuing_authority": {
"text": "The issueing authority of New York city Area",
"confidence": 0.995008111000061,
"valid": null,
"coords": [
[
[
441,
208
],
[
646,
201
],
[
646,
240
],
[
441,
246
]
],
[
[
681,
201
],
[
976,
201
],
[
976,
236
],
[
681,
236
]
],
[
[
1011,
201
],
[
1097,
201
],
[
1097,
236
],
[
1011,
236
]
],
[
[
502,
278
],
[
857,
278
],
[
857,
313
],
[
502,
313
]
],
[
[
889,
275
],
[
1065,
275
],
[
1065,
307
],
[
889,
307
]
],
[
[
502,
355
],
[
678,
355
],
[
678,
390
],
[
502,
390
]
],
[
[
713,
352
],
[
1065,
348
],
[
1065,
384
],
[
713,
387
]
]
]
},
"other_names": {
"text": "Ivanovich",
"confidence": 0.9980864524841309,
"valid": null,
"coords": [
[
[
659,
1366
],
[
1065,
1366
],
[
1065,
1417
],
[
659,
1417
]
]
]
},
"place_of_birth": {
"text": "New York city",
"confidence": 0.9998399019241333,
"valid": null,
"coords": [
[
[
643,
1536
],
[
745,
1536
],
[
745,
1568
],
[
643,
1568
]
],
[
[
790,
1536
],
[
1110,
1536
],
[
1110,
1568
],
[
790,
1568
]
]
]
},
"sex": {
"text": "male",
"confidence": 0.9768308401107788,
"valid": null,
"coords": [
[
[
540,
1449
],
[
665,
1449
],
[
665,
1500
],
[
540,
1500
]
]
]
},
"subdivision_code": {
"text": "292-000",
"confidence": 0.9457029104232788,
"valid": null,
"coords": [
[
[
825,
416
],
[
1052,
416
],
[
1052,
464
],
[
825,
464
]
]
]
},
"surname": {
"text": "Jhonson",
"confidence": 0.9971189498901367,
"valid": null,
"coords": [
[
[
742,
1132
],
[
944,
1132
],
[
944,
1184
],
[
742,
1184
]
]
]
},
"series_and_number": {
"text": "1104 000000",
"confidence": 0.9674372673034668,
"valid": null,
"coords": null
}
},
"color": true,
"error": null
}
],
"task_id": null,
"code": null,
"message": null,
"errno": null,
"traceback": null,
"fake": null
}
```
{% endcode %}
{% endtab %}
{% tab title="Not Done" %}
If **`task_id`** is found, but the classification or recognition of the document is not yet complete, the response code is **202.**
{% code title="HTTP-header:" %}
```http
content-length: 162
content-type: application/json
date: Tue08 Sep 2020 12:05:32 GMT
server: nginx/1.15.2
status: 202
```
{% endcode %}
{% code title="Your possible request using Russian Passport as an example" %}
```javascript
{
"detail": [
{
"msg": "Async task not done",
"type": "result_error"
}
],
"items": null,
"task_id": null,
"code": 202,
"message": "Async task not done",
"errno": 9,
"traceback": null
}
```
{% endcode %}
{% endtab %}
{% tab title="Can't Find" %}
If **`task_id`** is not found, the response code is **404**. Make sure you are requesting the correct **`task_id`**.
{% code title="HTTP-header:" %}
```http
content-length: 164
content-type: application/json
date: Tue08 Sep 2020 12:03:22 GMT
server: nginx/1.15.2
status: 404
```
{% endcode %}
{% code title="Your possible request using Russian Passport as an example" %}
```javascript
{
"detail": [
{
"msg": "Async task not found",
"type": "result_error"
}
],
"items": null,
"task_id": null,
"code": 404,
"message": "Async task not found",
"errno": 8,
"traceback": null
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
---
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