# reqwest HTTP Client Library

## Function

reqwest(url) Creates a synchronous HTTP request builder, supporting method, header, cookie, cookie_store, body, json, form, multipart, timeout, query, proxy, redirect_policy and send.

## API List

| API | Description |
| ------ | ------ |
| [reqwest.method](/en/docs/reqwest/method) | Set the HTTP request method. |
| [reqwest.header](/en/docs/reqwest/header) | Set one or a group of request headers. |
| [reqwest.cookie](/en/docs/reqwest/cookie) | Set the Cookie request header. |
| [reqwest.cookie_store](/en/docs/reqwest/cookie_store) | Enable or disable cookie storage for the current requesting client. |
| [reqwest.body](/en/docs/reqwest/body) | Set the string request body. |
| [reqwest.json](/en/docs/reqwest/json) | Set the JSON request body. |
| [reqwest.form](/en/docs/reqwest/form) | Set application/x-www-form-urlencoded form request body. |
| [reqwest.multipart](/en/docs/reqwest/multipart) | Set multipart/form-data request body. |
| [reqwest.timeout](/en/docs/reqwest/timeout) | Set the request timeout. |
| [reqwest.query](/en/docs/reqwest/query) | Append URL query parameters. |
| [reqwest.proxy](/en/docs/reqwest/proxy) | Set HTTP/HTTPS proxy. |
| [reqwest.redirect_policy](/en/docs/reqwest/redirect_policy) | Set redirect policy. |
| [reqwest.send](/en/docs/reqwest/send) | Send an HTTP request synchronously and return a response object. |

## Examples

```bt
response = reqwest('https://example.com').send()
result = type(response)

// Output: Object
print result
```

## Notes

- The current VM is a synchronous model, send() will wait for the HTTP request to be completed synchronously; the underlying process-level I/O runtime is reused.
-The HTTP client pool is enabled by default and is grouped and reused by proxy and redirection policies; the pool status can be viewed through `BT.stats().http`.
- `cookie_store(true)` only acts on this `send()` and its redirect link, and does not enter the shared client pool to avoid cross-request cookie pollution.
- Body, json, form, and multipart will all set the request body; the last request body set in the same request takes effect.

HTTP client pool default configuration:

| Environment variable | Default value | Description |
| ------ | ------ | ------ |
| BT_HTTP_CLIENT_POOL | true | Whether to enable the HTTP client pool. |
| BT_HTTP_CLIENT_POOL_LIMIT | 32, maximum 1024 | Maximum number of client configuration groups to retain. |
| BT_HTTP_CLIENT_IDLE_TTL_MS | 300000 | client idle retention time, in milliseconds; 0 means not to be eliminated based on idle time. |
| BT_HTTP_SLOW_MS | 0 | Slow HTTP call log threshold, in milliseconds; 0 means off. |