---
title: "Send two-way RPC request"
method: POST
path: "/api/rpc/twoway/{deviceId}"
tags: ["rpc-v-2-controller"]
---

# Send two-way RPC request

`POST /api/rpc/twoway/{deviceId}`

Sends the two-way remote-procedure call (RPC) request to device. Sends the one-way remote-procedure call (RPC) request to device. The RPC call is A JSON that contains the method name ('method'), parameters ('params') and multiple optional fields. See example below. We will review the properties of the RPC call one-by-one below. 

```json
{
  "method": "setGpio",
  "params": {
    "pin": 7,
    "value": 1
  },
  "persistent": false,
  "timeout": 5000
}
```

### Server-side RPC structure

The body of server-side RPC request consists of multiple fields:

* **method** - mandatory, name of the method to distinct the RPC calls.
  For example, "getCurrentTime" or "getWeatherForecast". The value of the parameter is a string.
* **params** - mandatory, parameters used for processing of the request. The value is a JSON. Leave empty JSON "{}" if no parameters needed.
* **timeout** - optional, value of the processing timeout in milliseconds. The default value is 10000 (10 seconds). The minimum value is 5000 (5 seconds).
* **expirationTime** - optional, value of the epoch time (in milliseconds, UTC timezone). Overrides **timeout** if present.
* **persistent** - optional, indicates persistent RPC. The default value is "false".
* **retries** - optional, defines how many times persistent RPC will be re-sent in case of failures on the network and/or device side.
* **additionalInfo** - optional, defines metadata for the persistent RPC that will be added to the persistent RPC events.

### RPC Result
In case of persistent RPC, the result of this call is 'rpcId' UUID. In case of lightweight RPC, the result of this call is the response from device, or 504 Gateway Timeout if device is offline.

Available for users with 'TENANT_ADMIN' or 'CUSTOMER_USER' authority.

## Path parameters

- `deviceId` string, required

## Request body

- string — A JSON value representing the RPC request.

## Response `200`

Persistent RPC request was saved to the database or lightweight RPC response received.

- string

## Other responses

- `400` — Invalid structure of the request.
- `401` — User is not authorized to send the RPC request. Most likely, User belongs to different Customer or Tenant.
- `413` — Request payload is too large
- `504` — Timeout to process the RPC call. Most likely, device is offline.

---

[API](https://skmtc.net/thingsboard/apis/thingsboard-rest-api.md) · [All operations](https://skmtc.net/thingsboard/apis/thingsboard-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/thingsboard/thingsboard-rest-api/revisions/40169ccdec5c/schema)