> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.telekesher.dev/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.telekesher.dev/_mcp/server.

# Play prompt and collect DTMF digits

POST https://api.telekesher.dev/v1/sessions/{uuid}/dtmf/collect
Content-Type: application/json

An individual `dtmf.received` event is emitted immediately for every
key press, whether or not a DTMF collection is active. It contains one
key and its `duration_ms`; it does not group digits or apply collection
rules.

Use this operation when you need a complete response. It plays the
prompt, groups the caller's keys, and applies the configured digit-count,
timeout, terminator, and regular-expression validation rules. When the
cycle ends, one `digits.collected` event reports the collected value and
outcome `status`. Individual `dtmf.received` events continue throughout
the collection.

**Rate limit: Per command** · **Burst:** 4 · **Refill:** 0.8 req/s

This POST has its own bucket. The cancel DELETE is configured identically, but uses a separate bucket.

Play an audio prompt and collect DTMF digits from the caller.

Configure the allowed digit count, first- and between-digit timeouts,
terminators, and optional regular-expression validation. The command
returns `202 Accepted` when queued. Store its `operation_uuid` and use
the same field on `digits.collected` to correlate the final result.

**Single-shot:** the gateway runs exactly one prompt/collect cycle and
emits one `digits.collected` carrying a `status`. The gateway never
retries on its own — **the client owns the retry loop**: inspect the
`status` field and re-issue this command with whatever prompt fits
(e.g. an "invalid PIN" prompt on `status: invalid`).

**Triggered webhook:** `digits.collected`.

For every finite prompt source, the
gateway probes with HEAD first and falls back to a ranged GET. A prompt
that cannot be prepared returns a synchronous HTTP error and emits no webhook.

Reference: https://docs.telekesher.dev/api/keypad-input/collect

## Authentication

- `Authorization` header (bearer token, required) — Application auth. Send `Authorization: Bearer <app_uuid>:<api_key>`. See [Authentication](https://voice-platform.docs.buildwithfern.com/api/authentication) for details.

## Request

### Path parameters

- `uuid` (string, required) — [Session](/api/sessions) UUID (format `{5-char-prefix}-{uuid}`).

### Headers

- `Idempotency-Key` (string, optional) — Optional client-generated key for a mutating endpoint. It identifies one method, route, query, content type, and exact raw body within the authenticated app. Reusing it for a different request returns 422. While its record exists, a retry replays the original accepted response when available. Keys are valid for 1 hour. Allowed characters: letters, digits, dot, hyphen, underscore; max 128 characters. See the Idempotency guide.

### Body (application/json)

- `prompt_files` (list of string, required) — Audio URLs to play as the prompt (http(s) only).
- `operation_uuid` (string, optional) — Optional caller-supplied per-command correlation id, a bare lowercase RFC-4122 v4 UUID (no prefix). Echoed back as `operation_uuid` in the 202 ack. A later lifecycle webhook carries it only when the gateway can unambiguously associate that event with this command; the field is correlation, not proof of causation. When omitted, the gateway mints one. Not an idempotency key — request deduplication is the `Idempotency-Key` header. Invalid input (not a v4 UUID) is rejected with `400 invalid_request`.
- `between_digits_timeout_ms` (integer, optional, default: 2000) — Milliseconds to wait between digits before timing out.
- `first_digit_timeout_ms` (integer, optional, default: 5000) — Milliseconds to wait for the first digit before timing out.
- `max_digits` (integer, optional, default: 10) — Maximum digits to collect. Must be >= min_digits.
- `min_digits` (integer, optional, default: 1)
- `terminators` (list of enum, optional, default: ["#"]) — DTMF terminator characters. Only # and * allowed.
  - Allowed values: `#`, `*`
- `validation` (object, optional) — Optional input validation.
  - `regex` (string, optional) — RE2 regular expression the collected digits must match (no whitespace, \<=256 chars). On match-and-fail, status is `invalid`.

## Response

### 202

Command accepted for async execution

- `operation_uuid` (string, required)
- `status` (enum, required)
  - Allowed values: `in_progress`, `completed`
- `already_ended` (true, optional) — Optional. Set to `true` on idempotent terminal commands when the session was already in a terminal state at the time the request was received. Absent otherwise.

## Examples

**Request**

```json
{
  "prompt_files": [
    "https://cdn.example.com/enter-pin.wav"
  ],
  "between_digits_timeout_ms": 2000,
  "first_digit_timeout_ms": 10000,
  "max_digits": 6,
  "min_digits": 4,
  "terminators": [
    "#"
  ],
  "validation": {
    "regex": "^[0-9]{4,6}$"
  }
}
```

**Response**

```json
{
  "operation_uuid": "550e8400-e29b-41d4-a716-446655440000",
  "status": "in_progress"
}
```

**SDK Code**

```python Keypad Input_playPromptAndCollectDTMFDigits_example
import requests

url = "https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect"

payload = {
    "prompt_files": ["https://cdn.example.com/enter-pin.wav"],
    "between_digits_timeout_ms": 2000,
    "first_digit_timeout_ms": 10000,
    "max_digits": 6,
    "min_digits": 4,
    "terminators": ["#"],
    "validation": { "regex": "^[0-9]{4,6}$" }
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript Keypad Input_playPromptAndCollectDTMFDigits_example
const url = 'https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"prompt_files":["https://cdn.example.com/enter-pin.wav"],"between_digits_timeout_ms":2000,"first_digit_timeout_ms":10000,"max_digits":6,"min_digits":4,"terminators":["#"],"validation":{"regex":"^[0-9]{4,6}$"}}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Keypad Input_playPromptAndCollectDTMFDigits_example
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect"

	payload := strings.NewReader("{\n  \"prompt_files\": [\n    \"https://cdn.example.com/enter-pin.wav\"\n  ],\n  \"between_digits_timeout_ms\": 2000,\n  \"first_digit_timeout_ms\": 10000,\n  \"max_digits\": 6,\n  \"min_digits\": 4,\n  \"terminators\": [\n    \"#\"\n  ],\n  \"validation\": {\n    \"regex\": \"^[0-9]{4,6}$\"\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Keypad Input_playPromptAndCollectDTMFDigits_example
require 'uri'
require 'net/http'

url = URI("https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"prompt_files\": [\n    \"https://cdn.example.com/enter-pin.wav\"\n  ],\n  \"between_digits_timeout_ms\": 2000,\n  \"first_digit_timeout_ms\": 10000,\n  \"max_digits\": 6,\n  \"min_digits\": 4,\n  \"terminators\": [\n    \"#\"\n  ],\n  \"validation\": {\n    \"regex\": \"^[0-9]{4,6}$\"\n  }\n}"

response = http.request(request)
puts response.read_body
```

```java Keypad Input_playPromptAndCollectDTMFDigits_example
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"prompt_files\": [\n    \"https://cdn.example.com/enter-pin.wav\"\n  ],\n  \"between_digits_timeout_ms\": 2000,\n  \"first_digit_timeout_ms\": 10000,\n  \"max_digits\": 6,\n  \"min_digits\": 4,\n  \"terminators\": [\n    \"#\"\n  ],\n  \"validation\": {\n    \"regex\": \"^[0-9]{4,6}$\"\n  }\n}")
  .asString();
```

```php Keypad Input_playPromptAndCollectDTMFDigits_example
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect', [
  'body' => '{
  "prompt_files": [
    "https://cdn.example.com/enter-pin.wav"
  ],
  "between_digits_timeout_ms": 2000,
  "first_digit_timeout_ms": 10000,
  "max_digits": 6,
  "min_digits": 4,
  "terminators": [
    "#"
  ],
  "validation": {
    "regex": "^[0-9]{4,6}$"
  }
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp Keypad Input_playPromptAndCollectDTMFDigits_example
using RestSharp;

var client = new RestClient("https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"prompt_files\": [\n    \"https://cdn.example.com/enter-pin.wav\"\n  ],\n  \"between_digits_timeout_ms\": 2000,\n  \"first_digit_timeout_ms\": 10000,\n  \"max_digits\": 6,\n  \"min_digits\": 4,\n  \"terminators\": [\n    \"#\"\n  ],\n  \"validation\": {\n    \"regex\": \"^[0-9]{4,6}$\"\n  }\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Keypad Input_playPromptAndCollectDTMFDigits_example
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [
  "prompt_files": ["https://cdn.example.com/enter-pin.wav"],
  "between_digits_timeout_ms": 2000,
  "first_digit_timeout_ms": 10000,
  "max_digits": 6,
  "min_digits": 4,
  "terminators": ["#"],
  "validation": ["regex": "^[0-9]{4,6}$"]
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.telekesher.dev/v1/sessions/uuid/dtmf/collect")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```