> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nixflex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Keypad input

> Let callers type digits instead of saying them

Callers can type on their phone keypad instead of speaking. The digits arrive as a normal caller turn, so your agent handles them with the same prompt it uses for speech - no extra configuration, no separate flow.

Reading numbers aloud is where speech recognition fails worst. A mis-heard account number sends the caller round the loop, and a stray word can cut the agent off mid-sentence. A keypad press is exact.

<Note>
  Keypad input is **off by default**. Turn it on per agent in the dashboard, or per number through the API.
</Note>

## Turning it on

### Per agent (dashboard)

Open the agent, find **Call actions**, and switch on **Keypad input**. Every number on that agent accepts keypad entry from the next call onwards.

### Per number (API)

A single number can override its agent - useful when one line needs keypad entry and the rest do not.

```bash theme={null}
curl -X PATCH https://api.nixflex.com/v1/phone-numbers/+447700900123 \
  -H "Authorization: Bearer KEY_ID:KEY_SECRET" \
  -H "Content-Type: application/json" \
  -d '{"dtmf_enabled": true}'
```

| Value   | Meaning                                                   |
| ------- | --------------------------------------------------------- |
| `true`  | This number accepts keypad entry, whatever the agent says |
| `false` | This number does not, whatever the agent says             |
| `null`  | **Not set** - the number inherits the agent's setting     |

<Warning>
  `null` is not the same as `false`. `null` means "no opinion, follow the agent", so a `null` number under an agent with keypad input **on** will accept keypad entry. To switch one number off while the agent stays on, send `false`, not `null`.
</Warning>

See [Update phone number](/api-reference/phone-numbers/update).

## What your agent receives

Digits are handed to the model as a caller turn, tagged so it knows they were typed rather than spoken:

```
[Caller pressed on keypad: 5869]
```

That tag matters. The model should read a typed account number back to confirm it, and it should not treat a lone `1` as the caller saying the word "one" mid-sentence.

<Tip>
  Ask for keypad entry in your prompt and the model will use it naturally: *"If the caller needs to give a reference number, ask them to type it on the keypad and then read it back to confirm."*
</Tip>

## When an entry is finished

Two things end an entry:

| Trigger                                  | Behaviour                                              |
| ---------------------------------------- | ------------------------------------------------------ |
| The caller presses `#`                   | Sent immediately. The `#` is **not** part of the value |
| Three seconds pass with no further press | Sent automatically                                     |

The three-second timer **restarts on every press**, so a caller slowly reading a long card number is never cut in half. There is no maximum length.

<Note>
  The three-second pause and the `#` send key are fixed and not configurable today.
</Note>

`*` is accepted as an ordinary key and comes through as part of the value.

## Where it works

|                | Supported                                                                                                                 |
| -------------- | ------------------------------------------------------------------------------------------------------------------------- |
| Inbound calls  | Yes                                                                                                                       |
| Outbound calls | Yes                                                                                                                       |
| Both carriers  | Yes - keypad presses are translated to one shape internally, so behaviour is identical whichever carrier the number is on |

## Behaviour you can rely on

* **The agent never waits for speech to process digits.** Once an entry is finished it goes straight to the model - a caller who types ten digits and says nothing still gets a reply.
* **Typing does not trigger the silence hang-up.** The inactivity timer resets on every entry, so a slow typer is not cut off.
* **A half-typed entry is discarded when the call ends.** Digits can never arrive after hangup.
* **Junk is ignored, never fatal.** Anything that is not a single `0-9`, `*` or `#` is dropped rather than raising an error, so a malformed frame cannot take down a live call.

## Common uses

* **Account or reference numbers** - exact where speech is not
* **Menu choices** - "press 1 for sales, 2 for support"
* **Postcodes and card numbers** - long strings that speech recognition mangles
* **Dates of birth** - digits with no spelling ambiguity

## Testing it

<Steps>
  <Step title="Turn it on">
    Switch on **Keypad input** for the agent, or PATCH `dtmf_enabled: true` on the number.
  </Step>

  <Step title="Call the number">
    Ask the agent something, then type a few digits on your keypad.
  </Step>

  <Step title="Press hash">
    The entry is sent the moment you press `#`. Without `#`, it sends about three seconds after your last press.
  </Step>

  <Step title="Check the transcript">
    The call transcript shows the entry as a caller turn: `[Caller pressed on keypad: 5869]`.
  </Step>
</Steps>

## Related

* [Update phone number](/api-reference/phone-numbers/update) - the `dtmf_enabled` field
* [Agent prompts](/concepts/agent-prompts) - asking for keypad entry in your prompt
* [Conversation control](/concepts/conversation-control) - how caller turns are handled