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# parameter

> Add a function parameter to the tool definition.

[ref-datamap]: /docs/server-sdks/reference/typescript/agents/data-map

Add a function parameter to the tool definition.

## **Parameters**

**`name`** `string` — required

Parameter name.

---

**`paramType`** `string` — required

JSON schema type for the parameter.

* `"string"` -- text value
* `"integer"` -- whole number value
* `"number"` -- numeric value including decimals
* `"boolean"` -- true or false value
* `"array"` -- list of values
* `"object"` -- nested key-value structure

---

**`description`** `string` — required

Description of the parameter shown to the AI.

---

**`opts`** `object`

Optional configuration.

---

**`opts.required`** `boolean`

Whether this parameter is required.

---

**`opts.enum`** `string[]`

Optional list of allowed values for this parameter.

---

## **Returns**

[`DataMap`][ref-datamap] -- Self for method chaining.

## **Example**

```typescript {6-7}
import { DataMap } from '@signalwire/sdk';

const weather = new DataMap('get_weather');
weather
  .purpose('Get current weather for a city')
  .parameter('city', 'string', 'City name', { required: true })
  .parameter('units', 'string', 'Temperature units', { enum: ['fahrenheit', 'celsius'] });

console.log(weather.toSwaigFunction());
```

> Add a function parameter to the tool definition.