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# Helper Functions

> Convenience functions for creating common DataMap patterns.

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

[ref-functionresult]: /docs/server-sdks/reference/typescript/agents/function-result

```typescript {3}
import { createSimpleApiTool } from '@signalwire/sdk';

const weatherTool = createSimpleApiTool({
  name: 'get_weather',
  url: 'https://api.weather.com/v1/current?q=${args.location}',
  responseTemplate: 'Weather: ${response.current.condition.text}, ${response.current.temp_f}F',
  parameters: {
    location: { type: 'string', description: 'City name', required: true },
  },
});
```

Create a DataMap for a straightforward single-endpoint API call with minimal
configuration.

## **Parameters**

**`name`** `string` — required

Function name.

---

**`url`** `string` — required

API endpoint URL.

---

**`responseTemplate`** `string` — required

Template string for formatting the response.

---

**`parameters`** `Record<string, { type?: string; description?: string; required?: boolean }>`

Parameter definitions. Keys are parameter names, values are objects with
`"type"`, `"description"`, and optional `"required"` keys.

---

**`method`** `string` — default: GET

HTTP method.

---

**`headers`** `Record<string, string>`

HTTP headers.

---

**`body`** `Record<string, unknown>`

Request body for POST/PUT.

---

**`errorKeys`** `string[]`

Keys indicating an error response.

---

## **Returns**

[`DataMap`][ref-datamap] -- A fully configured DataMap ready for further chaining or conversion.

---

```typescript {3}
import { createExpressionTool, FunctionResult } from '@signalwire/sdk';

const controlTool = createExpressionTool({
  name: 'playback_control',
  patterns: {
    '${args.command}': ['play.*', new FunctionResult('Playing.')],
  },
  parameters: {
    command: { type: 'string', description: 'Playback command', required: true },
  },
});
```

Create a DataMap for pattern-matching responses without API calls.

## **Parameters**

**`name`** `string` — required

Function name.

---

**`patterns`** `Record<string, [string, FunctionResult]>` — required

Object mapping test values to `[pattern, FunctionResult]` tuples.

---

**`parameters`** `Record<string, { type?: string; description?: string; required?: boolean }>`

Parameter definitions (same format as `createSimpleApiTool`).

---

## **Returns**

[`DataMap`][ref-datamap] -- A fully configured DataMap.

## **Example**

```typescript {9}
import {
  AgentBase,
  FunctionResult,
  createSimpleApiTool,
  createExpressionTool,
} from '@signalwire/sdk';

// Simple API tool -- one line instead of a full DataMap chain
const weather = createSimpleApiTool({
  name: 'get_weather',
  url: 'https://api.weatherapi.com/v1/current.json?key=KEY&q=${enc:args.city}',
  responseTemplate: 'Weather in ${args.city}: ${response.current.condition.text}',
  parameters: {
    city: { type: 'string', description: 'City name', required: true },
  },
  errorKeys: ['error'],
});

// Expression tool -- pattern matching without API calls
const greeting = createExpressionTool({
  name: 'greet',
  patterns: {
    '${args.language}': ['spanish|espanol', new FunctionResult('Hola!')],
  },
  parameters: {
    language: { type: 'string', description: 'Language to greet in' },
  },
});

const agent = new AgentBase({ name: 'helper-demo' });
agent.setPromptText('You are a helpful assistant.');
agent.registerSwaigFunction(weather.toSwaigFunction());
agent.registerSwaigFunction(greeting.toSwaigFunction());

agent.run();
```

> Convenience functions for creating common DataMap patterns.