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

# n8n node

> Install the n8n-nodes-slng community node to run SLNG text-to-speech, speech-to-text, and voice-agent calls inside n8n workflows.

`n8n-nodes-slng` is a community node for [n8n](https://n8n.io/). It brings two nodes to your workflows: **SLNG**, which runs text-to-speech, speech-to-text, and outbound voice-agent calls, and **SLNG Trigger**, which lets a voice agent call a workflow as a tool mid-call. Both share one credential and reach every model on the SLNG platform.

## Install

In your n8n instance, go to **Settings → Community Nodes**, click **Install**, and enter the package name:

```
n8n-nodes-slng
```

Restart n8n after installing or upgrading.

<Note>
  This is a community node, so it needs a self-hosted n8n instance. n8n Cloud does not support unverified community nodes.
</Note>

## Credentials

Create an SLNG key in the [dashboard](https://app.slng.ai/api-keys), then add a **SLNG API** credential in n8n and paste it. The key is sent as a Bearer token and validated against `GET https://api.slng.ai/v1/me`. The same credential covers both the Voice API (`api.slng.ai`) and the Agents API (`api.agents.slng.ai`).

## Actions

The **SLNG** node runs one operation per execution:

| Resource       | Operation     | What it does                                                                                                                  |
| -------------- | ------------- | ----------------------------------------------------------------------------------------------------------------------------- |
| Text to Speech | Generate      | Converts text into spoken audio, returned as a binary file on the item.                                                       |
| Speech to Text | Transcribe    | Transcribes an audio file from a binary field into text.                                                                      |
| Agent          | Dispatch Call | Places an outbound phone call from a SLNG voice agent. Checks the agent has outbound telephony configured before dispatching. |

The **Model** field (and the **Voice** field for Text to Speech) is a dropdown populated live from the SLNG catalog; the voice list is filtered to the chosen TTS model. Switch either to **By ID** to hardcode a model path or voice ID.

## Trigger

The **SLNG Trigger** node registers a webhook tool on an existing agent when you activate the workflow, and removes it when you deactivate. When the agent calls the tool during a call, the workflow runs.

* **Tool type** — *LLM tool (contextual)*: the agent decides when to call it, and you define the parameters it sends with a field builder (name, type, description, required). *System tool*: fires automatically on a call lifecycle event (call start, first user message, call end, tool succeeded or failed).
* **Authentication** — *HMAC* (SLNG signs the body with `X-Signature-256`) or *Bearer*. Leave the secret empty to auto-generate one on activation; the node registers it with SLNG and validates incoming requests.
* **Respond** — *Using Last Node* (default) returns the workflow's final output to the agent. *Immediately* acknowledges the call and runs the workflow in the background. To shape the JSON the agent receives, keep *Using Last Node* and have the final node emit the object you want.

<Note>
  n8n blocks expression access to `$json.arguments`, so the trigger exposes the agent's tool arguments as `toolArguments`. Reference them downstream with `{{$json.toolArguments}}` or `{{$json.toolArguments.fieldName}}`.
</Note>

## Next steps

<CardGroup cols={2}>
  <Card title="Agent skills" icon="https://mintcdn.com/slng/2xZHLyyFGVnnnXpA/images/sdks/claude.svg?fit=max&auto=format&n=2xZHLyyFGVnnnXpA&q=85&s=3952b103294f073e198c949c2532daae" href="/sdks/skills" width="24" height="24" data-path="images/sdks/claude.svg">
    Let a coding agent build your SLNG integration instead.
  </Card>

  <Card title="Voice agents" icon="bot" href="/voice-agents">
    Build and configure the agents you dispatch and trigger from n8n.
  </Card>

  <Card title="GitHub repo" icon="github" href="https://github.com/slng-ai/n8n-nodes-slng">
    Setup guide, version history, and ready-made workflow templates.
  </Card>
</CardGroup>