> ## 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

> The n8n-nodes-slng community node runs SLNG text to speech, speech to text, and voice-agent calls inside n8n workflows, plus a trigger a voice agent can call mid-call.

`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 platform.

This page is the node reference. For a step-by-step setup walkthrough, see the
[n8n integration guide](/guides/integrate/n8n). To wire a workflow up as an agent
tool, see [Use n8n for tools](/guides/agents/tools-and-mcp/n8n-for-tools).

## Install

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

```text theme={null}
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), or see
[Create your API key](/guides/get-started/quickstart#create-your-api-key), then
add an **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`), so every SLNG node in a workflow can share it.

## The SLNG node

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

| 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 an 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 catalog; the voice list is filtered to the chosen text to
speech model. Switch either to **By ID** to enter a model path or voice ID
directly.

## The SLNG Trigger node

When you activate the workflow, the **SLNG Trigger** node creates an organization
tool, tests and publishes it, and attaches it to the agents you select. Those
agents must be in shared tool mode. Deactivating the workflow removes the tool
and its attachments. When an agent calls the tool during a call, the workflow
runs.

* **Tool type**: an **LLM tool (contextual)** lets the agent decide when to call
  it, and you define the parameters it sends with a field builder (name, type,
  description, required). A **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="n8n guide" icon="book-open" href="/guides/integrate/n8n">
    A step-by-step setup walkthrough for both nodes.
  </Card>

  <Card title="Use n8n for tools" icon="wrench" href="/guides/agents/tools-and-mcp/n8n-for-tools">
    Give an agent workflow-backed tools with the trigger node.
  </Card>

  <Card title="Outbound calls" icon="phone-outgoing" href="/guides/agents/telephony/outbound">
    Set up the outbound telephony that Dispatch Call uses.
  </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>


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