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n8n-nodes-slng is a community node for n8n. 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. To wire a workflow up as an agent tool, see Use n8n for tools.

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Install

In your n8n instance, go to Settings → Community Nodes, click Install, and enter the package name:
Restart n8n after installing or upgrading.
This is a community node, so it needs a self-hosted n8n instance. n8n Cloud does not support unverified community nodes.

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Credentials

Create an SLNG key in the dashboard, or see Create your API key, 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), so every SLNG node in a workflow can share it.

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The SLNG node

The SLNG node runs one operation per item: 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.

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The SLNG Trigger node

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: 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.
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}}.

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Next steps

n8n guide

A step-by-step setup walkthrough for both nodes.

Use n8n for tools

Give an agent workflow-backed tools with the trigger node.

Outbound calls

Set up the outbound telephony that Dispatch Call uses.

GitHub repo

Setup guide, version history, and ready-made workflow templates.