Description

n8n-nodes-generic-rest-chat-model-ai

A community sub-node that plugs any REST-based LLM into the n8n AI Agent as a Chat Model — without writing code or creating a custom node for each API.

Supports IBM watsonx Orchestrator, Ollama, Groq, and any OpenAI-compatible REST endpoint.

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How it works

The node acts as a Chat Model sub-node (the same slot used by the built-in OpenAI or Anthropic nodes). It sends the conversation history to a REST endpoint using a configurable JSON body template and extracts the reply using a JSONPath expression.

AI Agent ──► Generic REST Chat Model ──► Your REST API
               ↑
        Simple Memory (optional)

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Installation

In your n8n instance, go to Settings → Community Nodes → Install and enter:

@welsonviana/n8n-nodes-generic-rest-chat-model-ai

Or in a self-hosted Docker instance:

docker exec -it n8n npm install @welsonviana/n8n-nodes-generic-rest-chat-model-ai

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Credentials

Create a Generic REST Chat Model API credential and choose one of the auth types:

| Auth Type | When to use |
|—|—|
| IBM IAM | IBM watsonx Orchestrator — exchanges your IBM API Key for a Bearer token automatically (cached with TTL) |
| Bearer Token | Groq, OpenRouter, or any API that uses Authorization: Bearer |
| API Key Header | APIs that use a custom header (e.g. X-Api-Key) |
| None | Ollama or any unauthenticated local endpoint |

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Node parameters

| Parameter | Description |
|—|—|
| Endpoint URL | Full POST URL of the LLM endpoint |
| Model / Agent ID | Injected as {{model}} in the body template |
| Stateful Mode | Send only the last message + session ID (server manages history). When enabled, set Simple Memory’s Context Window Length to 1 |
| Session ID | Injected as {{sessionId}} — visible only when Stateful Mode is on |
| Inject History Into Message | Concatenates the full conversation history into the last user message as plain text. Use when the API ignores the messages array (e.g. watsonx Orchestrator) |
| Request Body Template | JSON template with placeholders (see below) |
| Response Path | JSONPath to the text field in the API response (e.g. $.choices[0].message.content) |
| Debug Mode | Attaches the raw request and response to the execution output (AI panel). Sensitive headers are masked. Disable in production |
| Max Retries | Automatic retries on transient network errors with exponential backoff (1 s, 2 s, 4 s). HTTP errors are never retried. Default: 2 |
| Additional Headers | Extra HTTP headers as a JSON object |

Body template placeholders

| Placeholder | Replaced with |
|—|—|
| {{messages}} | Full messages array [{ role, content }, ...] |
| {{lastMessage}} | Last user message as a string |
| {{sessionId}} | Session ID (stateful mode) |
| {{model}} | Model / Agent ID |

A placeholder that is the sole value of a JSON string (e.g. "messages": "{{messages}}") is replaced with the raw value, injecting the array directly into the body.

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Examples

Ollama (local, no auth)

Credential: None

Endpoint URL:

http://host.docker.internal:11434/api/chat

Body Template:

{
  "model": "{{model}}",
  "stream": false,
  "messages": "{{messages}}"
}

Model / Agent ID: llama3

Response Path: $.message.content

—

Groq (Bearer Token)

Credential: Bearer Token → your Groq API key

Endpoint URL:

https://api.groq.com/openai/v1/chat/completions

Body Template:

{
  "model": "{{model}}",
  "stream": false,
  "messages": "{{messages}}"
}

Model / Agent ID: llama-3.3-70b-versatile

Response Path: $.choices[0].message.content

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IBM watsonx Orchestrator (IBM IAM + Inject History)

Credential: IBM IAM → your IBM API Key

Endpoint URL:

https://api.br-sao.watson-orchestrate.cloud.ibm.com/instances/{instanceId}/v1/orchestrate/{agentId}/chat/completions

Body Template:

{
  "model": "{{model}}",
  "stream": false,
  "messages": "{{messages}}",
  "additional_properties": {}
}

Model / Agent ID: your Agent ID (same as the one in the URL)

Inject History Into Message: enabled

Response Path: $.choices[0].message.content

> watsonx Orchestrator ignores the messages array for context. Enabling Inject History Into Message concatenates the full conversation history into the last user message so the agent receives it.

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License

MIT