Description

n8n-nodes-opencode

This is an n8n community node that integrates OpenCode as a chat model for use with n8n's AI Agent and LangChain workflows.

n8n is a fair-code licensed workflow automation platform.

OpenCode is an open-source AI coding agent built for the terminal with support for multiple LLM providers.

Installation

Follow the installation guide in the n8n community nodes documentation.

Option 1: npm

npm install n8n-nodes-opencode

Option 2: Manual Installation

1. Clone this repository
2. Run npm install and npm run build
3. Copy the dist folder to ~/.n8n/custom/ (create if it doesn't exist)
4. Restart n8n

Prerequisites

• n8n version 1.0.0 or later
• OpenCode server running (see OpenCode documentation)

OpenCode Server Setup

Local Development

# Install OpenCode CLI
npm install -g @opencode-ai/cli

# Start the server
opencode serve

By default, OpenCode server runs on http://localhost:4096.

Credentials

This node requires OpenCode API credentials:

1. In n8n, go to Credentials → New
2. Search for "OpenCode API"
3. Configure:
   • Base URL: Your OpenCode server URL (default: http://localhost:4096)
   • API Key: (Optional) If your OpenCode instance requires authentication

Usage

1. Add the OpenCode Chat Model node to your workflow
2. Select or create OpenCode API credentials
3. Configure the model:
   • Agent: Choose the OpenCode agent type (build, chat, debug)
   • Model Provider: Select provider (Anthropic, OpenAI, Google, Groq, Ollama)
   • Model ID: Specify the model (e.g., claude-3-5-sonnet-20241022)
4. Connect to an AI Agent node or other LangChain-compatible nodes

Example Workflow

┌─────────────────┐     ┌──────────────────┐     ┌────────────────┐
│  Chat Trigger   │────→│   AI Agent       │────→│  Respond       │
└─────────────────┘     └──────────────────┘     └────────────────┘
                               │
                               ↓
                        ┌──────────────────┐
                        │ OpenCode Chat    │
                        │     Model        │
                        └──────────────────┘

Supported Models

The node supports models from these providers (via models.dev):

Anthropic

• claude-sonnet-4-5-20250929 (latest)
• claude-sonnet-4-20250514
• claude-3-7-sonnet-20250219
• claude-3-5-sonnet-20241022
• claude-3-5-sonnet-20240620
• claude-opus-4-1-20250805
• claude-opus-4-20250514
• claude-haiku-4-5-20251001
• claude-3-5-haiku-20241022

OpenAI

• gpt-5 (latest)
• gpt-5-mini
• gpt-5-nano
• o3
• o3-mini
• gpt-4.1
• gpt-4.1-mini
• gpt-4o
• gpt-4o-mini
• o1
• o1-mini
• gpt-4-turbo

Google

• gemini-2.5-pro (latest)
• gemini-2.5-flash
• gemini-2.5-flash-lite
• gemini-2.0-flash
• gemini-2.0-flash-lite
• gemini-1.5-pro
• gemini-1.5-flash
• gemini-1.5-flash-8b

Groq

• llama-3.3-70b-versatile
• llama3-70b-8192
• llama-3.1-8b-instant
• qwen-qwq-32b
• mistral-saba-24b
• gemma2-9b-it

Mistral

• mistral-large-latest
• mistral-medium-latest
• mistral-small-latest
• pixtral-large-latest
• codestral-latest
• ministral-8b-latest
• ministral-3b-latest

Meta (Llama)

• llama-4-maverick-17b
• llama-4-scout-17b
• llama-3.3-70b-instruct
• llama-3.2-1b-instruct
• llama-3.1-70b-instruct
• llama-3.1-8b-instruct

DeepSeek

• deepseek-chat
• deepseek-reasoner

Alibaba (Qwen)

• qwen3-max
• qwen3-32b
• qwen3-14b
• qwen3-8b
• qwen-max
• qwen-plus

Moonshot AI (Kimi)

• kimi-k2-0905-preview
• kimi-k2-0711-preview

Ollama (Self-hosted)

• Any model available in your Ollama instance
• Examples: qwen2.5-coder:32b, codellama:34b, llama3:70b

Configuration Options

Agent Types

• Build: Optimized for implementing features and writing code
• Chat: General-purpose conversational agent
• Debug: Specialized for debugging and troubleshooting

Model Parameters

• Temperature: Control randomness (0-2, default: 0.7)
• Maximum Tokens: Limit response length (-1 for unlimited)

Features

• ✅ Full LangChain integration
• ✅ Multiple model providers (Anthropic, OpenAI, Google, Groq, Ollama)
• ✅ Session management with automatic cleanup
• ✅ Tool calling support (via OpenCode's native capabilities)
• ✅ Comprehensive error handling and validation
• ✅ TypeScript support with full type definitions

Troubleshooting

Connection Issues

Problem: "Failed to create OpenCode session"
Solution: Verify OpenCode server is running and accessible at the configured base URL.

# Test connection
curl http://localhost:4096/app

Authentication Issues

Problem: "Unauthorized" errors
Solution: If your OpenCode server requires authentication, ensure the API key is correctly configured in credentials.

Model Not Available

Problem: Model ID not recognized
Solution: Ensure the specified model is configured in your OpenCode server and the corresponding provider API keys are set.

Development

Build

npm install
npm run build

Watch Mode

npm run dev

Lint

npm run lint
npm run lintfix

Architecture

This node implements a custom LangChain BaseChatModel that:

1. Session Management: Creates and manages OpenCode sessions via REST API
2. Message Handling: Converts LangChain messages to OpenCode prompt format
3. Streaming: Implements Server-Sent Events (SSE) for real-time responses
4. Event Parsing: Processes message.part.updated and session.updated events

Key Components

• OpenCodeChatModel.ts: Custom LangChain chat model implementation
• LmChatOpenCode.node.ts: n8n node wrapper
• OpenCodeApi.credentials.ts: Credentials definition

API Endpoints Used

• POST /session: Create new session
• POST /session/:id/prompt: Send prompt with message parts
• GET /event: Server-Sent Events stream for responses
• DELETE /session/:id: Clean up session

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Run tests and linting
5. Submit a pull request

License

MIT

Resources

• n8n community nodes documentation
• OpenCode Documentation
• OpenCode GitHub
• LangChain Documentation

Support

For issues and questions:

• GitHub Issues
• n8n Community Forum
• OpenCode Discord