How can I add custom AI chat integrations for any models include deepseek?

[Vadim-Zenin]

I'm using Theai IDE version 1.61.0 (compiled from source).

How can I add custom AI chat integrations for:

• DeepSeek
• [Model2]
• [Model3]

I have the following configuration values for each:

• API endpoint URL
• API key
• Model identifier

Specific queries:

Extensions: Do I need to install any extensions (pre-compilation or post-compilation) to enable custom AI integrations?
Configuration: Is modifying settings.json sufficient, or are other files involved?
Template: What exact syntax/structure should be added to settings.json for these custom AI providers?

[planger]

Hi there,

Great to hear you’re exploring custom AI integrations with Theia IDE 1.61.0!

To connect AI models like DeepSeek (or others), Theia AI is quite flexible and supports multiple ways of integrating them.

Extensions

Yes, you’ll need the appropriate extension for each LLM provider. For example:

• Use @theia/ai-openai for OpenAI-compatible APIs (many providers like DeepSeek follow that API schema).
• If your models aren't OpenAI-compatible, you can use our other existing LLM providers, like Anthropic or Ollama, or create your own provider by extending the LLM provider interface.

These can be added pre-compilation or as part of a custom Theia build.

More general info is also available in the docs:
👉 LLM Providers Overview

Configuration

You can configure the models via settings.json, which is the easiest approach. But if you're building a more tailored experience (e.g. for tools you plan to ship), you can also register providers (custom LLM providers or configurations) programmatically pre-build.

For DeepSeek specifically, we wrote a blog post with full instructions:
👉 DeepSeek Integration in Theia

[Vadim-Zenin]

Hi Philip,

Thanks for the answer.

I confirm that this settings work 2025-05-22:

"ai-features.openAiCustom.customOpenAiModels": [
    {
        "model": "deepseek-reasoner",
        "url": "https://api.deepseek.com",
        "id": "deepseek-reasoner", // Optional: if not provided, the model name will be used as the ID
        "apiKey": "your-api-key", // Optional: use 'true' to apply the global OpenAI API key
        "developerMessageSettings": "system" //Optional: Controls the handling of system messages: user, system, and developer will be used as a role, mergeWithFollowingUserMessage will prefix the following user message with the system message or convert the system message to user message if the next message is not a user message. skip will just remove the system message. Defaulting to developer.
    },
    {
        "model": "deepseek-chat",
        "url": "https://api.deepseek.com",
        "id": "deepseek-chat", // Optional: if not provided, the model name will be used as the ID
        "apiKey": "your-api-key", // Optional: use 'true' to apply the global OpenAI API key
        "developerMessageSettings": "system" //Optional: Controls the handling of system messages: user, system, and developer will be used as a role, mergeWithFollowingUserMessage will prefix the following user message with the system message or convert the system message to user message if the next message is not a user message. skip will just remove the system message. Defaulting to developer.
    }
],