Installation

Create a project

npm install -g @thenajs/cli
thena create my-agent
cd my-agent
npm install

thena create generates a project that is ready to edit:

src/
  agents/
    assistant/
      assistant.agent.ts    # the logic
      assistant.agent.md    # the prompt
  providers/
    ollama.provider.ts      # which model to use
  workflows/
    assistant.workflow.ts   # the order of the steps
  config.ts                 # log and report
  main.ts                   # entry point

Point it at a model

The project ships configured for a local Ollama. If you do not have the model yet:

ollama pull qwen2.5-coder:7b

Adjust src/providers/ollama.provider.ts if you use a different host or model:

import { OllamaProvider } from "@thenajs/core";

export class LocalOllamaProvider extends OllamaProvider {
  constructor() {
    super({
      host: "http://localhost:11434",
      model: "qwen2.5-coder:7b",
      sampling: { temperature: 0 }, // see the note below
    });
  }
}

Start at temperature: 0

An agent is not a chat: you want the same input to produce the same decision. We measured this on qwen2.5-coder:1.5b — the same question three times gave three different answers with no sampling, and three identical ones with temperature: 0 and a seed. Raise the temperature later, where you actually want variety.

For OpenAI instead of Ollama:

import { OpenAIProvider } from "@thenajs/core";

export class GptProvider extends OpenAIProvider {
  constructor() {
    super({
      apiKey: process.env.OPENAI_API_KEY!,
      model: "gpt-4o-mini",
      sampling: { temperature: 0 },
    });
  }
}

Run it

npm start

You should see the agent answer in the terminal. If something fails here, Troubleshooting covers the first-run errors.

Add it to an existing project

If you would rather install into a project you already have, instead of using the CLI:

npm install @thenajs/core zod

The other packages are optional: @thenajs/tools for ready-made tools such as ParallelTool, @thenajs/qdrant-client for vector memory, @thenajs/flow to watch a run live, and @thenajs/cli for scaffolding.

Then enable decorators in tsconfig.json:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "experimentalDecorators": true,
    "strict": true
  }
}

experimentalDecorators, not the Stage 3 decorators

ThenaJS uses TypeScript's legacy decorators, because it relies on parameter decorators (@input(), @context(), @state(), @memory()) — and the Stage 3 proposal does not have those. Leaving experimentalDecorators off is the most common cause of a project that will not compile.

Next: create your first agent.