Vibe code a private journaling app with Venice AI

What you're building and what vibe coding means

This guide builds Sanctuary, a private local-first mood journaling app that saves entries on your computer and uses Venice AI for mood insights. No servers, no internet dependency for storage, and private models where personal data is involved.

Vibe coding is AI-assisted software development. The term, coined by an OpenAI co-founder, refers to the point where the code itself fades into the background and you describe what you want in plain language while the AI writes it. You do not need to be a coder to do this.

Setting up VS Code and the RooCode extension

Start with an integrated development environment (IDE), the software developers use to write code. This guide uses Visual Studio Code, a free, open-source editor from Microsoft. Download and install it, then click Open, create a new folder called Vibe Coding, and open it. That gives you a fresh workspace where everything happens.

Next, install the agent that does the coding. RooCode is a free, open-source extension that lets you plug in any model from any provider. Search for it in the VS Code marketplace, confirm it is verified by Roo, and click install. Once installed, toggle on the right sidebar to find where the RooCode agent lives.

Generating your Venice API key and connecting it

The agent needs intelligence, which comes from the Venice API. In the Venice interface, open the API page and generate a new key. Name it something like "roo code", create it, and copy the key.

Back in VS Code, open the RooCode settings icon and create a new configuration profile called Venice. Select the OpenAI compatible provider. Venice is not listed by name, but it is OpenAI compatible, so this works. Set the base URL and paste in your key, then choose your model.

Base URL: https://api.venice.ai/api/v1

For coding, set the model to GLM 4.6. It is a strong coding model, it is private and open source, and it is far cheaper than a premium model like Opus. Save the profile.

Your first vibe code and the smart model strategy

Test your setup with a simple request in code mode:

Create a HTML web page that says hello world I am learning vibe coding. Use a red and yellow color scheme.

The agent creates and saves the file in front of you. Open it in your browser to see the result.

RooCode has several modes: architect, code, ask, debug, and orchestrator. These are sub-agents the main agent calls for specific tasks, each with its own instructions. Architect is the planner, described as an experienced technical leader who gathers context and creates detailed plans. The key strategy: assign different models to different modes. Use a powerful, expensive model like Claude Opus 4.5 for architect mode to plan like a senior developer, and a cheaper model like GLM 4.6 for code mode to do the actual building. This keeps quality high where it matters and cost low everywhere else.

Writing the PRD and the coding plan

A product requirements document (PRD) acts as a single source of truth for your project. It is not strictly required, but it is best practice. As the agent gets busier and you start new conversations, the AI forgets details. A PRD keeps everything on track.

In architect mode (using your powerful Opus profile), prompt the agent to create a PRD for Sanctuary, a private local-first mood tracking application. The agent expands your idea into detailed sections, design decisions, and component mockups. Review and refine it, then ask for any additions, such as more detail on the Venice API integration section. Finalize it.

Then, still in architect mode, hold Shift and drag your PRD file into the chat:

We are ready to start building. Create a comprehensive coding plan for the PRD.

The agent reads the PRD and may ask about architecture. For a private local app, choosing basic HTML and vanilla JavaScript for your minimum viable product (MVP) is a sound starting point. You can upgrade later if needed. The result is a detailed file structure, styles, and build order.

Watching the build and approving actions

Tell the agent to start building phase one. RooCode switches to code mode, which automatically loads your cheaper GLM 4.6 profile, and works through tasks one at a time, checking them off as it goes.

As it works, RooCode asks permission before certain actions because it has full command-line access to your computer and could change things. You can grant auto-approval for actions like reading files, writing files, and using the browser so the agent does not interrupt you. It is wise to leave some actions, like answering questions, for yourself. The more you auto-approve, the more freely the agent runs while you step away, since a full build takes a while.

Debugging when the build breaks

Builds break. That is normal vibe coding. When the app does not load, your first move is not the AI, it is the browser console. Right-click the page, choose Inspect, and open the Console tab. Errors there are an excellent source of information for debugging.

Copy the errors, start a new task, switch to debug mode, and paste them in with a short description of the problem. Even in a fresh conversation without the plan, the agent reads your files and recognizes the app. In this guide, one error came from opening the HTML file directly rather than serving it properly, and the agent identified the fix. After fixing, the journal saved entries, showed history, and ran entirely in localhost with no servers or internet involved.

Adding private Venice AI insights and choosing models

To add mood insights, start a new chat, drag in your coding plan and app folder, and ask the agent to continue the build with Venice AI integration.

The model choice for processing journal data matters for privacy. This guide uses Llama 3.3 70B, an open-source, private, reasonably priced model. When an app processes personal information, you must use a private model. Anonymized data will not identify you, but if names or sensitive data are involved and you use a non-private model, that data goes to providers like OpenAI, Anthropic, or Google. A useful rule of thumb: code itself does not need to be private, but an app that processes personal content should use a private model.

In the app's settings, enable AI insights and paste your Venice API key. By default the app sends only anonymized mood statistics, never your notes. Because Venice keeps things private, you could choose to send the full entries for richer, more reflective responses, which you would add by prompting the change in architect mode.

When to upgrade to premium models

Open-source models are cheaper but sometimes do not handle complex agentic tasks as reliably as premium models. When debugging stalls, switching your code profile back to a stronger model often resolves it. In this guide, the Venice Coder profile was temporarily switched to Claude Opus to get the API integration working, after which the insights feature ran correctly.

Opus is powerful but expensive, so consider middle options based on your budget and the result you need. Gemini 3 Flash is a capable, cheaper Google coding model, and Gemini 3 Pro Preview is another option. The overall approach: build with the best model you can afford, lean on open-source private models when privacy matters, and reserve premium models for planning and tough debugging.

Key takeaways

• Vibe coding lets you build real software in plain language using VS Code, RooCode, and the Venice API, no coding background required.
• Match models to modes: a powerful model like Opus for architect-mode planning, a cheaper model like GLM 4.6 for code-mode building.
• A PRD and coding plan keep the agent on track as conversations reset and features grow.
• Use the browser console to debug, and always choose private models when your app processes personal data.