Creating Custom Tools for Vox
Vox ships with 47+ built-in tools. But your workflow is unique — maybe you need to query an internal API, trigger a Zapier webhook, or run a custom script every time the agent processes a report. Custom tools let you extend Vox with exactly the capabilities you need.
Three types of custom tools
Write code that runs in a sandbox
Write a JavaScript function body. Vox executes it in an isolated Docker container — no access to your machine. Perfect for data transformations, API calls with secrets, and calculations.
Call any endpoint
Point Vox at a URL. When the tool is called, Vox sends a POST with the arguments as JSON. Works with Zapier, Make, n8n, or any custom API.
Run on your machine
Trigger any action on your desktop. Used for opening apps, running scripts with local file access, or anything that needs to run outside the sandbox.
Adding a tool
Click the wrench icon in the left sidebar → My Tools → Add Tool. A drawer opens where you fill in:
Secrets
If your tool needs an API key, add it in the Secrets section. Secrets are encrypted at rest (AES-256-GCM) and injected as environment variables when the tool runs — they're never returned to the client or visible in logs.
For a JS function that calls the Notion API, add NOTION_API_KEY as a secret. Inside your function, read it as process.env.NOTION_API_KEY.
How the agent finds your tool
When you create a tool, Vox generates a vector embedding from its name and description. When the agent needs a capability, it searches that library using semantic similarity — so if you describe a tool as "fetch a page from my Notion workspace," the agent will find it when you ask "add this to my Notion reading list."
You never need to tell the agent which tool to use. Just describe what you want.
The agent can also create tools autonomously. If it writes a useful script while completing a task, it can save it as a reusable tool — so the next time you ask for the same thing, it's instant.
Put Vox to work on your computer.
Download Vox for Mac and start with the local setup flow.
macOS · Apple Silicon & Intel