Set up your agent

Niv · Docs Published on October 8, 2026

Niv doesn't bring its own AI model to the chat. It runs the command-line agent you install, signed in with your own account. What you type, and the notes it reads, go from your device to that agent's provider, under its terms.

Install an agent

Install one in Terminal, then sign in with it once. These are the commands Niv shows for each:

Claude Code: npm install -g @anthropic-ai/claude-code, then run claude to sign in.
Codex: npm install -g @openai/codex, then codex login.
Cursor: curl https://cursor.com/install -fsS | bash, then cursor-agent login.
OpenCode: npm install -g opencode-ai, then opencode auth login.
Grok: install the Grok CLI from x.ai/cli, then grok login.

Niv finds agents the same way your shell does, so an agent you update in Terminal is the one Niv uses next time it checks.

Antigravity

Antigravity is different: Niv downloads Google's official runtime for you, only when you ask. In Settings › AI, choose Download the runtime, then Sign in with Google. The sign-in happens in your browser. After you approve, the browser lands on a page that looks broken. That's expected: copy the full address from the address bar, paste it into Niv, and choose Finish sign-in.

Check what Niv found

Settings › AI › CLI tools shows each agent, its version and where Niv found it.

Check again looks again, after you install or update one.
Use a specific binary… points Niv at one you choose.
Let Niv pick the newest goes back to the default: when several are installed, Niv uses the newest.

In the chat's Model list, each agent shows whether it's ready, needs a sign-in, or wasn't found.

Instruction files

AGENTS.md and CLAUDE.md at the top of your folder tell the agent how to work here: its tone, which files it may edit, and how to link notes. They are plain notes; open and edit them like any other.

In Settings › AI › Instruction files, Niv shows whether each file is in place. If one is missing, Niv can create it with its defaults. Restore defaults… replaces your file with the defaults, after copying your current one to the folder's trash.

These two files stay on this device. See Local-only files.

Your agent's own tools

If you set up MCP servers for Claude Code or Codex, Niv's chat uses them too. Settings › AI lists them under Claude MCP servers and Codex MCP servers, with whether each is connected. Whether a tool call asks you first depends on the access level. See Access levels.

Niv's own AI

Niv's own AI is on the way. Today, the chat runs the agent you install.