Use Claude in the terminal

You can talk to Claude from any terminal with your own Anthropic API key. No browser tab, no monthly plan: you pay Anthropic only for what you use, and you see the cost of every answer.

This guide uses kunji, a free open-source terminal app that works with Claude and every other major AI provider.

1. Install kunji

pip install kunji

On Windows, use python -m pip install kunji, or download the .exe (no Python needed). See Install kunji for every option.

2. Get an Anthropic API key

1. Open console.anthropic.com/settings/keys and sign in.
2. Add a little credit under Billing. The API is billed separately from a Claude.ai subscription.
3. Create a key and copy it.

3. Add the key to kunji

kunji keys add anthropic

Paste the key when asked. kunji checks it, then saves it in your operating system’s keychain (Windows Credential Manager, macOS Keychain or Secret Service on Linux), never in a plain text file. Pick a default Claude model from the list it shows.

4. Chat with Claude

kunji chat

› explain recursion in one line
  A function that solves a problem by calling itself on a smaller piece of it,
  until it reaches a case simple enough to answer directly.
  claude-sonnet-4-5 · 19 in · 33 out · $0.0006 · 0.7s

The grey line under each answer shows the model, tokens and what that answer cost. Type / to see chat commands, and press Ctrl+D to leave.

Prefer menus? Run kunji on its own for an arrow-key menu.

One-off questions and pipes

kunji ask "what does chmod 755 mean?"
npm test 2>&1 | kunji ask "why is this failing?"
kunji ask -f app.py "find the bug in this file"

Use -m to pick a model for one command, for example -m anthropic:claude-sonnet-4-5.

Switch between Claude and other models

Inside a chat, /model switches model and keeps the conversation:

› /model openai:gpt-4o-mini
✓ Switched to openai:gpt-4o-mini  conversation kept

Useful for a second opinion, or to move cheap follow-up questions to a cheaper model. See Switch and pick models.

Keep spending under control

kunji budget set anthropic 2     # daily limit, in your display currency

kunji warns at 80% and stops at 100%. See Costs and budgets.

Is my data private?

kunji talks to Anthropic directly from your computer. There is no kunji server in between, so your key, prompts and answers never pass through anyone else. Details: Privacy and security.