Setting Up PI Agent with OpenRouter

pi_agent.md

This the clean setup of Pi on OpenRouter by default

0) Install Pi

npm install -g @mariozechner/pi-coding-agent

Check that it installed:

pi --version

Windows note

Pi needs a bash shell on Windows. For most people, installing Git for Windows is enough: https://git-scm.com/download/win

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1) Create Pi’s config folder

Mac / Linux

mkdir -p ~/.pi/agent

Windows PowerShell

New-Item -ItemType Directory -Force "$HOME/.pi/agent"

On Windows, that usually lives here:

C:\Users\YOUR_NAME\.pi\agent\

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2) Add your OpenRouter API key

Pi supports credentials in auth.json, and that takes priority over environment variables. That’s the cleanest move here.

Mac / Linux

nano ~/.pi/agent/auth.json

Windows PowerShell

notepad $HOME\.pi\agent\auth.json

Paste this in:

{
  "openrouter": {
    "type": "api_key",
    "key": "sk-or-your-key-here"
  }
}

Get your key here:

https://openrouter.ai/keys

A couple things matter:

• keep "type": "api_key"
• keep "key"
• do not rename it to apiKey

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3) Set OpenRouter as the default provider

Now tell Pi to boot into OpenRouter automatically.

Mac / Linux

nano ~/.pi/agent/settings.json

Windows PowerShell

notepad $HOME\.pi\agent\settings.json

Paste this in:

{
  "defaultProvider": "openrouter",
  "defaultModel": "anthropic/claude-sonnet-4"
}

That gives you:

• OpenRouter as the default provider
• Claude Sonnet 4 as the default model through OpenRouter

If you want a different model, swap this line:

"defaultModel": "anthropic/claude-sonnet-4"

for any OpenRouter-supported model in this format:

author/model-name

Browse models here:

https://openrouter.ai/models

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4) Run Pi

Mac / Linux

pi

Windows

Start with:

pi

If PowerShell complains, use:

pi.cmd

If everything worked, Pi should open using OpenRouter by default.

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5) Windows fallback if Pi can’t find bash

Pi needs bash on Windows. If Git for Windows is installed and Pi still doesn’t detect it, add shellPath to settings.json.

Use this:

{
  "defaultProvider": "openrouter",
  "defaultModel": "anthropic/claude-sonnet-4",
  "shellPath": "C:\\Program Files\\Git\\bin\\bash.exe"
}

Only do this if Pi isn’t picking up Git Bash automatically.

---

Useful shortcuts after setup

• switch models: Ctrl+L or /model
• cycle scoped models: Ctrl+P
• change thinking level: Shift+Tab
• continue last session: pi -c
• browse older sessions: pi -r

Thanks 💚

thank you!