You write messages in a chat.md file, save it, and Chudbot appends the assistant reply right into the same file.

What you need

• A computer (Windows or Mac)
• Node.js (free)
• An OpenRouter account + API key

Step 1: Install Node.js

Windows

1. Go to nodejs.org
2. Download the LTS installer
3. Run it (Next, Next, Finish)
4. Open PowerShell (Start menu → type “PowerShell”)

Mac

1. Go to nodejs.org
2. Download the LTS installer
3. Run it
4. Open Terminal

To confirm Node is installed, run:

node -v
npm -v

Step 2: Install Chudbot

Install it globally:

npm install -g chudbot

Confirm it works:

chudbot --help
# alias also works
chud --help

Optional: check for updates

chud update

If an update is available, Chudbot prints the exact install command. To install automatically, use -y/--yes or set CHUDBOT_AUTO_UPDATE=1.

Step 3: Create an OpenRouter account and API key

1. Create an account:

https://openrouter.ai

1. Create an API key:

https://openrouter.ai/settings/keys

You’ll paste that key into Chudbot’s .env in a minute.

Step 4: Create a folder and open a terminal in it

Create a new folder anywhere you want, for example:

• Desktop/chudbot-test

Now open a terminal and make sure you’re “in” that folder.

If you already have a terminal open, you can always use cd to switch into the folder.

Windows

Option A (easiest): open PowerShell directly in the folder

1. Open File Explorer and open your chudbot-test folder
2. Click the address bar (where the folder path is)
3. Type powershell and press Enter

Option B: open PowerShell first, then cd

cd $HOME
cd Desktop
cd chudbot-test

Mac

Option A: open Terminal, then cd

1. Open Terminal
2. Type cd (with a space)
3. Drag the folder into the Terminal window
4. Press Enter

Option B (if enabled): open Terminal at the folder

• In Finder, right-click the folder → Services → New Terminal at Folder

Step 5: Initialize the folder

This creates a starter chat.md in your folder.

It also creates ~/.chudbot/.env if it doesn’t exist yet.

chudbot init

Step 6: Paste your API key into Chudbot’s .env

Chudbot reads its API key from your user folder:

• Mac: ~/.chudbot/.env
• Windows: %USERPROFILE%\\.chudbot\\.env

Open that file and set:

OPENROUTER_API_KEY=YOUR_KEY_HERE
OPENROUTER_MODEL=openrouter/free
OPENROUTER_DEFAULT_MODEL=openrouter/free

OPENROUTER_MODEL is the primary env var for model selection. If set, it takes precedence.

OPENROUTER_DEFAULT_MODEL is also supported as a fallback when OPENROUTER_MODEL is not set.

openrouter/free routes to a currently-free option on OpenRouter. If it ever errors later, pick a different model.

Step 7: Use it

Open chat.md, type under the last # %% user block, save the file, then run:

chudbot run

It only runs if the chat ends with a non-empty # %% user message.

On success it appends # %% assistant with the reply, then appends a fresh # %% user header so you can type the next message.

Optional file context injection

You can inject one or more local files into model context without copy/paste:

chudbot run -f src/a.js -f notes/todo.md
chudbot run -files src/a.js,notes/todo.md
chudbot run -f src/a.js -files notes/todo.md,README.md

Paths are resolved relative to your current working directory. Files are prepended in deterministic order: repeated -f/--file entries first (in the order provided), then -files entries left-to-right.

You can also set files in chat.md front matter:

---
files:
  - src/a.js
  - notes/todo.md
---

These entries are appended after CLI -f/--file and -files values.

Optional trim limits from CLI

You can cap how much chat history is sent to the model:

chudbot run --max-messages 24
chudbot run --max-tokens 4000
chudbot run --max-messages 24 --max-tokens 4000

You can also pass the same limits in watch mode:

chudbot watch --max-messages 24 --max-tokens 4000

And you can set global defaults once per invocation:

chudbot --max-messages 24 --max-tokens 4000 run
chudbot --max-messages 24 --max-tokens 4000 watch

Watch mode (auto-reply on save)

chudbot watch

Stop with Ctrl+C.

How the chat format works

A chat file is just blocks. Each block starts with a header line:

• # %% system
• # %% user
• # %% assistant

Everything under that header (until the next header) is the message content.

Important rule: only type into the LAST # %% user block.

Optional: create memory.md

If you create a memory.md, it gets injected as extra system instructions.

Example memory.md:

- My name is Craig
- Keep answers short and practical
- I like humor

Advanced: front matter

At the very top of chat.md, you can add front matter to set the model and memory file for that chat:

---
model: openrouter/free
memory: memory.md
---

If you want the local memory file to override root memory instead of merging, add:

---
memory.override: true
---

You can also trim long chats before model calls:

---
max_messages: 24
max_tokens: 4000
---

Trimming is deterministic: system messages are kept, the first user message is kept as seed continuity, and then the newest remaining messages are kept within the message/token limits.

Where files are loaded from

Chat:

• Uses chat.md in your current folder by default (or --chat)

Env:

• Mac: ~/.chudbot/.env
• Windows: %USERPROFILE%\\.chudbot\\.env

Memory:

• Root memory: ~/.chudbot/memory.md (Windows: %USERPROFILE%\\.chudbot\\memory.md)
• Local memory: memory.md next to your chat.md
• Default behavior is merge (root + blank line + local)
• If memory.override: true is set in chat front matter, local memory overrides root

Troubleshooting

• “Missing OPENROUTER_API_KEY”
  • Put your key into ~/.chudbot/.env (Windows: %USERPROFILE%\\.chudbot\\.env)
• “It didn’t reply”
  • Make sure the chat ends with a # %% user block that has real text
• “401 / unauthorized”
  • Your API key is missing or wrong
• “Model not found”
  • Try a different OPENROUTER_MODEL
  • Or set OPENROUTER_DEFAULT_MODEL if you want a fallback env key
  • Or set model: in chat front matter
• “It replied twice / weird loop”
  • Only edit the last # %% user block, and let the bot append assistant blocks