Cassady (cass) is a minimal Rust terminal coding agent with a looped chat UI, filesystem tools, access modes, JSONL conversation persistence, and OpenAI-compatible LLM support. The default endpoint is Fireworks.

Install

cargo install --path .

This installs both commands:

cass
cassady

Configure

By default Cass creates ~/.cass/providers.json and ~/.cass/models.json with Fireworks configured:

base URL: https://api.fireworks.ai/inference/v1
model: accounts/fireworks/models/qwen3p7-plus
API key: "$FIREWORKS_API_KEY"

Set your key:

export FIREWORKS_API_KEY=...

User preferences live at ~/.cass/config.json:

{
  "default_model": "accounts/fireworks/models/qwen3p7-plus",
  "default_access_mode": "read-only",
  "show_reasoning": false
}

Provider connection details belong in ~/.cass/providers.json. Model metadata belongs in ~/.cass/models.json. API keys may be literal strings or environment-variable references like "$FIREWORKS_API_KEY".

Validate config with:

cass check

Extra global instructions can be placed in ~/.cass/global.md.

Bundled documentation from this build is embedded into the binary and installed to ~/.cass/docs on startup. See ~/.cass/docs/configuration.md for full configuration docs.

Usage

cass [--model MODEL] [--base-url URL] [--api-key-env ENV] [--cwd PATH]
cass --resume <chat-id>
cass --resume
cass check

cass --resume without an ID lists chats for the current directory.

Keys

Type /: show command autocomplete, including command arguments like /model <model> and /new
Up/Down: move through an autocomplete menu
Tab/Enter: fill autocomplete selection
Enter: send message / run command when no autocomplete menu is open
Ctrl-J: insert newline
Shift-Tab: toggle read-only/full-access mode while idle
Ctrl-O: toggle compact/full tool output display
Ctrl-Shift-R: toggle reasoning display
Up/Down or mouse wheel: scroll transcript when no autocomplete menu is open
PageUp/PageDown: transcript scroll
Ctrl-C twice within 1.5 seconds: exit

Commands

cass check: validate Cass config files
/model <model>: switch the model for future turns; model autocomplete lists entries from ~/.cass/models.json
/new: create a new chat for the current directory
/resume <chat>: resume a saved chat; chat autocomplete lists chats for the current directory
/status: show current chat status

On exit Cass prints:

Resume this chat with: cass --resume <id>

Tools

Tool calls are shown compactly by default; press Ctrl-O to expand full tool output.

Reasoning is hidden by default unless show_reasoning is enabled; press Ctrl-Shift-R to toggle it. When providers stream reasoning fields, Cass persists that reasoning and sends it back in future model context using the provider's reasoning field, such as reasoning_content or reasoning.

Read-only mode allows ls, read, and grep within the launch cwd/--cwd and the bundled docs directory at ~/.cass/docs.

Full-access mode additionally allows write and edit. Mutating tools use atomic writes where practical: Cass writes to a temporary file first, then renames it into place after validation/write success. write and edit are always blocked under ~/.cass/docs.

There is no shell/bash tool in v1.