yaca — Yet Another Coding Agent

中文

yaca is a general-purpose AI agent for the terminal that runs on old machines. Windows XP, Server 2008, CentOS 7: places where today's agents won't even start.

Put it on a USB stick, plug it into the machine that's misbehaving, and ask. There's nothing to install. It can write code over a long session too, but it's built for the everyday job of walking up to a system and fixing something.

Note

yaca isn't released yet. The core works; target qualification pending on the three platforms below.

Why yaca

It runs where others don't. Most current coding agents need Node.js, Python or a recent OS, and many won't run on anything older than Windows 10 1809. yaca goes back to Windows XP SP3. It brings its own HTTPS client and certificate list, so an old system's outdated TLS doesn't stop it from reaching the model.

It's portable. yaca is a single executable. Settings and history live in a __yaca__ folder right next to it, wherever you start it from, so the whole thing moves with the USB stick.

It's simple. One conversation, one agent, one tool at a time. It asks before it writes, deletes or runs anything, and shows you what it's about to do.

Platform	Oldest system
Windows 32-bit (x86)	Windows XP SP3
Windows 64-bit (x86_64)	Windows 7 SP1
Linux x86_64	CentOS 7 (glibc 2.17)

Editions

Each platform comes in three sizes. The yaca inside is identical; only the extra tools differ.

Edition	Contents	Good for
clean	yaca only	Machines that already have the tools you need
std	+ Python 2.7, SSH/SCP/SFTP, curl, 7-Zip	Most troubleshooting (recommended)
full	+ Git, Python 3, compilers, SQLite, jq and more	Fixing and building code on a bare machine

The extra tools sit in a tools/ folder next to yaca. yaca tells the agent they're there; it doesn't need them to start. Lua 5.5 is built into yaca itself, in every edition.

Getting started

Unzip anywhere you can write to, then run it:

C:\yaca\yaca.exe

The first run walks you through connecting a model. yaca speaks the OpenAI Chat Completions and Anthropic Messages APIs, so most providers and local servers work. You'll need:

• the full endpoint URL (including the API path, not just the host name)
• the model name, for a model that supports tool calling
• an API key, if your provider uses one

Then open a folder and talk to it:

C:\yaca\yaca.exe C:\work\broken-service

Try "why won't this service start?" or "free up space on drive D". Step-by-step guides: Windows · Linux.

What the agent can do

It has nine tools: list, read, search, write, patch, rename, delete, exec (run a command) and lua (run Lua code).

What it may do without asking depends on the permission profile:

Profile	Read	Write / delete	Run commands	Outside the folder
Std (default)	yes	asks	asks	asks
Readonly	yes	no	no	no

Important

A command or Lua script runs with your own user rights, like any program you start yourself. yaca asks before running one but doesn't sandbox it. Read the command before you approve it.

In the chat

Type normally to give a task. Commands start with a dot:

Command
.help	All commands
.ask	Ask a quick question without tools and without changing the task
.multiline	Enter several lines at once
.cancel	Stop the current turn
.status	Current conversation, model and settings
.model	Switch model
.context	Switch to another saved conversation
.compact	Summarize the history to save space
.quit	Exit

Every conversation is saved automatically. .status shows its short hash; yaca --continue <hash> picks it up again later.

Command-line options

Command
yaca [folder]	Start a chat in a folder (default: current folder)
yaca --continue <name or hash>	Continue a saved conversation
yaca --context-repl recent	Browse, rename, delete or export conversations
yaca --model-repl	Add, edit or test models
yaca --config-repl	Edit other settings, or repair a broken config
yaca --export <hash>	Print a conversation as Markdown
yaca --self-test	Check that this machine and your model work
yaca --status	Show configuration status without opening a chat
yaca --lua ...	Run the built-in Lua 5.5 interpreter
yaca --help [topic]	Help

On Windows, /h, /c and the other short forms also work.

Settings and data

Everything lives in __yaca__ next to the executable:

• config.ini holds models, permissions and network settings. Edit it with --model-repl and --config-repl, or by hand. A proxy goes under [Network] as ProxyUrl.
• CONTEXT/ holds saved conversations, one file each.

To upgrade, quit yaca, back up __yaca__, and replace the executable. There's no auto-update.

Not included

No web UI, image or audio input, MCP, plugins, sub-agents, telemetry or automatic updates. yaca is a terminal program and stays small.

Development

Development notes (in Chinese) are in .develope-docs/, starting with the current state. Run the tests from the repository root:

bash .tools/run_with_resource_guard.sh bin/lua55 test/run.lua

License

GPL v3.