# pty-agent

An ultra-minimal observable PTY-backed coding agent in Rust using Rig.

```sh
OPENAI_API_KEY=... cargo run -- "fix the failing tests"
```

The process immediately starts a persistent PTY shell and streams that PTY
directly to stdout. The terminal you watch is the same terminal the Rig agent
observes and controls. The agent has exactly one tool, `terminal`, and all work
happens by typing into that PTY.

## Model

```text
user request -> Rig agent -> terminal tool -> shared PTY view -> memory/history -> continue
```

The shell launch order is `$SHELL`, then `/bin/bash`, then `/bin/sh`.

## Terminal Tool

The only tool is `terminal`.

Actions:

- `type`
- `enter`
- `type_and_enter`
- `ctrl_c`
- `key`
- `observe`

Observe modes:

- `screen`
- `recent_output`
- `command_history`
- `command_output`
- `memory_summary`
- `full_state`

## Terminal Mirror

There is no TUI framework, side panel, or hidden execution path. PTY output is
copied byte-for-byte to stdout as it arrives. Sparse status lines are written to
stderr with a `[pty-agent]` prefix so you can see when the agent is thinking,
typing, waiting, or finished without replacing the terminal view.

## Editing Behavior

The agent is prompted to use `vim` for all file edits and file creation. It
navigates on the rendered PTY screen, makes explicit keystroke edits, saves, and
returns to the shell. Shell commands are used for inspection, builds, tests, and
git operations.

## Memory

The implementation keeps:

- a live VT-rendered screen model via `vt100`
- bounded raw and cleaned scrollback
- semantic command records with full output excerpts
- a rolling long-term text summary for older commands

This is intentionally small and hackable. It favors observability over
sandboxing: YOLO mode means no confirmations, no safety prompts, and no command
blocking.

## Docker

The Docker path uses `debian:bookworm-slim` and installs Rust plus native build
dependencies needed by the Rig/OpenAI stack. Debian publishes native ARM64 and
AMD64 images, so this works cleanly on Apple Silicon without emulation.

Run the agent inside a clean container-owned `/workspace` with no host project
mounted:

```sh
OPENAI_API_KEY=... /path/to/pty-agent/scripts/run-pty-agent-docker.sh "fix the failing tests"
```

By default the image runs:

```sh
cargo install pty-agent
```

The image includes `vim-tiny` so the agent has a real fullscreen editor
available inside the shared PTY.

Pin a crates.io version with:

```sh
PTY_AGENT_VERSION=0.1.0 ./scripts/run-pty-agent-docker.sh "fix the failing tests"
```

Before `pty-agent` is published to crates.io, test the same container using the
local checkout:

```sh
OPENAI_API_KEY=... ./scripts/run-pty-agent-docker.sh --local "fix the failing tests"
```

To launch the same container directly into a clean shell with `pty-agent`
installed from crates.io:

```sh
./scripts/shell-pty-agent-docker.sh
```

For a Rust-only shell without installing `pty-agent`:

```sh
./scripts/shell-pty-agent-docker.sh --no-install
```

Force a full rebuild after Dockerfile changes:

```sh
./scripts/shell-pty-agent-docker.sh --rebuild
./scripts/run-pty-agent-docker.sh --rebuild "fix the failing tests"
```

For local development only, mount this checkout at `/src/pty-agent`:

```sh
./scripts/shell-pty-agent-docker.sh --local
```
