# AGENTS.md

## Project overview

This repository builds and publishes a Docker image for [OpenCode](https://opencode.ai), the open source AI coding agent. The image runs OpenCode in headless server mode (`opencode serve`) and is automatically rebuilt and pushed to Docker Hub (`jcabillot/opencode`) every night by a Gitea Actions pipeline.

## Repository structure

```
.
├── Dockerfile                            # Image definition
├── .gitea/workflows/docker-build.yaml    # CI/CD pipeline (Gitea Actions)
├── renovate.json                         # Dependency update automation (Renovatebot)
├── opencode-attach                       # Helper script for attaching to a running server
└── README.md                             # Usage documentation
```

## Dependency management

- **Always pin versions** in the Dockerfile `npm install` command (e.g. `opencode-ai@1.16.2 n2-soul@9.0.9`). Never leave packages unpinned.
- **Update renovate customManagers** when adding, removing, or renaming a dependency tracked in the Dockerfile. Each pinned package must have a corresponding `customManager` entry in `renovate.json` with a regex `matchStrings` pattern that captures the version. If a dependency is added without a renovate entry, Renovatebot will not open automated PRs for it.
- **apt packages** (apt-get install lines in Dockerfile) and **COPY --from** image references are not currently tracked by Renovate. Pinning these manually is acceptable for now but adding renovate managers for them is encouraged.

## Dockerfile conventions

- **Base image**: `node:24` — Debian-based Node.js image (not Alpine, needed for apt packages).
- **Install**: `npm i -g opencode-ai@<version> n2-soul@<version>` — installs OpenCode and Soul globally, both pinned.
- **Version check**: `RUN opencode --version` after install to validate the build and record the installed version in build logs.
- **Dedicated user**: a non-root `opencode` user and group are created with `groupadd`/`useradd` (UID/GID 1000). All runtime steps run as this user.
- **Cluster tooling**: `kubectl` is copied from the official `registry.k8s.io/kubectl` image (multi-stage COPY).
- **Entrypoint**: `["opencode"]` — arguments are passed at runtime (e.g. `serve`).

## CI/CD conventions (Gitea Actions)

- Pipeline triggers on push to `main`, PRs targeting `main`, and a nightly cron (`cron: '0 0 * * *'`).
- Image is pushed to Docker Hub only on non-PR events (main branch pushes and cron runs).
- Docker Hub credentials are stored in Gitea Actions secrets (`DOCKERHUB_USERNAME`, `DOCKERHUB_TOKEN`).
- The image is published as `jcabillot/opencode:latest` with digest and branch tags.

## Useful commands

```bash
# Build the image locally
docker build -t opencode .

# Run the server on all interfaces
docker run -it -p 4096:4096 opencode --hostname 0.0.0.0

# Run with a project mounted
docker run -it -p 4096:4096 \
  -v $(pwd):/home/opencode/project \
  opencode --hostname 0.0.0.0

# Protect with a password
docker run -it -p 4096:4096 \
  -e OPENCODE_SERVER_PASSWORD=secret \
  opencode --hostname 0.0.0.0
```

## opencode serve options

| Flag | Default | Description |
|------|---------|-------------|
| `--port` | `4096` | Port to listen on |
| `--hostname` | `127.0.0.1` | Hostname to bind |
| `--mdns` | `false` | Enable mDNS discovery |
| `--cors` | `[]` | Additional allowed browser origins |

## Environment variables

| Variable | Description |
|----------|-------------|
| `OPENCODE_SERVER_PASSWORD` | Enables HTTP basic auth |
| `OPENCODE_SERVER_USERNAME` | Overrides the default username (`opencode`) |