feat: import

README.md

@@ -1,2 +1,95 @@
-# opencode
+# opencode Docker
 
+Docker image for running [OpenCode](https://opencode.ai) as a headless HTTP server.
+
+## What is OpenCode?
+
+OpenCode is an open source AI coding agent available as a terminal interface, desktop app, or IDE extension. This image runs it in server mode (`opencode serve`), exposing an HTTP API that clients can connect to.
+
+## Pull
+
+```bash
+docker pull jcabillot/opencode
+```
+
+The image is rebuilt and pushed to Docker Hub automatically every night via the Jenkins pipeline.
+
+## Build locally
+
+```bash
+docker build -t opencode .
+```
+
+## Run
+
+```bash
+docker run -it -p 4096:4096 jcabillot/opencode
+```
+
+By default the server listens on `127.0.0.1:4096`. To expose it on all interfaces:
+
+```bash
+docker run -it -p 4096:4096 jcabillot/opencode --hostname 0.0.0.0
+```
+
+### Mount a project
+
+```bash
+docker run -it -p 4096:4096 \
+  -v $(pwd):/home/opencode/project \
+  jcabillot/opencode --hostname 0.0.0.0
+```
+
+### Secure with a password
+
+```bash
+docker run -it -p 4096:4096 \
+  -e OPENCODE_SERVER_PASSWORD=your-password \
+  jcabillot/opencode --hostname 0.0.0.0
+```
+
+Authentication uses HTTP basic auth. The default username is `opencode`, override it with `OPENCODE_SERVER_USERNAME`.
+
+## Troubleshooting helper
+
+The image includes an `opencode-attach` wrapper in `PATH` that runs:
+
+```bash
+opencode attach -p "${OPENCODE_SERVER_PASSWORD}" "${OPENCODE_API_URL}"
+```
+
+Example:
+
+```bash
+export OPENCODE_SERVER_PASSWORD=your-password
+export OPENCODE_API_URL=http://127.0.0.1:4096
+opencode-attach
+```
+
+## API
+
+Once running, the server exposes an OpenAPI 3.1 spec at:
+
+```
+http://localhost:4096/doc
+```
+
+Key endpoints:
+
+| Method | Path | Description |
+|--------|------|-------------|
+| `GET` | `/global/health` | Health check and version |
+| `GET` | `/session` | List sessions |
+| `POST` | `/session` | Create a session |
+| `POST` | `/session/:id/message` | Send a message |
+| `GET` | `/event` | Server-sent events stream |
+
+See the [OpenCode server docs](https://opencode.ai/docs/server/) for the full API reference.
+
+## Image details
+
+- **Base image**: `node:24` (Debian)
+- **Install**: `opencode-ai` via npm global install
+- **User**: dedicated non-root `opencode` user
+- **Entrypoint**: `opencode serve`
+- **Default port**: `4096`