✨ feat: add OpenCode plugin with embedded server and dual auth

- Embedded HTTP server runs inside OpenCode process (no separate server needed)
- Config hook auto-injects augment provider with all 8 models
- Two auth methods: Auggie CLI session (auggie login) and API key
- Per-model client pooling, retry with exponential backoff, SSE streaming
- Port collision safe: OS-assigned random port per instance
- Liveness check, startup lock, process cleanup handlers
- Debug logging suppressed by default (enable with DEBUG=true)

Author: hletrd

plugin/README.md

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+# opencode-augment-auth
+
+OpenCode plugin for [Augment Code](https://augmentcode.com) — access Claude and GPT models **at zero cost** through Augment Code's infrastructure.
+
+**No separate server process needed.** The plugin embeds the API server directly inside OpenCode and auto-configures everything.
+
+## Quick Start
+
+### 1. Install the Auggie CLI and authenticate
+
+```bash
+npm install -g @augmentcode/auggie
+auggie login
+```
+
+### 2. Add the plugin to your `opencode.json`
+
+```json
+{
+  "plugin": ["opencode-augment-auth"],
+  "model": "augment/claude-opus-4-6"
+}
+```
+
+That's it — no provider config needed. The plugin auto-registers all models.
+
+### 3. Authenticate in OpenCode
+
+```bash
+opencode auth login
+# Select "Augment Code (auto-detect session.json)"
+```
+
+### 4. Use it
+
+```bash
+opencode
+```
+
+## How It Works
+
+1. **Config hook** auto-injects the `augment` provider with all 8 models into OpenCode
+2. **Auth hook** validates your `~/.augment/session.json` from `auggie login`
+3. **Embedded server** starts automatically on a random port when OpenCode loads the provider
+4. Requests flow: OpenCode → embedded server → Auggie SDK → Augment Code API → Claude/GPT
+
+No separate process to manage. No port conflicts. Everything runs inside OpenCode.
+
+## Available Models
+
+Use `augment/<model-id>` in OpenCode (e.g., `augment/claude-opus-4-6`).
+
+| Model ID | Description | Context | Output |
+|----------|-------------|---------|--------|
+| `claude-opus-4-6` | Most capable Claude | 200K | 32K |
+| `claude-opus-4-5` | Previous Opus gen | 200K | 32K |
+| `claude-sonnet-4-5` | Balanced performance | 200K | 16K |
+| `claude-sonnet-4` | Previous Sonnet gen | 200K | 16K |
+| `claude-haiku-4-5` | Fast, lightweight | 200K | 8K |
+| `gpt-5` | GPT-5 | 128K | 16K |
+| `gpt-5-1` | Strong reasoning | 128K | 16K |
+| `gpt-5-2` | Smarter, slower | 128K | 16K |
+
+## Local Development
+
+```bash
+cd plugin
+npm install
+npm run build
+```
+
+Reference the local build in `opencode.json`:
+
+```json
+{
+  "plugin": ["/path/to/auggie-wrapper/plugin"]
+}
+```
+
+## Troubleshooting
+
+| Issue | Solution |
+|-------|----------|
+| "Session file not found" | Run `auggie login` to authenticate |
+| Auth login fails | Ensure `~/.augment/session.json` exists and has `accessToken` + `tenantURL` |
+| Model not found | Use hyphenated IDs: `claude-opus-4-6`, not `claude-opus-4.6` |
+
+## License
+
+MIT

plugin/index.ts

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+import { AugmentAuthPlugin } from "./src/plugin.js";
+export { AugmentAuthPlugin };
+export default AugmentAuthPlugin;
+