---
title: "OpenCode"
description: "The default open-source coding agent harness in Shiba, supporting multi-provider AI Gateway routing."
---

> Documentation Index
> Fetch the complete documentation index at: https://tryshiba.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# OpenCode

[OpenCode](https://opencode.ai/docs/) is Shiba's default coding agent harness. It is open source, highly extensible, and supports multi-provider LLM backends through your Cloudflare AI Gateway.

## Agent Overview

| Attribute | Specification |
| --- | --- |
| **Harness ID** | `opencode` (default) |
| **CLI Binary** | `opencode` |
| **Pinned Version** | `1.18.34` (in Dockerfile) |
| **Default Model** | `google/gemini-3.5-flash-lite` |
| **Supported Providers** | Google AI Studio, Anthropic, OpenAI, xAI (Grok), OpenCode Go |
| **Credential Model** | AI Gateway BYOK (dummy key inside sandbox; real key injected at egress) |
| **Invocation** | `opencode run "<task>" --format json` |

## Multi-Provider Support

OpenCode can route tasks across multiple AI providers by prefixing the model with the provider slug:

```bash
# Google Gemini
google/gemini-3.5-flash-lite
google/gemini-1.5-pro

# xAI Grok
xai/grok-4

# Anthropic Claude
anthropic/claude-sonnet-4-6

# OpenAI
openai/gpt-4o
```

## How It Works

```
Developer Request
  └── CodingOrchestrator generates delegate_coding_task({ harness: "opencode" })
      └── Human signs off on exact prompt & repository
          └── Ephemeral Cloudflare Sandbox boots
              ├── Writes per-run .opencode.json configuration
              ├── Executes: opencode run "<task>" --format json
              ├── Streams newline-delimited JSON events
              └── Collects git status and builds unified diff
```

> **Egress Host Allowlists**
>
> Each run dynamically configures `Sandbox.allowedHosts` strictly to the selected model provider and GitHub. All unapproved external network destinations are dropped by default.

## Configuration & Deployment

### 1. Configure Providers in AI Gateway
Add your provider keys (Google, Anthropic, OpenAI, xAI) to your Cloudflare AI Gateway.

### 2. Set Default Model
In `wrangler.jsonc` or via environment variables:

```bash
pnpm wrangler secret put CODING_MODEL --config apps/backend/wrangler.jsonc # enter "google/gemini-3.5-flash-lite"
```

## Selecting OpenCode in a Task

OpenCode is used by default if no harness is explicitly provided:

```json
{
  "repoUrl": "https://github.com/acme/web",
  "task": "Add dark mode toggle to navigation bar",
  "baseBranch": "main",
  "harness": "opencode",
  "codingModel": "xai/grok-4"
}
```

## Related Documentation

- [Coding Harnesses Overview](/docs/claude-code/)
- [Models & Costs](/docs/costs/)
- [Security & Credential Boundaries](/docs/security/)

Source: https://tryshiba.dev/docs/agents/opencode/index.mdx