opencode-sandbox

Spin up an isolated opencode instance from prebuilt public GHCR images and hand it to Claude Code as an MCP server. No build step, no checkout of the opencode fork — each instance is its own Docker Compose project with its own named volumes, and its workspace is a named volume rather than a host bind, so it cannot see your filesystem. Images are public and pull anonymously; the backend reports opencode 1.18.4 and the MCP bridge exposes 80 tools.

Install

Build from source and drop the binary on your PATH:

bun run build
cp dist/opencode-sandbox ~/.local/bin/

(bun run install-local does both in one step.) Or grab a prebuilt binary from this repo's GitHub Releases.

Related MCP server: devcontainer-mcp

Quickstart

Create an instance. Any provider API key already in your shell (ANTHROPIC_API_KEY, OPENAI_API_KEY, GOOGLE_GENERATIVE_AI_API_KEY, OPENROUTER_API_KEY) is forwarded into it at create time — there's no UI login step and no auth.json to manage.

opencode-sandbox create scratch --seed ./my-project --config ./opencode.jsonc

--seed copies a directory into the fresh workspace before the instance first starts; --config places an opencode.jsonc for that instance alone. Both are optional.

Register it with Claude Code. create prints this line, and url reprints it later:

opencode-sandbox url scratch
claude mcp add --transport http scratch http://127.0.0.1:4784/mcp

Now use it — the instance's 80 tools (read, write, run shell commands, all scoped to its own /workspace) are available in that Claude Code session. When you're done:

opencode-sandbox destroy scratch --yes

destroy removes the containers and their volumes, including the workspace.

A web UI is available too, behind --web on create; without it, the MCP bridge is the only interface.

Security note

The MCP bridge has no inbound authentication of its own. Anyone who can reach its port gets the full opencode tool surface — reading and writing files and running shell commands inside that instance's /workspace. The published port is bound to 127.0.0.1 by default; keep it that way. Do not widen it to 0.0.0.0 or put it behind a public reverse proxy without a real auth layer in front of it.