OpenCode Advisor MCP

OpenCode Advisor MCP is an unofficial local MCP server that lets Codex ask a read-only OpenCode advisor for a second review pass on Git changes.

This project is for people who already use Codex and OpenCode locally and want a second review tool in the loop without giving that reviewer write access.

Project Status

• Latest tagged GitHub release: v0.2.0
• main includes unreleased stabilization changes after v0.2.0
• Current scope: one MCP tool, ask_opencode_advisor
• Supported mode: source/GitHub install with a local OpenCode agent template
• npm package publication is planned for a future release and is not available yet

Unofficial Compatibility Notice

This is an unofficial community project. It is not affiliated with, endorsed by, or sponsored by OpenAI, Codex, OpenCode, or the maintainers of those products. "Codex" and "OpenCode" are referenced only for compatibility and integration context.

Responsible Use

Use this tool only on repositories and diffs you are authorized to inspect and disclose.

Important boundaries:

• The tool sends Git status, Git diff context, your question, and working-directory context to your configured OpenCode runtime.
• Depending on your OpenCode configuration, that runtime may use a remote model provider. Do not assume this means "nothing ever leaves the machine."
• The included advisor template blocks writes and denies .env reads, but that is not a complete confidentiality guarantee.
• Keep OPENCODE_ADVISOR_ALLOWED_ROOTS narrow. Do not point it at broad parent directories unless you deliberately want that scope.

Who It Is For

• People already running Codex locally
• People already running OpenCode locally
• Repositories where a second review pass is useful
• Teams that want a read-only reviewer template with explicit install steps

What It Is Not For

• Reviewing code you are not allowed to disclose
• Handling secrets or sensitive repositories by default
• Acting as an autonomous coding agent
• Replacing your normal review process or judgment

Install From Source

Clone the repository, then install and verify dependencies:

git clone https://github.com/henrydontbbai/opencode-advisor-mcp.git
cd opencode-advisor-mcp
npm install
npm run smoke
npm test

Copy the bundled advisor template into your OpenCode agents directory:

New-Item -ItemType Directory -Force -Path <agent-dir>
Copy-Item -LiteralPath ".\agents\codex-advisor.md" -Destination "<agent-dir>\codex-advisor.md" -Force

Add this MCP config to Codex:

[mcp_servers.opencode_advisor]
command = "node"
args = ["<repo-root>\\src\\server.mjs"]
startup_timeout_sec = 30
tool_timeout_sec = 180

[mcp_servers.opencode_advisor.env]
OPENCODE_ADVISOR_ALLOWED_ROOTS = "<allowed-root-or-semicolon-list>"
OPENCODE_ADVISOR_TIMEOUT_MS = "120000"
OPENCODE_ADVISOR_MAX_DIFF_CHARS = "60000"

Replace <repo-root> with the absolute path to this source checkout.

npm Package Status

The package metadata and CLI entrypoints are present for packaging checks, but opencode-advisor-mcp has not been published to npm yet. Use the source install path above for now.

Usage

Codex gets one MCP tool:

ask_opencode_advisor

Typical prompt:

Ask opencode_advisor to review the current changes.
Focus on risks, missing tests, privacy issues, and release readiness.

The server returns structured JSON with stable error codes such as invalid_cwd, invalid_paths, git_failed, opencode_not_found, opencode_failed, and timeout.

Local Verification

From the repository:

npm install
npm run smoke
npm test

Release and acceptance steps live in:

• docs/INSTALL.md
• docs/USAGE.md
• docs/ACCEPTANCE.md
• RELEASING.md