normalizeDirectory rejects Windows absolute paths (C:\..., \server\share)

[samuelgudi]

Summary

normalizeDirectory in src/helpers.ts rejects Windows absolute paths, so every tool that accepts a directory parameter is effectively unusable for Windows MCP clients. The validation hardcodes a POSIX assumption (normalized.startsWith("/")) that is only true on path.posix.

Repro

On Windows, from any MCP client:

opencode_run({ directory: "C:\Users\me\my-project", prompt: "..." })

or equivalently through any other tool that accepts directory.

Expected

The path is accepted and the request is scoped to that project.

Actual

Error: Invalid directory: "C:\Users\me\my-project" is not an absolute path.
Provide a full path like "/home/user/my-project".

Root cause

src/helpers.ts, function normalizeDirectory:

const normalized = resolve(directory);

// Must be an absolute path
if (!normalized.startsWith("/")) {
  throw new Error(
    `Invalid directory: "${directory}" is not an absolute path. ` +
      `Provide a full path like "/home/user/my-project".`,
  );
}

path.resolve is platform-aware and produces C:\Users\me\my-project on Windows, which does not start with "/", so every Windows absolute path (including UNC paths like \server\share) is rejected.

Fix

Use the platform-aware path.isAbsolute from node:path in place of startsWith("/"). resolve already guarantees an absolute path on every platform, so the check becomes correct on both POSIX and Windows without changing POSIX behavior.

Workaround

Omit the directory parameter entirely. The OpenCode server then inherits the cwd of the process that spawned it, which is usually fine for single-project setups but breaks multi-project workflows.

Impact

Complete loss of the directory parameter for every Windows client (Claude Code, Cursor, Windsurf, any MCP client on Windows). 79 tools are affected, since every tool uses directoryParam.

Environment

• opencode-mcp: v1.10.1
• Node.js: v22.x
• OS: Windows 11
• Tested on a regular C: drive path and a mapped X: drive.

PR

A fix is ready — I'll open a PR right after this issue and link it here.