mschat-relay

Drive your local coding CLIs (Codex / Claude Code / OpenCode) from a cloud ms-chat browser tab — no cloud servers, no tunnels.

You open the cloud ms-chat page in your own browser; this tiny relay runs on your machine and spawns the coding CLI locally. Because the browser and the CLI are on the same machine, http://localhost from the page reaches your machine.

cloud ms-chat (your browser) ──fetch http://localhost:5200──▶ mschat-relay ──spawn──▶ codex / claude / opencode
        pick 「本地 Codex」 agent                              (runs in --cwd)          (streams back over SSE)

Install & run

# one-off
npx mschat-relay --cwd /path/to/your/project

# or install globally
npm install -g mschat-relay
mschat-relay --cwd /path/to/your/project

Then in the cloud ms-chat build set VITE_CLAUDE_RELAY_URL=http://localhost:5200, open it in your browser, and pick the 本地 Codex / 本地 Claude Code / 本地 OpenCode agent in the chat.

Options

| flag | env | default | meaning | |---|---|---|---| | -C, --cwd <dir> | RELAY_CWD | current dir | directory the CLI operates in | | -p, --port <n> | CLAUDE_RELAY_PORT | 5200 | port to listen on | | -s, --sandbox <mode> | RELAY_SANDBOX | workspace-write | codex sandbox: read-only | workspace-write | danger-full-access | | --cli <name> | RELAY_CLI | — | default CLI; each request's cli field overrides |

⚠️ workspace-write lets codex edit files in --cwd (real development). Use --sandbox read-only to look/answer without writing.

Prerequisites

You need the CLI you select installed and authenticated on your machine:

• Codex — codex on PATH
• Claude Code — claude on PATH
• OpenCode — ~/.opencode/bin/opencode

The relay picks the CLI per request (body.cli), spawns it in --cwd, and streams its output (claude stream-json / codex exec --json / opencode --format json) back to the chat as SSE.

Protocol

POST / with { "message": "...", "cli": "codex", "model"?: "...", "sandbox"?: "..." } → text/event-stream of data: {"text": "<cumulative>"} lines, ending with data: [DONE] (or data: {"error": "..."}). GET / returns a health JSON. CORS + Private-Network-Access headers are set so an HTTPS cloud page can reach http://localhost.