Threaded Hosted MCP

Endpoints

/mcp for MCP JSON-RPC transport.
/health for deploy and uptime checks.
/oauth/start begins Cognito PKCE sign-in (requires THREADED_MCP_API_BASE_URL).
/oauth/callback completes Cognito redirect for local dev.

Active environment (this process)

Tier: sandbox (Railway Cognito sandbox). Hosted MCP origin: https://mcp-sandbox.threadedmfg.dev.

API base URL: https://threaded-threaded-cognito-sandbox.up.railway.app

Execute app host: https://threaded-threaded-cognito-sandbox.up.railway.app

OAuth redirect origin: https://mcp-sandbox.threadedmfg.dev

Threaded stacks (operator catalog)

Sandbox MCP lists local + sandbox only; this deploy binds to the sandbox row.

Tier	Label	API	App	Hosted MCP
`local`	Local development	`http://127.0.0.1:8000`	`http://127.0.0.1:8080`	machine-local (Wrangler / Node)
`sandbox`	Railway Cognito sandbox	`https://threaded-threaded-cognito-sandbox.up.railway.app`	`https://threaded-threaded-cognito-sandbox.up.railway.app`	`https://mcp-sandbox.threadedmfg.dev`

Runner Safety Defaults

Tool calls are constrained to these configured Threaded app origins:

https://threaded-threaded-cognito-sandbox.up.railway.app

Current implementation status

Runner dispatch (THREADED_MCP_RUNNER_KIND): cloudflare.

Script runner dispatch: THREADED_MCP_RUNNER service binding to the isolate runner Worker (no public runner DNS).

Local (local) path: a minimal hand-rolled runner for smoke commands (echo, pwd, sleep in milliseconds, threaded --version stub). Not a full shell.

Remote (cloudflare) path: jobs are dispatched to the just-bash runner Worker (service binding when deployed; loopback URL for local pnpm run dev:isolate-runner). That worker runs just-bash (just-bash/browser) with an allowlisted builtin set and a hosted threaded command backed by @threaded/threaded/hosted (same Commander tree as the CLI: task …, auth status / orgs, instructions, client-info, help). auth login, logout, and refresh are rejected; credentials come from the job token, not disk. Not Cloudflare Sandbox containers yet. Production would replace that URL with a hardened runner while keeping the same JSON contract.

OAuth

Threaded API origin for OAuth and job tokens is fixed at deploy time (THREADED_MCP_API_BASE_URL); it is not selected per MCP client.

Threaded web app origin for script runs is fixed at deploy time (THREADED_MCP_EXECUTE_APP_HOST, or implied when exactly one origin is listed in THREADED_MCP_ALLOWED_APP_HOSTS); execute_threaded_script does not take a per-call URL.

Redirect origin for callbacks (THREADED_MCP_OAUTH_REDIRECT_ORIGIN):

https://mcp-sandbox.threadedmfg.dev

Hosted MCP Cognito client id in env: no.

Requested scopes (when set in env):

Not configured yet.