Multimeter is a Git-native REST client and API testing tool for VS Code. Requests, tests, mocks, and docs are YAML .mmt files in Git — the same files in the visual editor and in CI via testlight. Apache 2.0. No account.

How do I use Multimeter with Cursor, Copilot, or Claude?

Install the VS Code/Cursor extension or add MCP with npx -y mmt-mcp. Agents should call scaffold_test, validate, format, and run instead of guessing .mmt syntax.

Yes. Apache License 2.0. No account required.

Connections — Multimeter docs

Watch live HTTP keep-alive and WebSocket sessions from the Multimeter activity bar.Markdown (no JavaScript)# Connections Watch live HTTP keep-alive and WebSocket sessions from the Multimeter activity bar. Use the **Connections** panel ({{btn:plug:Connections}}) to see what Multimeter has open right now — long-lived WebSocket sessions from the API tester, and HTTP/HTTPS keep-alive sockets reused across sends. Close individual connections or clear them all when you need a clean slate. ![Connections panel showing a live WSS session with status, protocol badge, and duration](../screenshots/connections-panel.png) ## What you can use it for - Confirm a WebSocket **Connect** in the API tester is still open - Spot idle or stuck keep-alive HTTP connections to a host - Close a session without restarting VS Code or reloading the window - See how long a connection has been open and when it was last active ## How it works - Connections appear when Multimeter opens a live socket through the extension network bridge - **WebSocket** — click **Connect** on a `protocol: ws` API in the [API tester](../files/api/index.md); the session stays open until you disconnect, close it here, or the server ends it - **HTTP / HTTPS** — keep-alive sockets are tracked when the HTTP client reuses a connection across sends - One-shot HTTP sends that do not keep a socket open may not appear (or only briefly). Many public hosts (including Cloudflare in front of `test.mmt.dev`) close the TCP connection after each response, so an HTTPS row may never stay visible even though Multimeter asks for `Connection: keep-alive` - `https://local.mmt.dev` is answered in-process (no real socket), so it does not appear here - CLI and core-only runs do not populate this panel — it tracks live sessions in the VS Code extension ## Connection details Each row shows: | Element | What it shows | |---|---| | **Status dot** | Lifecycle state — see [Connection states](#connection-states) | | **Protocol icon** | HTTP or WebSocket icon | | **Host** | Hostname and port (e.g. `test.mmt.dev:443`) | | **Protocol badge** | `HTTP`, `HTTPS`, `WS`, or `WSS` | | **State** | Current lifecycle label (`open`, `idle`, …) | | **Request count** | Number of requests or messages on that connection (when greater than zero) | | **Duration** | Time since the connection opened — updates every second | | **Last activity** | When state is **idle**, shows `last: … ago` since the last request or message | Rows are sorted by most recent activity. ## Connection states | State | Indicator | Meaning | |---|---|---| | **connecting** | Blue (pulsing) | Handshake in progress | | **open** | Green | Active connection | | **idle** | Orange | Open but no recent activity | | **closing** | Red | Shutting down | ## Panel controls Toolbar actions (top right of the view): | Control | What it does | |---|---| | {{btn:refresh:Refresh Connections}} | Reload the connection list from the tracker | | {{btn:trash:Close All Connections}} | Close every tracked connection | Per connection: | Control | What it does | |---|---| | {{btn:close:Close}} | Appears on row hover (same pattern as Temp Files). Closes that connection — WebSocket disconnect or destroy the keep-alive socket | When no connections are active, the panel shows an empty state with a plug icon and **No active connections**. ## WebSocket vs HTTP - **WebSocket (`WS` / `WSS`)** — appears when you click **Connect** on a WebSocket API in the tester. Live **Send** uses this open session; it is separate from one-shot test or CLI runs. - **HTTP / HTTPS** — tracks keep-alive sockets reused by the HTTP client. Each send on the same socket increments the request count; sockets may move to **idle** between requests. ## Notes and limits - The panel reflects the extension’s live network bridge only — not mock servers, CLI runs, or suite execution - Closing a connection here does not change your API YAML or environment - Very short-lived connections may appear and disappear quickly --- ## See also - [WebSocket](../files/api/protocols/websocket.md) — Connect and live Send in the API tester - [API](../files/api/index.md) — API tester and Connect button - [HTTP](../files/api/protocols/http.md) — HTTP sends and keep-alive reuse - [Cache](./cache.md) — in-run test-call and live-env `cache:` entries - [Getting Started](../quick-start.md) — install and a first API file - [Panels](./index.md) — all sidebar and bottom panels For AI agents · llms.txt · Home