MCP Tauri Automation

A small local MCP server for testing Tauri desktop apps. Connect to a test app, inspect a bounded UI snapshot, click/type/wait, and capture a screenshot.

2.0.0-rc.2 requires Node.js 22 or newer. It supports an already running embedded WebDriver server (including macOS) and the external tauri-driver flow. This is a release candidate; see CHANGELOG.md for compatibility changes and the distinction between automated protocol tests and native proof. The rc.2 candidate passed synthetic native acceptance on Linux ARM64 with both embedded and external drivers; see native evidence. The earlier rc.1 embedded flow passed a macOS arm64 Saga smoke on September 7, 2026. Windows and the new rc.2 capabilities on macOS remain unverified.

Install

From source:

git clone https://github.com/Radek44/mcp-tauri-automation.git
cd mcp-tauri-automation
npm ci
npm test

The server uses stdio. Start it with Node and an absolute path:

node /absolute/path/to/mcp-tauri-automation/dist/index.js

Register with Codex (official configuration guide):

codex mcp add tauri-automation -- node /absolute/path/to/mcp-tauri-automation/dist/index.js

Or Claude Code:

claude mcp add --transport stdio tauri-automation --scope user -- node /absolute/path/to/mcp-tauri-automation/dist/index.js

Any stdio MCP client can use the same command and arguments. No provider API key or additional model service is needed. Restart/reconnect the MCP client after changing its configuration.

Connect a test app

Embedded WebDriver — macOS, Linux, Windows

Build your app with the optional tauri-plugin-wdio-webdriver test plugin. Launch that build yourself with a dedicated port and isolated test data:

TAURI_WEBDRIVER_PORT=4445 WDIO_EMBEDDED_SERVER=true /absolute/path/to/test-app

Then call connect_app with {"port":4445}. It creates a new session on 127.0.0.1; it does not discover apps, take over an existing session, or launch a process. close_app deletes that session; your externally launched app remains running. The launcher remains responsible for stopping the exact process.

The WebDriver plugin belongs in test builds, and visible UI tests need an unlocked desktop. See the Tauri WebDriver guide and plugin setup.

External tauri-driver — Linux and Windows

Install and run the platform driver as described in Tauri's manual setup. Then call launch_app with {"appPath":"/absolute/path/to/app"}. The driver owns launching the app; deleting its session requests teardown. Native process behavior ultimately belongs to that driver.

Tools

Tool	Inputs / behavior
connect_app	Optional port; create a session on a running embedded server.
launch_app	Optional appPath, args, env; use TAURI_APP_PATH when path is omitted.
close_app	Delete the owned session.
get_app_state	Session metadata and a live title/location probe; reports failed health checks.
inspect_ui	Optional CSS selector, limit (1–100, default 20), maxTextLength (0–1000, default 160).
click_element	CSS selector only; standard primary WebDriver click. Button overrides are rejected.
focus_element	One unique CSS target; scroll, focus and verify without typing or activation.
type_text	selector, text, optional clear (false appends, true clears then types).
wait_for_element	selector, optional timeout and state: attached (default), visible, or hidden; optional conditions described below.
get_element_text	CSS selector; maximum 12,000 characters, otherwise use a narrower selector.
capture_screenshot	Native MCP PNG by default; returnBase64:false saves a local file. Optional basename filename and timeout (1–60,000 ms).
execute_tauri_command	Compatibility/debug tool: command, optional args; requires an enabled global Tauri invoke bridge.

inspect_ui returns bounded text, role/name hints, enabled/visible/focused state, viewport intersection, rectangles, and own/effective opacity. Truncation flags disclose omitted results. It does not return HTML, input values, application stores, or an accessibility-tree conformance claim. A screenshot is still needed for visual judgment; geometry does not prove appearance or interaction.

Start with inspect_ui, narrow the selector if necessary, perform the action, then use wait_for_element or a targeted read to confirm the result. Capture images when they answer a visual question. This reduces repetitive diagnostic calls and large DOM dumps; no measured model-token saving is claimed.

For state waits, conditions accepts textEquals, enabled, and ariaBusy; all supplied conditions must match. Conditions cannot accompany hidden. Text concatenates public visible text nodes in DOM order, preserving inline adjacency, then normalizes whitespace. It excludes form/editable contents and is not a full rendered-text or accessibility algorithm. Each observation is bounded to 2,000 text nodes and 12,000 raw text characters, including excluded nodes; narrow the selector when that budget is insufficient. ariaBusy:false requires an explicit aria-busy="false". Each poll reacquires the element, and all observations share one deadline.

A screenshot timeout overrides the configured request timeout for that call only. Omitting it uses the configuration; zero does not mean unlimited. Right/middle clicks remain deferred: the tested native WebKit driver can emit an unintended primary click. See native acceptance.

All calls execute in arrival order, including schema validation. Cancellation while queued prevents execution; an input operation already started is allowed to finish and is never replayed. Action requests are never automatically retried. If an action times out, it may already have happened: inspect before retrying. If session creation has an unknown outcome, restart the isolated app/driver and this MCP server before creating another session. A failed session deletion retains ownership so close_app can retry cleanup.

Configuration

All variables are optional. Invalid numeric configuration fails startup.

Variable	Default
TAURI_APP_PATH	No default
TAURI_WEBDRIVER_PORT	4444; connect_app.port overrides it
TAURI_DEFAULT_TIMEOUT	5000 ms, range 1–60,000; per WebDriver request
TAURI_SCREENSHOT_DIR	./screenshots, resolved when the MCP process starts

Only 127.0.0.1 is used; redirects are rejected. Responses are capped at 1 MiB, or 16 MiB for screenshot JSON. Screenshot filenames cannot include directories; existing files are never overwritten. TAURI_DRIVER_PATH was never used to spawn a driver and remains unnecessary.

UI text, names, titles, and images can contain user content. Use disposable test data and expose only the tools appropriate to the task. Page locations omit credentials, query strings, and fragments; this is not a general secret scanner.

For Saga/Vuea, use this server for native UI evidence with a test-owned data directory. Use SagaDoc's own validated MCP tools for document authoring and its normal review controls for human decisions. Exclude execute_tauri_command from that automation profile; it must not become a shortcut around the document service or human Finish Session boundary. See the local example and Saga smoke recipe.

Development

npm ci
npm run verify

The gate builds TypeScript, runs Node's test runner against local fake WebDriver servers and real MCP transports, audits runtime dependencies, and checks the package contents. It does not require a desktop session. Native testing is separate and must identify the app build, isolated data, platform, and results.

The runtime uses Node fetch for the narrow W3C command set; it does not download browsers or require WebdriverIO. Diagnostics go to stderr; stdout carries MCP. The package contains the compiled runtime, docs/examples, and native probe.

MIT license. Contributions welcome; keep additions tied to a demonstrated workflow and include a deterministic failure/success oracle.