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Momentic’s MCP server exposes tools that let agents browse, edit, create, and run tests with a live browser directly from your editor.
Requires Momentic CLI 2.54.0 or later.

Prerequisites

  • Momentic CLI installed locally (MCP runs on your machine)
  • A project with a valid momentic.config.yaml
  • A MOMENTIC_API_KEY available to the MCP process (most editors do not inherit your shell environment)

Setup instructions

General

Momentic’s MCP is a local stdio server. Every editor ultimately runs:
For mobile testing, substitute momentic-mobile mcp. See momentic mcp and momentic-mobile mcp for every supported flag (headful browser, pixel ratio, daemon mode, etc.). Along with the server, install the Momentic skills for your editor. Skills give agents explicit operating guidance so they don’t make malformed tool calls:
  • momentic-test: how to build reliable tests, steps, and modules
  • momentic-result-classification: how to analyze and classify failures
  • momentic-spec: how to write affected tests before product changes
After registering the server with one of the clients below, restart the client and start a new chat. Ask the agent which MCP tools are available. You should see momentic_* tools such as momentic_get_artifacts. If they do not appear, fully restart the client. The setup for each editor is below.

Claude Code

Register the server:
Verify with claude mcp list. On native Windows, wrap with cmd /c:
Pass MOMENTIC_API_KEY via the CLI’s --env flag or by running the command from a shell that already has it exported. See Claude Code MCP docs for scoping and auth options. Restart Claude Code and run /mcp to confirm the server is active.

Codex

Register the server:
Saved to ~/.codex/config.toml. For project-scoped configs, edit .codex/config.toml in a trusted project. See Codex MCP docs for env vars and timeouts. Restart Codex, then run /mcp in the TUI to verify.

Cursor

Open the command palette, select View: Open MCP Settings, click Add a new Custom MCP server, then paste and restart Cursor:

Devin

Follow the dedicated Devin integration page. Devin requires additional machine-configuration steps so it can install browsers, set ANDROID_HOME / JAVA_HOME, and pre-install skills before MCP starts.

OpenCode

Edit opencode.json in your project root or ~/.config/opencode/:

VS Code (Copilot)

Open the command palette, select MCP: Add Server, pick Command (stdio), then paste:
Name the server momentic when prompted. Then add MOMENTIC_API_KEY to the generated entry in mcp.json:
Your org may need to allow MCP. Copilot only exposes MCP in agent mode.

Other clients

Any MCP-compatible client can launch the server with:
  • Command: npx
  • Arguments: momentic mcp --config /absolute/path/to/momentic.config.yaml
  • Env: MOMENTIC_API_KEY=your-api-key

Install skills

After registering the MCP server with your editor, install the Momentic skill files from your project root:

Invoke the skill

Agents don’t always pick up installed skills. Some load them on their own; naming the skill in the prompt is the only way to be sure. The examples below use Codex’s $<skill> syntax. In Claude Code and Cursor, replace $ with /. For other agents, ask for the skill by name.

Authorship

Use momentic-test to create or extend Momentic tests:
Use momentic-mobile-test for Android and iOS. Naming the skill keeps the agent on Momentic’s test format and MCP workflow instead of hand-rolling browser automation.

Maintenance

Use momentic-test to repair stale test steps while preserving the intended behavior. Use momentic-result-classification when you want the agent to explain or classify a failing run before changing anything:

Spec-driven development

Once your repo is on the simplified format, Momentic tests are readable enough to double as product specs. Invoke momentic-spec when implementing a feature so the agent creates or updates the smallest set of affected Momentic tests before changing product code:
To make this the default behavior for your repository, also add a spec-driven section to your AGENTS.md (or .cursor/rules, etc.). Tune the wording to your team’s workflow:
See Agentic testing for more on act and AI action V3.

Usage tips

  • Model: use the newest model your editor offers. High reasoning gives the best results; Medium is about 20% faster with some quality loss.
  • Invoke the relevant skill explicitly when authoring, maintaining, or changing product behavior.
  • Be specific in prompts. For exploratory runs, include a step limit.
  • Let sessions terminate: the agent calls momentic_session_terminate to close the browser. Hard-stopping your editor leaks browser processes.
  • Gitignore .momentic-mcp/. MCP stores screenshots, videos, and traces there.
  • Long-running steps: momentic_run_step returns within 30 seconds. If the step range hasn’t finished, it returns a stepRunnerId that you can poll with momentic_poll_runner. Pass an optional timeoutSeconds (0-30, default 0) to hold the poll open briefly instead of busy-polling.