mcp: add fetchable agent-setup page (AGENT_SETUP.md)

[sujithps]

Adds a one-page, agent-facing setup document in the style of Cloudflare's agent-setup prompt: a user tells their coding agent

Fetch https://raw.githubusercontent.com/Skyvern-AI/rustwright/main/mcp/AGENT_SETUP.md and follow the instructions

and the agent installs, registers, and verifies the Rustwright MCP server itself.

Contents

• Written in second person to the agent, imperative ("complete the steps yourself by running the commands directly")
• Prerequisite checks: uv (with install one-liners), browser (installed Chrome via RUSTWRIGHT_MCP_CHANNEL=chrome, or the bundled Chromium)
• Per-client registration: Claude Code (with the -- variadic-flag gotcha called out), Codex CLI (config.toml), Cursor, Claude Desktop, VS Code agent mode, and a generic stdio fallback
• A verification step with the expected snapshot output for example.com and a completion report template
• Env-var reference and troubleshooting for the known failure modes (missing separator, CDP launch timeout, headless bot-blocking, stale refs)
• Linked from mcp/README.md and the root README's agent section

Verified

• The raw URL serves the markdown as fetched by an agent
• The uvx server one-liner (boots and answers MCP initialize), claude mcp add registration, the python -m rustwright CLI exposure through uvx, and the example.com verification snapshot content

[sujithps]

Pushed a self-review pass (a3f6126) after a thorough audit of the page. Fixes, most important first:

• Claude Desktop section could never work as written: GUI-launched apps on macOS do not inherit the shell PATH, so bare "command": "uvx" fails with spawn ENOENT. The section now requires the absolute path (which uvx)
• Troubleshooting mapped the wrong error to the wrong cause: Could not find a Chromium executable (no browser) and did not expose a CDP endpoint (browser found but failed to start, usually missing system libs in containers) are now separate entries, the latter pointing at python -m rustwright install-deps
• Linux arm64 dead end: the bundled Chrome-for-Testing download is x86_64-only; added the distro-Chromium + RUSTWRIGHT_MCP_EXECUTABLE escape hatch
• Windows: -ExecutionPolicy ByPass on the uv installer (matches uv's official docs), a note that multi-line commands are POSIX-shell, and winget/brew alternatives to curl|sh
• Codex: startup_timeout_sec = 120; the first cold uvx git build exceeds Codex's 10s default and looks like an intermittent failure
• uv PATH: agents now get the source ~/.local/bin/env hint instead of concluding the install failed in the same shell
• ALLOW_EVAL row: accepted values corrected to 1/true/yes (matches server.py) plus leave-unset-unless-asked guidance, since the audience is an autonomous agent scanning for options
• Spoofing guard: the preamble now tells the agent to verify the fetched URL points at Skyvern-AI/rustwright before running anything (same mitigation the Cloudflare agent-setup page uses)
• Raw URLs use /HEAD/ rather than /main/ so a default-branch rename cannot 404 copies of the prompt that live outside the repo
• The local-browser prerequisite and env-var table no longer claim to be complete, so the page stays correct when mcp: attach to a remote browser over CDP #93 (remote CDP attach) lands

[suchintan]

Reviewed this in depth (two independent review rounds — a correctness/security pass and a factual-accuracy pass verifying every claim against the code) and pushed fixes on top rather than round-tripping comments. Great page overall — almost every command, error string, and platform claim checked out exactly against the source, and it is clear it was actually exercised. What the two follow-up commits change:

Round 1 (3a14768) — merged current main into the branch, then:

• RUSTWRIGHT_MCP_ALLOW_EVAL inverted the real default. The server exposes browser_evaluate when the variable is unset (_allow_eval() in mcp/rustwright_mcp/server.py, pinned by test_browser_evaluate_is_default_on_and_explicitly_disableable), so "leave unset" left arbitrary page-JS enabled while the agent reported it absent. Every config block now ships RUSTWRIGHT_MCP_ALLOW_EVAL=0, the table row states the true default, and Step 3 verifies the tool is absent.
• Codex CLI: codex mcp add one-liner as the primary path (flags verified against Codex 0.144.4), global-scope note, kept the startup_timeout_sec block.
• Troubleshooting: missing system libraries crash the browser and produce Chromium process exited before CDP endpoint became available, not the launch-timeout message — split the bullets so the install-deps advice is attached to the string agents will actually see; aligned the stale-ref bullet with the server's real message.
• Step 3: restart handoff for clients that only load MCP servers on restart, with a paste-ready verification prompt.
• Windows: where.exe / Get-Command for locating uvx, JSON backslash escaping.
• README: moved the agent-setup pointer into the MCP section (it had drifted into the CLI section in the branch-update merge).

Round 2 (664b4e8) — fresh-eyes review of the updated page:

• Quote only the invariant prefix of the process-exited error (the emitted string ends with a real exit status, so the (status: ...) form could never match verbatim).
• "Agent-supplied page evaluation (browser_evaluate)" instead of "page-world evaluation" broadly — the server still runs its own internal page scripts for snapshots/health checks.
• Guardrails for a page agents execute directly: ask the user before the uv installer script or install-deps (apt-get, possibly sudo); merge the rustwright entry into existing client configs instead of replacing files; Cursor gets the same project-scope-first guidance as the other clients; the pin note no longer claims full reproducibility (Python deps still resolve at install time).

One open product question deliberately not changed here: the configs inherit the server's default mirror toolset (24 tools with eval off). If agent-driven installs should default to the leaner profile instead, that is a one-line addition (RUSTWRIGHT_MCP_TOOLSET=lean) but a product call, not a docs fix.

[suchintan]

Two full review rounds (details in the thread comment); fixes pushed and re-verified. Approving.

[github-actions]

Synced to rustwright-cloud: https://github.com/Skyvern-AI/rustwright-cloud/pull/113