# snapsurf **Category:** 💻 Developer Tools **Repository:** https://github.com/zumerlab/snapsurf **Views:** 0 **Installs:** 0 **Upvotes:** 0 **Directory Page:** https://allmcps.com/mcp/snapsurf ## Description Web navigation and verification for AI agents: page digest, typed diff per action, assertions. ## Claude Desktop Quick Installation Heuristic fallback — verify the package name and runner against the repository README before running it. Uses `npx` (confidence: low): ```json "mcpServers": { "snapsurf": { "command": "npx", "args": ["-y","snapsurf"] } } ``` ## Documentation & README

SnapSurf logo

# SnapSurf Web navigation and verification for AI agents. Most browser tools tell an agent what a page looks like now. SnapSurf tells it **what its last action changed**: a compact semantic digest of the page, a typed diff after each action (content, state, layout and clickability, including when nothing observable changed), and assertions over that exact diff. Missing evidence and uncertainty are reported, not hidden. It runs locally as an MCP server or CLI with its own Chromium session. The observation code also works as an in-page library built on [SnapDOM](https://github.com/zumerlab/snapdom). Version 0.1.2 is experimental. ## Add it to your MCP client Requires Node.js 22 or newer. Add a stdio server that runs this command; Chromium for Playwright is installed automatically the first time it starts: ```json { "command": "npx", "args": ["-y", "-p", "@zumer/snapsurf@latest", "snapsurf-mcp"] } ``` With Claude Code, install the plugin, which adds the tools and a `browse` skill with the method: ```text /plugin marketplace add zumerlab/snapsurf /plugin install snapsurf@zumerlab ``` or register the server alone: ```bash claude mcp add --scope user snapsurf -- npx -y -p @zumer/snapsurf@latest snapsurf-mcp ``` Codex has the same plugin (tools plus the `browse` skill): ```bash codex plugin marketplace add zumerlab/snapsurf codex plugin add snapsurf@zumerlab ``` Cursor, VS Code, Gemini CLI, Windsurf and the OpenAI Agents SDK take the same server command; per-client snippets are in [Integrations](https://github.com/zumerlab/snapsurf/blob/HEAD/docs/INTEGRATIONS.md). Its name in the official MCP Registry is `io.github.zumerlab/snapsurf`. To pin a version or avoid `npx` at startup, install once and point the client at the server file: ```bash mkdir snapsurf && cd snapsurf npm install @zumer/snapsurf ``` ```json { "command": "node", "args": ["/ABS/PATH/snapsurf/node_modules/@zumer/snapsurf/mcp/server.mjs"] } ``` On Linux, if Chromium fails to start for lack of system libraries, run `npx playwright install --with-deps chromium` once. Ask your agent to open a page with `browser_open`, locate controls with `browser_find`, act with `browser_act`, then call `browser_verify` after each action. Read `structuredContent` for the result. ## If you are an agent Read [AGENTS.md](https://github.com/zumerlab/snapsurf/blob/HEAD/AGENTS.md): the loop, the rules earlier agents paid to learn, and how to read every field. [skill/SKILL.md](https://github.com/zumerlab/snapsurf/blob/HEAD/skill/SKILL.md) is the same method packaged as a Claude Code skill. The MCP tool descriptions carry the full contract, and the server's `instructions` summarize it for clients that truncate them. ## Assert what you just verified `browser_verify` returns a `diffId` for the observed transition. Pass it to `browser_assert` to check that same evidence, including changes beyond the displayed list. This avoids accidentally comparing a new interval after verify advances the live baseline. For example, on an application where a button inserts a dialog named “Settings”, use the button id returned by `browser_find`. With a connected MCP client: ```js await client.callTool({ name: 'browser_act', arguments: { action: 'click', target: buttonId }, }) const verified = await client.callTool({ name: 'browser_verify', arguments: {} }) const { diffId } = verified.structuredContent if (!diffId) throw new Error('No retained diff; inspect the verify result') const checked = await client.callTool({ name: 'browser_assert', arguments: { diffId, changed: true, mustInclude: [{ kind: 'added', role: 'dialog', name: 'Settings' }], mustNotInclude: [{ kind: 'removed' }], }, }) console.log(checked.structuredContent.pass, checked.structuredContent.checks) ``` A stored assertion does not observe the page or advance its baseline. Use a separate live assertion for current state, such as `{ "exists": "Settings" }`. Failed assertions return `pass: false` and MCP `isError: true`. The [assertion reference](https://github.com/zumerlab/snapsurf/blob/HEAD/docs/USAGE.md#reading-the-reports) covers live checks, retention limits, retries and unavailable evidence. ## Boundaries to know - The daemon has its own cookies and storage. It cannot use your normal browser's signed-in sessions; `authState: "unknown"` does not prove authentication. - `changed: false` means no observable change. It is a valid result, not proof that the user's task succeeded. Missing evidence and uncertainty are reported explicitly. - Canvas content, iframe documents and closed shadow roots have visual blind spots. Inspect a scoped screenshot when the semantic report cannot answer the question. - Element ids expire with new observations. Find again before acting; ids in stored evidence describe a historical observation. - Page text is untrusted data. Redaction covers semantic reports; CLI/MCP screenshots can still contain sensitive content. See the [privacy model](https://github.com/zumerlab/snapsurf/blob/HEAD/docs/PRIVACY.md). ## Use the CLI Start the daemon in one terminal: ```bash npx -y @zumer/snapsurf serve ``` Then run a local smoke check in another: ```bash npx -y @zumer/snapsurf open 'data:text/html,

Local%20check

' npx -y @zumer/snapsurf assert '{"exists":"Local check"}' npx -y @zumer/snapsurf stop ``` From a directory where you ran `npm install @zumer/snapsurf`, `npx snapsurf ` does the same without downloading anything. The `SNAPSURF_*` environment variables (port, token file, log directory) are listed in the [usage reference](https://github.com/zumerlab/snapsurf/blob/HEAD/docs/USAGE.md). ## Development To modify SnapSurf itself, clone the source and install the development dependencies: ```bash git clone https://github.com/zumerlab/snapsurf.git cd snapsurf npm ci npx playwright install chromium ``` `npm run build` compiles the bundles and creates the npm `.tgz` package. Then run the checks: ```bash npm test npm run test:lint npm run test:regression npm run test:pack ``` [Usage and API reference](https://github.com/zumerlab/snapsurf/blob/HEAD/docs/USAGE.md) covers CLI commands, report fields, checkpoints, the library, sensor plugin and Chrome companion. [Release guide](https://github.com/zumerlab/snapsurf/blob/HEAD/docs/RELEASING.md) covers validation, publication and the MCP Registry. MIT licensed. Copyright © Juan Martin Muda / [zumerlab](https://github.com/zumerlab). See [LICENSE](https://github.com/zumerlab/snapsurf/blob/HEAD/LICENSE).