@silverbackbase/mark · v0.1.8

Headless micro-analytics for AI agents. A one-line snippet on your site, and your agent reads visitor behavior directly — no dashboard, no UI.

Part of SilverBackBase — a library of agent-first primitives for AI-powered marketing and product work.

How it works

Mark has two surfaces:

• HTTP server — accepts events from any browser via a one-line JS snippet, and exposes query endpoints for agents or any LLM with function calling
• MCP stdio — exposes tools for Claude Code, Codex CLI, and Claude Desktop

Data is stored in PostgreSQL. Every event is scoped to a workspace_id — a string you choose freely (e.g. "local", "my-project").

Quick start

1. Requirements

• Node.js 18+
• PostgreSQL database

2. Start the server

npx -y @silverbackbase/mark

Or install globally:

npm install -g @silverbackbase/mark
mark

The server starts on the port defined by PORT (default 7331). Migrations run automatically on startup.

3. Add the snippet to your site

Paste before </body> on every page:

<script async src="https://your-instance.com/mark.js?slug=my-site&wid=local"></script>

slug identifies the site. wid is your workspace ID — use any consistent string.

Once loaded, auto-tracking activates: page_view, clicks on buttons/links, form_submit, page_exit, and scroll_depth at 25/50/75/100%. Custom events:

window.markjs.track('signup_complete', { plan: 'pro' })
window.markjs.identify('user-123')   // link events to an entity
window.markjs.setTag('variant-a')    // tag events for segmentation

4. Query from the agent

mark_funnel("my-site", ["page_view", "scroll_50", "scroll_100"])
// → { drop_at: "scroll_100", rates: [1.0, 0.61, 0.28] }

mark_funnel("my-site", ["page_view", "form_submit", "merci"])
// → { drop_at: "form_submit", rates: [1.0, 0.43, 0.31] }

mark_friction("my-site")
// → where sessions stop, ordered by sequence

mark_compare("my-site", pivot="2026-06-01", event="form_submit")
// → { before: { completions: 48 }, after: { completions: 71 }, delta: "+47.9%" }

MCP tools

| Tool | Description | |------|-------------| | mark_snippet | Returns the <script> tag to embed on the site | | mark_ingest | Injects a synthetic event from the agent (testing, seeding) | | mark_list | Lists all active slugs with session and event counts | | mark_summary | Overview: sessions, events, top events over N days | | mark_funnel | Conversion rate through an ordered list of events | | mark_compare | Behavior before vs after a date pivot | | mark_friction | Where sessions stop progressing | | mark_journey | Full event history for a specific entity | | mark_purge | Delete all data for a slug (irreversible) |

HTTP endpoints

POST /e                                  Ingest an event (open — called from browsers)
GET  /mark.js?slug=:slug&wid=:wid        Serve the browser tracker script
GET  /health                             Health check
GET  /logs/recent?limit=50               Recent events
GET  /q/list                             List active slugs
GET  /q/summary/:slug?days=7             Session and event overview
GET  /q/funnel/:slug?steps=a,b,c         Funnel conversion by step
GET  /q/compare/:slug?pivot=ISO          Before vs after comparison
GET  /q/friction/:slug                   Drop-off points
GET  /q/journey/:slug?entity_id=ID       Entity event history
GET  /q/schema                           Full endpoint schema

Event ingestion payload (POST /e)

{
  "workspace_id": "local",
  "slug": "my-site",
  "session_id": "abc123",
  "event_name": "signup_start",
  "properties": { "optional": "metadata" },
  "tag": "variant-a",
  "entity_id": "user-123"
}

workspace_id is required — all data is scoped by it.

Environment variables

| Variable | Required | Description | |----------|----------|-------------| | DATABASE_URL | Yes | PostgreSQL connection string | | PORT | No | HTTP server port (default 7331) | | MARK_PUBLIC_URL | No | Public base URL for snippet generation (default http://localhost:PORT) | | MARK_WORKSPACE_ID | No | Workspace ID used by MCP stdio tools (default "local") | | MARK_INTERNAL_SECRET | No | If set, query endpoints (/q/*, /logs/*) require x-internal-secret: <value>. Ingestion (POST /e) and /mark.js remain open. |

MCP configuration

Claude Code

Add to ~/.claude.json:

{
  "mcpServers": {
    "mark": {
      "command": "npx",
      "args": ["-y", "@silverbackbase/mark"],
      "env": {
        "DATABASE_URL": "postgresql://user:pass@host/db",
        "MARK_PUBLIC_URL": "https://your-instance.com",
        "MARK_WORKSPACE_ID": "local"
      }
    }
  }
}

Claude Desktop

Same config in ~/Library/Application Support/Claude/claude_desktop_config.json.

Anti-adblock (optional)

Ad blockers may block requests to mark.silverbackbase.com. To proxy through your own domain, add a rewrite rule in your Next.js config:

// next.config.js
rewrites: async () => [
  {
    source: "/m/:path*",
    destination: "https://your-instance.com/:path*",
  },
]

Then update your snippet to use /m/mark.js and /m/e as the ingestion endpoint.

Part of SilverBackBase

Related primitives: Trail (multi-touch attribution), Range (local SEO position tracking), Root (business memory).