# MarkLayer (npm · marklayer-mcp)

Work visual annotations on a live webpage: watch, acknowledge, resolve, reply, or leave your own.

- Trust score: 86/100 (high trust)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-21

## Components

- npm · `marklayer-mcp`: 86/100 (this document), [markdown](https://verifymcp.io/servers/thevrus-marklayer/marklayer-mcp.md), [page](https://verifymcp.io/servers/thevrus-marklayer/marklayer-mcp)

## Channel facts

- Registry: `npm`
- Package: `marklayer-mcp`
- Version: `0.5.0`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-09-21.

- **Supply Chain Security**: 98/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - 31 of 97 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 97/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to thevrus/MarkLayer).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 12 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 75/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1714 tokens (~142/item across 12 items; 12 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 43/100
  - Stability observed for 13 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 91/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 74% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 12 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 13 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the MarkLayer MCP server?

MarkLayer runs locally as an npm package, launched with npx -y marklayer-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add thevrus-marklayer -- npx -y marklayer-mcp
```

### Cursor

```json
{
  "mcpServers": {
    "thevrus-marklayer": {
      "command": "npx",
      "args": [
        "-y",
        "marklayer-mcp"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "thevrus-marklayer": {
      "command": "npx",
      "args": [
        "-y",
        "marklayer-mcp"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add thevrus-marklayer -- npx -y marklayer-mcp
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "thevrus-marklayer": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "marklayer-mcp"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add thevrus-marklayer --command npx --arg -y --arg marklayer-mcp
```

### Hermes

```yaml
mcp_servers:
  thevrus-marklayer:
    command: "npx"
    args: ["-y", "marklayer-mcp"]
```

### Netclaw

```json
{
  "McpServers": {
    "thevrus-marklayer": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "marklayer-mcp"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add thevrus-marklayer -t stdio -c npx -a -y marklayer-mcp
```

### Other

```json
{
  "mcpServers": {
    "thevrus-marklayer": {
      "command": "npx",
      "args": [
        "-y",
        "marklayer-mcp"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-21 (score 86, +1)

No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-19 (score 85, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-17 (score 84, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-15 (score 83, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-13 (score 82, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-10 (score 81, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-09 (score 80, +11)

- [security regression] Tool safety: pass → unverified
- [security improvement] Provenance: fail → pass
- [security] Stability: Stability not yet verified: we do not have a sandbox capture of the MCP schema this version of the package serves yet.
- [security] The attested source repository moved: thevrus/MarkLayer
- [functional regression] Schema quality: 1496 → 1714
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional improvement] Stability: unverified → 0.03
- [functional] First check of Schema quality: unverified
- [functional] Package version: 0.4.0 → 0.5.0

### 2026-09-08 (score 69)

First indexed and scored.

## MCP tools (12)

### `marklayer_read_page` (~149 tokens)

Read the page this room annotates — its headings, paragraphs, links, buttons and labels, each with the CSS selector and tag that locate it. Call this FIRST when asked to review, audit or improve a page and no annotations exist yet: without it you can only answer feedback someone else left, never find anything yourself. Every entry is already in the shape marklayer_suggest_edit and marklayer_create_annotation take, so pass `selector`, `tag` and `markdown` straight through to anchor a mark to the element you are talking about. If the answer says the page renders client-side, the copy is not in the HTML and you should say so rather than review an empty shell.

### `marklayer_connect_room` (~60 tokens)

Connect to a MarkLayer room (annotation session) by URL or bare room id. Disconnects any prior room.

Input parameters:

- `room` (string, required): Room URL like https://marklayer.app/s/abc123 or a bare room id like abc123.

### `marklayer_room_info` (~25 tokens)

Get metadata about the connected room: page URL, viewport width, timestamps.

### `marklayer_list_annotations` (~115 tokens)

List every annotation in the connected room across all tools (comment, area, selection, inspect). Each entry carries a `kind` discriminator and, where the user marked an element, a `target` block with selector + markdown so you can address the change without reopening the page. Filter by status: open, in_progress, resolved, approved, dismissed, or all (default). `approved` means the person who asked for the change confirmed the fix, so those need nothing from you.

Input parameters:

- `status` (string)

### `marklayer_get_annotation` (~52 tokens)

Get full detail for a single annotation of any kind (comment, area, selection, inspect), including its element `target` context and — for comments — the reply thread.

Input parameters:

- `id` (string, required)

### `marklayer_watch_annotations` (~258 tokens)

Block until there is work, then return a batch of whatever arrives within a short window. CALL THIS AGAIN IMMEDIATELY EVERY TIME IT RETURNS, including when it returns nothing — an empty result means the window expired, not that the reviewer is done. Nothing pushes work to you: between your calls, a comment someone leaves reaches no one. Keep looping until the person tells you to stop or ends the session. Each event has a `kind`: "new" is an annotation someone just left; "handoff" is one given to you — assigned to you, a reply that @mentions you, or a reply on a thread you already own. A handoff also carries `request`, the reply that asked: read it, it is the instruction, and act on it rather than only acknowledging. Every event carries the full annotation with its `target` element context.

Input parameters:

- `batchMs` (integer): After the first new annotation arrives, wait this long for more before returning. Default 750.
- `timeoutSeconds` (integer): How long to block before returning empty. Defaults to 50, which fits inside the 60s request timeout most clients use. Raise it only if you know yours allows a longer tool call.

### `marklayer_acknowledge` (~40 tokens)

Mark an annotation as in_progress and tag it with this agent so the human sees you are working on it.

Input parameters:

- `id` (string, required)

### `marklayer_resolve` (~59 tokens)

Mark an annotation as resolved. Pass a summary describing what was changed — it will be posted as a reply to the thread.

Input parameters:

- `id` (string, required)
- `summary` (string): Short description of what changed, posted as a reply.

### `marklayer_dismiss` (~52 tokens)

Mark an annotation as dismissed when it cannot be acted on. The reason will be visible to the human.

Input parameters:

- `id` (string, required)
- `reason` (string, required): Why you cannot act on this annotation.

### `marklayer_reply` (~42 tokens)

Post a reply to an annotation thread without changing its status. Use to ask clarifying questions.

Input parameters:

- `id` (string, required)
- `text` (string, required)

### `marklayer_create_annotation` (~278 tokens)

Leave a new comment annotation yourself — proactive feedback (a bug, a UX issue, an accessibility gap, an idea) rather than only responding to a human’s. For an exact text replacement (a copy or grammar fix), use marklayer_suggest_edit instead — it renders as a diff the human can accept, rather than prose describing one. Use this after you have looked at the page with your own tools (a screenshot, a DOM read) and decided something is worth flagging; call it once per finding so each becomes its own pin the human can triage. x/y are document pixels (not viewport pixels — scroll offset already added in). Pass selector + tag + markdown together to anchor the pin to that element so it re-resolves if the page reflows; omit all three for a fixed-point pin.

Input parameters:

- `markdown` (string): Short markdown snapshot of the element, for the human to see.
- `priority` (string): Triage priority, if this warrants one.
- `selector` (string): CSS selector of the element this is about.
- `tag` (string): Tag name of that element, e.g. "button".
- `text` (string, required): The feedback itself.
- `x` (number, required): Document-space X in CSS pixels.
- `y` (number, required): Document-space Y in CSS pixels.

### `marklayer_suggest_edit` (~263 tokens)

Propose an exact replacement for a piece of text on the page — a copy or grammar fix — as a diff the human can accept, rather than a comment describing the change in prose. `rects` are the on-page bounding boxes of `text`, in document pixels: one per line it spans, so a wrapped sentence highlights as several boxes rather than one box swallowing the whole paragraph between its first and last line. Pass selector + tag + markdown together to anchor it to the containing element so it re-resolves if the page reflows.

Input parameters:

- `comment` (string): Optional note explaining the fix, if it is not self-evident.
- `markdown` (string): Short markdown snapshot of the element, for the human to see.
- `priority` (string): Triage priority, if this warrants one.
- `rects` (array, required): Document-pixel bounding box(es) of `text` on the page — one per line it spans.
- `selector` (string): CSS selector of the element containing this text.
- `suggestion` (string, required): The exact replacement text.
- `tag` (string): Tag name of that element, e.g. "p".
- `text` (string, required): The exact text on the page being replaced.

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/thevrus-marklayer/marklayer-mcp#diagnostics

## Score history

- 2026-09-21: 86
- 2026-09-20: 85
- 2026-09-19: 85
- 2026-09-18: 84
- 2026-09-17: 84
- 2026-09-16: 83
- 2026-09-15: 83
- 2026-09-14: 82
- 2026-09-13: 82
- 2026-09-12: 81
- 2026-09-11: 81
- 2026-09-10: 81
- 2026-09-09: 80
- 2026-09-08: 69

## Common questions

### What is the MarkLayer MCP server?

MarkLayer is an MCP server listed in the public MCP registry as io.github.thevrus/marklayer. Work visual annotations on a live webpage: watch, acknowledge, resolve, reply, or leave your own. This page covers its npm package (marklayer-mcp).

### Is the MarkLayer MCP server safe to use?

MarkLayer scores 86 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 21 September 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the MarkLayer MCP server expose?

MarkLayer exposes 12 tools: marklayer_read_page, marklayer_connect_room, marklayer_room_info, marklayer_list_annotations, marklayer_get_annotation, and 7 more. Their descriptions and schemas cost roughly 1,393 tokens of context every time the server is loaded.

### Is the MarkLayer MCP server still maintained?

MarkLayer is still listed as active in the MCP registry. We last reached this channel on 21 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the MarkLayer MCP server under?

MarkLayer declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/marklayer-mcp
- Socket report: https://socket.dev/npm/package/marklayer-mcp
- Repository: https://github.com/thevrus/MarkLayer
- Website: https://marklayer.app/
- Changelog RSS feed: https://verifymcp.io/servers/thevrus-marklayer/marklayer-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/thevrus-marklayer/marklayer-mcp.json
- HTML version of this page: https://verifymcp.io/servers/thevrus-marklayer/marklayer-mcp