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Diffgrab MCP

  • Updated April 15, 2026
  • QuartzUnit/diffgrab

io.github.ArkNill/diffgrab is an MCP server that tracks web page changes and returns structured diffs via markgrab and snapgrab integration.

About

io.github.ArkNill/diffgrab is a Monitoring-oriented MCP server for founders who need to know when the outside web moves—competitor pricing, docs, changelogs, or partners’ pages—without babysitting bookmarks. It focuses on structured diffs built on markgrab and snapgrab integration, so agents reason about what changed rather than re-reading entire pages. The natural first journey beat is Idea competitor research, but the same tooling extends to Operate monitoring of critical URLs and Grow content timing when external announcements should trigger your posts. Version 0.1.0 is early; plan on owning scheduling, storage, and alert delivery in your app. Use alongside Browsegrab when you need both interactive browsing and reliable diff history over time.

  • Web page change tracking with structured diffs (PyPI diffgrab v0.1.0)
  • Integrates markgrab + snapgrab from the QuartzUnit grab family
  • stdio MCP server for agent-driven monitoring workflows
  • Complements Browsegrab for capture plus longitudinal compare
  • GitHub source: QuartzUnit/diffgrab

Diffgrab MCP by the numbers

  • Data as of Aug 10, 2026 (Skillselion catalog sync)
terminal
claude mcp add diffgrab -- uvx diffgrab

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Packagediffgrab
TransportSTDIO
AuthNone
Last updatedApril 15, 2026
RepositoryQuartzUnit/diffgrab

What it does

Monitor web pages for meaningful changes and surface structured diffs to your agent using markgrab and snapgrab integration.

Who is it for?

Best when you're doing competitor watches, changelog surveillance, or lightweight production URL monitoring through your agent.

Skip if: Skip if you need enterprise observability, internal APM, or monitoring behind auth without additional tooling.

What you get

After registration, your agent can compare snapshots and explain structured diffs for monitored URLs on demand.

  • Structured before/after diffs for tracked web pages
  • Agent-readable change summaries for competitor and dependency sites
  • Foundation for alert or editorial workflows built on grab-family captures

By the numbers

  • Server version 0.1.0
  • PyPI identifier diffgrab with stdio transport
  • Documented integration: markgrab + snapgrab
README.md

diffgrab

PyPI Python License

한국어 문서 · llms.txt

Web page change tracking with structured diffs. markgrab + snapgrab integration, MCP native.

from diffgrab import DiffTracker

tracker = DiffTracker()
await tracker.track("https://example.com")
changes = await tracker.check()
for c in changes:
    if c.changed:
        print(c.summary)     # "3 lines added, 1 lines removed in sections: Introduction."
        print(c.unified_diff) # Standard unified diff output
await tracker.close()

Features

  • Change detection — track any URL, detect content changes via content hashing
  • Structured diffs — unified diff + section-level analysis (which headings changed)
  • Human-readable summaries — "5 lines added, 2 removed in sections: Intro, Methods"
  • Snapshot history — SQLite storage, browse past versions of any page
  • markgrab powered — HTML/YouTube/PDF/DOCX extraction via markgrab
  • Visual diff — optional screenshot comparison via snapgrab
  • MCP server — 5 tools for Claude Code / MCP clients
  • CLI includeddiffgrab track, check, diff, history, untrack

How It Works

flowchart TD
    A["diffgrab track URL"] --> B["Fetch initial snapshot\n(markgrab + snapgrab)"]
    B --> C["Store baseline"]
    C --> D["diffgrab check"]
    D --> E["Fetch current page"]
    E --> F{"Content\nhash match?"}
    F -->|"changed"| G["Compute structured diff\n+ section analysis"]
    F -->|"unchanged"| H["No changes"]
    G --> I["📊 DiffResult\nadded / removed / modified"]

Install

pip install diffgrab

Optional extras:

pip install 'diffgrab[cli]'      # CLI with click + rich
pip install 'diffgrab[visual]'   # Visual diff with snapgrab
pip install 'diffgrab[mcp]'      # MCP server with fastmcp
pip install 'diffgrab[all]'      # Everything

Usage

Python API

import asyncio
from diffgrab import DiffTracker

async def main():
    tracker = DiffTracker()

    # Track a URL (takes initial snapshot)
    await tracker.track("https://example.com", interval_hours=12)

    # Check for changes
    changes = await tracker.check()
    for change in changes:
        if change.changed:
            print(change.summary)
            print(change.unified_diff)

    # Get diff between specific snapshots
    result = await tracker.diff("https://example.com", before_id=1, after_id=2)

    # Browse snapshot history
    history = await tracker.history("https://example.com", count=20)

    # Stop tracking
    await tracker.untrack("https://example.com")

    await tracker.close()

asyncio.run(main())

Convenience Functions

from diffgrab import track, check, diff, history, untrack

await track("https://example.com")
changes = await check()
result = await diff("https://example.com")
snaps = await history("https://example.com")
await untrack("https://example.com")

CLI

# Track a URL
diffgrab track https://example.com --interval 12

# Check all tracked URLs for changes
diffgrab check

# Check a specific URL
diffgrab check https://example.com

# Show diff between snapshots
diffgrab diff https://example.com
diffgrab diff https://example.com --before 1 --after 3

# View snapshot history
diffgrab history https://example.com --count 20

# Stop tracking
diffgrab untrack https://example.com

MCP Server

Add to your Claude Code MCP config:

{
  "mcpServers": {
    "diffgrab": {
      "command": "diffgrab-mcp",
      "args": []
    }
  }
}

Or with uvx:

{
  "mcpServers": {
    "diffgrab": {
      "command": "uvx",
      "args": ["--from", "diffgrab[mcp]", "diffgrab-mcp"]
    }
  }
}

MCP Tools:

Tool Description
track_url Register a URL for change tracking
check_changes Check tracked URLs for changes
get_diff Get structured diff between snapshots
get_history Browse snapshot history
untrack_url Stop tracking a URL

DiffResult

Every diff operation returns a DiffResult:

@dataclass
class DiffResult:
    url: str                           # The tracked URL
    changed: bool                      # Whether content changed
    added_lines: int                   # Lines added
    removed_lines: int                 # Lines removed
    changed_sections: list[str]        # Markdown headings with changes
    unified_diff: str                  # Standard unified diff
    summary: str                       # Human-readable summary
    before_snapshot_id: int | None     # DB ID of older snapshot
    after_snapshot_id: int | None      # DB ID of newer snapshot
    before_timestamp: str              # When older snapshot was taken
    after_timestamp: str               # When newer snapshot was taken

Storage

Snapshots are stored in SQLite at ~/.local/share/diffgrab/diffgrab.db (auto-created). Custom path:

tracker = DiffTracker(db_path="/path/to/custom.db")

QuartzUnit Ecosystem

Package Role PyPI
markgrab HTML/YouTube/PDF/DOCX to markdown pip install markgrab
snapgrab URL to screenshot + metadata pip install snapgrab
docpick OCR + LLM document extraction pip install docpick
feedkit RSS feed collection pip install feedkit
diffgrab Web page change tracking pip install diffgrab
browsegrab Browser agent for LLMs Coming soon

Used in

  • newswatch — RSS news monitoring pipeline (feedkit → markgrab → embgrep → diffgrab)
  • watchdeck — Web page monitoring with visual diffs and safety guards

License

MIT


Part of the QuartzUnit ecosystem — composable Python libraries for data collection, extraction, search, and AI agent safety.

Recommended MCP Servers

How it compares

Structured web diff MCP monitor, not interactive Playwright browsing (see Browsegrab) or a database CDC pipeline.

FAQ

Who is io.github.ArkNill/diffgrab for?

Developers and operators who want Claude or Cursor to track external web page changes with structured diffs instead of manual checks.

When should I use io.github.ArkNill/diffgrab?

Use it during Idea competitor research, Operate monitoring of critical pages, or Grow content planning when external site changes should inform your moves.

How do I add io.github.ArkNill/diffgrab to my agent?

Install PyPI package diffgrab 0.1.0, register the stdio MCP server, and configure markgrab/snapgrab workflows per the repository README.

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