Mercury Parser

mercury-parser

An MCP wrapper around jocmp/mercury-parser (a maintained fork of Postlight Parser). Fetches a web page with a headless Chromium (Playwright) so JavaScript-rendered content is captured, then runs Mercury Parser to extract the article and returns it as Markdown. Follows pagination links automatically.

Tool

The server exposes a single tool:

extract

Argument	Type	Required	Description
url	string	yes	URL of the page to extract
proxy	string	no	Proxy URL for the headless browser, e.g. http://host:port, socks5://host:port, http://user:pass@host:port. Overrides the MERCURY_PROXY env var for this call.

Returns the article as Markdown (title, author, date, summary, content). On Playwright failure (HTTP/2 protocol errors, navigation timeouts, etc.) falls back to a direct fetch via Mercury Parser so partial content is still returned.

Environment variables

Variable	Default	Description
MCP_TRANSPORT	stdio	stdio or http. Use http for remote/Streamable HTTP transport.
MCP_HOST	127.0.0.1	Bind address when MCP_TRANSPORT=http.
MCP_PORT	3000	Bind port when MCP_TRANSPORT=http.
MCP_PATH	/mcp	URL path when MCP_TRANSPORT=http.
MERCURY_PROXY	—	Default proxy for the headless browser. Overridden per-call by the proxy tool argument.

Usage

Claude Desktop (local stdio)

Add to claude_desktop_config.json:

{
    "mcpServers": {
        "mercury-parser": {
            "command": "npx",
            "args": [
                "@koichikawamura/mercury-parser",
                "mercury-parser-mcp"
            ]
        }
    }
}

To route the headless browser through a proxy on every call:

{
    "mcpServers": {
        "mercury-parser": {
            "command": "npx",
            "args": [
                "@koichikawamura/mercury-parser",
                "mercury-parser-mcp"
            ],
            "env": {
                "MERCURY_PROXY": "socks5://localhost:1080"
            }
        }
    }
}

Remote MCP (Streamable HTTP)

Run the server over HTTP — useful behind a reverse proxy / Cloudflare Tunnel:

MCP_TRANSPORT=http \
MCP_HOST=127.0.0.1 \
MCP_PORT=3030 \
MERCURY_PROXY=http://your-proxy:3128 \
npx @koichikawamura/mercury-parser mercury-parser-mcp

Clients reach it at http://<host>:<port>/mcp. Pair with mcp-remote on the client side, or register directly as a connector in Claude.ai / ChatGPT if the endpoint is gated by an OAuth-aware proxy (e.g. Cloudflare Access).

CLI (ad-hoc testing)

node extractContent.js <url> [proxy]

Requirements

• Node.js 18+
• Playwright Chromium (auto-installed on first launch if missing)

License

MIT — see LICENSE.