errdown-mcp

Pre-release (alpha).

An MCP server with one tool, fetch. On success it returns the page as Markdown. On any failure (HTTP error, bot challenge, DNS / TLS / connection failure) it returns a structured error in Cloudflare's agent format instead of an HTML dump:

---
error_code: 502
error_name: nginx_bad_gateway
error_category: upstream_unavailable
status: 502
retryable: true
retry_after: 5
owner_action_required: false
errdown_source: nginx
---

# Bad gateway

## What Happened

The server returned HTTP 502 with an error page from nginx.

## What You Should Do

Wait 5 seconds, then retry with exponential backoff. Stop after a few attempts and report the error if it persists.

So the agent knows whether to retry, ask the user for credentials, or stop at a CAPTCHA.

Install

Claude Code:

claude mcp add errdown -- uvx --prerelease allow errdown-mcp

Claude Desktop / Cursor / any MCP client (mcpServers config):

{ "errdown": { "command": "uvx", "args": ["--prerelease", "allow", "errdown-mcp"] } }

Node alternative: npx -y errdown-mcp@alpha.

Tool arguments: url, max_length (default 20000), start_index (continue truncated content), raw (HTML instead of Markdown). The server sends Accept: text/markdown, */*, so sites that support Markdown for agents return it natively.

Note: like other fetch servers, it can reach any URL the host machine can, including local network addresses.

Built on errdown. Not affiliated with Cloudflare. License: Apache-2.0.