Bounceban MCP Server

@pipeworx/bounceban

Verify a single email address via BounceBan's waterfall-tuned endpoint (bounceban.com), including catch-all detection. Part of enrich-waterfall's enrich_verify_email ordered verifiers (fleet #2860).

Part of Pipeworx — an MCP gateway connecting AI agents to 1743+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

• bounceban_verify(email, _apiKey) — status/result, explicit catch_all, disposable/role/free flags.

Auth

BYO only. Pass your BounceBan API key as _apiKey (header Authorization, no Bearer prefix). Find your key at https://bounceban.com/app/api/settings. No platform key (D4).

Data sources

• https://api-waterfall.bounceban.com/v1/verify/single — BounceBan's waterfall-specific host, built to block synchronously (up to 80s) for a definitive result rather than handing back a task to poll. BounceBan also publishes a standard api.bounceban.com host for the same verb; this pack deliberately uses the waterfall one since that is the shape enrich_verify_email needs.

Verification notes (fleet #2860, 2026-10-08, no vendor key held)

• Edge-probed the EXACT host/path this pack calls. No Authorization header: HTTP 401 {"error":"Authorization header is required"}. An invalid key: HTTP 401 {"msg":"Authorization information is missing or invalid."}. Two different bodies for two different failures confirms the header is read, not just a blanket 401. This pack's code checks both error and msg fields when surfacing the reason.
• BounceBan documents a 408 for a timed-out verification (its own waterfall-integration guide) — this pack surfaces that as a named, distinct error ("verification timed out server-side") rather than letting it fall through to a generic HTTP-error path, since a caller retrying or moving to the next verifier needs to know it was a timeout, not a bad email or a bad key.
• Response field names (status/result, is_catch_all) are inferred from BounceBan's public no-code-integration docs and GitHub skill-email-verification description, not a confirmed live success payload — we hold no BounceBan key. The parser accepts either is_catch_all/catch_all as a boolean, or falls back to checking whether the status string itself contains "catch" if neither field is present.
• Not verified (no key held): the exact field name BounceBan uses for the main verdict (status vs result); the full enumeration of status values beyond "catch-all" and the obvious valid/invalid.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "bounceban": {
      "url": "https://gateway.pipeworx.io/bounceban/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/bounceban/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1743+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

This pack takes your own API key (_apiKey) — we don't front one for it, so there's no curl here that would run without it. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/bounceban_verify. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "bounceban": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-bounceban"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-bounceban

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Bounceban data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT