SignupBouncer

com.signupbouncer/checkerVersion 1.1.1

An API that checks new signups for disposable emails and repeat accounts.

Status

Responds363 msNov 14, 2026, 14:15 UTCAnswered our handshake without sign-in.

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Last checked: Nov 14, 2026, 14:15 UTC
Latency: 363 ms
Remotes responding: 1 of 1
Sign-in: No sign-in
Hosting: Hosted outside the EU (detected)
Registry data as of: Nov 14, 2026, 22:14 UTC

Data from the official MCP Registry, checked by run.zero. How we check

Connect

Streamable HTTP

https://signupbouncer.com/mcpResponds363 msNov 14, 2026, 14:15 UTC

No sign-in

Claude Code

claude mcp add --transport http checker https://signupbouncer.com/mcp

Claude Desktop and claude.ai

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Settings > Connectors > Add custom connector
Name: checker
Remote MCP server URL: https://signupbouncer.com/mcp

Cursor

{
  "mcpServers": {
    "checker": {
      "url": "https://signupbouncer.com/mcp"
    }
  }
}

VS Code

code --add-mcp '{"name":"checker","type":"http","url":"https://signupbouncer.com/mcp"}'

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Tools

4 tools

Tools of SignupBouncer
	Description		Read-only	Idempotent	Open world
`check_email`Checks one email address, and optionally the signup's IP address, the way SignupBouncer checks a new signup. Returns the result as "verdict" (allow, challenge or block), a 0-100 score, the reasons with their reason codes, the normalized inbox (Gmail dots and +tags folded) and the IP's network. When the domain looks like a typo of a big mail provider (gmial.com), "suggestion" holds the corrected address. Looks up the domain's mail servers live. Every reason is listed, including ones only paid plans count. We don't store or log the email or IP address it checks. We cache the email's domain and its mail servers for up to an hour. For the rate limits we keep a keyed hash of the calling IP address, or of the account when the client sends a key, for up to 24 hours. When the client sends a key, we also keep a hash of the key in memory, and keyed hashes of the calling IP address and its network (/24 or /64), for up to two minutes. The IP hashes limit guessed keys. A valid key's hash is also stored with its account.	Checks one email address, and optionally the signup's IP address, the way SignupBouncer checks a new signup. Returns the result as "verdict" (allow, challenge or block), a 0-100 score, the reasons with their reason codes, the normalized inbox (Gmail dots and +tags folded) and the IP's network. When the domain looks like a typo of a big mail provider (gmial.com), "suggestion" holds the corrected address. Looks up the domain's mail servers live. Every reason is listed, including ones only paid plans count. We don't store or log the email or IP address it checks. We cache the email's domain and its mail servers for up to an hour. For the rate limits we keep a keyed hash of the calling IP address, or of the account when the client sends a key, for up to 24 hours. When the client sends a key, we also keep a hash of the key in memory, and keyed hashes of the calling IP address and its network (/24 or /64), for up to two minutes. The IP hashes limit guessed keys. A valid key's hash is also stored with its account.	No	Yes	Yes	Yes
`explain_reason`Explains a SignupBouncer reason code (for example disposable_domain, burner_mx, repeat_inbox, datacenter_ip): what it means, how many points it adds or whether it blocks alone, and the lowest plan on which it counts. Without a code, lists every code.	Explains a SignupBouncer reason code (for example disposable_domain, burner_mx, repeat_inbox, datacenter_ip): what it means, how many points it adds or whether it blocks alone, and the lowest plan on which it counts. Without a code, lists every code.	No	Yes	Yes	No
`integration_guide`Returns the steps and the copy-paste code that checks new signups with SignupBouncer in one stack: supabase (a hook, no code), ory (a web hook, no code), fetch (any TypeScript server), nextjs, express, hono, python, firebase or better-auth. Use it when the user asks for code that checks or blocks signups in their app. The code reads the API key from SIGNUPBOUNCER_API_KEY. The call has a 1.5-second limit, and any failure lets the signup through.	Returns the steps and the copy-paste code that checks new signups with SignupBouncer in one stack: supabase (a hook, no code), ory (a web hook, no code), fetch (any TypeScript server), nextjs, express, hono, python, firebase or better-auth. Use it when the user asks for code that checks or blocks signups in their app. The code reads the API key from SIGNUPBOUNCER_API_KEY. The call has a 1.5-second limit, and any failure lets the signup through.	No	Yes	Yes	No
`lookup_burner_domain`Says whether a domain is on SignupBouncer's disposable (burner) email list, only on an old burner list (a challenge, not a block), a known relay service or a free subdomain mail service, or a known real mailbox provider, and when our harvester observed it. Uses only the loaded lists, no DNS lookup, so a brand-new burner domain on a burner mail server is caught only by check_email. Accepts a domain or an email address.	Says whether a domain is on SignupBouncer's disposable (burner) email list, only on an old burner list (a challenge, not a block), a known relay service or a free subdomain mail service, or a known real mailbox provider, and when our harvester observed it. Uses only the loaded lists, no DNS lookup, so a brand-new burner domain on a burner mail server is caught only by check_email. Accepts a domain or an email address.	No	Yes	Yes	No

Details

Registry status: Active
Published: Oct 16, 2026
Updated: Oct 16, 2026
Website: https://signupbouncer.com/docs#mcp⁠ (opens in a new tab)
Repository: Not given
Categories (suggested): CommunicationSuggested categories are assigned automatically from the registry text and may be wrong. Verified operators can correct them.
GDPR: Not declared

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