Grok Bot · custom MCP

Add Proof Inbox from the custom server form

Grok Bot is not the same product as Grok chat or Grok Build. It only accepts a remote HTTP MCP: a name, a public URL, and optional headers. Proof Inbox is not in the Grok Bot Marketplace. Add it as a custom server, then the bot hits payment_required and opens checkout.

No token yet. You can still add the URL. After the first payment_required, complete Link checkout and reuse the workspace_token it creates.

If you are a Grok Bot

Open Settings → Plugins. Leave the Marketplace tab. Add a custom MCP server.
Fill the form exactly as below. Transport is HTTP / Streamable HTTP. Not stdio. Not localhost.
Confirm the server appears under Plugins → Yours. Then run the first prompt.
On payment_required, open the returned checkout_url. Do not invent one.

Custom MCP form

Name:     Proof Inbox
URL:      https://mcp.proofinbox.com/mcp
Headers:  Authorization: Bearer <workspace_token>

Form fields

Name

Proof Inbox

URL

https://mcp.proofinbox.com/mcp

Header name

Authorization

Header value

Bearer <workspace_token>

The header is optional if every tool call includes workspace_token. Prefer the Bearer header so the bot does not have to paste the token each time.

First prompt

Paste into the bot chat

Call balance on Proof Inbox. Then verify_email with not-an-email. If a tool returns payment_required, open checkout_url and wait for me to finish Link checkout.

balance and not-an-email cost 0. A fresh real address costs 1. Same address for 30 days is free.

Bot instructions

Paste this into the Grok Bot instructions so it reuses one workspace and does not invent verify results. This is also the prompt for a public reference bot.

Grok Bot instructions

You verify email addresses with Proof Inbox. You do not send mail. You do not find emails.

Add this custom MCP if it is not already connected. Grok Bot Settings → Plugins → add a custom MCP server (not the Marketplace catalog). Form fields:
Name: Proof Inbox
URL: https://mcp.proofinbox.com/mcp
Headers: Authorization: Bearer <workspace_token from checkout>

Use MCP https://mcp.proofinbox.com/mcp.
Pass workspace_token on every tool call, or Authorization: Bearer <workspace_token>.
Tools: balance, verify_email, receipts.
If a tool returns payment_required, open checkout_url, complete Link checkout, wait for credits, retry.
Save workspace_token and reuse it. Never invent a new one.
Never invent verify results. If status is unknown, say unknown.
After a pack purchase, call receipts and show me the Stripe session id.

Setup page: https://proofinbox.com/grok-bot
Checkout: https://proofinbox.com/buy/verify-500
Official registry: com.proofinbox/verify

First calls:
1. balance — costs 0.
2. verify_email on not-an-email — invalid syntax, costs 0.
3. Then a real address. Fresh checks cost 1. Same address for 30 days is free.
4. On payment_required, open the returned checkout_url. Do not invent one.
5. After a pack purchase, call receipts and show the Stripe session id.

status is only valid | invalid | catch_all | unknown. unknown is not valid.
Connectors are account-wide. Do not add this server twice. Add custom remotes one at a time.

Short install prompt

Use MCP https://mcp.proofinbox.com/mcp.
Pass workspace_token on every tool call, or Authorization: Bearer <workspace_token>.
Tools: balance, verify_email, receipts.
If a tool returns payment_required, open checkout_url, complete Link checkout, wait for credits, retry.
Save workspace_token and reuse it. Never invent a new one.
Never invent verify results. If status is unknown, say unknown.
After a pack purchase, call receipts and show me the Stripe session id.

Not these products

grok.com/connectors is Grok chat. grok mcp add is Grok Build. Those configs do not install a Grok Bot plugin. Grok Bot uses Settings → Plugins → custom MCP. Connectors you add there are account-wide: every bot on the account gets the same tools.

Grok Build only

If you meant the coding agent, not Grok Bot, this CLI writes a different config:

grok mcp add

grok mcp add --transport http proof-inbox https://mcp.proofinbox.com/mcp --header "Authorization: Bearer $PROOF_INBOX_WORKSPACE_TOKEN"

What breaks

The URL must be public HTTPS. Grok Bot calls run on Cursor's backend, not your laptop. Localhost dies with fetch failed.
Add custom remotes one at a time and confirm tools before adding the next. One hung remote can take down discovery for every connector with DeadlineExceeded, and the hung server can be invisible under Yours.
Do not look for Proof Inbox in the Marketplace catalog. Cursor Marketplace plugins must be free; this product sells a $9 pack.

Directories

Official name: com.proofinbox/verify. These listings do not go through Cursor Marketplace review.

Official MCP Registrylive
Canonical listing: com.proofinbox/verify. Other directories ingest from here.
Smitherylive
Public listing proofinbox/verify. Hosted HTTP. No Cursor review.
cursor.directorylive
Public listing. Hosted HTTP MCP plus skill. Not Cursor Marketplace.
PulseMCPingest
Usually pulls the official registry. New submissions were paused mid-August 2026; re-check the banner before emailing hello@pulsemcp.com.

Buy Verify 500 — $9 Token-aware connect