Book a Sponsor plugin

Newsletter sponsor data for AI agents (Claude, ChatGPT, Cursor, Grok Build): which brands sponsor newsletters like yours, which brands sponsor newsletters by topic, and what newsletters charge for a sponsor slot.

This plugin connects your agent to the Book a Sponsor MCP server at https://bookasponsor.com/mcp (streamable HTTP, no sign-in) and adds a skill that tells the agent which tool to use.

Tools

Tool	What it does
find_newsletter_sponsors	Give it a newsletter's web address; it finds similar newsletters and the brands that sponsored them, with where and when each ad ran
get_sponsor_scan	Reads back a scan that was still running
list_brands_sponsoring_newsletters	Brands seen in the most newsletters in the last 12 months, overall or by topic
get_newsletter_sponsorship_rates	Median price newsletters list for the main sponsor slot, by list size

Results name brands, never people or email addresses.

Try it

• "Which brands might sponsor my newsletter, yourname.substack.com?"
• "What brands sponsor AI newsletters?"
• "What should I charge for a sponsor slot at 12,000 subscribers?"

Install

• Claude Code / Cursor / other Agent Plugin hosts: install this repo as a plugin, or add the server yourself: claude mcp add --transport http book-a-sponsor https://bookasponsor.com/mcp
• Any MCP client: use .mcp.json / mcp.json in this repo.

Also listed in the official MCP registry as com.bookasponsor/book-a-sponsor.

Site: https://bookasponsor.com · Privacy: https://bookasponsor.com/privacy · Terms: https://bookasponsor.com/terms

License: MIT (this plugin). The data stays Book a Sponsor's.