AgentDrives

Resend publishes an MCP Server Card and an AI Catalog

Clients that support the new files can find Resend's MCP server from its domain. Our agent got into 51 of 134 products with an MCP server on its own.

The numbers

As of 26 October 2026: from the drives of 155 products, 1 to 26 October 2026. Each one links to its definition and evidence.

134 of 155Have an MCP server

AgentDrivesPublished 27 October 2026155 products, driven 1 Oct to 26 Oct2 min readTopic MCP and interfacesFor agents Markdown

134 of 155 products with an MCP server

What happened

Resend published an AI Catalog and an MCP Server Card on 26 Oct 2026, in its changelog. “Resend now publishes an AI Catalog and an MCP Server Card, so supporting clients can discover the Resend MCP server from just a URL.” Resend says the catalog sits at resend.com/.well-known/ai-catalog.json and the Server Card at mcp.resend.com/mcp/server-card, with the server’s name, Streamable HTTP endpoint and supported protocol versions. Sign-in does not change: OAuth, or a Resend API key sent as a Bearer token when no browser is involved. Server Cards are an official MCP extension, Resend says. Read Resend’s changelog entry1.

What our drives saw

As of 26 October 2026, 134 of 155 products we drove have an MCP server, and 128 of 155 have an official one. Our agent got into 51 of 134 of those products on its own, and 83 of 134 stopped it at the door.

On its latest drive, Resend’s own sign-up answered our agent’s email and password form with a generic error, while a passive bot check ran. The full record is on Resend’s page. The numbers behind this note are in our facts.

What it means

For owners: a Server Card tells a client where your MCP server is and which protocol versions it speaks, before it connects. That saves an agent the trip through your docs. It does not open the account the server sits behind. If an agent can’t make that account or get a key without a person, discovery leads it to a sign-in it can’t finish. Publishing the card and checking your sign-up path for agents are separate jobs, and you need both.

For builders: if your client supports Server Card discovery, you can point it at resend.com instead of the full server URL. Your agent still needs a Resend account and either an OAuth sign-in or an API key you hand it. Plan for that step as a person’s task.

What we don’t know

Resend’s post doesn’t say which MCP clients read an AI Catalog or a Server Card today. The Server Card, as Resend describes it, lists the endpoint and protocol versions; the post doesn’t say whether it also describes the sign-in a client should expect. Our drives record whether a product has an MCP server and whether our agent got in; whether a product publishes a Server Card is outside this data.

Where our agent stopped in each.

1 product in this note, by level.

  • ResendEmail infrastructure
    • Find
    • Get in
    • Use
    • Pay
    • Leave
    Can't sign up on its own: a bot check stops it    L1Needs a personDriven 19 Oct 2026

Let your agent check before it picks a tool.

Every drive as JSON and over our MCP server, free. Paid calls $0.01 each: top up $5 for 500 calls, or pay each call with x402 or MPP.

Connect your agent Read llms.txt

Where these numbers come from.

How we test
Products
155
Driven
1 to 26 October 2026
Numbers
Each one links to its definition and the products behind it.

Every number, with its productsHow we drive and score

Written with AI from these drives.

Pages this note cites.

As linked when it was written. ↩ goes back to where the text cites it.

  1. 1resend.com · Read Resend’s changelog entrychangelog/ai-catalog-mcp-server-card↩

Cite this

AgentDrives. “Resend publishes an MCP Server Card and an AI Catalog.” 27 October 2026. agentdrives.com/notes/2026-10-27-resend-publishes-an-ai-catalog-and-an-mcp-server

Drive data is CC BY 4.0. The text as Markdown. Every fact with its evidence.

More from the drives.

All research
Report · 23 Oct 2026 · 148 products, 1–22 Oct 2026How far does an AI agent get in SaaS on its own? 148 testedNo product reached Autonomous: 27 run on their own, and five took an agent payment with no card.Read Blog · 31 Oct 2026 · 191 products, 1–29 Oct 2026Does an MCP server mean an AI agent can use your product?Neon, Cloudinary and Apify handed our agent a working credential through their own routes, with no sign-up form in its way.Read Data story · 31 Oct 2026 · 193 products, 1–31 Oct 2026CLI for AI agents: 11 of 14 databases have oneAn agent working in forms, invoicing or file storage has the API or the MCP server to work through, where those are listed.Read