# Resend

> Probe-verified (tier 2 of 3). Last checked 2026-08-23. 4 of 5 capability checks passed.

- host: resend.com
- url: https://resend.com/
- category: email api
- type: saas
- language: en

## Probe-verified · tier 2 of 3

Probed live on 2026-08-23 against rubric v1. 4 of 5 checks passed.

- PASS — Markdown negotiation
- fail — Markdown twin at a predictable URL
- PASS — llms.txt
- PASS — API catalog
- PASS — MCP server answers

## Unverified actions

Read from the page's own content, with the wording each was drawn from. Inference is kept separate from tested facts; an agent completing the action is tier 3.

- **read** — "Full documentation" → `https://resend.com/docs/llms.txt`
- **read** — "Pricing (Markdown)" → `https://resend.com/pricing.md`
- **read** — "Blog index (Markdown)" → `https://resend.com/blog.md`
- **read** — "Changelog index (Markdown)" → `https://resend.com/changelog.md`
- **read** — "Handbook index (Markdown)" → `https://resend.com/handbook.md`
- **read** — "Customers index (Markdown)" → `https://resend.com/customers.md`
- **read** — "Legal index (Markdown)" → `https://resend.com/legal.md`
- **download** — "Install" → `https://resend.com/install.sh`
- **read** — "OpenAPI spec (YAML)" → `https://resend.com/openapi.yaml`
- **read** — "OpenAPI spec (JSON)" → `https://resend.com/openapi.json`

## Summary

Resend provides an email API for developers to send transactional and marketing emails at scale with CLI tools and extensive documentation.

## Context

12 sites in this index share the category "email api"; 2 are transactional.

## How we grade

- tier 1 — **Declared**: The site says agents are welcome in its robots.txt. A permission, not a capability.
- tier 2 — **Probe-verified** (this site): We fetched the site and tested each signal ourselves. Dated, repeatable, re-checked on a schedule.
- tier 3 — **Behaviourally verified**: An agent completed the action end to end — booked, bought, submitted — and it worked.

## About this record

Known-Good probes sites live and publishes what was tested and when.
Method: https://knowngood.sh/about.md · Rubric: https://knowngood.sh/benchmark